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How Instrumentation Technology Drives Efficiency in Modern Industry

Instrumentation technology plays a vital role in driving efficiency, accuracy, and reliability across modern industrial operations. With the growing demand for automation and smart manufacturing, industries rely heavily on advanced industrial instrumentation systems to monitor, measure, and control critical process parameters. Technologies such as pressure transmitters, flow meters, temperature sensors, and level measurement instruments provide real-time data that enables precise process control and reduces manual intervention. By implementing reliable instrumentation solutions, industries can optimize production cycles, minimize operational losses, and ensure consistent product quality across various applications.

Modern industries such as oil and gas, chemical processing, pharmaceuticals, power plants, and water treatment facilities depend on accurate measurement and monitoring to maintain efficiency and safety. Advanced process instrumentation equipped with digital communication protocols like HART, Modbus, and Profibus enables seamless integration with PLC, DCS, and SCADA systems. This connectivity allows operators to analyze performance data, identify inefficiencies, and implement predictive maintenance strategies that reduce downtime and extend equipment life. High-precision instruments such as Coriolis flow meters, differential pressure transmitters, and smart temperature sensors significantly enhance process stability and energy efficiency.

As industries move toward Industry 4.0 and data-driven manufacturing, instrumentation technology continues to evolve with intelligent diagnostics and remote monitoring capabilities. Platforms like Instronline support this transformation by offering a wide range of automation and instrumentation products from globally recognized brands, helping engineers and procurement teams source reliable solutions quickly and efficiently. By leveraging world-class instrumentation technology, modern industries can achieve improved productivity, enhanced safety, regulatory compliance, and long-term operational excellence in an increasingly competitive industrial environment.

Empowering Industrial Automation with World-Class Instrumentation Solutions

Industrial automation has become the backbone of modern manufacturing, enabling industries to achieve higher productivity, safety, and operational accuracy. Empowering industrial automation with world-class instrumentation solutions requires precise measurement, reliable control, and seamless integration of advanced technologies. Leading platforms like Instronline provide a comprehensive range of industrial instrumentation products, including pressure transmitters, flow meters, temperature sensors, and level measurement devices that help industries monitor and optimize their processes efficiently. With accurate data collection and real-time monitoring, automation systems powered by high-quality instrumentation reduce downtime, improve energy efficiency, and enhance overall process performance.

World-class instrumentation plays a critical role in industries such as oil & gas, chemical processing, pharmaceuticals, power generation, and water treatment, where precision and reliability are essential. Advanced process control instruments, smart sensors, and digital transmitters with communication protocols like HART, Modbus, and Profibus enable seamless connectivity with modern automation systems. By offering trusted brands and certified products, Instronline ensures consistent performance, compliance with international standards, and long-term reliability. These solutions not only improve measurement accuracy but also support predictive maintenance and automation strategies that drive sustainable industrial growth.

As industries continue to adopt Industry 4.0 and smart manufacturing practices, the demand for intelligent instrumentation and automation solutions continues to rise. Instronline’s extensive portfolio of automation components, calibration instruments, and measurement solutions empowers engineers and procurement professionals to select the right products for their applications. By combining advanced technology, global brand partnerships, and technical expertise, Instronline helps businesses build efficient, safe, and future-ready industrial automation systems that deliver long-term value and operational excellence.

What’s a Digital Positioner & Why Should You Use One?

A valve positioner is a gadget mounted on the actuator that applies or diminishes gaseous tension as important to ensure the valve accomplishes the right position.

At the point when there is no positioner, the control signal goes straightforwardly to the actuator. At the point when a positioner is introduced, it blocks this sign and afterward yields an alternate sign to the actuator.

Positioners permit more tight command over the cycle variable by speeding up and exactness of the actuator reaction. Since a positioner's responsibility is to ensure the valve is perfectly located, it likewise helps in defeating factors that influence control valve execution, like contact, as well as issues prefer non-linearity and deadband. Positioners can likewise enhance or opposite an information signal on a case by case basis.

Basically, a positioner guarantees that the last control component in a circle applies ideal control.

There are three kinds of positioners:

• Pneumatic positioners. These gadgets gets a pneumatic (air) signal from the regulator and result a pneumatic sign to the actuator.

• Simple, or electro-pneumatic, positioners. Here, the info signal is electrical, as opposed to pneumatic.

• Computerized, or savvy, positioners. These positioners likewise get an electrical sign, however it's advanced instead of simple.

Computerized positioners came on the scene around quite a while back, however they just truly begun acquiring prevalence as of late as robotization has begun to take off in plants and along pipelines.

The primary explanation computerized positioners are famous is that they can do substantially more than simply control the place of the valve. The freshest positioners available can likewise gather information about the valve to consequently caution clients about how the valve and its get together are performing, and even guide in diagnostics and upkeep.

Since they have less mechanical moving parts, computerized positioners last longer than their conventional pneumatic and simple partners. Also, they drain no air while the valve is very still, which diminishes energy utilization.

For instance, the Masoneilan SVI II AP computerized positioner permits you to:

• Auto tune the positioner in minutes, rather than the hours simple positioners can take

• Get analytic data about the wellbeing and execution of your control valves

• Distinguish likely issues before they occur

• Coordinate the positioner with other control frameworks so your information is all in one spot

What this all reduces to is higher valve efficiency, diminished free time, and generally better plant execution.

How Valve Suppliers Can Help the Power Industry Meet Their Biggest Challenges

From maturing plants and a maturing labor force to the push for manageability, the power age industry today faces many difficulties. As we plan ahead, these difficulties will just develop, and the power organizations that act now to address them will be the ones best situated to succeed.

To address these difficulties in a convenient and practical way will require cooperation among the power organizations and their accomplices and providers. As is commonly said, "no business is an island."

This is the way valve providers can assist the power business with meeting the greatest difficulties of today and tomorrow.

Valve estimating and choice

Valves utilized in power plants are under developing strain. As Rich Ford wrote in a 2014 Valve World article, "Progressively unpredictable cyclic circumstances in current influence plants are rapidly heightening both the requests and the pressure being put upon process hardware, particularly with regards to valves."

As a result of this pressure, and furthermore in view of the number of valves that are utilized in power plants, it's basic to guarantee you pick the right valve for each application. That requires thinking about the size and materials of development, yet in addition the temperature and tension evaluations, kind of seat (metal-versus delicate situated), and different plan attributes. Evaluating these elements and distinguishing the best arrangement requires a profound information on valves and their applications, which just an accomplished valve provider can give.

Valve upkeep and fix

The typical power plant in the United States is over 40 years of age. As offices age, appropriate support and fix become much more critical to guarantee valves and other gear accomplish ideal execution.

This isn't simply really smart. It's fundamental for productivity. Simply in the beyond couple of years, there have been a few accounts of ineffectively kept up with valves at thermal energy stations prompting impromptu closures. By one gauge, a 4-day impromptu closure can cost a power plant a normal of $2.6 million.

Normal upkeep is one of the critical ways of expanding the existence of your valves. It additionally saves you from expensive spontaneous personal time.

Computerization

Power plants aren't the main thing that is maturing. The labor force is as well. As per 2017 BLS information, around one-fourth of force industry workers are 55 or more established, and that implies they will probably resign in the following 10 years. Simultaneously, the conventional energy area is experiencing issues drawing in top youthful ability.

That is the reason many power age organizations are putting resources into computerization innovations, like advanced valve positioners.

A computerized positioner consequently screens the valve and changes the sign to the actuator as important to guarantee the valve accomplishes the right position. It likewise gathers information from the valve and sends it back to a unified data set, where the information can be broke down for any difficult situations. This lessens costs by permitting a solitary administrator to screen the presentation of each of the valves in an office, and furthermore by recognizing potential issues early so they can be fixed before they cause a closure.

Consistence

A brief glance at the day's business titles uncovers the steadily moving scene of administrative consistence. Indeed, even in the ongoing environment of liberation, things are changing constantly. Moreover, associations like the ASME and ASTM often issue new guidelines.

It's ridiculous for your plant or tasks chiefs to keep up on these progressions without some assistance. Here accomplices like your valve provider can show their value by assisting you with exploring new administrative turns of events and guidelines to guarantee you're in consistence.

Worker preparing

At last, despite the fact that having believed providers is significant, your workers actually should have the option to work your gear and give the primary line of safeguard when things turn out badly. That requires preparing.

At Allied Valve, we believe ourselves to be in the assistance business. That is the reason we give preparing — as studios, Lunch and Learn projects, and that's only the tip of the iceberg — to guarantee that your on location administrators are both sure and capable working with the hardware we sell.

Do you really want assistance handling the difficulties confronting your power business? Reach us to get more familiar with how we can help you.

What is process control?

Process control covers an assortment of disciplines and innovations. It very well may be mass stream, pressure, liquid stream, temperature or position. Standards of interaction control keep similar guidelines of estimation kept by change of a cycle variable to keep up with control of the cycle. The more exact the control, the greater the finished result and, all the more significantly, the higher the productivity.

Process control is a modern interaction that use the capacity to screen and change levels to give an ideal result. It is utilized to further develop execution and keep a degree of consistency, economy and security that couldn't be accomplished by human manual control.

The primary target of cycle control is to control the actual boundaries of temperature, pressure, stream rate and power. The actual boundaries in a cycle control framework are impacted by interior and outer aggravations. Thus, restorative activity is continually expected to keep them at a predictable level.

Components of an interaction control framework

There are 6 fundamental components that make up an interaction control framework. They are:

Controlled variable - This is the thing you need to control (temperature, stream rate, pressure, aspects, position).

Estimated variable - This is the thing you see to decide the state of the controlled variable.

Setpoint - The ideal worth of the controlled variable. For instance, setting the temperature at a particular degree.

Deviation - This is the distinction between the setpoint and the worth of the control variable. For instance, in the event that you'd like a room temperature to be at 25°C and the indoor regulator is perusing as 20°C, the deviation is 5 degrees.

Controlled variable - This is the variable that is changed in accordance with close the hole between the setpoint and the controlled variable.

Aggravations - Anything that could cause deviation from the setpoint and influence the cycle. While considering room temperature, this could be a window left open or a harmed indoor regulator.

6 Steps to making a productive interaction control

To make a completely working cycle control framework in its most productive limit, there are six stages you ought to go through.

1. Explore the ongoing framework

The initial step to making a productive interaction control framework is to screen the framework's exhibition and observe any indications of unfortunate control or blunders. This might incorporate irregularities, varieties in energy, or controls set to manual rather than programmed.

2. Actually look at instruments and parts

Whenever you have observed the framework execution and noticed any irregularities or mistakes, right now is an ideal opportunity to check genuine parts of the cycle control framework. Any defective gear should be fixed right away, and checks finished to guarantee that all parts have additionally been introduced accurately.

Guarantee controls work proficiently

Whenever fixes have been made on parts, guarantee that all controls are working appropriately and proficiently. Setting controls to programmed is a more proficient approach to working. Once finished, survey controls to check they're designed accurately.

4. Upgrades in charge

Make a rundown of upgrades that could be made in charge. This incorporates considering ways of further developing energy and effectiveness in a minimal expense non-tedious way. Set up an arrangement with respect to how you can approach further developing controls in the process framework.

5. Make a move and further develop controls

Guarantee that any new hardware or parts are introduced accurately, and anybody working straightforwardly with the framework is prepared completely. Set new focuses for the framework to screen in the short and long haul to lay out on the off chance that the new practices set up are proceeding true to form.

6. Screen execution

When everything is set up, the time has come to screen execution. Like the initial step, mark out any parts that require work and fix any issues that emerge. The cycle control framework ought to run effectively since past issues have been resolved.

What are process ball valves?

Process ball valves are ordinarily utilized in modern applications, giving solid sealed security. They can be utilized physically, pneumatically or electrically and are produced in an assortment of development materials. Keep perusing to figure out all you really want to be familiar with ball valves.

What is an interaction ball valve?

A ball valve is a stopped valve that oversees stream estimation and control of fluids, fumes and gases into a funneling framework by turning the ball inside. A cycle ball valve regularly alludes to a ball valve introduced as a component of instrumentation frameworks and cycles in modern offices that help petroleum gas and oil dispersion.

The ball inside is mounted against two seats in a shaft that associates with a control system that turns the ball. At the point when the handle is lined up with the line, the stream is open and permits liquid through from the valve. At the point when it is opposite to the line, liquid is kept from moving through. At the point when open, the liquid stream rate relies upon the region of the drag presented to the liquid.

Portions of a ball valve

There are five essential components that make up a cycle ball valve. They are:

• Lodging

• Shaft

• Cap

• Ball

• Seat

Lodging

The lodging, once in a while alluded to as the body, contains every one of the interior pieces of the cycle ball valve. It is commonly made of hard metal, thermoplastic or thermoplastic-lined metal that safeguards everything inside.

Shaft

The shaft interfaces the ball to the control component, which is utilized to turn the ball. With the utilization of O-rings and pressing rings, the shaft and hat are fixed firmly, which assists with keeping away from any spillages. The shaft can be physically worked or constrained by a pressure driven, pneumatic or electric activity.

Hat

The hat is essential for the lodging that is utilized to safeguard the shaft and its pressing. It very well may be welded or darted to the body and covers the opening produced using interfacing the shaft to the control system.

Ball

The ball has an opening in its middle which is known as a drag. This fills in as the opening for liquid to course through. At the point when turned in the other bearing, the liquid is kept from dealing with. The interaction ball valve could be strong or empty, with the previous having a consistent opening measurement, which assists liquid with easily streaming at a steady speed.

At the point when the ball is empty, the space inside it permits more liquid to go through the valve, yet the empty ball makes higher speeds. It is more lightweight than a strong ball, and less expensive as well.

Seat

The seat gives fixing between the ball and the body, with the upstream seat adjoining the channel side of the interaction ball valve. The downstream seat is on the contrary side, which is nearby the release side of the valve.

Various sorts of interaction ball valves

There are a wide range of kinds of cycle ball valves, and they can be grouped by their lodging, ball valve, and bore profile.

Lodging

The various kinds of interaction ball valves under the lodging characterization are one-piece ball valves, split body ball valves (two-piece and three-piece), and top-section ball valves.

A one-piece ball valve has a solitary piece body that houses the inner parts, which dispenses with the gamble of spillage of the liquid. They are the least expensive ball valves and consistently have a diminished drag.

Part body ball valves are gathered on their balls and are either a two-piece or a three-piece. The two-piece comprises of lodging separated into two pieces and fitted together. The primary segment houses the ball and an association with one end, while different holds the inward parts and interfaces with the opposite end. Two-piece ball valves are the most ordinarily utilized sort of interaction ball valve since they can be dismantled for cleaning and upkeep.

In a three-piece ball valve, the lodging and inner parts are catapulted together at its two finishes, and afterward strung and welded to the line. They can be cleaned and overhauled effectively which make them famous in the food and refreshment, and drug enterprises.

Top passage ball valves permit admittance to the internals by eliminating the cap on top of the valve. This permits upkeep of the inner parts without the need to eliminate the ball valve from the line.

Ball plan

There are three sorts of cycle ball valves related with the plan of the actual ball, and they are: drifting, trunnion and vented. The drifting ball valve is the most well-known plan utilized. The ball is suspended and allowed to move in a sidelong heading when the valve is shut. At the point when opened, the shaft association with the space at the highest point of the ball keeps the ball from moving.

In a trunnion ball valve, the ball is upheld by a shaft at the base, which is known as a trunnion. This holds the ball set up and confines its development to its pivot. The ball can move in the event that the valve shaft turns.

A vented ball valve works the same way as a standard ball valve, with the exception of the vented ball has little holes bored into its side. At the point when the valve is shut, the opening is coordinated to the power source side of the valve. The bored opening is utilized to vent caught gases which causes a development of interior tension inside the valve, forestalling spillage, disappointment and blast.

Exhaust profile

Like the lodging and ball plans, the drag profile sort of cycle ball valves has three primary plans: pedal to the metal, diminished bore and sectioned.

A pedal to the metal has a breadth like the line measurement. Stream opposition is extremely low as the region for the liquid remaining parts consistent. Likewise, insignificant rubbing misfortune is experienced during the liquid stream, implying that the strain drop is low. Siphoning becomes troublesome in the event that there's a high tension drop, yet since the drag width matches the size of the line, it requires a bigger ball size and lodging, which makes it more costly.

A decreased drag - more normal than a pedal to the metal - has a measurement that is more modest than the line size. It implies the stream region for the liquid becomes smaller at the downstream outlet, which brings about frictional misfortunes and a tension drop. Because of a steady stream release, the speed increments with the reduction in stream region.

A sectioned ball valve has an angular indent on its ball and has great stream rate control. It likewise has great turned down capacities. The stream rate in a divided ball valve increments as the ball arrives at its completely opened position.

Orifice Plates Used in Flow Measurement

Opening plates are one of the most well known gadgets for the estimation and control of liquid stream. It is regularly utilized more than some other stream meter. The opening comprises of a slim metal plate with a straight opening bored in it. At the point when a liquid goes through a hole, the stream is frequently not exactly the sum determined. The supposition that will be that the energy is monitored and the stream conveying through the opening is uniform and equal.

Opening Plates are regularly mounted between a bunch of Orifice Flanges and are introduced in a straight run of smooth line to stay away from unsettling influence of stream designs from fittings and valves.

Hole plates cover a wide scope of uses including liquid and other working circumstances. They give a satisfactory degree of vulnerabilities at most minimal expense and long existence without standard support.

Concentric Bore - The most well-known opening plate is the square-edged, concentric exhausted plan. It's utilized on most cycles including clean fluids, gases and steam stream. It is normally made of treated steel. Different materials like nickel and Monel are utilized for a decent destructive safe property. This sort of opening plate has an extremely high exactness.

Flighty Bore - Eccentric drag opening plates will be plates with the hole askew, or unconventional, rather than concentric. Area of the drag forestalls collection of strong materials or unfamiliar particles and makes it helpful for estimating liquids containing suspended strong particles. Flighty drag opening plates are more unsure when contrasted with the concentric hole.

Segmental Bore - The segmentally drilled opening plates contain an opening that is a fragment of a concentric circle. Like the offbeat opening plate plan, the segmental opening ought to be balanced descending in gas stream applications. Segmental bores are for the most part utilized for estimating fluids or gases which convey non-rough pollutions, for example, sewage treatment, steel, compound, water molding, paper and petrochemical businesses.

Quadrant Edge Bore - The quadrant edge bore is an opening with the bay edge adjusted. The upstream side of the drag is formed like a stream spout while the downstream side goes about as a sharp edge hole plate. This plan is prescribed to quantify the progression of high consistency liquids like weighty crudes, syrups and slurries. The quadrant bore delivers a generally consistent coefficient when the Reynolds Number is under 10,000.

Ring Type Joint (RTJ) Orifice Plates - The RTJ type opening plate integrates a fundamental gasket for mounting between ring type joint spines. It depends on demonstrated innovation, has no moving parts and is appropriate for high temperature and tension applications. Opening plates are suggested for clean fluids, gases and low speed steam streams. Plate thicknesses rely upon line size and differential tension, and ought to be adequate to keep the plate from bowing under working circumstances.

Motors that can be used with variable frequency drives?

The different sorts of modern engines that can be utilized with variable recurrence drives are:

Dc engine: dc engines are still underway albeit the quantity of dynamic producers has diminished impressively, explicitly those that are as yet fabricating enormous dc engines (> 1 MW).

Ac nonconcurrent squirrel confine engine: This sort of engine is the most normally involved engine in modern cycles with variable recurrence drives.

Ac nonconcurrent wound rotor engine: This sort of engine was generally utilized in factor recurrence drive when the heap required a high beginning force and the strength of the power supply network was lacking to allow Direct On-Line (DOL) beginning. Variable speed activity is acquired by differing the successful obstruction in the rotor circuit.

Ac coordinated engine with brush less ac or brushed excitation.

Ac coordinated engine with super durable magnet excitation: This sort of engine is explicitly intended for activity with a variable recurrence drive. Simultaneous engines are utilized basically in the powerful ranges to limit costs by limiting the ongoing rating of the variable recurrence drive and because of the non accessibility of squirrel confine acceptance engines.

The most widely recognized electrical VFD utilized in industry today is the variable recurrence drive utilizing Voltage Source Inverter (VSI) typology and controlling offbeat squirrel confine engines.

The power scope of VSI sorts of variable recurrence drives reach out from fragmentary kW like 0,18 kW to 2 000 kW in the low voltage range and from 200 kW through to 30 MW in the medium voltages. The low voltages that are important to the nearby market are the standard IEC (International and Electrotechnical Commission) voltages in particular 230 V single-stage, 400 V three-stage, and 690 V three stage, all at the 50 Hz input recurrence. To fulfill the 525 V market, variable recurrence drives with an evaluated voltage of 600 V and 690 V are utilized. At the medium voltage level the voltages of interest are 3 300 V, 6 600 V and 11 000 V. Financial matters ought to be the deciding element regarding the evaluated voltage of the drive given the necessary power rating, albeit this isn't generally the situation.

Winery Industry: Pressure Gauges and Diaphragm Seals

Truly exceptional wine cannot be rushed. Making it, however, involves more than just time. At all stages of production, careful monitoring and testing are essential. Fortunately, Instronline has the reliable instruments you need to make sure your wine is of the utmost quality. Our extensive product line includes winery pressure gauges, diaphragm seals, and thermometers. Our company understands the challenges involved in running a winery. For that reason, we’ve tailored our product offerings to include only the highest quality instruments, as well as a number of custom options. Don’t hesitate to contact us with any questions about our Instruments.

Bimetal Thermometers

Temperature is a critical factor when producing wine. Accurate measurements are important, of course, but you also need a measuring instrument that truly matches your specific needs. That’s why our bimetal thermometers are the perfect option for your winery. With 2”, 3”, and 5” dials available, it’s easy to pick the size that’s right for your operation. Our hermetically sealed thermometers feature stainless steel cases and dual Fahrenheit and Celsius scales. With a range of custom options available, you’ll be able to choose the perfect thermometer for your particular requirements.

Pressure Gauges

Pressure instruments are vital for any winery operation. MIEPL is proud to offer gauges that include a variety of helpful features. Our stainless-steel gauges come dry or liquid-filled according to your request. The 4001 is a heavy-duty gauge with a 4” stainless steel case featuring a single PSI scale, while the MEX5 offers dual BAR and PSI scales. No matter what option you choose, you may rest assured that the gauge you purchase will provide accurate, reliable measurements.

Diaphragm Seals

As with any food or beverage operation, a winery requires sanitary equipment that matches FDA regulations precisely. MIEPL is proud to offer sanitary diaphragm seals for wineries so you can meet these requirements and maintain the highest levels of quality. Our sanitary seal features a 316 stainless-steel upper housing with a separating diaphragm. Available clamp sizes range from 1/2” to 4”. Please note that the pressure rating is based on the clamp and gasket used in assembly. There are many benefits to using sanitary diaphragm seals for your winery, but the most important is the avoidance of contamination. Using our sanitary seals will keep bacteria from developing, protecting your product, your company, and the consumer.

Common Types of Diaphragm Seals

Diaphragm seals are commonly categorized according to their process connection. The type of connection used must be determined based on the intended application. Please take the time to learn more about a few common types of seals.

Threaded

Threaded diaphragm seals feature threaded process connections. Several types of this seal are available. Depending on the application and seal type, they may be mounted to pressure gauges, transmitters, switches, or to a cooling element.

Some threaded seals may also be connected with a flexible capillary. In all cases, the filling fluid used in the measuring system must be chosen based on the application. Features available with threaded diaphragm seals may include:

-- Internally Welded Diaphragms

-- Exchangeable Lower Parts

-- Exotic Material Options for Wetted Parts

-- Cleaning Rings

-- All-Welded Designs

-- Full Stainless Steel Materials

-- Compact Designs

-- Flush Diaphragms

Flanged

Flanged diaphragm seals allow direct mounting on pipes, tanks, and standardized flange connections. Typically, they are mounted to pressure gauges and switches directly, or with the use of a flexible capillary. As with all seals, the flanged option should be selected based on process compatibility. Various diaphragm materials may be used to keep the seal in line with selected process fluids and applications.

Sanitary

Sanitary diaphragm seals feature hygienic process connections. This ensures efficient cleaning. They also help to avoid pollution and the development of bacteria during hygienic production processes. These are essential in the food and beverage industry where contamination must be avoided at all costs.

Likewise, the laboratory and medical fields have strict standards in place to ensure safety. Diaphragm seals must conform to FDA requirements or possibly match Sterilization In Place (SIP) and Clean In Place (CIP) methodologies.

In-Line

In-line diaphragm seals are internal to metallic bodies. They are used with a range of connection types and come in various sizes. These seals replace the process “T” in media flow and allow for laminar flow to occur. Use of an in-line seal greatly reduces the risk of mishandling a diaphragm. This prevents unnecessary damage from occurring, protecting your investment. In-line seals also remove dead space where bacteria grows and prevent media from building up in the diaphragm over time.

Finding the Right Type of Diaphragm Seal

With so many options available, it can be difficult to decide on the right diaphragm seal for your application. Trust the team at MIEPL to provide you with the expert advice you need to make the right decision.

BASICS OF VALVE POSITIONERS

There are many sorts of valve positioners out there. How can you say whether you want a pneumatic, electric or electro-pneumatic positioner? Here, we'll cover the rudiments of valve mechanization with positioners, and an outline of valve positioner types.

A valve positioner is a gadget that changes the valve actuator's position in view of a control signal. These positioners are best utilized in charge applications on account of their accuracy.

Valve positioners are normally mounted on the yolk or top packaging of a pneumatic actuator for direct control valves, or close to the furthest limit of the shaft for turning control valves. For one or the other design, the positioner is associated precisely to the valve stem or valve shaft. This considers the valve's situation to be contrasted and the position mentioned by the regulator. At the point when a control signal varies from the valve actuator's situation, the valve positioner sends the fundamental input to move the actuator until the right position is reached.

We thought of 10 Reasons to Install a Valve Positioner so you can find ways that a positioner could further develop your control interaction. Here is a fast outline of motivations to utilize a valve positioner on your rotational or straight control valves:

• Capacity to have fine command over an exact cycle.

• Speed up reaction to change in process, taking into consideration quicker stacking and venting.

• Consider split running (one regulator for two valves).

• Beat seating grating in turning valves.

Take into account expanded use of 4 - 20mA electronic sign.

• Limit valve stem pressing contact impacts and the subsequent hysteresis. This is especially significant for high temperature pressing materials like graphite.

Invalidate stream incited responses to higher tension drops and makes up for inward power lopsided characteristics.

• Permit the utilization of trademark cams in rotational valves.

There are a couple kinds of valve positioners accessible. Contingent upon the sort of positioner, it either utilizes air or power to move the actuator. How about we examine a portion of the famous choices.

Pneumatic

Pneumatic positioners get pneumatic signs (generally 3-15 psig). The positioner then supplies the valve actuator with the right pneumatic stress to move the valve to the necessary position. Pneumatic positioners are naturally protected and can give a lot of power to close a valve.

Electric

Electric valve positioners get electric (generally 4-20 mA) signals. They fill similar role as pneumatic positioners do, however use power rather than gaseous tension as an info signal. There are three electric incitation types: single-stage and three-stage substituting flow (AC), and direct flow (DC) voltage.

Electro-Pneumatic

Electro-pneumatic valve positioners convert current control signs to comparable pneumatic signs. It utilizes a blend of both power and air, as inferred by the name.

Digital

Computerized or "savvy" situating gadgets utilize a microchip to situate the valve actuator while checking and recording information. They work in basically the same manner to a simple kind positioner, aside from the electronic sign transformation is computerized instead of simple. Shrewd positioners are exceptionally precise, utilize less air than simple positioners, and take into consideration online advanced diagnostics. For more data, read our blog entry about Reducing Air Loss with Smart Valve Positioners.

Figure valve positioners could help your interaction? Get in touch with us. We're here to help!

Why You Should Use Control Valve Positioners

Process control is a great deal like baking, says Jerry Butz, Director of Engineering and Technical Support here at Automation Service.

Baking requires explicit amounts of fixings and a consistent inventory of intensity. To keep the stove at the ideal temperature, your broiler indoor regulator takes estimations and sends the information to a regulator, which then turns the warming component on or off as required.

Recipes in the process business indicate factors like the level in a tank and the stream rate in a channeling framework. To keep those factors consistent, a sensor takes estimations and sends the information to a regulator, which then, at that point, chokes a control valve as required.

As you can see from these models, control frameworks work in three essential stages:

Measure a variable (temperature, pressure, stream, and so on.)

Contrast that estimation with the ideal level (i.e., the setpoint)

Change the framework (e.g., open or close a valve) at whatever point there's an error between the deliberate worth and the setpoint

To accomplish exact control, the speed and precision of these stages are significant. Here, we'll dive into how you can support the speed and precision of the last stage — opening or shutting a control valve to take the deliberate worth back to the setpoint.

What is a valve positioner?

In a standard framework, the interaction regulator conveys a message straightforwardly to the actuator, which moves the valve. This framework works, yet it tends to be slow, and actuators generally have a specific counterbalanced, so they are just exact inside a reach.

In applications where changes are made regularly or accuracy is required, a bonus is expected to guarantee quick, exact reactions. That bonus is a valve positioner.

A valve positioner is a gadget that points of interaction with the cycle regulator and the actuator, and is associated with the valve stem so it can detect the specific place of the valve. The positioner gets an information signal from the interaction regulator and results a sign to the actuator to move the valve.

Peruse more about how valve positioners work here: Control Valve Actuator Bench Set Requirements

5 top advantages of valve positioners for control valves

Not all applications require valve positioners. However, in numerous applications, valve positioners offer benefits, particularly in frameworks where changes can be grievous for efficiency or quality.

More precise control. Since valve positioners know the valve's accurate position, they give more exact control than can be accomplished by an actuator all alone. Also, positioners further develop exactness in the lower some portion of the valve stroke, where mistakes are more normal.

Quicker control. Positioners assist with controlling valves answer quicker to changes in the process variable, limiting how much time the framework is working above or beneath the setpoint.

Steady valve position, even with shifting tensions. Shifting differential strain across the valve can demonstrate precariousness in the control circle. A positioner is one answer for assist with balancing out valve position.

More adaptable designs and capacities. A positioner permits you to put distance between the regulator and the control valve, as well as to utilize stomach or cylinder controlled actuators. You can likewise switch among immediate and turn around control activity or change the stream attributes when essential. You could involve one regulator for two valves (i.e., split running).

Insignificant impacts of contact, which causes hysteresis and deadband. Erosion in the valve stem pressing adds to both hysteresis and deadband, which decrease efficiency.

These aren't the main advantages of positioners — the worth you can acquire from them relies upon your application and the design of your framework. To figure out how introducing positioners assisted one oil with companying keep their framework running at maximized execution.

WORKING PRINCIPLE OF DOUBLE ACTING HYDRAULIC CYLINDER

We were discussing hydraulic actuators and its various types in our previous post, where we have seen the basics of hydraulic actuators and simultaneously we have classified the hydraulic actuators in linear actuators i.e. hydraulic cylinders and rotary actuators i.e. hydraulic motor. We have also seen the fundamentals of single acting cylinders in our previous post.

Today we will see here the fundamentals of double acting hydraulic cylinders

Double acting hydraulic cylinders

Double acting hydraulic cylinder is also one type of hydraulic cylinder which is used for pulling, lifting, moving and holding the load. Double acting hydraulic cylinder is displayed here in following figure. Double acting hydraulic cylinder, as shown in figure, will have two ports i.e. cap end port and rod end port. Double acting hydraulic cylinder, as name indicates, will be operated hydraulically in both direction i.e. forward direction and return direction.

Double acting hydraulic cylinder will have one piston within a cylindrical housing. When hydraulic oil will be supplied to its cap end port, hydraulic pressure force will be applied over the piston or plunger and hence piston will be extended and this stroke of cylinder will be termed as forward stroke. During extension of the cylinder piston or plunger, hydraulic oil at rod end side will be pushed out and will be directed towards reservoir.

For return stroke or retraction of cylinder, hydraulic fluid direction will be reversed with the help of direction control valve. During return stroke, hydraulic oil will be supplied to its rod end port and therefore hydraulic pressure force will be applied over the piston or plunger from rod end side and hence piston will be retracted and this stroke of cylinder will be termed as return stroke. During retraction of the cylinder piston or plunger, hydraulic oil at cap end side will be pushed out and will be directed towards reservoir.

Hence double acting hydraulic cylinders will be operated hydraulically in both directions i.e. during extension or forward direction and also during retraction or return stroke. Direction of hydraulic oil will be changed with the help of double acting directional control valve or reversible pump could also be used for changing the direction of flow of fluid.

The working principle of strain gauge-based pressure transducers

Pressure transducers and tension sensors frequently comprise of a spring component on which numerous strain checks are introduced. Subsequently, they work much the same way to drive transducers. A stomach is every now and again utilized as the strain touchy estimating body in the lower pressure range, while the spring component frequently comprises of a solitary, rounded piece of steel in the high-pressure range.

Process pressure applies a mechanical burden to the spring component, which encounters a twisting prior to getting back to its unique state. This distortion can be estimated by strain checks (SGs) and broke down by estimation gadgets.

Preferably, the strain measures are introduced in the space of most noteworthy positive and negative strain or stress to acquire the most noteworthy conceivable SG awareness. Since the specific strain angle and strain conveyance in the estimating body are known at the tension transducer's plan stage, the shape, position, and length of the estimating framework can be advanced.

Four strain checks, introduced on the estimating body, are associated with a Wheatstone span. An estimating speaker takes care of the strain checks with an excitation voltage and secures and processes the extension circuit's result sign to roll out the improvements in SG opposition apparent. The subsequent estimation sign can be handled by a modern estimating enhancer and communicated to a programmable rationale regulator (PLC). On the other hand, a high-accuracy enhancer can be utilized to straightforwardly imagine the sign. Additionally, the estimation chain can be set up utilizing an all inclusive intensifier, which moves the sign to a product for additional investigation and capacity. Figure 2 shows instances of these three estimation chains.

Electromagnetic Flow Meter

The electromagnetic stream meter is a gadget utilized for estimating the progression of the fluid when it goes through the pipeline. Or on the other hand we can say that the electromagnetic flowmeter use for estimating the stream pace of the electrically directing liquid. The electrically conductive fluid means the fluid permits the flow to go through it.

The electromagnetic flowmeters work on the rule that the hindrance is made in the way of the fluid and the tension of the fluid incites the voltage across the curl.

Working Principle of Electromagnetic Flow Meter

The electromagnetic flowmeter chips away at the rule of Faraday's Law of electromagnetic enlistment. This regulation expresses that when the conductive fluid goes through the attractive field, the voltage actuates across the guide. The extent of the voltage is straightforwardly relative to the speed, length of the guide and the strength of the attractive field.

The attractive field is created by the loop which is mounted on the outer metallic body of the line. The fluid goes about as a guide and when goes through the attractive field actuate the voltage across the loop. The extent of the voltage relies upon the speed of the fluid.

Development of Electromagnetic Flow Meter

The electromagnetic stream meter comprises the electrically protected pipe made of fiber. Anodes put inverse to one another, attractive curl put on the line for producing the attractive field and so on. The protected line conveys the fluid whose stream should be estimated.

The electromagnet is put around the protected line. This electromagnet instigates the attractive field around the line. The course of action is like the guide moving in the attractive field. The voltage is instigated across the curl due to the progression of the fluid. The incites voltage is communicated as,

Benefits of Electromagnetic Flow Meter

• The result voltage of the electromagnetic stream meter is relative to the stream pace of the fluid.

• The result is uninfluenced by the changing quality of fluid like thickness, pressure, temperature and so on.

• The electromagnetic stream meter can gauge the progression of slurries, oily, and can deal with the destructive liquid fluids.

• It is utilized as a bidirectional meter.

• The very low stream rate can likewise be estimated by the electromagnetic stream meter.

Impediments of Electromagnetic Flow Meter

• The electromagnetic stream meter has low exactness.

• It is weighty and incredibly enormous in size.

The electromagnetic stream meter is otherwise called the magmeter.

What is the Photoelectric Tachometer

The tachometer which involves the light for estimating the speed of revolution of shaft or plate of machines is known as the photoelectric tachometer. The misty circle with openings on its outskirts, light source and laser are the fundamental pieces of the photoelectric tachometer.

The tachometer comprises the murky circle which is mounted on the shaft whose speed should be estimated. The circle comprises the same openings around the outskirts. The light source is put on one side of the plate and the light sensor on the opposite side. They are in accordance with one another.

Whenever the plate pivots their openings, and the misty part comes on the other hand between the light source and light sensor. At the point when the openings come in the line of the light source and the light sensor, then, at that point, the light goes through the openings and breakdown to the sensor. Henceforth the beat is created. These heartbeats are estimated through the electric counter.

At the point when the dark part comes in the line of light source and sensor, then, at that point, the circle obstructed the light source, and the result becomes zero. The development of heartbeats relies upon the accompanying component.

1. The quantity of openings on the circle.

2. The speed of turn of the circle.

The openings are fixed, and henceforth the beat age relies upon the speed of the revolution of the plate. The electronic counter is utilized for estimating the beat rate.

Benefits of Photoelectric Tachometer

1. The advanced result voltage is acquired, and subsequently there is no need of simple to computerized change.

2. The beats of steady abundancy are acquired which work on the electronic hardware.

Drawbacks of Photoelectric Tachometer

1. The existence of the light source is around 50,000 hours. Thus the light source should be supplanted convenient.

2. The exactness of this strategy relies upon the blunder which is addressed by the unit beat. These mistakes can be limited by utilizing the gating time frame. The gating time frame implies the meter estimates the recurrence by counting the info beats.

The complete number of heartbeats created at one upheaval is likewise utilized for limiting the mistake.

Tachometer the new generation counting machine

All industries use many categories of machines and equipment in their factories. The prosperous production of goods and merchandise is the sole goal of every company. To maintain the quality of the products manufactured, they are subjected to multiple checks. Once the inspection is complete, it is forwarded for distribution on the market. But before production there are certain criteria by which each product is manufactured. The use of many high-end devices is becoming popular in the industrial sector. Electronic devices used to save time and manpower are highly appreciated by all business people.

There are many machines that are used to make common parts for many products. And the correct instance of each machine is very important for better product quality. Previously, workers had to constantly monitor the number of times the machine had done its job, and sometimes miscalculations occurred. But with the development of science and technology these problems are overcome. The use of highly sophisticated devices simplified the work. Today, every device has potential

Whenever a car spins the motor or mixer, you can't read exactly how long it takes to complete a spin. Therefore, this leads to confusion and inaccuracy, which makes the job more complicated. With the launch of the new technology, the job of counting meters such as the tachometer has become simple. These meters are in great demand in many industrial and commercial purposes. With the change in technology, the need for this device has become very essential. This device works as a counting device for any machine that rotates over a constant period of time. To record machine rotations per hour or minute, this tool helps you to give the exact result.

The daily advancement in the field of machinery has made the tachometer used in various fields. The rise of complex machines has influenced the production of highly refined digital meters. The meters of this new generation have been designed using some of the most up-to-date methods in digital technology and electronics. It has the ability to record rotations at high speed and produce results with perfect precision in the form of a recordable digitized format. The various categories of this device help users to choose the ideal model with many specifications.

The launch of laser technology meters is also generating great demand in the market. It has the specialty of the quality of reading the rotations through the laser beams emitted by the device without coming into contact with the equipment. The need for this highly optimized device is mainly in the automotive industries. It has played an important role for these industries as most of the parts produced in these industries need proper accountability. In order to select the correct category of tachometer, the compatibility of the equipment must first be examined.

Digital Counter Make Counting Convenient and Easy

The digital counter is considered a unique gift of modern technology. These counters work in a simple way. Just press the button every time you want to add to the current number. With this device, you can get a new total in seconds, as the new amount is added to the total immediately.

Digital counters are usually battery powered and are usually made of plastic. You can clearly see the numbers in digital form on the LCD screen. These new digital counters are better than the old version. The digital display is clearly visible without any problems. The new digital counters are better than previous mechanical versions. They are also accurate and completely reliable. The main use of the counter is pulse counting and is based on the concept of flip-flops. The array of flip-flops with a clock signal became the basis of a simple digital counter. These electronic devices are now also used in many professional applications. It is also used to count people who come to large pubs, shops, social events, clubs and the like. People who want to regulate their business for business purposes now use digital counters. This makes the calculation simple and very easy. The digital counter simply shows the number of people who have visited these businesses, how many times they have visited and also shows the digital times even when they leave. This specific data provided by the digital counter helps established companies provide better services by giving more working people a peak life.

Digital counters are widely used in schools and educational institutions. Teachers now store digital counters to keep track of the number of children who go on day trips.

Even dispatchers can now easily control and count cars on any particular part of the road or at a busy intersection using digital counters. In fact, there are many tools that can be used with a digital counter. Now, if you need to do counting in any professional and accurate way, you need to buy and use digital counters. This is actually the best way to ensure that you never lose a count again.

working of monoflange

Monoflanges join the capacity of up to three valves in an especially smaller body, because of an exact organization of inward entries and valve chambers. Be that as it may, what truly occurs inside a monoflange valve, once introduced?

In a compound cycle a high reaction speed is expected for most control applications. One of the factors that influence the reaction time is the volume and the distance among cycle and instruments. In the event that the medium to be estimated is gas, and the interaction will in general vary unequivocally now and again or on the other hand assuming the control is basic, mounting the instrument close to the cycle is the arrangement.

Vibrations are additionally basic, for instance, in the event that that motivation lines are associated with a vessel. The more drawn out the attach, the more extensive is the sufficiency of the vibration causing potential disappointments of the spout. A monoflange incorporates one, a few needle valves inside a minimized, rib molded body, permitting a critical decrease in volume, aspects, weight and potential spillage focuses.

Monoflange is the arrangement

Contingent upon the prerequisites of the plant it is introduced in, the monoflange can consolidate one, a few valves. In a monoflange with two valves (block and drain), one valve (with a blue cap) secludes the cycle and the other (with a red cap) controls the venting of the medium caught inside the instrument. This is for the most part utilized in applications that are generally careless (for example low strain) or where a first turned down valve is given not long before the monoflange.

The most secure arrangement, and the one we exhort for forceful media or basic working circumstances, is the three-valve monoflange or the alleged twofold square and drain (DBB), which highlights two shut-off valves in series and one valve for venting.

Monoflange usefulness

The monoflange bodies are penetrated inside with openings which interface the annular valve chambers.

The stream enters the monoflange from the pipeline and stops underneath the main shut-off valve [1];

Whenever the principal shut-off valve [1] opens, the stream continues towards the second turned down valve [2] ; when the valve [2] is open, the instrument is subsequently associated with the cycle line;

At the point when the primary shut-off valve [1] is shut, the medium caught among valve and instrument can be released by means of the vent valve [3] through the vent outlet. The two shut-off valves [1, 2] are in a calculated position, which permits the stream to go through them.

The two shut-off valves permit a superior separation from the cycle: in the event that the main shut-off valve doesn't seclude the medium appropriately, the subsequent one will go about as a wellbeing implies against unplanned holes. Sometimes, client details don't permit the medium to be in contact with the instrument when it isn't estimating. Therefore the medium will be released utilizing the vent line. In different cases - because of the vent line - instruments can be handily adjusted without getting off them from the line.

Guide To Choose Control Valve

The most used type of actuator is the air-operated because it entails much less ancillary equipment (as cabling, switchgear) whilst as compared to different types of actuators. If you are looking best products like intelligent Level Controller, ultrasonic liquid level switches, with utility Control valves is increasing in the closing years, due to growing procedure automation in most industries. Those forms of valves are utilized in irrigation structures, water remedy flora, oil and fuel plants, energy technology, fireplace prevention structures, meals processing industries by streamlining the reaction to modifications in methods and offering greater safety to personnel and system.

TYPES OF CONTROL VALVES:-

Types of control valve almost any type of valve can be used for manage by way of becoming an actuator and positioned, even though care needs to be taken to make certain that there's no immoderate backlash gift and it will likely be recognized many will not showcase a good characteristic for precise manipulate.

Globe:-(Plug and Seat) those are the maximum traditionally used manage valves - commonly to be had from 12 to 400mm in all castable substances. Large sizes are available but it becomes greater commonplace to move to an attitude construction on these sizes.

Eccentric Plug: -A preferred purpose valve that offers price effective solutions over an extensive range of fashionable packages. It offers better CV values than globe - length for size with special features.

Butterfly:- The least expensive of all control valves. Sizes range from 50 to 3000mm. Pressure ratings are generally up to 1600 kappa (G). Temperatures are up to 100∞C. This valve is good for corrosive applications but does not handle high pressure drops well. It is the lightest valve available -size.

Diaphragm / Pinch:-These valves are inexpensive and very simple in operation. They are used extensively in the mining industry for control of slurries and Very good for low-pressure abrasive applications and you can this type product with Temperature Transmitter Suppliers which will help you out to choose right products. At Instronline radar level transmitter, electromagnetic flow meter Dealers, Siemens Electromagnetic flow meter Suppliers, Siemens Electromagnetic flow meter Dealers

Selection of accessories:-

Cost is a major factor in material selection:-

Now not simply the value of fabric in bucks in keeping with the pound, however also the fee of fabrication and inspection contribute to the uninstalled cost valve. Set up cost consists of not best the fee of installation but additionally the cost of any harm from fallacious setup and value the inspection. The final includes things like analysis of material chemistry, radiographic and surface examination of castings and welds, and take a look at to see that the established valve is the precise one and that its miles nicely oriented.

The selection of the ideal or most reliable manage valve type relies upon on the particular take a look at of the pipe machine and the conditions of its fluid, however the length of the manipulate valve need to be such that stress drops through it and now not the drop of strain of the pipe is the one that controls the waft.If you are looking full specification of products like rf level transmitter, Ultrasonic Level Transmitter Dealers In Delhi NCR, low radar level transmitter Exporters of All valves, along with steam control valves, are designed to satisfy an allowable internal leakage preferred (FCI / ANSI) you can find these all on. The better the quality of products and updated price list on Instronline.

VALVE SELECTION FOR SLURRY SERVICE: NOT A PERFECT SCIENCE

Slurries can be an intense liquid to move! They can be rough, destructive, and contain a high level of solids. You'll observe slurries in paper factories, wastewater plants, and frac sand mines. Most administrators would concur that slurries are hard on process gear. In a past post, we examined the rudiments of slurries and siphon determination. Today, we'll discuss significant elements and qualities you ought to consider prior to choosing a valve for your slurry application.

Valve choice is a "element of the assistance and the value the client will pay". The specific sort of slurry administration fundamentally affects the kind of valve chose; hence cost ought not be the central consideration. For instance, for low temperature and low tension slurries, stomach or squeeze valves are commonly utilized. For heavier obligation slurries with high temperatures and strain, the valves become more particular. Most standard valve plans won't hold facing slurries, particularly rough slurries. Rough not set in stone by their properties, and cause critical wear on process hardware.

Slurry applications require valve makers and specialists to painstakingly consider three essential powers that sway how the valve will work additional time:

-- Wear brought about by scraped area or consumption of the actual slurry

-- Valve entryways and seats should be made of materials that can endure the cycle conditions.

Rubbing

Is it metal-to-metal or metal-to-elastic contact? The sliding of the door against the valve seat makes grinding that burdens valve parts.

Pressure

Shutting a valve under tension is normally more troublesome and requires more enthusiastically materials.

To appropriately choose a valve and thin the choices, an administrator ought to consider the accompanying qualities of the slurry to ensure the right material of development, type, and size of valve is chosen:

Level of Solids

Slurries are normally comprised of 30-60 percent strong material. On the super side, a few slurries can comprise of 60-70 percent solids or higher.

Molecule Size

Assuming that a slurry contains bigger particles they will probably become stuck assuming the valve has limited limitation.

Stream Rate

This is significant while thinking about wear and material misfortune.

Temperature and Pressure

The most extreme temperature and tension of the slurry is particularly significant while choosing sleeve or seat materials for use in the valve. A few elastomers turn out incredible for raised temperatures, while others are the most appropriate for use at surrounding temperatures. As a rule, elastomers and polymers with great wear attributes have administration temperature restrictions of 120 degrees.

Structure

Destructiveness should be considered for not just choosing the right sleeve or seat material, yet additionally while choosing a viable material of development for the metal body, lodging, or entryway of the valve.

Gooey and rough media is known to cause serious scaling, so understanding the potential for scaling or crystallization with your slurry's significant. Scaling limits creation and can be impeding to the existence of hardware. In any case, most valves, including the seat, covering, actuator control plans can be intended to oblige any development of scale or solidified media inside the valve.

For slurry applications, valve determination is certainly not an ideal science, so you should work with a certified architect for the best suggestions in light of the slurry attributes and powers that can cause untimely valve disappointment while perhaps not painstakingly thought of.

HOW DO AIR-OPERATED DIAPHRAGM PUMPS WORK?

Air-worked twofold stomach (AODD) siphons are utilized in offices, everything being equal, and in a wide range of enterprises. From petrochemical to food and refreshment, these siphons are well known and flexible. Their remarkable plan is great for moving profoundly rough or thick items. However, how would they work?

An AODD siphon is a sort of certain uprooting siphon that utilizations packed air as a power source. The compacted air is moved from one chamber to the next by a connected shaft that permits the chambers to at the same time move. This ever changing movement powers fluid out of one chamber and into the release funneling while the other chamber is being loaded up with fluid simultaneously.

Packed Endlessly air CONSUMPTION

Something imperative to note about compacted air: when the air leaves the blower, it's generally expected wet, grimy, warm, and unregulated. Messy, unregulated air can harm AODD siphons. To place air-worked stomach siphons in a good position, providing them with the most ideal quality air's significant.

Channel controllers are accessible to give air filtration and strain guideline. This part will eliminate strong and fluid pollutants and give perfect, controlled, steady pneumatic force.

Stomachs

These siphons use responding elastomeric stomachs and actually take a look at valves to siphon liquid. These adaptable stomachs are produced using a wide assortment of materials and ought to be chosen in view of compound similarity first.

The fluid chambers are filled and exhausted by liquid that is drawn through a typical bay and released through a solitary outlet.

Air-worked twofold stomach siphons have great attractions lift qualities and can deal with oozes or slurries with a generally high measure of coarseness and strong substance. AODD siphons are additionally all around applied to applications including profoundly thick fluids.

BALL VALVE PUMPS VS FLAP VALVE PUMPS

Contingent upon the kind, sythesis, and conduct of the solids in the siphoned liquid, the AODD siphon might have ball valves or fold valves. These valves work involving the tension distinctions in the siphoned fluid.

Fold valves are best for huge solids (up to the line size) or solids-loaded slurries. Ball valves perform best with solids that settle, float, or suspend.

One more unmistakable distinction between ball valve siphons and fold valve siphons is the attractions and release ports. In ball valve siphons, pull ports are on the lower part of the siphon. In fold valve siphons, pull ports are on top, empowering it to more readily deal with solids.

Throb

It is essential to take note of that there is normally some throb of release stream in air-worked stomach siphons. This can cause overabundance development in the siphoning framework. This throbbing stream can be diminished fairly by involving throb dampeners in the release funneling.

Throb dampeners ingest energy from the beat wave made by AODD siphons. They make an area of low strain in the framework with enough volume to retain the throb.

The throb dampener has a film with a pad of compressible gas/air behind it that flexes to retain the beat, permitting a laminar stream downstream of the dampener.

AODD siphons offer basic innovation and solid siphoning for some liquids across numerous ventures. Inquire as to whether this sort of siphon accommodates your application. With its somewhat low price tag and upkeep cost, it very well may be the ideal fit for the application and the spending plan.

What is Bourdon Tube Pressure Gauge

whenever a versatile transducer ( bourdon tube for this situation ) is exposed to a strain, it deserts. This diversion is relative to the applied tension when aligned.

Depiction of Bourdon tube Pressure Gauge

The fundamental pieces of this instruments are as per the following:

A versatile transducer, that is bourdon tube which is fixed and open toward one side to get the strain which is to be estimated. The opposite finish of the bourdon tube is free and shut.

The cross-part of the bourdon tube is eliptical. The bourdon tube is in a twisted structure to resemble a roundabout bend. To the free finish of the bourdon tube is joined a flexible connection, which is thusly associated with an area and pinion as displayed in chart. To the shaft of the pinion is associated a pointer which clears over a tension adjusted scale.

Activity of Bourdon tube

Tthe strain to be estimated is associated with the proper open finish of the bourdon tube. The applied tension follows up on the inward dividers of the bourdon tube. Because of the applied tension, the bourdon tube will in general change in cross - segment from curved to roundabout. This will in general fix the bourdon tube causing a relocation of the free finish of the bourdon tube.

This dislodging of the free shut finish of the bourdon tube is corresponding to the applied strain. As the free finish of the bourdon tube is associated with a connection - area - pinion game plan, the removal is enhanced and changed over to a rotating movement of the pinion.

As the pinion turns, it makes the pointer to accept another situation on a strain adjusted scale to show the applied tension straightforwardly. As the strain for the situation containing the bourdon tube is generally barometrical, the pointer demonstrates check pressure.

Utilizations of Bourdon Tube pressure measure

They are utilized to quantify medium to exceptionally high tensions.

Benefits of Bourdon tube pressure measure

• These Bourdon tube pressure measures give exact outcomes.

• Bourdon tube cost low.

• Bourdon tube are basic in development.

• They can be changed to give electrical results.

• They are protected in any event, for high strain estimation.

• Precision is high particularly at high tensions.

Limits of bourdon tube pressure measure

• They answer gradually to changes in pressure

• They are exposed to hysteresis.

• They are touchy to shocks and vibrations.

• Enhancement is an absolute necessity as the removal of the free finish of the bourdon tube is low.

• It can't be utilized for accuracy estimation.

How are the Ultrasonic Level Switch Works

A ultrasonic switch is a gadget that utilizes imperceptible high-recurrence sound (ultrasound) to identify the presence or nonattendance of a fluid at an assigned point. The gadget comprises of an electronic control unit and a sensor. Ultrasonic level switches utilize the properties of sound transmission in fume and fluids to identify fluid level. At the point when sound goes in air, it loses a lot of sign strength. While going in fluid, sound holds practically the entirety of its sign strength.

To distinguish fluid level, we should decide whether there is a fluid or gas (air) in the hole. Since fluids have a higher thickness than gasses, sending sound through them is simpler. One side of the sensor hole communicates sound, the opposite side identifies it. At the point when fluid is available, a high measure of sound is gotten at the discovery side. Whenever gas (air) is available, a modest quantity of sound is gotten. The hardware identify this distinction and switch a hand-off in like manner.

Ultrasonic switch sensors contain two piezoelectric gems, one communicates sound and one gets sound. Every gem is mounted on one side of a hole in the metal sensor. The send gem creates high recurrence sound (1MHz to 3 MHz) that is guided across the hole to the collector gem. The beneficiary precious stone proselytes the sound energy got into an electric sign, which is handled by the hardware to decide whether the hole has fluid or air in it.

Ultrasonic Gap Switch/Level Switch Working Principle

Ultrasonic Switches utilize a couple of piezoelectric precious stones that are exemplified inside epoxy at the tip of the transducer.

The gems are comprised Ultrasonic Gap Switch Working Principle of an earthenware material that vibrates at a given recurrence when exposed to an applied voltage. Whenever the voltage is sent from the hardware, one of the two precious stones, the "communicating gem" changes the voltage over to a ultrasonic sign.

The presence of fluid inside the transducer hole permits the subsequent precious stone, the "getting gem" to detect the ultrasonic sign and converts it back into an electronic sign. The sign illuminates the hardware that fluid is available inside the transducer hole. Assuming no fluid is available, the ultrasonic sign is constricted and can't be identified by the getting precious stone.

The ultrasonic transducer ceaselessly screens the hole to decide the presence of fluid. When utilized as an undeniable level switch, the gadgets will quickly incite a hand-off assuming it identifies a wet gap.Similarly when utilized as a low-level switch, it consistently screens the hole for a dry condition.

Applications:

Ultrasonic level switches can be utilized in a wide assortment of uses with no adjustment or arrangement. Notwithstanding, there are limits to the kinds of interaction they will work in.

The variables beneath should be thought about prior to choosing a ultrasonic level switch for your application.

 Fluids just - the interaction media should be a fluid. The ultrasonic level switch can't identify the contrast between two gases or a gas and a strong. The even thickness of a fluid is expected for appropriate discovery.

 Clean fluids just - a fluid that has too high a level of solids won't send sound all around ok to permit recognition. Regularly 5% suspended solids are the most extreme sum permitted.

 The fluid should stream - an application where the fluid can't deplete out of the sensor hole will cause misleading problems. In the event that a fluid is too gooey to even consider streaming out of a 3/4" hole then the unit won't work as expected. Here and there this can be tackled by various mounting, yet a few fluids are simply excessively thick.

 No (or not many) bubbles - particularly in liquids with a higher thickness. Huge air pockets in thick liquids will obstruct the sound sign from crossing the hole. Low consistency liquids can have a genuinely a lot of air pockets as they will generally be tiny (Alka-Seltzer in water). In the event that these rules are appropriately noticed, the ultrasonic level switches will give inconvenience free activity with next to no alignment or intermittent change.

Advantages of Using an Industrial Butterfly Valve

It doesn't make any difference in the event that you're simply beginning your vocation in the petrol business or then again assuming you've worked in the business for a really long time you've probably known about butterfly valves. They're one of the most widely recognized kinds of valves in the business, and as it should be. Maintain perusing to become familiar with the upsides of utilizing a modern butterfly valve.

Profoundly effective

One of the primary reasons organizations and pipeline laborers lean toward butterfly valves is on the grounds that they're effective. Also, the valves are not difficult to change and require insignificant exertion from laborers because of butterfly valves having different incitation choices. At long last, the basic and lightweight development makes butterfly valves probably the least demanding valve to keep up with.

Accessible in a few sizes

Butterfly valves are perhaps the most flexible choice accessible to the business since they're accessible in various sizes. The size choices make these valves viable with most pipelines, no matter what the line's size. At times, a specific pipeline might require a valve with a reduced size, and the butterfly valve is the most ideal choice for that need.

Incredible fixing in low-pressure situations

Each valve available has its own assets and shortcomings. Be that as it may, butterfly valves have uncommon fixing abilities for any circumstance including low strain. The explanation these valves are ideal in low-pressure situations is on the grounds that the plate is lightweight, which makes fixing a lot more straightforward. On the off chance that you needed to seal a high-pressure stream, you might be in an ideal situation with a ball valve, just like a heavier obligation elective.

Butterfly valves, however they don't seem like much from the outset, are enormously helpful and generally acknowledged as a norm in the pipeline business. Assuming you're searching for new valves for your pipeline with low strain, look no farther than butterfly valves. You've previously seen a portion of the benefits of utilizing a modern butterfly valve, why not add them to your assortment?

Around here at Instronline, we have faith in making top notch items that are dependable and easy to understand for the diligent employees in the petrol business. Whether you're searching for a versatile situated butterfly valve or some other valve type, we have what you really want. Shop our broad stock today!

Diaphragm valve vs globe valve for chemical processing applications

Both diaphragm valves and globe valves are used to control the flow of liquids through a pipeline. Each has both advantages and disadvantages, particularly when looking at chemical resistant valves for use with the types of aggressive media that might be found in chemical processing applications. We take a look at both diaphragm and globe valves, consider their differences and offer some guidance on which might be the best solution for your specific application.

Globe valves

A Globe valve is a linear motion valve which is primarily designed to stop, start and regulate flow. A globe valve consists of a movable plug and a stationary seat in a spherical body. When the valve handle is turned the plug (or disc) is lowered or raised by means of the valve stem. When the disc is fully lowered, the fluid flow is shut off and when the disc is fully raised, the fluid flow is at its maximum rate. Variable flow rates proportional to the opening size are also possible with globe valves. Manual globe valves tend to have a threaded stem with a hand wheel to open and close it using a screw motion, whereas automated globe valves generally have smooth stems and are controlled through an actuator. The sealing surface is resilient, meaning that it withstands wear very well and provides both good sealing properties and a long service life. This means that globe valves are a good solution for applications with frequent operational requirements.

Advantages of globe valves:

• Their simple design means that they are easy to maintain and cost-effective to manufacture.

• They are quick to open and close, with an overall relatively low valve height and a short stroke.

• Ideal for smaller spaces.

• Suited to connections that require flanges.

• Good shut-off results.

• Resilient, with a long service life.

• Available in a variety of designs, each with a unique application in mind.

Disadvantages of globe valves:

• They can be difficult to open and close, and large valves require considerable power to do so.

• Heavier than other valves of similar pressure ratings.

• The direction of the media flow is limited.

Diaphragm valves

A diaphragm valve consists of a valve body (which has two or more ports), an elastomeric diaphragm and a weir or seat that the diaphragm presses on to close the valve. The elastomeric diaphragm is a versatile and dynamic seal, often constructed from a rubber or plastic moulded solution with an insert in either a metal or an engineering plastic. When the rubber diaphragm comes into contact with the seat at the top of the valve, a seal is formed. The seat of the valve comes in two different options: a straight-through design or a saddle design. The saddle design for the diaphragm valve has a weir effect and is more commonly used for chemical resistant valves because a bonnet over the diaphragm and control mechanism keeps the liquid contained, preventing leakage, as well as the saddle shape meaning that the valve is self-draining. Solenoid diaphragm valves are a popular solution, providing automated control of the opening and shutting of the solenoid diaphragm valve.

Advantages of diaphragm valves:

• A simple, cost-effective solution.

• The flow media only comes into contact with the diaphragm, protecting the valve from contamination.

• The seal is leak-proof thanks to the tight shut-off and the elastic nature of the diaphragm material.

• Suitable as a chemical resistant valve as it copes well with corrosive fluids.

Disadvantages of diaphragm valves:

• Not ideal for larger pipe diameters.

• Poor pressure resistance.

• Suitable only for moderate temperatures.

Applications for globe valves and diaphragm valves

Globe valves lend themselves to use in applications where fast action, leak tightness, maintenance and safety are major concerns. They can be used in water treatment, chemical production, oil and gas transport and almost any valve application where pressure drop is not an issue.

Diaphragm solenoid valves are ideally suited to corrosive applications, where the body and diaphragm materials can be chosen for chemical compatibility. Diaphragm valves are also well-suited to abrasive applications, where the body lining can be designed to withstand abrasion and the diaphragm can be easily replaced once worn out.

How does a monoflange work?

Monoflanges combine the function of up to three valves in a particularly compact body, thanks to a precise network of internal passages and valve chambers. But what really happens inside a monoflange valve, once installed?

In a chemical process a high response speed is required for most control applications. One of the variables that affect the response time is the volume and the distance between process and instruments. If the medium to be measured is gas, and the process tends to fluctuate strongly at times or if the control is critical, mounting the instrument near the process is the solution.

Vibrations are also critical, for example, in case that impulse lines are connected to a vessel. The longer the hook-up, the wider is the amplitude of the vibration causing possible failures of the nozzle. A monoflange includes one, two or three needle valves inside a compact, flange-shaped body, allowing a significant reduction in volume, dimensions, weight and potential leakage points.

Monoflange is the solution

Depending on the requirements of the plant it is installed in, the monoflange can incorporate one, two or three valves. In a monoflange with two valves (block & bleed), one valve (with a blue cap) isolates the process and the other (with a red cap) regulates the venting of the medium trapped inside the instrument. This is mostly used in applications that are relatively uncritical (e.g. low pressure) or where a first shut-off valve is provided just before the monoflange.

The safest configuration, and the one we advise for aggressive media or critical operating conditions, is the three-valve monoflange or the so-called double block & bleed (DBB), which features two shut-off valves in series and one valve for venting.

Monoflange functionality

The monoflange bodies are drilled internally with holes which connect the annular valve chambers.

The flow enters the monoflange from the pipeline and stops below the first shut-off valve [1];

When the first shut-off valve [1] opens, the flow proceeds towards the second shut-off valve [2] ; when the valve [2] is open, the instrument is thus connected to the process line;

When the first shut-off valve [1] is closed, the medium trapped between valve and instrument can be discharged via the vent valve [3] through the vent outlet. The two shut-off valves [1, 2] are in an angled position, which allows the flow to pass through them.

The two shut-off valves allow a better isolation from the process: In case the first shut-off valve does not isolate the medium properly, the second one will act as a safety means against accidental leaks. In some cases, customer specifications do not allow the medium to be in touch with the instrument when it is not measuring. For this reason the medium shall be discharged using the vent line. In other cases – due to the vent line – instruments can be easily calibrated without dismounting them from the line.

How does a thermocouple work and what are thermocouple types?

For many of us who work in automation, especially process automation, questions like what is a thermocouple, how does a thermocouple work, or what are the types of thermocouple can seem like very basic questions. Most of them will just say it’s a thermometer and leave it to that.

When we ask about the thermodynamics behind it, people actually don´t talk about it. The article will tell you what is a thermocouple exactly, and everything else you need to know about thermocouples.

What is a thermocouple?

Thermocouples are electrical devices consisting of two dissimilar electrical conductors forming different electrical junctions at various temperatures.

Building on the thermoelectric effect, a thermocouple produces temperature-dependent voltage, which can be used to measure temperature.

In addition to thermocouples, the market has a wide variety of temperature sensors – resistance temperature detectors (RTDs), infrared sensors, thermistors, silicon diodes – just to name a few. The pros and cons of each make them more suited for some applications and less ideal for others.

But before we start talking about different thermocouple types, let’s understand how exactly they work.

How does a thermocouple work?

The working principle of the thermocouple relies on a law of physics. We call it the Seebeck effect, after Thomas Johann Seebeck. This French scientist found out that if we join two different metals and heat them on one end, the temperature differential between the two ends produces an electromotive force (EMF). Let’s have a look at the picture below to understand this better:

This EMF depends on the type of metals used and the temperature. Therefore, if we know the characteristics of both metals, we can calculate the temperature change by measuring the millivoltage produced. To relate the voltage to the temperature change, we’ll need the help of a thermocouple table.

Each thermocouple type will have its own reference table, which brings us to the next topic. The following section discusses the types of thermocouples available in the market.

Thermocouple types

A thermocouple consists of two metals that produce an EMF when one end experiences a temperature change. However, one thermocouple can’t handle all temperature ranges, so we use different metals to measure all the ranges we need. You can tell the thermocouple types apart by the cable colors.

But one needs to be careful because those colors change between countries and standards. This table will give you an idea of the most common thermocouple types, their temperature ranges in some of the most common standards.

Thermocouple replacement

Thermocouples have very wide temperature ranges so they are often used in extreme conditions. This makes thermocouple replacement a key aspect of maintenance. Luckily, smart transmitters can monitor the health of your primary element as well as its own health. These devices can give you enough data on your process to plan preventive maintenance based on predictive analyses.

Furthermore, they can also give you data on the performance of different sensors, so you can choose sensors with better performance and life for your process.

Metal Seated Valves vs Soft Seated Valves

Metal Seated Ball Valves

Engineered to excel in the most demanding industrial settings where valve deficiencies can endanger safety, plant efficiency and reduce profitability, metal seated ball valves stand out.

These long-lasting valves are perfect for the oil and gas industries, refining and power generation.

Metal Seated Valves vs. Soft Seated Valves

Deciding on the right seat material can be a difficult decision when it comes to ball valves because you’ll have several options.

Determining factors you will need to consider include the materials used in construction, the appropriate size, and the type of design features including V-port, bleed, double bock, 1, 2, or 3 pieces, etc. An even more important consideration is the seat type.

Having a complete understanding of the process conditions should be the starting point when it comes to choosing seated valves.

Does your situation require a bubble tight shut off?
Is the fluid corrosive?
Does it contain abrasive particulates?
Will it be under high pressure or temperatures?

Once you have a firm grasp on these factors, the choice will be apparent.

Advantages of Metal Seated Ball Valves

The key advantage of metal seated valves when compared to soft seated valves is that they can withstand high temperatures and severe service conditions.

Metal seats can stand up to extreme flashing, hydraulic shock, abrasive process fluid, and high temperatures up to and exceeding 1,000° F. They are also ideal for high erosion or corrosion applications.

Another important factor is that metal seats can be hardened by specialized coatings.

Soft Seated Ball Valves

Soft seats are typically composed of thermoplastic components like PTFE. These valves are appropriate for applications in which chemical compatibility is crucial, and in situations where having the tightest seal is important.

Soft seats, however, aren’t suitable for processing abrasive or dirty fluids. These valves are known to break down under conditions like these, resulting in a leaky valve. Complications introduced by soft seated valves are related to the fact that they don’t stand up to applications that challenge their service limits.

Metal seated ball values on the other hand can hold up under high temperatures and extreme service conditions. Well established in the field, metal seated ball valves deliver uninterrupted service with the maximum shut off standards.

The valves also work for longer time periods than soft seated valves. These durable valves can basically handle the majority of abrasive applications.

Metal Seated Valves Coating Options

With metal to metal seating, and depending on the service conditions, applying various coatings make it possible for ball and seat rings to be hard faced on sealing locations.

Examples of these specialized coatings include satellite hard facing, chromium carbide, tungsten carbide and electrolysis nickel plating. Sealing is achieved by the metal-to-metal contact in between two hard coated surface areas.

Metal-Seated Ball Valve Costs

Even though metal seated valves are more expensive, the cost of downtime resulting from failure, coupled with the replacement of soft seated valve break downs, should be factored in.

The efficiency and longevity of metal seated ball valves will pay off and counteract the higher price.

Bottom line, metal seated ball valves are the best, long lasting, economical options for critical applications.

Installation

The installation of metal seated valves can comply with shut off standards which include ANSI/FCI 70-2-1976 and designed for allowed leakage.

The most frequently specified leakage classes include Class V and VI. Class VI is often misinterpreted as “bubble tight.”

In fact, a certain amount of leakage is permitted, measured by the amount of air bubbles that escape per minute during testing. “Bubble tight” shut-off is more accurately related to resilient-seated valves.

The metal seated ball valves include the following characteristics.

Available in flanged or threaded connection ends, in sizes that range from 1/4″ to 4″.
For this configuration, the service temperature limitation is 450°F (232.2°C).
Configurations include metal seat with body seals polymeric seat seals, stem packing.
The body seal is spiral wound flexible/SS316 graphite (flexible/die-formed graphite).
Intended usage is in erosive and/or abrasive applications in which higher temperatures aren’t a concern.
The polymeric seals incorporated in this metal seat configuration are replaced with flexible, die-formed graphite seat seals with stem packing.

Recognizing your process condition is critical when it comes to choosing the appropriate seat for your specific application.

If you determine that the best solution is metal seated ball valves you’ll find them to be long lasting, cost effective solutions for critical applications.

Fundamentals Of Pressure Measurement

Pressure, by definition, is a derived para-meter. One cannot create an artifact of one pound per square inch or any other measure of pressure. Pressure is derived by the combination of a mass measurement imposed upon an area. It is commonly expressed in terms of pounds force or per unit area (Pounds per square inch). Pressure can also be expressed in terms of the height of a liquid column (Inches of water or millimeters of mercury) that produces the same pressure at its base.

Gauge Versus Absolute Pressure

Pressure measurements are always expressed as the difference between the measured pressure and some base pressure. Gauge pressure is the pressure measured from, or in addition to, atmospheric pressure. Gauge pressure is normally expressed in terms such as PSIG or pounds per square inch gauge. Absolute pressure is measured from a base of zero pressure and is expressed as PSIA or pounds per square inch absolute. Negative pressures such as vacuum are expressed as the difference between atmospheric pressure and the measured pressure.

Vacuum or negative pressures are normally expressed as inches or millimeters of mercury or water vacuum.

Nominal Versus Actual Pressure

Pressure standards manufactured by other manufacturers, Ruska, D.H., refer the output pressure to the actual output pressure as stated on the certification or computed by an equation included within the certification. Instronline accuracy is therefore the difference between the output pressure and the nominal pressure stated in percentage of the reading.

Instronline further states the ability of the instrument to repeat identical pressures with identical weights and piston as the percentage of “Repeatability”. Ruska, D&H accuracy as stated is the statistical ability of the instrument to repeat the identical pressure with the same weights and piston. This is comparable to Instronline’s stated percentage for instrument repeatability.

Units of Pressure Measurement

Pressure is measured in several different units depending upon the application and the country in which the measurement is taken. Within the United States, the most common unit of measure is Pounds (Force) per Square Inch, for low pressure measurements a measure of Inches of Water Gauge and for vacuum Millimeters of Mercury Vacuum. The official unit of pressure measurement within United States is the Pascal which is defined as Newton per square meter. A detailed listing of the various measures of pressure and the equivalent pressure in pounds per square inch is as follows:

Units of Mass Measurement

The term mass as used in the mathematical expressions for pressure is understood to be the true mass or the mass value that would be measured in a vacuum. Although this is the value required for the pressure equation, many different methods have been used by both Deadweight Tester manufacturers and calibration facilities. These methods fall into two categories: true mass and apparent mass versus some material of a different stated density. Typical materials and conditions for apparent mass are brass with a density of 8400 kg/m3 and stainless steel at 8000 kg/m3, both measured at 20ºC.

Gravity

The term force that is used within the deadweight tester mathematical expression for pressure is defined as the mathematical product of the true mass and the local gravity. The total variation due to gravity over the surface of the earth can vary as much as 0.5%. Acceleration due to gravity can be calculated as follows:

Primary and Secondary Pressure Standards

Primary Pressure standards must be directly traceable to the physical standards of length and mass, and any errors must either be eliminated or evaluated. Within the deadweight tester the area of the piston and cylinder or the ball and nozzle can be measured and directly traceable to the physical standard of length. The weights can be measured directly traceable to the physical standard of mass. The only other pressure measurement device that fulfills this definition of primary is the U tube manometer wherein the column difference is traceable to length and the fluid density is traceable to both mass and length.

All other devices for measuring pressure, regardless of accuracy, uncertainty, etc. are considered as secondary. This includes electronic, quartz tube, vibrating cylinder, etc. type pressure measuring instruments.

What is a flow meter calibration system?

A flow meter quantifies the speed at which gas or fluid moves across it. Professionals who specialize in testing and measuring often rely on flow meters wherever the measurement of accurate flow is imperative. There is a wide range of applications (not limited to) such as utilities, energy, HVAC, agriculture, aerospace, the pharmaceutical industry and clean water production. In all these applications, accurate calibration of a flow meter to make necessary measurements is vital. Consistent calibrations ensure that the flow measurement is giving measurements, which are correct and in sync with the listed specifications.

What is calibration and why is it so important?

When engineers and scientists talk about calibration, they are referring to traceable standards to correct or establish specific factors to an individual flow meter. The calibration process requires that the meter tested is matched with the master standard flow meter in the laboratory.

Flow meter calibration is vital to obtaining precise and consistent flow measurements. An exact flow measurement is what is required in some crucial processes that occur all around the world such as transferring fuel to a different custody, producing clean water and generating electricity.

However, it is important to note that even high precision flow meters can easily deter from calibration. Similar to technological gadgets, the performance of all flow meters reduces over time. Parts may break down or wear out. Flow meters are also affected by dirt from the media that flows across them as well as corrosion. A flow meter can become easily damaged from impact, improper installation, and variations in procedures.

What are some standard best practices of flow meter calibration?

Standard best practices of flow meter calibration ensure that the measurements obtained from testing are accurate and reliable. The process of calibration is applicable for all test equipment, not just flow meters.

Flow meter calibration has best practices, which help to ensure accuracy. These are:

The standard used to calibrate the flow meter must be precise enough to undergo calibration. The rule of thumb is that the standard must be at least four times more exact than the unit under test or UUT. However, keep in mind that this will vary according to the requirements of the standardization.

The standard you use ought to be traceable to a documented standard. It is known as traceability, and it provides a continuous trail of documentation that proves how the measurement it generates compares to accurate standards. A traceable measurement helps prove that your measurements are exactly what your flow meter says they are.

The rate of flow between the calibration standard and the unit under test should be in a stable state. The flow rate of the UUT and the standard are related in real time during standardization; therefore the system flow must not vary with time.

All media that is measured by the calibration standard should also be calculated by the flow meter, at equivalent times. No significant temperature changes or leaks in intermediate volumes can occur as these will impact measurement.

Calibration should occur under conditions that are similar to the flow meter’s actual operation.

Calibration of a flow meter is necessary to obtain accurate measurements.

The evolution of dual cylinder actuation

Traditional clamp and press mode actuation applications have a rapid stroke at a low force while requiring a steep ramp-up to a high force for a short period. These demanding parameters typically result in the expensive oversizing of the hydraulic infrastructure to meet speed and force requirements.

Within this large machine footprint, position and force control goals present complex motion and expense variables. In addition to having too many overall pieces in the equation, other factors include: oversized and continuously running pumps, large hoses that often leak and require maintenance, and the energy consuming frequency of stopping/starting with valves repeatedly turning on/off, while transitioning from high speed (low force) to lower speed (high force).

To solve this problem, motion control/actuation specialists Kyntronics, Cleveland, have developed a patent-pending HSHF (High Speed/High Force) All-In-One Actuator. Combining technologies from its servo-based SMART Hydraulic Actuator (SHA), coupled with a high-speed actuator and a high-force pair of actuators — the HSHF is a solution in a scalable, modular, ‘power-on-demand’ machine platform. The design is self-contained with no hoses that eliminates the expensive leaky infrastructure.

The dual cylinder system configuration delivers myriad benefits, resulting in lower operating costs and better performance across a wide range of OEM applications. This actuation technology is a step forward in modularity and takes advantage of hydraulics to overcome inherent issues with existing clamp and press mode technologies including:

CLAMP MODE: In this mode, rapid cycling times are needed while holding a lot of force (170,000 lb-ft / 756 kN) going back and forth. This mode is predominant in injection and blow molding applications which require rapid back/ forth position and hold, which puts a lot of pressure onthe actuator.

Traditional systems include hydraulics that feature check valves that lock in position. These types of systems require a large footprint and higher costs. Electromechani- cal is also an option but requires large and expensive com- ponents including motors, gearboxes, and roller screws/ball screws. Furthermore, the consistent metal-to-metal contact can result in reduced life.

PRESS APPLICATION: Typically, this mode is used for 20-80 ton presses which need to come down quickly, and do work within a small distance (1⁄4 -1⁄2-in. [6-13 mm]) for short periods. This application is dominated by hydraulic systems with huge power units, and excessive pumps and hoses.

The Instronline provides accurate force control for both clamping and press applications’ performance. This next generation of actuation has rapid movement with high force clamping and a high force press (small distance) — at a low cost, with no hoses, in a small envelope.

The simplicity of this design eliminates oversizing methods and solves several of the issues associated with current options in a cost-effective package — representing upwards of 50% savings in equipment and operating costs.

The reduced space and machine footprint are significant, as it eliminates the hydraulic infrastructure and all oversized elements — providing substantial cost savings. Because it only uses power-on-demand, energy savings are built-in. Because there is no cylinder or pump waiting for the cycle to start, the Instronline uses minimal energy for the long stroke and proportional energy for the load-stroke.

Ease-of-integration with machine control systems and versatile control is also an inherent benefit, as the Instronline Actuator is compatible with Fieldbus, I/O (selectable indexes), and Analog (0-10 Vdc or 4-20 mA).

The Instronline Actuator’s patent-pending concept mechanically connects a high-speed cylinder to a larger high-force dual cylinder. The dual cylinder combines a larger (high-speed zone) cylinder (e.g., a 6-in.) and a slightly smaller (high force zone) cylinder (e.g., a 5-in.) with a piston designed to seal in the smaller cylinder and move freely through the larger cylinder. The high-speed cylinder pulls (e.g., a 1-in.) the dual cylinder’s piston through the longer stroke, (e.g., oil flows freely around the piston) into the smaller cylinder, (high force zone) and seals the piston allowing for either the press or clamp mode.

With SMART actuation, the system knows the exact position where the piston enters the smaller high force cylinder zone and creates a seal. As the smaller high-speed cylinder approaches the high force zone, the system slows down and seamlessly combines the fluid flow to both the high-speed cylinder (e.g., 1-in.) and the high-force cylinder (e.g., 5-in.) without stopping the motion. The system continues to press forward based on force or position. After the operation is completed, the high-speed cylinder retracts, pulling the unique piston back to the retracted position. The high-speed cylinder provides the speed to reduce the overall cycle times with minimal flow, force and heat reducing energy consumption.

During a press mode, maximum power is required for a short period of the cycle (slower speed with high force) — minimizing the motor and drive size along with the overall heat. During a clamp mode, minimum power is required to move the cylinder (extend/retract). During the clamping, zero power is required as the check valves in the HF cylinder lock the actuator in position, and the HS cylinder is placed in float mode to prevent cylinder damage.

The all-in-one operation provides an optimal servo-controlled, closed loop-controlled force, as well as a closed loop-controlled position solution. Vertical market industries such as automotive, aerospace, packaging, and plastics, along with unique applications including injection molding, blow molding, toggle/platen clamping, metal forming, injection carriage actuation, trim press actuation, thermoforming platen actuation, will benefit from HSHF Actuator’s lower costs and higher precision.

The Instronline Actuator is a production enhancing product via cycle time reduction at a lower cost versus current alternative hydraulic and electromechanical options. Accurate position, force, and speed control move quickly under the low load, then the balance of the cycle (5-10%) retracts/repeats quickly like nothing else on the market.”`

Types of Sensors used in Vibration Measurement

BRIEF EXPLANATION OF VIBRATION SENSOR PRINCIPLES:

1. VELOCITY SENSORS

Electromagnetic linear velocity transducers : Typically used to measure oscillatory velocity. A permanent magnet moving back and forth within a coil winding induces an emf in the winding. This emf is proportional to the velocity of oscillation of the magnet. This permanent magnet may be attached to the vibrating object to measure its velocity.

Electromagnetic tachometer generators : Used to measure the angular velocity of vibrating objects. They provide an output voltage/frequency that is proportional to the angular velocity. DC tachometers use a permanent magnet or magneto, while the AC tachometers operate as a variable coupling transformer, with the coupling coefficient proportional to the rotary speed.

2. ACCELERATION SENSORS

Capacitive accelerometers : Used generally in those that have diaphragm supported seismic mass as a moving electrode and one/two fixed electrodes. The signal generated due to change in capacitance is post-processed using LC circuits etc., to output a measurable entity.

Piezoelectric accelerometers : Acceleration acting on a seismic mass exerts a force on the piezoelectric crystals, which then produce a proportional electric charge. The piezoelectric crystals are usually preloaded so that either an increase or decrease in acceleration causes a change in the charge produced by them. But they are not reliable at very low frequencies.

Potentiometric accelerometers : Relatively cheap and used where slowly varying acceleration is to be measured with a fair amount of accuracy. In these, the displacement of a spring mass system is mechanically linked to a viper arm, which moves along a potentiometric resistive element. Various designs may have either viscous, magnetic or gas damping.

Reluctive accelerometers : They compose accelerometers of the differential transformer type or the inductance bridge type. The AC outputs of these vary in phase as well as amplitude. They are converted into DC by means of a phase-sensitive demodulator.

Servo accelerometers : These use the closed loop servo systems of force-balance, torque-balance or null-balance to provide close accuracy. Acceleration causes a seismic mass to move. The motion is detected by one of the motion-detection devices, which generate a signal that acts as an error signal in the servo-loop. The demodulated and amplified signal is then passed through a passive damping network and then applied to the torquing coil located at the axis of rotation of the mass. The torque is proportional to the coil current, which is in turn proportional to the acceleration.

Strain Gage accelerators : these can be made very small in size and mass. The displacement of the spring-mass system is converted into a change in resistance, due to strain, in four arms of a Wheatstone bridge. The signal is then post-processed to read the acceleration.

3. PROXIMITY SENSORS

Eddy Current Sensor Probe : Eddy currents are formed when a moving (or changing) magnetic field intersects a conductor, or vice-versa. The relative motion causes a circulating flow of electrons, or currents, within the conductor. These circulating eddies of current create electromagnets with magnetic fields that oppose the effect of the applied magnetic field. The stronger the applied magnetic field, or greater the electrical conductivity of the conductor, or greater the relative velocity of motion, the greater the currents developed and the greater the opposing field Eddy current probes sense this formation of secondary fields to find out the distance between the probe and the target material.

Capacitance Proximity Sensors : Capacitive sensors use the electrical property of “capacitance” to make measurements. Capacitance is a property that exists between any two conductive surfaces within some reasonable proximity. Changes in the distance between the surfaces change the capacitance. It is this change of capacitance that capacitive sensors use to indicate changes in position of a target. High-performance displacement sensors use small sensing surfaces and as result are positioned close to the targets .

Difference between contactors and relays

Contactors and relays are two closely related terms leading to confusions and misinterpretations most of the times. Both of them are electrically operated switches used for control and switching of loads. The basic principle of operation of the contactor and the relay are the same. The difference between them is in term of their application and where they are used. This article can give you a clear picture of the difference between relays and contactors.

Constructional Features:

Contactors and relays have similar construction. Both have an external envelope to protect all the internal parts from the external environment. An electromagnetic coil is provided for opening and closing of contacts. The contacts are opened and closed by exciting this electromagnetic coil.

Operation of Relays and Contactors

A Contactor is used for switching of motors, capacitors, lights etc, that drains very high current. It has at least a single pair of three-phase input and output contacts. It would be normally open. Some contactors come with additional auxiliary contacts that may be either NO or NC. These auxiliary contacts get activated along with the main contacts. Switching is achieved by energization and De-energization of the contactor coils. Contactors are chosen upon the ampere ratings of the load. Contactors require an additional supply (either AC or DC depending upon the type of contactor we use) for excitation. It is used for power switching.

A relay consists of at least two contacts and an excitation coil. These contacts may be normally open or normally closed. These contacts are closed or opened by exciting the coil. Relays are used for switching of control circuits and cannot be used for power switching with relatively higher ampacity. It can be used for switching of small lights, sirens, indication lamps etc.

-- Relays are switching devices used in any control circuit for checking a condition or multiplying the number of contacts available.

-- Contactors are switching devices used to control power flow to any load.

Difference between contactors and relays

RELAYS

-- Relays are switching devices used in any control circuit for checking a condition or multiplying the number of contacts available.

-- Relatively smaller in size

-- Used in circuits with lower ampacity. (Max 20A)

-- Mainly used in control and automation circuits, protection --- circuits and for switching small electronic circuits.

-- Consists of at least two NO/NC contacts

-- Relays do not have an arc suppression system built-in.

CONTACTOR

-- Contactors are switching devices used to control power flow to any load.

-- Larger when compared to Relays

-- Used in circuits with low and higher ampacity up to 12500A

-- Used in the switching of motors, capacitors, lights etc.

-- Consists of a minimum one set of three-phase power contacts and in some cases additional auxiliary contacts are also provided.

-- Normally, contactors have in- built arc chutes for suppression.

Why We Use Process controllers

The importance of process control theory basics, Components of control loops and ISA symbology, Controller algorithms and tuning, Process control systems as you precede through the module, solution the questions within the activities column on the proper aspect of every web page. Also, be aware the utility packing containers (double-bordered containers) positioned throughout the module. Application packing containers provide key statistics about how you could use your baseline understanding within the area. Whilst you see the workbook exercise picture at the lowest of a page, visit the workbook to finish the distinctive exercising before shifting on in the module. Workbook sporting activities help you measure your progress closer to assembly every segment’s mastering goals.

Process control is an engineering subject that offers with architectures, mechanisms and algorithms for keeping the output of a selected manner within a favored variety. For example, the temperature of a chemical reactor may be managed to keep a steady product output.

Technique control is notably utilized in enterprise and allows mass production of constant merchandise from continuously operated processes such as oil refining, paper manufacturing, chemicals, energy plant life and lots of others. Process manipulate permits automation, through which a small team of workers of running personnel can perform a complex system from a valuable manage room.

Process Controllers are available in the market widely.Controller is Reliable and easy to use.There is large No of brands like, Honeywell process controller, Gefran1200-1300 Configurable controllers, Yokogawa UT35A/UT32A digital indicating controller.

Instronline is very good portal online that enable you to buy a Process controller online at just the right kind of prices that you might have been looking for. Instronline.com providing very good products in Worldwide including Delhi NCR.

Apart from their reliability, SIPART DR controllers excel due to their ease of use. Various software packages are available to make their handling easy and intuitive and to extend their scope of application. The standard version already offers comprehensive controller hardware. It can be upgraded quickly and easily for specific applications with a large number of optional input and output modules .control are often called hybrid applications.

All-round process controller for all processs specific tasks in 72x144 mm format, including mathematical calculations, logic operations, open-loop controls and time scheduled closed-loop controls. Up to four independent control loops.

Benefits of using These Controller:-

• Director sensor connection

• Integrated control program

• Continuous or step controller (K/S) (0/4 until 20mA / relays)

Temperature Instruments and Controllers Dealers

A decent illustration would be an application where the controller takes a contribution from a temperature sensor and has a yield that is associated with a control component, for example, a warmer or fan. The controller is normally only one a player in a temperature control framework, and the entire framework ought to be broke down and considered in selecting the best possible controller.

Simillarly, Digital temperature transmitter is an electrical instrument that interfaces a temperature sensor to an estimation or control gadget. Normally, temperature transmitters segregate, intensify, channel clamor, linearize, and change over the info signal from the sensor then send an institutionalized yield sign to the control gadget. There are various Digital temperature instrument dealer in and around Delhi/ NCR. Instronline is best temperature Instruments and Controllers Dealers, temperature transmitter exporters who supplies various electrical and other instruments like Wika temperature transmitter, Wika Hand-held temperature calibrator, Temperature Gauge Exporters,Digital Temperature Humidity Indicator etc.

Why Use a Rotameter (Variable Area Meter) to Measure Flow

What is a rotameter? A rotameter (variable area meter) is a flow meter that measures volumetric flow of liquids and gases. There is no difference between a rotameter and flow meter, and these terms are used interchangeably. The technique for measuring flow is accomplished by a freely moving float finding equilibrium in a tapered tube. The flow rate is then read from either a scale next to the tube or a scale on the tube. The rotameter is estimated to be in its second century of serving customers and their many and various flow flow meter applications. Rotameter applications extend across industries because it was and still is an economical way of measuring very low to high flow rates. Customers have been asked why they select rotameters. Their top six responses are clues as to why a rotameter continues to be successful even after a hundred years.

• No external power required – Rotameters are mechanical devices which do not require power to provide flow measurement. This allows rotameters to be installed in hazardous areas and remote areas where it would be expensive to supply power.

• You can see the process – Customers not only get a flow measurement reading but a look into their process. Is the process dirty or cloudy looking which could mean filters need to be changed? Is the process the correct color, are their bubbles in the liquid.

• Rotameters are cost effective – Both rotameter price and function contribute to savings on the job. Rotameters can be installed with other flow measurement technologies and be used to complement each other at an economical price.

• Simple to install and maintain – Rotameters are quickly installed by connecting the process line to the inlet and the outlet of the rotameter. Make sure the meter is vertical and you are now ready to measure flow.

• Low pressure drop – Most small rotameters have only a few inches of water column pressure drop. This means rotameters can be installed in many places in the process. Small pressure drops mean smaller pumps!

• Repeatability – Given the same process conditions a rotameter will accurately repeat the flow measurement day after day.

These six features assure rotameters will continue to be important products to measure flow now and in the future.

Short Notes on Differential Pressure Flow Meters

Differential pressure flowmeters are a type of inferential flowmeter where the flowrate is calculated from a non-flow measurement. In this case various methods of obstructing flow are used to create a pressure drop across a section of pipe. The flow rate is then easily calculated from the measured pressure drop using Bernoulli’s prinicple.

Differential pressure meters account for approximately 30% of all flowmeters. They are easily adaptable to a wide variety of applications and are good for handling high temperatures and pressures. They are however, expensive to install relative to other types of flowmeters.

Differential pressure flowmeters, also known as DP flowmeters, create a cross sectional change in the flow tube, which causes the velocity of the flowing fluid to change. A change in velocity occurs whenever there is a change in flow cross-section; i.e., with a decrease in velocity, an increase in pressure occurs. Differential pressure flowmeters can be used as liquid flowmeters or gas flowmeters; however, a single flow meter may not be configured to measure both liquid and gas phases.

Types of Differential Pressure Flowmeters

Orifice Flowmeters: flat metal plate with an opening in the plate, installed perpendicular to the flowing stream in a circular pipe. As the flowing fluid passes through the orifice, the restriction causes an increase in velocity and decrease in pressure. A differential pressure transmitter is used to measure pressure between the orifice and the pipe flow stream. There is always a permanent pressure loss. No dirty liquids allowed. Orifice differential pressure flowmeters can be constructed to measure gas, liquid or steam. Orifice plates are primary flow elements which measure flow as a function of differential pressure

Venturi Flowmeters: a restriction with a relatively long passage having a smooth entry and exit. A venturi produces less permanent pressure loss than an orifice but is more expensive. They are often used in dirty streams because there is no build-up of the foreign material. Venturi flow meters can be constructed to be either gas flowmeters or liquid flow meters.

Nozzle Flowmeters: smooth entry and sharp exit. Permanent pressure loss is on the same level as an orifice, with the added ability to handle dirty and abrasive fluids. A differential pressure transmitter is used to measure pressure between the nozzle and the pipe flow stream. This type of differential pressure flowmeter technology can be constructed to measure either gas or liquids.

Pitot-static tube Flowmeters: a device consisting of a Pitot tube and an annular tube combined with static pressure ports. The differential pressure between the two ports is the velocity head. A differential pressure transmitter is used to measure pressure differential between the two ports. This indication of velocity combined with the cross-sectional area of the pipe provides an indication of flow rate. Pitot tube flow meters, can measure either liquids or gases.

Elbow Flowmeters: a differential pressure is caused by centrifugal force between the inside diameter and the outside walls of the pipe elbow. It does not introduce any additional pressure loss other than that caused by the elbow. A differential pressure transmitter is used to measure pressure between the walls. This type of flow meter technology can be configured as either a gas or a liquid flow meter.

Wedge Flowmeters: a wedge-shaped element that is perpendicular to the flow at the top of the conduit which means that the bottom part is unrestricted. Therefore, it is useful in slurry measurement. A differential pressure transmitter is used to measure pressure between either sides of the wedge. However, this type of differential pressure flow meter technology can be constructed to work as either a gas or a liquid flow meter.

V-Cone Flowmeters: consists of a V-shaped cone element placed at the center of the pipe which creates an annular space for the passage of fluid. It has lower permanent pressure loss than orifice flowmeter. The cone element conditions the flow at the same time it is creating the pressure differential, providing for smoother and less noisy differential pressure readings vs. the orifice technology. A differential pressure transmitter is used to measure pressure before and after the cone. This type of differential pressure flow meter can be constructed to measure gases, liquids, or steam.

Spring-Loaded Variable Aperture Flowmeters: This type of flow meter relates a change in flow rate to the differential pressure across a spring-loaded cone. The cone repositions itself to balance the force. This in turn changes the aperture for the flow. Flow rate has a relationship with the differential pressure of the flow meter and the position of the spring-loaded cone. A differential pressure transmitter is used to indicate flow. This type of differential pressure flow meter technology can be constructed to measure either a gas or liquids

Laminar Flowmeters: Flow rate is linearly proportional to the differential pressure and inversely proportional to the viscosity of the flowing fluid. A flow can be made laminar by passing through a bundle of small diameter tubes. A differential pressure transmitter is used to measure pressure before and after the tubes. This type of differential pressure flow meter technology can be constructed to measure either gas or liquids.

What a relay is and how they work!

A Relay is a electrically operated switch

Used for many different applications

Allows for a low voltage circuit to operate a higher voltage circuit

Can be used to monitor the status of electrical equipment (such as a motor)

What parts make up a relay?

Coil (is a tightly wound spool of wire). When current is applied, it will act as an eltromagnet

Contact (a lever that can be opened and closed). Is acted upon by the coil.

Terminals (points where wires can be connected to the relay)

How does it work?

When current is applied to the coil it will pull the contact (which is normally open) closed allowing current to pass through the contact side of the relay.

Some relays have multiple options on the contact side of the relay. They can have both a normally open (NO), or normally closed (NC) set of contacts. When both options are available on one relay, this is refereed to as a double throw relay

What is Shutdown Valve ?

A shutdown valve (also referred to as SDV or Emergency Shutdown Valve, ESV, ESD, or ESDV) is an actuated valve designed to stop the flow of a hazardous fluid upon the detection of a dangerous event.

Shutdown Valve

This provides protection against possible harm to people, equipment or the environment. Shutdown valves form part of a Safety Instrumented System. The process of providing automated safety protection upon the detection of a hazardous event is called Functional Safety.

Types of valve

For fluids, metal seated ball valves are used as shut-down valves (SDV’s). Use of metal seated ball valves leads to overall lower costs when taking into account lost production and inventory, and valve repair costs resulting from the use of soft seated ball valves which have a lower initial cost.

Straight-through flow valves, such as rotary-shaft ball valves, are typically high-recovery valves. High recovery valves are valves that lose little energy due to little flow turbulence. Flow paths are straight through. Rotary control valves, butterfly valve and ball valves are good examples.

When an external hydrocarbon, such as methane gas, is present in the atmosphere, it can be sucked into a diesel engine causing over speed or over revving, potentially leading to a catastrophic failure and explosion. When actuated, ESD valves stop the flow of air and prevent these failures.

Types of Actuation

As shutdown valves form part of a SIS. It is necessary to operate the valve by means of an actuator.

These actuators are normally fail safe fluid power type.

-- Typical examples of these are:

-- Pneumatic cylinder

-- Hydraulic cylinder

-- Electro-hydraulic actuator

In addition to the fluid type, actuators also vary in the manner in which the energy is stored to operate the valve on demand as follows:

Single acting cylinder – Or spring return where the energy is stored by means of a compressed spring

Double acting cylinder – Energy is stored using a volume of compressed fluid

The type of actuation required depends upon the application, site facilities and also the physical space available although the majority of actuators used for shutdown valves are of the spring return type due to the fail safe nature of spring return systems.

Measuring Performance

The required level of performance is dictated by the Safety Integrity Level (SIL). In order to adhere to this level of performance it is necessary to test the valve. There are 2 types of testing methods available being

Proof test – A manual test that allows the operator to determine whether the valve is in the “as good as new” condition by testing for all possible failure modes and requires a plant shutdown

Diagnostic Test – An automated on-line test that will detect a percentage of the possible failure modes of the shutdown valve. An example of this for a shutdown valve would be a partial stroke test. An example of a mechanical partial stroke test device.

What is a Digital Positioner and Why Should You Use One?

A valve positioner is a device mounted on the actuator that exerts or reduces air pressure as necessary to make sure the valve achieves the correct position.

When there is no positioner, the control signal goes directly to the actuator. When a positioner is installed, it intercepts this signal and then outputs a different signal to the actuator.

Positioners allow tighter control over the process variable by increasing the speed and accuracy of the actuator response. Because a positioner’s job is to make sure the valve is in the right place, it also helps in overcoming factors that affect control valve performance, such as friction, as well as problems like non-linearity and deadband. Positioners can also amplify or reverse an input signal as needed.

Essentially, a positioner ensures that the final control element in a loop exerts optimal control.

There are three types of positioners:

Pneumatic positioners. These devices receives a pneumatic (air) signal from the controller and output a pneumatic signal to the actuator.

Analog, or electro-pneumatic, positioners. Here, the input signal is electrical, rather than pneumatic.

Digital, or smart, positioners. These positioners also receive an electrical signal, but it’s digital as opposed to analog.

Digital positioners came on the scene about 20 years ago, but they only really started gaining popularity recently as automation has started to take off in plants and along pipelines.

The main reason digital positioners are popular is that they can do much more than just control the position of the valve. The newest positioners on the market can also collect data about the valve to automatically alert users about how the valve and its assembly are performing, and even aid in diagnostics and maintenance.

Since they have fewer mechanical moving parts, digital positioners last longer than their traditional pneumatic and analog counterparts. Plus, they don’t bleed any air while the valve is at rest, which reduces energy consumption.

For example, the Siemens SITRANS VP300 digital positioner allows you to:

Auto tune the positioner in minutes, as opposed to the hours analog positioners can take

Get diagnostic information about the health and performance of your control valves

Identify potential problems before they happen

Integrate the positioner with other control systems so all of your data is in one place

What this all boils down to is higher valve productivity, decreased downtime, and overall better plant performance.

IMI Norgren pressure switches and fittings

At Instronline, we supply a vast range of pressure switches and fittings from pressure experts Norgren. In this blog, we look at their product line in more detail, as well as taking a closer look at how Norgren pressure switches work, what pressure switches to use and how they work in conjunction with air compressors.

Norgren’s pressure switches and fittings are important components in pneumatic applications as they improve safety and operation. Pressure switches are critical when pressure monitoring for when higher functionality is needed. While fittings are of vital importance because they connect crucial parts together and make them operate more smoothly.

How do pressure switches work?

An electronic pressure switch is a device that is designed to monitor a process pressure and provides an output when a set pressure has been reached. It does this, by applying pressure to either a diaphragm or a piston to generate force. Another use of a pressure switch is to detect the presence of fluid pressure.

Most pressure switches currently use a diaphragm or bellow as the sensing element. The sensing element’s movement is used to actuate one or more switch contact to either indicate an alarm or initiate a control action.

What pressure switch do I need?

In today’s market, there are a variety of different pressure switches that you can select. At the forefront is Norgren’s offer. Instronline is partnered with Norgren, meaning we can supply their complete range. Norgren offers two main types of pressure switches: electro-mechanical pressure switches and electronic pressure switches.

If you are looking for an electro-mechanical pressure switch, we recommend Norgren’s Electro-Mechanical Pressure Switch Pneumatic. With its high number of switching cycles, micro switch with gold plated contacts and its vibration resistance of up to 15g, it is hard to beat.

As well as Electro-Mechanical Pressure Switches, we also stock Pneumatic Electronic Norgren Pressure Switches. These reliable, high-quality Pneumatic Electronic Pressure Switches from Norgren are extremely popular thanks to their impressive features. These unbeatable features include high accuracy and resolutions, switching status that is indicated by LED, multiple versions with analogue output signal on request, and two PNP and NPN outputs.

How a pressure switch works on air compressors

When it comes to air compression, air compressor pressure switches are necessary components in any set-up. The main reason they are recommended is they help to measure the pressure inside your air tank. It is then used to switch off your compressor when your air tank reaches the desired air pressure.

Another advantage is that an air compressor pressure switch will allow you to go about your work in confidence, as it helps your machinery maintain the correct pressure level. The switch also has the ability to turn on your compressor when the tank air pressure levels have dropped and there is a need for more air.

Norgren fittings

Norren has one of the widest ranges of fittings available in the industry. Their product portfolio includes composite, push in, pneumatic compression fittings and more. Two of their better known fittings are their push in pneumatic fittings and pneumatic compression fittings.

Their range of push in pneumatic fittings are compact units featuring retained collets and positive tube anchorage. Further features include silicone free O-ring seals; easy tube insertion for fast assembly; reliability; and corrosion resistance. They can be used for quick and simple assembly of pneumatic circuits.

Another series of Norgren Fittings are their pneumatic compression fittings. These are ideal for most industrial applications with their rugged and durable materials. They have a wide range of different types and sizes. They come supplied assembled with tubing sleeves, nuts and appropriate seals.

Speak to us today about our complete range of Norgren pressure switches and fittings by email us at info@instronline.com

The Benefits of a Venturi Meter

With the introduction of new measurement technologies and the myriad of performance claims from sale literature, it’s easy to lose sight of the important elements that an effective flow meter offers no matter what technology is used. Long known for their longevity, reliability, and long term performance, Venturi meters provide the widest variety of measurement options in piped systems for liquids, gas, steam, and mixed media of any metering technology – all while offering the highest degree of traceable accuracy.

Venturi meters are a versatile solution in that their laying length can be changed to fit a defined space; they can be modified to provide rate of flow control or measure sewage; they can be used reliably for billing or custody transfer; and they can be used for rectangular or circular metering. In addition, Venturi meters can be oriented in any plane and can measure accurately whether the line fluid is flowing upwards or downwards. To this end, Venturi meters are not subject to downstream piping effects and, with specially designed modified short form type Venturi meters, very short upstream straight pipe is required.

It is also important to note that most major independent laboratory flow calibration facilities around the world use Venturi meters as their primary standard. In addition, pump and blower manufacturers also use Venturi meters and other differential type devices as efficiency testing standards. Venturi meters have no moving parts, and can function reliably and accurately for decades, with some examples in service for more than 100 years. To this end, Venturis should be would render other devices ineffective.

However, it’s important to note that as accurate and reliable as these meters are, there are still some limitations. Typically, the energy loss through a Venturi meter is between 0.10 to 0.25 psig. In addition, Venturi meters do consume energy but, unlike other devices, the recovery cone design of the modified short form type meters recovers a significant portion of the consumed energy. There are no intrinsic design limitations on either temperature or pressure of a proposed application or line size, which allows these meters to be effective in a variety of applications without the susceptibility of excess headloss when providing measurements. In addition, wide range flow measurement can be accurately accomplished by using multiple Differential Pressure (DP) transmitters, each calibrated for a certain flow rate range. Range of 50 or 100 to 1 on flow can be easily and accurately handled with the proper secondary instrument system. The Classical Venturi designs have also been characterized by relatively long laying lengths, and, therefore, they have generally been relatively expensive to manufacture compared to other known flow metering devices

Designs

One of the significant benefits of the Venturi meter is that the design can be modified to fit almost any requirement, and it can be constructed with a broad range of materials depending upon application and the matter that will be measured. The actual Venturi meter design has not remained static over the last century, and there are two versions in particular that have made significant impacts on Venturi metering – the Modified Short Form Venturi meter and the Insert Venturi meter.

Modified Short Form Venturi Meters

Unlike the ASME and ISO codes for Classical Venturis, the Modified Short Form Venturi meter design was developed and patented by Dezsoe Halmi. His goal was to develop a venturi meter which was more accurate, had lower headloss, required no downstream and short upstream straight pipe and had a much smaller footprint thus was less expensive. In its patented form, the Modified Short Form Venturi eliminated a number of features that were disadvantageous, such as “annular pressure chambers” and excessively long component sections; thus improving the life expectancy of the meter and lowering its cost and headloss, while improving its basic accuracy. These improvements, and many more made since the mid-1960s, are the result of continual design refinements by top manufacturers who methodically applied knowledge and careful testing processes to even the most minute change.

The Modified Short Form Venturi is governed by an “interactive” code, which means that the designer/manufacturer is free to make modifications to the basic hydraulic shape of the meter as long as appropriate testing and documentation is provided to support all claims. Interactive codes foster performance evolution because they provide a basic structure and design from which creative engineering minds can contemplate then execute beneficial changes. Once the hydraulic shape of the Venturi meter has been defined, it must be thoroughly tested to determine its:

Discharge coefficient value
Shape of the coefficient as defined by its relationship to pipe Reynolds number
Installation sensitivity based on testing “typical” disturbers for both upstream and downstream conditions
Tap location sensitivity
Headloss across the profile
Accuracy and repeatability
Applicability for liquids, gasses, slurries, sludge, mixed media and varying viscosities must be determine and proven

Modified Short Form Venturi meters are inherently more tolerant of upstream conditions, including asymmetric flow patterns, because they are shorter than the other Classical Venturi design, which features substantially straight and elongated structures. Due to the overall shorter laying length, these meters have intersecting angles that are much greater and the discharge end of the recovery cone does not end in the full downstream pipe line size, but rather, is truncated, while the flange is designed to mate directly to the downstream pipe flange. This means that there are no downstream straight pipe requirements for standard accuracy, the meters have lower headloss, are less susceptible to blockages and plugging, and are extremely accurate, which can be field verified.

The design of the Modified Short Form Venturi can be constructed with reduced manufacturing costs for the manufacturer. It also places a lower burden on the physical formation of the installation since piping configurations pose less problems for accuracy, energy loss, and potential for blockage.

Insert Venturi Meters

Another useful addition to the world of Venturi metering is the Insert Venturi meter. This design is similar to the shape of a true, Classical Venturi, but the profile is entirely inside the pipeline, aside for the thickness of the center flange. This type of meter is similar in its installation, to that of an orifice plate as it’s inserted rather than placed between to piping unions.

But the benefit of this design is that it utilizes a static low pressure throat tap. Unlike a “true Venturi meter” its high pressure sensation comes from a corner location on the inlet side of the center flange. In order to claim that a tap senses “true static pressure”, the tap must sense pressure perpendicular to the axis of the flowing line fluid. The Classic and Modified Short Form Venturi meters do that very successfully in the flanged design, but without an upstream section available to locate the high pressure tap, the Insert Venturi meters must handle the flow directly or “head on” at the high pressure tap location.

While this makes the Insert Venturi meter more sensitive to the effects of upstream non-straight piping, the basic accuracy of these meters is identical to the flanged design at +/-0.50% of the actual rate of flow. However, the Insert Venturi meter design with a static high pressure tap off of the center flange and into the upstream spool piece has the same installation insensitivity as the traditional flanged, full body Venturi design at the proper static pressure sensing location.

Calibration

When it comes to obtaining accurate meter readings, Venturi meters are designed to a single flow metering shape equation that secures a flow metering mechanism. Although performing an internal inspection/measurement may be required to verify effectiveness, if a Venturi meter’s internal dimensions and surface conditions have not changed, its reading will stay the same. The metering mechanism is a design that provides a discharge coefficient without impacting line size, Beta ratio, or Reynolds numbers above a manufacturers or code stated minimum.

Most other types of meters – particularly electronic meters – cannot be field calibrated properly. Venturi meters can be field inspected and, assuming no change to the critical cross sections, the DP transmitter can be accurately calibrated to the signal produced by the Venturi meter. With proper material selection, the risk of internal corrosion or scaling is low, and the ability to inexpensively field rehabilitate any Venturi meter is widely available thus making the use of Venturi meters a step towards sustainable technology since they last much longer than any of the electronic type meters on the market today, even in harsh environments.

Venturi meters are designed to provide an accurate and repeatable differential pressure signal based on a defined internal profile, surface finish, and tolerance program. A significant advantage of the Venturi meter technology is that each given design has its own discharge coefficient that is determined by building a number of line and throat size meters of that design, and submitting them to independent flow calibrations by third-party experts. Assuming the laboratory calibrations prove that the discharge coefficient is independent of line size and throat size, as it should if the basic design is appropriately engineered and manufactured, the laws of hydraulic similitude eliminate the need to calibrate every meter and also allow the use of a Venturi meter for lines that are too large to lab calibrate. In addition, unless there is a change to the internal geometry of the Venturi meter, the discharge coefficient will not change.

Conclusion

Despite their rich history and proven track record, Venturi meters have faced stiff competition from electronic measurement devices, which have neither the versatility nor the verifiable accuracy of a Venturi. With continual improvements over the years, Venturi meters – including the Modified Short Form Venturi and Insert Venturi – have proven to be adaptable to virtually any installation or application without the drawbacks of piping configurations or flow conditions.

The benefits of Venturi meters are indisputable, as is the fact that they serve as the standard measurement device in the world’s preeminent flow measurement labs, calibration facilities, and research centers.

Working Principle of Vibration Switch

A vibration switch is a device that recognizes the amplitude of the vibration to which it is exposed and provides some sort of response when this amplitude exceeds a predetermined threshold value. The switch response is typically an electrical contact closure or contact opening. The electrical contact may be either an electromechanical relay or solid-state device.

Why use a vibration switch?

Vibration switches are primarily used for protecting critical machinery from costly destructive failure by initiating an alarm or shutdown when excessive vibration of the machinery is detected. Conversely, a vibration switch can be utilized to warn when there is an absence of vibration, such as when a conveyor ceases to function due to a broken drive belt.

Working Principle

Vibration Switch is working according to the pendulum switching principle.

A swinging permanent magnet holds a magnetic switch situated below in a particular position. Due to vibration, the magnetic field between Reed Switch and magnet changes. Thus the switch is actuated resulting in the stoppage of the equipment. The responding sensitivity of the system can be changed by adjusting the gap between switch and magnet. Thus vibrations with amplitude below a set value can be suppressed. The free pendulum length and the responding frequency of the switch with a frequency slider can be adjusted exactly to the natural frequency of the equipment to be protected.

Applications include all types of rotating or reciprocating machinery such as cooling tower fans, pumps, compressors etc.

Uses and structural characteristics of pneumatic ball valves

The pneumatic ball valve is a pneumatic actuator-equipped ball valve. With the fastest operating speed of 0.05 seconds per second, pneumatic actuators operate very rapidly, so they are typically often called pneumatic fast plugging ball valves. In order to complete in-site control and remote centralized control, pneumatic actuated ball valves are normally fitted with different accessories, such as solenoid valves, air supply handling triples, limit switches, positioners, control boxes, etc., in the control room to be able to control the valve transfer, do not need to rush to the scene or high altitude and hazardous places to operate manually, in a wide range. This saves human capital, time, and security.

Pneumatic ball valves could be firmly locked by rotating at 90 degrees with a pneumatic actuator and a with very low torque. A very narrow and clear flow passage for the medium creates a perfectly similar valve body cavity. Ball valves are commonly considered to be more appropriate for direct opening and shutting.

Fluid control pneumatic ball valves are commonly used in the natural gas, gasoline, chemical and metallurgical sectors, paper manufacturing, electric, mining, printing and thinning sectors, biologics, chemical industries in everyday activities, the food industry, and beverages, in the processing and treatment of water and air.

The structural features of the series pneumatic ball valve are:

• Pneumatic actuator: Adopt a new series of GT AT type pneumatic actuators, with double action and single action (spring reset), rack and pinion drive, secure and reliable; large diameter valves are chosen from the HAW type pneumatic actuator fork drive series, with appropriate structure, large output torque, double effect and single effect (spring reset); Analyse the pneumatic actuator sample of our company.

• Shell structure: According to consumer specifications and realistic working conditions, the body of the fixed ball valve can be programmed as a casting structure, forging structure, and a complete welding structure. The full welding arrangement of the ball valve is primarily sufficient for submerged applications.

• Unique valve seat sealing structure: To guarantee the quality of sealing, the floating ball valve adopts lip-elastic sealing ring system planning. While using a ball valve, the seat sealing structure equipped with a leaf spring will guarantee long-term and effective sealing of the ball valve at low pressure, ultra-low pressure, or vacuum. Para-polyphenyl or metal may be the seat details of low and high-temperature ball valves.

Owing to the pressure level, medium properties, and sealing conditions, fixed ball valves pick the pre-ball sealing structure, post-ball sealing structure, or pre-and post-ball double sealing structure. Para-polyphenyl or metal can be the seat data of medium and high-temperature ball valves.

• Blocking and drainage: The upstream and downstream valve seats obstruct the liquid while the valve is closed, and the stagnation in the valve body cavity can be drained by the drainage system.

• Automatic pressure relief structure: Whenever the pressure in the side chamber rises abnormally, in order to push the valve seat, the medium in the middle chamber will release the pressure on its own thrust, maintaining the protection of the valve lift.

• Reliable sealing of the valve stem: The stem needs to adopt a reverse sealing download structure. If the medium pressure rises, the sealing force of the reverse seal increases so that effective stem sealing can be assured. Moreover, the stem will not eject while the stem is abnormally pressurized.

• Fireproof structure: The ball valve may be planned as a fire safety structure depending on the operating situation and the user’s demand. The ball valve fire-resistant design follows the specifications API607 and JB / T6899. The fire-resistant construction of the ball valves can avoid certain medium leaks and avoid more fire expansion in the case of a fire that destroys the soft seal ring.

• Anti-static structure: When controlling the valve, electrostatic charges from cattle will occur and collect on the ball due to contact between the ball and the valve bench. An electrostatic unit is mounted on the valve to derive the charges collected on the ball, to prevent electrostatic sparks.

• Full diameter structure and reduced diameter structure: The company’s ball valve products have two sets of full-diameter and shrinkage to suit the various needs of consumers. The inner diameter of the stream and the inner diameter of the full diameter ball valve pipeline are common, which is simple to clean, whereas the weight of the ball valves of the shrinkage series is relatively light, but the flow resistance is only about 1/7 of the same globe caliber valves, so the application prospect of the ball valves of the shrinkage series is relatively wide.

What Types of motors can be used with variable frequency drives?

The various types of industrial motors that can be used with variable frequency drives are:

Dc motor: dc motors are still in production although the number of active manufacturers has decreased considerably, specifically those that are still manufacturing large dc motors (> 1 MW).

Ac asynchronous squirrel cage motor: This type of motor is the most commonly used motor in industrial processes with variable frequency drives.

Ac asynchronous wound rotor motor: This type of motor was traditionally used in variable frequency drive when the load required a high starting torque and the strength of the power supply network was insufficient to permit Direct On-Line (DOL) starting. Variable speed operation is obtained by varying the effective resistance in the rotor circuit.

Ac synchronous motor with brush less ac or brushed excitation.

Ac synchronous motor with permanent magnet excitation: This type of motor is specifically designed for operation with a variable frequency drive. Synchronous motors are used mainly in the high power ranges to minimize costs by minimizing the current rating of the variable frequency drive and due to the non availability of squirrel cage induction motors.

The most common electrical VFD used in industry today is the variable frequency drive using Voltage Source Inverter (VSI) typology and controlling asynchronous squirrel cage motors.

The power range of VSI types of variable frequency drives extend from fractional kW such as 0,18 kW to 2 000 kW in the low voltage range and from 200 kW through to 30 MW in the medium voltages. The low voltages that are of interest to the local market are the standard IEC (International and Electrotechnical Commission) voltages namely 230 V single-phase, 400 V three-phase, and 690 V three phase, all at the 50 Hz input frequency. To satisfy the 525 V market, variable frequency drives with a rated voltage of 600 V and 690 V are used. At the medium voltage level the voltages of interest are 3 300 V, 6 600 V and 11 000 V. Economics should be the determining factor as to the rated voltage of the drive given the required power rating, although this is not always the case.

Types of Industrial Automation Systems

Industrial automation systems are categorized based on their integration level and flexibility in the manufacturing processes and operations. Different types of automation systems include:

Fixed Automation

Fixed automation systems are utilized in high volume production settings that have dedicated equipment. The equipment has fixed operation sets and is designed to perform efficiently with the operation sets. This type of automation is mainly used in discrete mass production and continuous flow systems like paint shops, distillation processes, transfer lines and conveyors. All these processes rely on mechanized machinery to perform their fixed and repetitive operations to achieve high production volumes.

Programmable Automation

Programmable automation systems facilitate changeable operation sequences and machine configuration using electronic controls. With programmable automation, non-trivial programming efforts are required to reprogram sequence and machine operations. Since production processes are not changed often, programmable automation systems tend to be less expensive in the long run. This type of system is mainly used in low job variety and medium-to-high product volume settings. It may also be used in mass production settings like paper mills and steel rolling mills.

Flexible Automation

Flexible automation systems are utilized in computer-controlled flexible manufacturing systems. Human operators enter high-level commands in the form of computer codes that identify products and their location in the system’s sequence to trigger automatic lower-level changes. Every production machine receives instructions from a human-operated computer. The instructions trigger the loading and unloading of necessary tools before carrying out their computer-instructed processes. Once processing is completed, the end products are transferred to the next machine automatically. Flexible industrial automation is used in batch processes and job shops with high product varieties and low-to-medium job volumes.

Integrated Automation

Integrated industrial automation involves the total automation of manufacturing plants where all processes function under digital information processing coordination and computer control. It comprises technologies like:

1. Computer-aided process planning

2. Computer-supported design and manufacturing

3. Flexible machine systems

4. Computer numerical control machine tools

5. Automated material handling systems, like robots

6. Automatic storage and retrieval systems

7. Computerized production and scheduling control

8. Automated conveyors and cranes

Additionally, an integrated automation system can integrate a business system via a common database. That is, it supports the full integration of management operations and processes using communication and information technologies. Such technologies are utilized in computer integrated manufacturing and advanced process automation systems.

When considering the right system for your business, the degree of industrial automation required for any manufacturing facility should be determined by the labor conditions, competitive pressure, manufacturing and assembly specifications, work requirements and the cost of labor. By taking these factors into consideration, you can ensure that your industrial software automation investment will be justified by a consistent profit increase.

What is a pneumatic actuator and how does it work?

Pneumatic actuators are deemed to be essential to literally hundreds of different industries, most notably for use within applications where the opening and closing of valves takes place. They also hold value within industrial applications where there is a fire or ignition risk. To understand why let’s take a closer look at what a pneumatic actuator actually is.

What is a pneumatic actuator?

By definition, a pneumatic actuator is a device that converts energy typically in the form of compressed air into mechanical motion. Within the industry, pneumatic actuators are recognised by several different names including pneumatic cylinders, air cylinders, and air actuators; all of which are one and the same.

Consisting of a piston, cylinder, and valves or ports, a pneumatic actuator can convert energy into linear or rotary mechanical motions. This is dependent on whether the application is using a pneumatic rotary actuator or a linear actuator.

Linear actuators are well suited for fitting to angle seat control valves built for high temperature and steam applications, whereas the pneumatic rotary actuators are better suited for fitting to quarter-turn valves depending on the specification of the application.

How a pneumatic actuator works?

Pneumatic actuators are reliant on the presence of some form of pressurised gas or compressed air entering a chamber where pressure is built up. Once this exceeds the required pressure levels in contrast to the atmospheric pressure outside of the chamber, it creates a controlled kinetic movement of a piston or gear which can be directed in either a straight or circular mechanical motion.

Pneumatic actuators are well suited to a wide variety of application types, serving across many different industry areas. Some of the most common applications include :

1. Combustible automobile engines

2. Air compressors

3. Packaging & production machinery

4. Railway application

5. Aviation.

Advantages of using pneumatic actuators over other alternatives

Most of the benefits of choosing pneumatic actuators over alternative actuators, such as electric ones, boil down to the reliability of the devices, as well as the safety aspects. The fact that they do not require ignition or electricity makes these devices highly sought after where parking and combustion are not tolerated. This is because a pneumatic actuator can store compressed air and use it again efficiently without the risk of fire.

Pneumatic actuators are also extremely durable and can, therefore, reduce the costs required to maintain its performance. Less maintenance means a longer product lifecycle and therefore greater output.

Functions of Temperature Detectors

Although the temperatures that are monitored vary slightly depending on the details of facility design, temperature detectors are used to provide three basic functions: indication, alarm, and control. The temperatures monitored may normally be displayed in a central location, such as a control room, and may have audible and visual alarms associated with them when specified preset limits are exceeded. These temperatures may have control functions associated with them so that equipment is started or stopped to support a given temperature condition or so that a protective action occurs.

Detector Problems

In the event that key temperature sensing instruments become inoperative, there are several alternate methods that may be used. Some applications utilize installed spare temperature detectors or dual-element RTDs. The dual-element RTD has two sensing elements of which only one is normally connected. If the operating element becomes faulty, the second element may be used to provide temperature indication. If an installed spare is not utilized, a contact pyrometer (portable thermocouple) may be used to obtain temperature readings on those pieces of equipment or systems that are accessible.

If the malfunction is in the circuitry and the detector itself is still functional, it may be possible to obtain temperatures by connecting an external bridge circuit to the detector. Resistance readings may then be taken and a corresponding temperature obtained from the detector calibration curves.

Environmental Concerns

Ambient temperature variations will affect the accuracy and reliability of temperature detection instrumentation. Variations in ambient temperature can directly affect the resistance of components in a bridge circuit and the resistance of the reference junction for a thermocouple. In addition, ambient temperature variations can affect the calibration of electric/electronic equipment. The effects of temperature variations are reduced by the design of the circuitry and by maintaining the temperature detection instrumentation in the proper environment.

The presence of humidity will also affect most electrical equipment, especially electronic equipment. High humidity causes moisture to collect on the equipment. This moisture can cause short circuits, grounds, and corrosion, which, in turn, may damage components. The effects due to humidity are controlled by maintaining the equipment in the proper environment.

Detector Uses Summary

1.Temperature detectors are used for:

Indication
Alarm functions
Control functions

2.If a temperature detector became inoperative:

A spare detector may be used (if installed)
A contact pyrometer can be used

3.Environmental concerns:

Ambient temperature
Humidity

How to Maintain and Determine Calibration Frequency of Equipment

The quality of the products manufactured by any enterprise can directly be associated with the accuracy of the instruments producing them. If the instruments are not calibrated properly, or if they are damaged and need repair work, they will surely affect the end products. ISO calibration lists out the general requirements for the competence of testing and calibration laboratories. All the labs must adhere to service specifications developed by the International Organization for Standardization.

It is important to remember that instruments and equipment will not always stay calibrated. At some point, the level of calibration will go down and it will affect the final measurements and quality of the products. You must keep the instruments and equipment in excellent condition at all times. Make sure that you conduct preventive maintenance and repair, and recalibrate the instruments regularly. So how do you know when it is time to recalibrate your equipment?

A lot of different variables determine how frequently your instruments should be calibrated or re-calibrated. Let us look at some of them:

Manufacturers’ Recommendations:

Every manufacturer mentions the ideal time frame of when you should recalibrate an instrument. Follow these instructions and specifications to the letter and you will face minimum maintenance issues. It is extremely important to remember that critical measurements may call for greater frequency.

Annually or Biannually:

Some instruments need to be re-calibrated once or twice every year. It depends on how often the critical measurements are taken. Additionally, the amount of damage sustained by the instruments during use also plays a role.

After a Damaging Incident:

If any instrument was damaged in an accident, if it was dropped hard or if it sustained any kind of injury, you must calibrate it immediately. Events where the instruments sustain damage usually experience a sharp impact that directly affects their readings. Check if the calibration was altered and carry out the necessary calibration procedures.

As Demanded by Projects:

When you carry out certain assignments, you have to use certified and calibrated test equipment, irrespective of how big or small the project is. When assignments call for such calibration based on project requirements, you must follow it.

Before or After a Major Project:

Some major projects require extremely accurate measurements. This means that the instruments must be calibrated before the project starts. However, it doesn’t end there. You must calibrate all the instruments that were used after the project comes to an end. Post-project calibration will show you if the testing that you conducted is indeed reliable or not, if the correct and consistent measurements were observed throughout the project.

Semiannually, Quarterly or Monthly:

Some instruments, based on their use and functions, need to be calibrated frequently. If you deal with critical measurements quite frequently, it would be ideal that you conduct frequent and consistent calibration check-ups, like every month or every three to six months.

Keeping your instruments calibrated will ensure that all your projects and tests are accurate and that high quality is maintained throughout.

Why Should You Use a Diaphragm Seal

Diaphragm seals are protective devices designed to isolate pressure gauges, pressure transmitters, and pressure switches from potentially damaging process media. Typical applications where a diaphragm seal provides a cost effective solution to protecting the pressure instrument are:

In applications where the process fluid is corrosive
In applications where the process fluid has a high viscosity, is comprised of slurries, sludge or other material that can actually coat or damage a traditional pressure measuring device
In applications where the process fluid can freeze or polymerize, thus causing a condition that might lead to the instrument becoming immobilized or incapable of transmitting an accurate pressure measurement or signal

Operational Theory:

diaphragm seals typically comprise a metal, TEFLON or elastomer diaphragm mounted between two housings and sealed to prevent leakage of process gases or fluids. The space on the instrument side of the diaphragm, the connections and the instrument- sensing element, are all completely filled with instrument oil, silicon or other suitable fluid.

When the process line pressure is applied, the diaphragm exerts equal pressure on the instrument side of the seal producing a reading on the gauge or process instrument. Instruments may be attached directly to the diaphragm seal or connected remotely by means of a filled system – typically a length of armored capillary tubing. Mansfield & Green diaphragm seals may be used with pressure or vacuum instruments including gauges, transmitters, and switches that utilize C-type, helical or spiral bourdons, bellows elements, diaphragms or electronic strain gauge sensing elements.

Pressure:

Seal pressure limitations vary according to seal design and their materials of construction. Thread attached, non-flow thru seals having a metal process bottom have a maximum working pressure rating from 2500 up to 5000 psig at 100°F (172 to 690 bar at 38°C). Type T TEFLON diaphragm seals have a maximum working pressure of 2500 psig at 100°F (172 bar at 38°C).

In-Line Flow Thru seal Types R, S, and T are rated at 1500 psi at 100°F (105 bar at 38°C). Type L seals are rated at 1250 psi at 100°F (88 bar at 38°C).

All flange attached seals are sized according to ANSI B16.5. ANSI standard flange attached and In-line Flow Thru seals are available with a maximum working pressure rating equal to the flange class pressure rating.

Seals having a lower housing made of nonmetallic materials should not be used for working pressures in excess of 100 psig at 140°F (7 bar at 60°C). TEFLON threaded connections are limited to pressures of 50 psig at 100°F (3.5 bar at 38ºC).

INSTRONLINE offers special diaphragm seal designs with a maximum working pressure rating of up to 5000 psig (690 bar). Please consult your INSTRONLINE representative for more information.

CHOOSE THE BEST – ELECTRIC ACTUATOR VS. HYDRAULIC ACTUATOR

Actuators are systems that convert energy into torque to move components in various equipment. Even if you’re unfamiliar with actuators, you encounter them daily in machines like vehicle brake lines, industrial robots, and cell phones. The motions that actuators produce can be linear (straight lines) or rotary (revolving on an axis).

Actuators get their power through several means, including electricity or a hydraulic system. Though they each have advantages and disadvantages, people tend to lean more toward electric over hydraulic actuators. Still, it’s best to have all the facts about linear actuators to determine which variety will suit your needs best.

What Is an Electric Actuator?

A linear electric actuator uses electricity from a motor to generate power. When electricity flows through the system, the motors rotate a lead screw with a nut on a thread. The direction in which the nut moves on the line depends on the direction the screw turns.

Advantages and Disadvantages

If you need an actuator with both speed and accuracy, it’s best to go with an electric over a hydraulic linear actuator. These systems can function at up to 80% efficiency with the ability to stop in any position.

The units tend to be small, require little maintenance, and have no external components. Many of them also have fail-safe brakes called acme screw units to initiate self-locking if the motor loses power.

A significant drawback to electric linear actuators is the cost. Their design, efficiency, and construction usually mean a higher upfront cost. These actuators are also not ideal for hazardous areas or continual running because they can overheat.

What Is a Hydraulic Actuator?

Unlike an electric actuator, the hydraulic version does not rely on an electric motor for energy. Instead, a hydraulic actuator gets its power from hydraulic fluid consisting of various oils. The presence of the liquid creates pressure that forces cylinders in the system to move in straight lines.

Advantages and Disadvantages

Hydraulic actuators are incredibly powerful with high load capacities, making them the ideal system for high-force applications. They function well under intense pressure. The hydraulic fluid responsible for creating movement is in compressible so that the actuator can hold an impressive amount of force.

Unfortunately, the presence of hydraulic fluid means these actuators are prone to leaks. They require a lot of maintenance and plumbing to ensure that the systems are in good condition. The linear actuators have a decent speed, but accurately controlling them can be challenging due to the periodic jerking motion that occurs when it shifts from being still to moving.

How Electric Actuators Are Better Than Hydraulic

If you’re wondering if you should choose an electric over a hydraulic actuator, it’s best to remember that both options have their purposes in various industries, despite their drawbacks. However, electric actuators are a favorite for many due to their precision, safety, small size, and speed.

Though some businesses find hydraulic actuators appealing due to their low upfront costs, they could spend more on routine maintenance and repairs for leaks and numerous external components. It costs more to install an electric actuator, but the installs are quick, and the units don’t require much care.

All About Thermowells

Today on the Instronline blog, we’re drilling down and learning all about thermowells. With over 30 years of experience engineering sensors solutions, Instronline is ready to create a custom solution to suit your needs. Our team provides engineered solutions with fast and dependable delivery. Get a quote today!

Thermowells

Thermowells are cylindrical fittings used to protect temperature sensors installed in industrial processes. In addition, a thermowell consists of a tube closed at one end and mounted in the process stream. A temperature sensor such as a thermometer, thermocouple or resistance temperature detector has an open end tube, which is in the open air outside the process piping or vessel and any thermal insulation.

Thermodynamically, the process fluid transfers heat to the thermowell wall, which transfers heat to the sensor. As a result, the sensor’s response to process temperature changes slows down because of the addition of the well. Also, the sensor is replaceable if it fails. Since the mass of the thermowell needs heat to the process temperature, and since the walls of the thermowell conduct heat out of the process, sensor accuracy and responsiveness is negatively impacted by the addition of a thermowell.

Above all, the four most common types of thermowells are threaded, flanged, welded and sanitary.

Types of Orifice Plates Used in Flow Measurement

Orifice plates are one of the most popular devices for the measurement and control of fluid flow. It is frequently used more than any other flow meter. The orifice consists of a thin metal plate with a straight hole drilled in it. When a fluid passes through an orifice, the flow is often less than the amount calculated. The assumption is that the energy is conserved and the flow distributing through the orifice is uniform and parallel.

Orifice Plates are normally mounted between a set of Orifice Flanges and are installed in a straight run of smooth pipe to avoid disturbance of flow patterns from fittings and valves.

Orifice plates cover a wide range of applications including fluid and other operating conditions. They give an acceptable level of uncertainties at lowest cost and long life without regular maintenance.

Concentric Bore – The most common orifice plate is the square-edged, concentric bored design. It’s used on most processes including clean liquids, gases and steam flow. It is usually made of stainless steel. Other materials like nickel and Monel are used for a good corrosive resistant property. This type of orifice plate has a very high accuracy.

Eccentric Bore – Eccentric bore orifice plates are plates with the orifice off-center, or eccentric, as opposed to concentric. Location of the bore prevents accumulation of solid materials or foreign particles and makes it useful for measuring fluids containing suspended solid particles. Eccentric bore orifice plates are more uncertain as compared to the concentric orifice.

Segmental Bore – The segmentally bored orifice plates contain a hole that is a segment of a concentric circle. Like the eccentric orifice plate design, the segmental hole should be offset downward in gas flow applications. Segmental bores are generally used for measuring liquids or gases which carry non-abrasive impurities such as sewage treatment, steel, chemical, water conditioning, paper and petrochemical industries.

Quadrant Edge Bore – The quadrant edge bore is an orifice with the inlet edge rounded. The upstream side of the bore is shaped like a flow nozzle while the downstream side acts as a sharp edge orifice plate. This design is recommended to measure the flow of high viscosity fluids such as heavy crudes, syrups and slurries. The quadrant bore produces a relatively constant coefficient when the Reynolds Number is below 10,000.

Ring Type Joint (RTJ) Orifice Plates – The RTJ type orifice plate incorporates an essential gasket for mounting between ring type joint flanges. It is based on proven technology, has no moving parts and is suitable for high temperature and pressure applications. Orifice plates are recommended for clean liquids, gases and low velocity steam flows. Plate thicknesses depend on line size and differential pressure, and should be sufficient to prevent the plate from bending under operating conditions.

What different types of flow control valves are used in fluid control?

If you need to control the flow rate of a fluid within a hydraulic circuit, flow control valves offer the perfect solution. They do this by varying the size of the flow passage as directed by a signal from a controller, usually a flow meter. From ball valves to needle valves, there are various different types of flow control valves available, as Fluid Controls explains here.

What is a flow control valve?

A flow control valve is a type of device that is used to modify a fluid’s flow rate within a hydraulic circuit. This is achieved by adjusting the orifice size within the valve. The method by which this is done will vary depending on the type of valve. Flow control valves are typically used in control circuits for devices such as cylinders, actuators and motors. Let’s explore how flow control valves work in a little bit more detail.

How do flow control valves work?

Flow control valves have an orifice (such as a disc or a plug) that controls the rate of flow. The size of the orifice and the amount of pressure applied to force the fluid through that orifice will determine the flow rate. Then there are variable orifice valves that are designed to modify actuator speed while a machine is running.

The most common example is a needle valve, which opens and closes an orifice with a tapered end. This is raised and lowered via the turn of a handle or remotely using an actuator.

Different types of flow control valves

Fluid Controls supplies numerous different types of flow control valves, including the following:

Ball Valves

Ball valves feature a hollow ball that pivots 90 degrees around its axis to open or close the flow. Our ball valves range includes miniature ball valves, ball check valves, cryogenic ball valves, high pressure ball valves, rotary plug valves and swing out ball valves. View our ball valve collection.

Check Valves

Check valves allow a medium to flow in one direction to prevent potential damage caused by back flow of the fluid. Fluid Controls stocks and supplies a wide range of uni-directional flow control check valves from Parker’s Instrumentation Division. Browse our check valve selection.

Metering Valves

Metering valves provide accurate and stable control of flow rates in analytical, instrumentation and research applications. We stock metering valves from Parker for their ability to work to high flow and high pressure specifications, as well as under high temperatures. Purchase Parker metering valves.

Needle Valves

As we mentioned earlier, needle valves open or close an orifice using a tapered end and can either be controlled manually or with an actuator. Fluid Controls stocks stainless steel needle valves from industry-leading manufacturers, Parker. Source needle valves from Fluid Controls.

Solenoid Valves

Solenoid valves are electro-mechanical valves that are commonly employed to control the flow of liquids or gases. From pilot operated solenoid valves to stainless steel solenoid valves, we can provide high-quality flow control valves for all industrial applications. Purchase solenoid valves today.

What are push to connect fittings?

At Instronline, we supply a wide array of pneumatic fittings to suit every application. As part of our extensive selection, we stock a premium range of push to connect fittings from global engineering giants, Parker and IMI Norgren. But what exactly are push-fit fittings and how can they benefit your applications? Find out more as Fluid Controls explains all.

What are push to connect fittings?

Push to connect fittings have nearly as many aliases as they have configurations. You may well see these handy pneumatic products variously referred to as ‘push-fit fittings’, ‘push-Lok fittings’ or ‘push-in fittings’. All of which are essentially the same thing: hose fittings for pneumatic applications. Designed with quick and simple assemblies in mind, the beauty of push-fit fittings is that they require no specialised tools whatsoever.

This is because push to connect fittings employ a ring of metal spurs within the fittings that grip any pipe that is inserted into the fitting sockets. Push fit fittings also feature a neoprene O-ring that provides a leak-tight seal against pipes. All things considered, push to connect fittings offer one of the quickest, easiest and most effective methods of creating extremely reliable hose and pipe connections.

What are the benefits of push fit fittings?

There are several benefits to using push fit fittings, not least the following standout advantages:

Rapid Connections

Perhaps the biggest benefit of push to connect fittings is the speed at which connections can be made. This makes them an especially attractive proposition when emergency repairs need to be made.

Zero Tools

As mentioned earlier, another great advantage of push-fit fittings is the fact that they require no specialised tools whatsoever. Pipe connections can be made without the need for soldering, clamps or glue.

Greater Convenience

Another benefit of push fit fittings is the convenience of being able to use them even when pipes aren’t perfectly dry. This provides welcome time savings, with every second saved boosting productivity and profits.

Versatile Options

Push-fit fittings are available in a wide range of materials and sizes suitable for a huge variety of pipe types. So whatever your pneumatic application, there is almost certainly a push to connect fitting to suit.

What is a Digital Positioner and Why Should You Use One?

A valve positioner is a device mounted on the actuator that exerts or reduces air pressure as necessary to make sure the valve achieves the correct position.

When there is no positioner, the control signal goes directly to the actuator. When a positioner is installed, it intercepts this signal and then outputs a different signal to the actuator.

Essentially, a positioner ensures that the final control element in a loop exerts optimal control.

There are three types of positioners:

Pneumatic positioners. These devices receives a pneumatic (air) signal from the controller and output a pneumatic signal to the actuator.
Analog, or electro-pneumatic, positioners. Here, the input signal is electrical, rather than pneumatic.
Digital, or smart, positioners. These positioners also receive an electrical signal, but it’s digital as opposed to analog.

Digital positioners came on the scene about 20 years ago, but they only really started gaining popularity recently as automation has started to take off in plants and along pipelines.

For example, the Siemens SITRANS VP300 digital positioner allows you to:

Auto tune the positioner in minutes, as opposed to the hours analog positioners can take
Get diagnostic information about the health and performance of your control valves
Identify potential problems before they happen
Integrate the positioner with other control systems so all of your data is in one place

What this all boils down to is higher valve productivity, decreased downtime, and overall better plant performance.

What is HART, Foundation Fieldbus & Profibus ?

HART stands for ‘Highway Addressable Remote Transducer’ and is a standard originally developed as a communications protocol for control field devices operating on a 4-20 mA control signal.

The HART protocol uses 1200 baud Frequency Shift Keying (FSK) based on the Bell 202 standard to superimpose digital information on the conventional 4-20 mA analogue signal. Maintained by an independent organisation, the HART Communication Foundation, the HART protocol is an industry standard developed to define the communications protocol between intelligent field devices and a control system.

HART technology is a master/slave protocol, which means that a smart field (slave) device only speaks when spoken to by a master. The HART Protocol can be used in various modes such as point-to-point or multidrop for communicating information to/from smart field instruments and central control or monitoring systems.

HART Communication occurs between two HART-enabled devices, typically a smart field device and a control or monitoring system. Communication occurs using standard instrumentation grade wire and using standard wiring and termination practices.

The HART Protocol provides two simultaneous communication channels: the 4-20mA analog signal and a digital signal. The 4-20mA signal communicates the primary measured value (in the case of a field instrument) using the 4-20mA current loop – the fastest and most reliable industry standard. Additional device information is communicated using a digital signal that is superimposed on the analog signal.

The digital signal contains information from the device including device status, diagnostics, additional measured or calculated values, etc. Together, the two communication channels provide a low-cost and very robust complete field communication solution that is easy to use and configure.

HART is probably the most widely used digital communication protocol in the process industries, and:

Is supported by all of the major suppliers of process field instruments.
Preserves existing control strategies by allowing 4-20 mA signals to co-exist with digital communication on existing 2-wire loops.
Is compatible with analogue devices.
Provides important information for installation and maintenance, such as Tag-IDs, measured values, range and span data, product information and diagnostics.
Can support cabling savings through use of multidrop networks.
Reduces operating costs via improved management and utilisation of smart instrument networks.

What is PROFIBUS ?

PROFIBUS is an open fieldbus standard for a wide range of applications in manufacturing and process automation independent of manufacturers. Manufacture independence and transparency are ensured by the international standards EN 50170, EN 50254 and IEC 61158.

It allows communication between devices of different manufacturers without any special interface adjustment. PROFIBUS can be used for both high-speed time critical applications and complex communication tasks. PROFIBUS offers functionally graduated communication protocols DP and FMS. Depending on the application, the transmission technologies RS-485, IEC 1158-2 or fibre optics can be used.

It defines the technical characteristics of a serial Fieldbus system with which distributed digital programmable controllers can be networked, from field level to cell level. PROFIBUS is a multi-master system and thus allows the joint operation of several automation, engineering or visualization systems with their distributed peripherals on one bus.

At sensor/actuator level, signals of the binary sensors and actuators are transmitted via a sensor/actuator bus. Data are transmitted purely cyclically.

At field level, the distributed peripherals, such as I/O modules, measuring transducers, drive units, valves and operator terminals communicate with the automation systems via an efficient, real-time communication system. As with data, alarms, parameters and diagnostic data can also be transmitted cyclically if necessary.

At cell level, programmable controllers such as PLC and IPC can communicate with each other. The information flow requires large data packets and a large number of powerful communication functions, such as smooth integration into company-wide communication systems, such as Intranet and Internet via TCP/IP and Ethernet.

What is Foundation Fieldbus?

Foundation Fieldbus is an all-digital, serial, two-way communications system that serves as a Local Area Network (LAN) for factory/plant instrumentation and control devices. The Fieldbus environment is the base level group of the digital networks in the hierarchy of plant networks. Foundation™ Fieldbus is used in both process and manufacturing automation applications and has a built-in capability to distribute the control application across the network.

Unlike proprietary network protocols, Foundation Fieldbus is neither owned by any individual company, nor regulated by a single nation or standards body. The Foundation Fieldbus, a not-for-profit organization consisting of more than 100 of the world’s leading controls and instrumentation suppliers and end users, controls the technology.

While Foundation Fieldbus retains many of the desirable features of the 4-20 mA analogue system, such as a standardized physical interface to the wire, bus-powered devices on a single wire, and intrinsic safety options, it also offers many other benefits.

Device interoperability

Foundation Fieldbus offers interoperability; one Fieldbus device can be replaced by a similar device with added functionality from a different supplier on the same Fieldbus network while maintaining specified operations. This permits users to ‘mix and match’ field devices and host systems from various suppliers. Individual Fieldbus devices can also transmit and receive multivariable information, and communicate directly with each other over a common Fieldbus, allowing new devices to be added to the Fieldbus without disrupting services.

Temperature Control Valve – Definition and Working Principle

Control valves are an integral part of various industrial applications, such as power generation units, oil and gas plants, fire prevention systems, and more. These control valves are available in different types and specifications. Temperature control valves are one of the popular valve types used today. These devices are designed to control the fluid temperature in the system to ensure efficient process operations. The temperature control valve controls the fluid flow, flow rate, and the process quantities, such as temperature, pressure, and liquid levels. Is that all? Obviously not. How does a temperature control valve work? What types of temperature control valves are in use today? Are you bothered with these questions? If yes, this post answers all questions regarding temperature control valves. So, stay tuned.

A Quick Overview of Temperature Control Valve

Temperature control valves are also called temperature regulators. They are common control elements used in the process control industry. They are similar to other control valves; however, the difference is in controlling process temperatures at a specific level. They are used to control the temperature of the fluid in compressors, engine jacket water, turbines, and so on. Often abbreviated as TCV, they are also used in cogeneration systems to control varying temperatures and ensuring the cooling of the engine. Temperature control valves are distinguished based on the number of ports they have. It means the control valve with two ports is a 2-way valve and the one with three ports is a 3-way valve.

How Does a Temperature Control Valve Work?

Before getting into the working of the temperature control valve, it is important to understand its structure. The structure of the temperature control valve comprises four main parts- - the temperature detecting element, sensor, power source, and controlling medium. The temperature detecting element is a temperature sensor responsible for sending either an electrical or mechanical signal to the actuator. Later, the actuator uses this signal to act on the power source that determines the valve’s position.

The temperature control valve operates on a mechanical temperature measuring instrument. The temperature control valve or temperature regulator uses a filled bulb as a temperature sensor. Due to the material’s thermal expansion properties, it expands with a temperature rise. This expansion trigger stress in the pressure of the actuator. This pressure changes the position of the valve on the regulator that controls a coolant’s flow rate.

The temperature control valves use two popular temperature control schemes as described below.

Mixing of Cold and Hot Process Fluid: In this, the hot and cold process fluids are set at two different temperatures- Tx and Ty. The temperature control valve (TCV) is set such that the cold process fluid is allowed to physically mix with the hot process fluid to get the required temperature. It is important to note that the fluids must not chemically react with each other. The sensor is installed in the hot process fluid. Ty measures and sends the hot process fluid’s temperature to the controller that has the set point Tx. The controller senses the change once the hot process fluid’s temperature surpasses Ty. The control valve will allow the cold process fluid to mix with the hot one till the set point temperature is achieved.

Exchange of Heat between Hot and Cold Process Fluid: In this method, energy transfer between the two hot and cold process fluids occurs instead of the fluids mixing. This means cold fluid passes energy through the tube, while the hot fluid passes through the shell of the exchanger. The hot fluid passes energy to the cold fluid, and the rise in temperature of cold fluid is sensed as well as controlled by the temperature sensor or temperature transmitter and sent to the temperature controller. The controller accordingly sends to TCV to remain open or shut depending upon the temperature elevation. It would remain open and facilitate energy transfer till the required temperature set point is achieved.

If you are looking to install temperature control valves for your applications, it is always a good practice to consult an industry-leading valve supplier before making any decision. The Instronline is a one-stop solution for you.

5 TYPES OF PRESSURE SENSORS YOU SHOULD KNOW

Just like a drill won’t work with a nail, the type of pressure sensor you’re using for a given application matters. What performs well when measuring oil and gas, for example, may not be the best fit for hydraulics.

That’s why it’s key to survey the range of pressure sensor types to best suit your needs before making a decision. For our purposes, we’ll define “pressure sensor” as a device capable of converting pressure into an electrical signal. Under that umbrella, we’ll include transducers and switches, which both assist with pressure sensing.

To explore the different types of pressure sensors available, we wanted to call out some specific examples and talk a little about their functionality.

Different Types of Pressure Sensors

Strain Gauge - Chemical Vapor Deposition Pressure Sensors CVD

Chemical Vapor Deposition (CVD) is a process utilized to manufacture very stable strain gauge pressure transducers. The CVD process provides a reliable option where so many other low-cost pressure sensors fail. Inside each of these transducers, resides an ASIC chip, which offers higher levels of linearity correction. CVDs pressure sensors are great for applications such as off-highway, HVAC, and semiconductor processing. In addition, the CVD pressure transducers offer a thicker diaphragm which makes it capable of handling intense pulsating pressures.

Strain Gauge - Sputtered Thin Film Pressure Sensors thin-film

Of all the various types of pressure sensors, Sputtered Thin Film strain gauges are some of the most dependable, known for their long-term durability and pinpoint accuracy even under extremely harsh conditions. Depending on its job, these types of sensors can be ordered in ranges from 0-100 through 0-30,000 PSI. The product offers unmatched performance in volatile environmental scenarios such as high temperatures, intense shock and vibration, or massive pressure spikes. Sputtered Thin Film sensors are an ideal fit for applications such as off highway, fire protection, refrigeration, and alternative fuel.

Variable Capacitance Pressure Sensors Capacitance-pressure

When you need a tough, dependable way to measure low pressure, capacitive transducers are the way to go. These sensors can be ordered in ranges from 0-2 PSI through 0-15 PSI to accommodate a range of applications including marine tank level indication. They boast a sturdy, physical configuration, stainless steel and ceramic wetted parts, and variable capacitor technology. Capacitive pressure sensors can also be used for high pressure in applications from industrial engines to hydraulic systems, process control to natural gas pipelines.

Solid-State Pressure Sensors

If your application’s needs deal with elements of high shock and vibration, Solid-State pressure switches are an excellent choice. These switches are built with a hermetic all stainless steel diaphragm and provide high accuracy measurements where tight system controls are necessary. They also offer an advantage over electromechanical pressure switches in cases where actuations exceed 50 cycles per minute. Applications for Solid-State Switches include off-highway, medical gas, compressors, and other demanding general industrial applications.

MMS Pressure Sensors

Micromachined silicon (MMS) strain gauge sensors offer very cost effective solution for low pressures in both absolute, compound, and gauge references. MMS pressure sensors offer 316L stainless steel wetted parts and an all welded construction makes for a compact unit that is highly compatible to harsh chemicals and environments. Applications appropriate for MMS include air conditioning refrigerant recovery, gas analysis instrumentation, and medical sterilizers. MMS-pressure

These are examples of the different types of pressure sensors you’ll find in the Gems portfolio, which support a range of different applications and functions. Whether it’s a differential pressure sensor or air pressure sensor, if you’re looking for some assistance determining which type is right for you, we’re here to help.

How to select the correct Pressure Sensor

Overview

A pressure sensor is device which is able to provide an output signal relative to the pressure force being exerted upon it. Pressure sensors are continuous output devices and vary their output in relation to the applied pressure. They should not be confused with pressure switches which are designed to switch electrical contacts at predetermined pressure level(s), however pressure sensors used

in conjunction with other devices such as trip amplifiers with relay outputs can be used to perform switching actions as well. The use of pressure sensors for measurement and control applications is widespread with pressure sensors available in many different types and configurations, each suited to different applications. Examples include the measuring of mains water pressure to help conserve water and ensure the water supply networks run efficiently, measuring air pressure in race car engine induction systems, and using the hydrostatic pressure principle to accurately measure liquid levels in chemical storage tanks.

Uses

For applications where a continuous output is required to indicate a measured pressure or depth of liquid in storage tank or reservoir, pressure sensors are often the measurement instrument of choice. Ranging from industrial process control to low power dataloggers, pressure sensors are a robust solution to pressure measurement applications. For example, submersible hydrostatic pressure sensors can be deployed in reservoirs to accurately monitor water levels and either be connected to a datalogger to store readings or a telemetry unit to give real-time level measurements. Specially designed pressure sensors can be deployed to monitor pipe line pressures submerged on the sea bed. Intrinsically safe ATEX approved pressure sensors can be used to monitor pressure in compressed gas storage tanks, whilst compact lightweight pressure sensors find uses for various pressure measurement tasks as part of a full race car telemetry system.

Function

Instronline pressure sensors use pressure sensor elements which utilise piezoresistive strain gauges deployed as a Wheatstone bridge circuit which are bonded or printed onto the pressure sensor diaphragm. When the sensor diaphragm flexes, the strain gauge produces a mV signal output. Instronline pressures sensors offer a choice of two sensor element technologies each with their own benefits. Piezoresistive ceramic pressure sensor elements have the benefit of being a cost-effective way to measure pressure from 1 Bar up to 700 Bar, the Al2O3 Ceramic diaphragm material having excellent chemical compatibility when paired with an appropriate O-ring seal polymer. The Piezoresistive silicone sensor elements offer the enhanced resolution required for accurate low-pressure (mBar) and small tank level measurements. The 316 Stainless steel diaphragm parts and the standard Viton seal provide a broad range of chemical compatibility. These sensor elements also have excellent over pressure characteristics should an unexpected over-pressure event occur.

Considerations

Instronline pressure sensors are highly configurable to the users’ needs. When selecting a pressure sensor for a given measurement application, it is vital the user has clear understanding of the pressure sensing application and the pressurized media that needs to measured. There are many factors that need to be considered, and in some cases, trade-offs will need to be made, to find the optimum pressure sensor configuration.

Process media to be measured: gas, liquid, media temperature.
Pressure range to be measured.
Pressure datum: Absolute, Gauge or Sealed Gauge
Overpressure requirements: Consider sources for pressure spikes such as pumps, valves and actuators.
Electrical output: 0-100mV 4-wire, 4-20mA 2-wire, 0-5V 3-wire are just some examples.
Accuracy: Typically <±0.25% /FS/ BFSL
Electrical connection: A wide range of electrical connectors and cables are available to choose from.
Process connection: 1⁄4” BSP or 1⁄4” NPT threads are stocked but other threads are available on request.
O-ring seal material: The O-ring seal needs to be compatible with the process media, Choose from Viton, EPDM, Nitriles as well as Perfluroelastomer and Fluorosilicone.
Chemical compatibility of wetted parts: Housing material is Typically 316L or 303 Stainless Steel
Ingress protection: Where is the sensor going to be used, what IP rating is required?
Approvals: WRAS, ATEX, NSF, etc.

Types

There are two types of pressure sensor package available, external pressure sensors which are designed to be screwed into a pipe manifold or pressure vessel, and submersibles which are designed to be submerged in tanks, reservoirs, rivers or the sea. Submersibles measure the hydrostatic pressure to determine the height of the liquid above the sensor. Other submersibles are designed to screw into submerged pipes and tanks and measure the pressure inside the submerged pipe or tank. Both package types offer vast array of configuration options so please contact Instronline with your requirements.

How to Select the Right Temperature Controller for Your Application

In many different types of industries and applications, measuring and controlling temperature is vital for ensuring quality and safe operations. Temperature controllers are used in research laboratories, product development centers, process plants and other industrial settings.

In a clean temperature-controlled lab setting, an inexpensive off-the-shelf controller may be the right product. However, these same controllers typically can't survive the harsh conditions common to heavy industry processes and remote areas.

While maintaining temperature control is imperative, it's also one of the most difficult parameters to successfully control. An inexpensive controller may be the best one for a simple application, but there are other important factors to consider in addition to initial cost.

Determining what controller to use can be confusing, because at a basic level all controllers work in a similar manner. The controller samples a value transmitted from a temperature sensor many times per second, and compares this process variable against the setpoint.

Whenever the process variable deviates from the setpoint, the controller sends an output signal to engage other devices, such as heating and cooling mechanisms, to bring the temperature back to the setpoint. Despite being fairy similar on initial inspection, different controller types have features and functions that offer important advantages, depending on the type of application.

Braving the Elements

A review of the input sensors is the best place to start when selecting a controller for deployment in areas subject to dust, extreme temperatures and noise. Depending on the application—input sensors may include thermocouples, RTDs and linear inputs such as mV and mA.

For harsh environments, thermocouple or RTD sensors are the usually best choice. Thermocouple sensors are economical, rugged and provide accurate measurements for a wide range of temperature values. Available in multiple types and configurations, they work well in many different types of industrial installations.

RTDs provide greater temperature accuracy than thermocouples, but they're more expensive, have narrower temperature range, and are less rugged. For example, RTDs have an upper temperature limit of approximately 1200 degrees Fahrenheit compared to 4200 degrees Fahrenheit for thermocouples.

Whatever temperature sensor type is selected, the controller should contain a "sensor break detect" feature. This alerts the controller when a sensor is faulty or absent, enabling it to adjust the output to a preset value that will prevent harm to equipment and personnel.

Protecting the Controller

Panel-mounted controllers are offered with various front panel enclosure ratings, with costs increasing along with the degree of protection. The proper Ingress Protection (IP) rating and the

National Electrical Manufacturers Association (NEMA) rating should be selected depending on the particular application.

IP ratings are usually IP65 or higher for most industrial applications. This means the controller is completely protected from dust, oil, and other non-corrosive material. The IP65 rating also ensures complete protection from contact with enclosed equipment, and from water projection by a nozzle from any direction.

Roughly corresponding to an IP65 rating would be a NEMA 4 or 4X rating. The 'X' in a NEMA 4X rating means that the controller's front panel won't corrode during normal operating conditions (Figure 1).

ON-OFF Controllers

An ON-OFF controller is inexpensive, but it can only determine if an output needs to be turned on or off. For example, if the setpoint on a boiler is 245 degrees and the process value temperature falls to 244 degrees, the controller will send an ON signal. This signal might turn a heater on, open a steam valve, or take other action to increase the boiler temperature. When the temperature reaches the setpoint, the controller output reverts to the OFF state.

This type of controller, similar to a home thermostat, works well in some applications, but has some serious limitations. The band in which the controller operates is set to the desired value, in the above case one degree. So, the controller doesn't change its output state unless the process variable changes by at least one degree.

Once the output state is changed, it typically takes some time for the process variable to change, meaning the actual temperature can deviate from the setpoint by more than one degree. This may be acceptable in some applications, but not all.

Another issue is that ON-OFF control is often highly inefficient because the controlling device must either be full on or full off. If the controlled device is a valve, an ON-OFF controller might require the valve to slam open and shut frequently, which can lead to excessive wear and tear.

In addition to their limited control capabilities, these devices usually lack a display and have limited communication capabilities. Therefore, these basic ON-OFF controllers should only be used for non-critical thermal systems without stringent accuracy requirements.

When PID Control Is Preferable

More advanced digital temperature controllers have multiple outputs and programmable functions. They're also usually placed in the front panel with a display for easy operator accessibility. These advanced controllers deliver more accurate and stable control by automatically calculating proportional-integral-derivative (PID) parameters to determine the exact output value needed to maintain the desired temperature.

For example, if the cycle time is set to 8 seconds, a system calling for 50 percent power will have the output on for 4 seconds and off for 4 seconds. When output power should be 25 percent for the same 8 second cycle time, the output will be on for 2 seconds and off for 6 seconds (Figure 2). This type of cycling output control is often used to control a solid-state device such as a thyristor.

If the controlled device has the capability to continuously vary its state, then the PID controller output can be set to vary continuously to control the device. For example, a 4-20 mA PID output could be used to continuously vary the position of a control valve. This type of continuous control can result in highly accurate temperature control.

These advanced digital temperature controllers typically offer the ability to program many different types of alarms. For instance, a high limit alarm could be set to prevent a heat source from damaging equipment by de-energizing the source if the temperature exceeded a preset value. Deviation alarms can be set at a determined plus-or-minus value from the set point to notify an operator if the temperature goes out of range.

Another useful feature provides an alarm when the output signal is 100 percent, but the input sensor doesn't detect any change in temperature after a certain time period, indicating a malfunction in the temperature control loop.

Highly Flexible Controllers

Single loop controllers typically have one input and one output. Multi-loop controllers have several inputs and outputs and can be used to simultaneously control numerous loops, enabling the supervision of more process system functions.

Moreover, multi-loop controllers are compact and modular, and can operate either in a stand- alone mode or as part of an advanced automation system such as a programmable logic controller, a programmable automaton controller, of a distributed control systems.

When used a replacement for temperature controls in any of these advanced automation systems, a multi-loop controller can provide fast PID control, and can off-load much of the memory-zapping calculations from the automation system processors.

As a replacement for multiple DIN controllers, multi-loop controllers provide a single point of software access to all control loops. These controllers also provide features not available on traditional panel-mounted controllers. They have higher loop density and a smaller footprint, and wiring is reduced by having a common connection point for power supply and digital communications interfaces.

As compared to simpler controllers, multi-loop temperature controllers usually have enhanced security features to prevent unauthorized access to critical settings. These features offer complete control over the information being read from or written to the controller, thus limiting the information an operator can read or change.

Advanced controllers also offer better communication capabilities, allowing them to communicate with advanced automation systems via digital communication links. They can be configured quickly and easily using PC-based software, allowing configurations to be easily saved for future use. When connected to the Internet or to an intranet, these controllers can be accessed remotely, allowing full remote viewing, configuration and control from any location with Internet or intranet access.

This article serves as an introduction to the various features and types of temperature controllers. From sensor types to accuracy requirements to remote access, there are many considerations beyond the initial cost in order to maintain safe and efficient operations. A cheaper controller can become very expensive if frequent repairs to associated components are required, if required accuracy can't be maintained, or if an accident occurs due to inadequate safety features. Each application should be examined in detail, with the right controller deployed depending on the process requirements.

Working Principles of Electromagnetic flow meter

A common magnetism flow meter is that the magnetic flow meter, additionally technically associate magnetism flow meter or a lot of unremarkably simply referred to as a magazine meter. A magnetic flux is applied to the tube, which ends up with potential proportional to the flow speed perpendicular to the flux lines. The physical principle of work is magnetic induction. The magnetic flow meter needs a conducting fluid, as an example, water that contains ions, associated an electrical insulating pipe surface, as an example, a rubber-lined steel tube.

If the magnetic field direction were constant, chemical science and alternative effects at the electrodes would create the potential tough to differentiate from the fluid flow induced potential. To mitigate this in fashionable magnetic flowmeter, the magnetic flux is consistently reversed, cancelling out the chemical science potential, that doesn't amendment direction with the magnetic flux. This but prevents the employment of permanent magnets for magnetic flow meters. If you are looking electromagnetic flowmeter online then you search best Temperature Transmitter Suppliers, Best Price Electromagnetic Flow meters on Instronline. Here you can also find best and updated Siemens Ultrasonic Level Transmitter Exporters, Siemens Ultrasonic Level.

Working Principle of Electromagnetic Flowmeter

The purpose of a flow meter system is to live the movement, or rate of flow, of a given volume of fluid Associate to specific it through an unambiguous electrical signal. a typical flow meter consists of a series of coupled parts that transmits signals indicating the degree, rate of flow, or volume of fluid moving through a particular channel, and it ideally functions with bottom interference from environmental conditions. A magnetic flow meter may be a comparatively noninvasive measuring system that's well-suited for rate of flow analysis as a result of its varying of functions.

A magnetic or electromagnetic force flowmeter are often put in relatively easy fashion to that degree as an existing pipe network are often reborn into a measuring system by applying external electrodes and magnets. These flow meters will track forward and reverse flow and are minimally laid low with flow disturbances associated with consistency or density. They’re linear devices which will be label to live a spread of various variables whereas additionally reacting to changes in fluid movement. Progress in flowmeter technology has targeted on manufacturing devices that are smaller, less costly, and capable of constructing additional refined measurements.

Faraday’s Law

Like several different electrical devices, magnetic flow meters operate underneath the principles of Faraday’s law of magnetic force induction. in step with this law, a conductor that passes through a field of force produces voltage proportional to the relative velocities between the field of force and also the conductor. The law is often applied to flowmeter systems as a result of several fluids are semi conductive to a precise degree. The quantities of voltage they generate as they move through a passage are often transmitted as a symptom measure quantity or flow characteristics.

Velocity and Voltage

When a flowmeter is installed and activated, its operations begin with a pair of charged magnetic coils. As energy passed through the coils, and then they produce a magnetic field that remains perpendicular to both the conductive fluid being measured and the axis of the electrodes take the measurements. The fluid moves along the longitudinal axis of the flowmeter, making any generated induced voltage perpendicular to the field and the fluid velocity. An increment in the flow rate of the conductive fluid will create a proportionate increase the voltage level.

Flow Profiles

Fluid movements within a flowmeter system are often characterized as sq., with a turbulent fluid velocity; distorted, with weak upstream flow; or parabolic, with a stratified speed. However notwithstanding the profile, a magnetic flowmeter can offer the common voltage from a metering cross-sectional, so the signal transmitted to operators tends to closely mirror the common speed of the flowing liquid. Given a set pipe diameter and a continuing magnetic flux, induced voltage can solely correlate to fluid speed. If the fluid has sensors connected to a circuit, the voltage can produce a current that may be translated as associate degree correct rate of flow measure.

Although flow meters area unit designed to produce as shut of a linear association between voltages and flow as potential, there are a unit various factors which can disrupt this relationship. Potential sources of interference include:

• Unintended extra voltage in the processing liquid.

• Electromechanical voltage accidentally induced in the electrodes or the fluid.

• Capacitive coupling between the signal circuit and the power source.

• Inductive coupling between the magnetic components in the system.

• Capacitive coupling between connective leads.

These and similar sources of external voltage or noise can disrupt normal flow measurement, so it may be worthwhile to set up a flowmeter under conditions as carefully controlled as possible.

Factors to Consider When Selecting a Gear Motor

When selecting a Bauer gear motor, there are important factors that have to be taken into account beyond the size and speed of the motor. There are certain applications that may require a specific speed and torque to meet overall requirements, typically in industrial or assembly applications.

There is a variety of options when it comes to Bauer’s gear motor line, but by choosing the right gearbox the motor can be optimized while meeting the required output speed and torque.

You can choose from the right angle worm, right angle bevel, planetary and parallel shaft gearboxes. Each of these types of gearbox possesses certain design characteristics that will dictate the performance of the reducer in the application. When making a choice for a gear box, it is also important to consider gearing components that include the worm, bevel, spur and helical gearing options that will complete the process of reduction according to their unique design attributes.

The reducer matrix must match an appropriate gearbox for the intended application. This requires careful consideration of key parameters like duty cycle, maximum input speed, maximum torque, efficiency, noise, limitations and back drivability. These common parameters are necessary when you are purchasing standard, off the shelf gearboxes since custom designed gearboxes can be tweaked to run outside of standard parameters. The three most common parameters that will affect your choice for a gearbox includes duty cycle, maximum input speed and maximum torque. These parameters can easily be gathered from the application design inputs and motor outputs.

Another important parameter is efficiency, because it has a big effect on performance. The efficiency of the gearbox is affected by quality, ratio, gear type, lubrication, bearing types and side loading. Generally, high efficiency is preferable for any application but it also means higher costs. Noise is also a factor, but it is subjective because what can be considered as noisy in a residential neighborhood might not be in an industrial setting. Additional protective measures can also be taken to protect staff from noise pollution.

Gearboxes also have their share of limitations and these require careful evaluation. There are gearbox designs with mechanical limitations due to limited output torque as a result of mechanical wear on components or thermal limitations due to heat that may be generated on the gearbox. Heat can directly affect the efficiency and life span of the gearbox. When there is high heat generated, it means that the gear box is not running as efficiently as expected.

In addition to the criteria for gearbox selection, there are other relevant factors that need to be taken account in your choice for Bauer gear motor. In order to ascertain the ideal setup, your business can count on our expert advice and consultation. Contact us today to learn more.

Difference Between Robotics and Automation

Robotics and automation both go hand in hand in terms of automating a system or machine to achieve its task in a very short span of time and with the highest level of accuracy.

Both of them are machines designed to work automatically in industries.

Let us see first the basic definition of both these terms to understand the difference between them more properly.

Robotics

Robotics is a field of engineering which deals in the design, construction, programming, and operation of robots.

Basically, you can term it as an artificial version of a human being. It is controlled by a set of programs and mechatronics control, which makes it able to various complex series of movements properly.

As robots are designed to work as human beings, they have various sets of sensors installed in them to capture audio, visual and tactile effects.

They use artificial intelligence (AI) and machine learning to carry out all the predefined software activities in it and work exactly like a human.

Automation

Automation is categorized under two names

1. Software and

2. Industrial

Software automation deals in performing computer-based tasks inside a computer automatically.

Industrial automation deals in performing physical tasks in a machine or system automatically.

If we consider the technologies used in them, it can be defined from a basic computer to PLC, DCS, SCADA, and other industrial automation techniques.

Robotics versus Automation

Simply, if you compare it with robotics, you will find that both of them are assigned to do a task automatically; with one major difference – component used.

Robotics uses robots whereas automation uses advanced levels of microprocessors and computer-like devices.

Some people also term robotics as a sub-category of industrial automation, as the robot is nothing but a set of sensors and processors built inside it for performing an industrial task in the same way as a PLC does.

One major difference of a robot is that as it is designed like a human resemblance with all the human activities, robots can work in dangerous and hazardous environments where a person cannot go for work or where an industrial computer cannot be installed.

Many engineers come across a common query. They ask that if they install a motion controller with servo drives and advanced hydraulic and mechanical machines driven by them, then they too will perform machine automation in the same way as robots.

But just due to the use of complex algorithms with human capability-type sensors installed in them, robots can perform a higher level of the task than standard industrial automation products.

The topic is very complex to debate because robotics too is just a type of automation.

Some consider robotics as a part of process automation (RPA); others categorize robotics as a very different world from automation.

Conclusion

We can just conclude that both the technologies differ in terms of devices and instruments used for automating a machine or system. Robotics is a more advanced version of technology when compared to automation.

In short, you can also say that once you learned the various techniques in software and industrial automation, you can go ahead with learning robotics which mixes more things in it apart from automation.

Industrial Automation in the Mining Industry

Industrial automation has taken over manual intervention and made life easier for production and industrial activities. One such industry is the mining industry.

Due to the hazards of the environment involved in mining, automation proves to be a good solution to it; where all the activities can be carried out without the presence of personnel.

Automation in Mining Industry

As mines are going deeper and increase the complexity to work, automation is increasingly gaining demand in this sector to reduce the risk of human life and also increase productivity and efficiency.

Let us see some of its advantages in the mining industry:

Analytics and Artificial Intelligence

Nowadays, even in a large industrial company with large-scale production, artificial intelligence and machine learning plays an important role. They can be used in mines too.

These machines can, for example, determine which are the hazardous areas in the mines through analytics and intelligence. They can then point out an area accordingly which will caution the operators to work more carefully in these areas.

Also, areas that are less hazardous and safe to work can be determined, which will indirectly reduce the cost of the company by reducing some environment-friendly devices installed there. It can be some type of ventilation or other technique.

They will not be required there and thus, a proper map of the area will be defined by these machines, so that the operators can work accordingly with less risk, less costing, and more production.

Also, they will help the operators to track and respond in a proper and efficient manner. The use of intelligent machinery and sensors provide live data of ore to be mined.

This will reduce the dependency on a human driller and instead focus on automated control of the drilling process with fewer human errors.

Driverless Trains

Nowadays, in metro cities, a trend has developed to drive a train without a driver. This same technology is used in mines.

Due to the absence of any driver and fully automated control, the risk of human life is reduced.

Real-time monitoring is possible with increased reliability. As mines are areas where less visibility and hazardous gases always pose a threat, driverless transport proves a very smart solution.

Trackless Transport

Now, this is a very useful feature of industrial automation which proves a great beneficiary in this case.

Laser guidance and GPS technology can help miners to navigate the mines and transport loads without the use of tracks. This also reduces the cost to a great extent.

Drones

Drones are extensively used in mines to go through the dangerous and inhibit areas of mines where navigation is not possible.

Due to this, the accessibility in remote areas increases in a great way. This reduces unwanted visits of humans and always saves their lives in case of a visit that would otherwise have proved dangerous.

Apart from these, traditional automation means like PLC control panels, robots and other things make life easier for an operator. Nowadays, they are just in a remote cabin and operate the area from there to overall increase the reliability, efficiency, and productivity of the system.

Relays and Actuators

Relays and actuators are important hardware parts of an embedded system. While an actuator acts as a device which helps to bring about necessary mechanical movements a relay basically works as a switch. Relays are used instead of switches because of several of their advantages over the mechanical switches which will be discussed here in this chapter. So this chapter will tell you more about actuators and relays.

Actuators

As mentioned above, actuators are devices which bring about necessary mechanical movements in a physical process in a factory. Actuator constitutes two distinct modules which are the signal amplifier and the transducer. While the amplifier converts the low power control signal into a high power signal the transducer converts this amplified signal into the required energy form.

Since the function of an actuator is similar to a transducer itself, actuators are classed as transducers. Just like a transducer, actuators convert an electrical signal into a corresponding physical quantity such as movement, force, sound etc. Actuators are normally operated by a low voltage command signal.

Based on the number of stable states the actuator output possess, actuators are classified as binary or continuous devices.

A relay is regarded as a binary actuator as it has two stable states. Relays are either energized and latched or de-energized and unlatched. Meanwhile, a motor is considered as a continuous actuator as it rotates through a full circle. Apart from the relays, lights, motors, and loudspeakers are also the most common types of output devices.

Relays

Switches are very commonly used devices but they have several disadvantages when compared to other similar devices available in the market. One of the main disadvantages is their comparatively larger size. Another main disadvantage is that these switches have to be manually turned on and off. In order to overcome these drawbacks of switches, relays are used. Relays are those devices which can be turned on/off by the application of a low voltage across the relay terminals.

Relays are commonly found in automatic control applications as they are able to control an equipment with the help of electric signals. According to the mode of operation, relays can be classified as normally open and normally closed. In the normally open relays, the contacts are connected when the actuation terminals are energized while in normally closed relays, it is connected to the power supply when the relay actuation terminals are not connected. There are relays with high current capacity and they are called contactors.

There is single pole single throw (SPST) relay, double pole single throw (DPST) relay, single pole double throw (SPDT) and double pole double throw (DPDT) relays as in the case of mechanical switches.

Electromechanical Relays

A relay has electrical and mechanical components and therefore can be regarded as an electromechanical device. such a device consists of three contact terminal known as common (COM), normally closed (NC) and normally opened(NO). In order to control the electric circuit, the relays close and open these contacts. An electromechanical relay consists of three terminals namely common (COM), normally closed (NC) and normally opened (NO) contacts. These can either get opened or closed when the relay is in operation.

Electromechanical relays can work on both AC and DC supply sources. Even though there are several differences in the constructional aspects, both the AC and DC relays work on the principle of electromagnetic induction. One of the major differences is that the AC relays have special circuit arrangement to provide continuous magnetic field as in an AC relay, the demagnetization of coil happens each time it reaches the current zero position.

Most of the electromechanical relays are either attracted type or induction type. The basic working principle of attracted type relays is the electromagnetic attraction. The armature is attracted towards the electromagnet and this electromagnetic force is directly proportional to the square of the magnetic flux or square of the current in the air gap. The attracted type relays are further classified as hinged armature type, plunger type, balanced beam type, moving coil type and reed type.

As is suggested by the name itself, the induction type electromechanical relays are working on the principle of electromagnetic induction and they can only work with AC sources. The force required for the operation which is otherwise called the actuation force is developed as two alternating magnetic fluxes interact. These types of relays are again classified into shaded pole, induction cup type, and watt-hour meter type relays.

Solid State Relays

Solid state relays came into existence as an answer to several drawbacks of electromechanical relays. The limitations of electromechanical relays include limited contact cycle life and high expenses to build. Besides, it switches very slowly and when it comes to larger power contactor relays, these limitations become more obvious. The solid state relays make use of TRIAC or transistor output to switch the controlled power, replacing the mechanical contacts.

There is an LED light source inside the relay which is optically connected to the output device. By applying a low voltage DC power, the relay is turned on. The output device (SCR, TRIAC, or transistor) is optically-coupled to an LED light source inside the relay.

Unlike electromechanical relays, solid state relays have no moving parts which make them easier and faster to switch on and off. Besides issues such as sparking between contacts and contact corrosion never happen in solid state devices.

The output device (SCR or TRIAC) in the solid state relays is a thyristor. The inherent hysteresis of this thyristor maintains the circuit continuity even if the LED is de-energized. And this will continue until the current falls below a threshold value which is called holding current. This will avoid the circuit breaking in the middle of a sine wave peak.

Relay Basics: What a relay is and how they work

What is a Relay?

A Relay is a electrically operated switch
Used for many different applications
Allows for a low voltage circuit to operate a higher voltage circuit
Can be used to monitor the status of electrical equipment (such as a motor)

What parts make up a relay?

Coil (is a tightly wound spool of wire). When current is applied, it will act as an eltromagnet
Contact (a lever that can be opened and closed). Is acted upon by the coil.
Terminals (points where wires can be connected to the relay)

How does it work?

When current is applied to the coil it will pull the contact (which is normally open) closed allowing current to pass through the contact side of the relay.
Some relays have multiple options on the contact side of the relay. They can have both a normally open (NO), or normally closed (NC) set of contacts. When both options are available on one relay, this is refereed to as a double throw relay

fiber optics (optical fiber)

Fiber optics, or optical fiber, refers to the medium and the technology associated with the transmission of information as light pulses along a glass or plastic strand or fiber. Fiber optics is used for long-distance and high-performance data networking.

Fiber optics is also commonly used in telecommunication services such as internet, television and telephones. For example, Verizon and Google use fiber optics in their Verizon FIOS and Google Fiber services, respectively, providing Gigabit internet speeds to users.

Fiber optic cables are used as they hold a number of advantages over copper cables, such as higher bandwidth and transmit speeds.

A fiber optic cable can contain a varying number of these glass fibers -- from a few up to a couple hundred. Surrounding the glass fiber core is another glass layer called cladding. A layer known as a buffer tube protects the cladding, and a jacket layer acts as the final protective layer for the individual strand.

How fiber optics works

Fiber optics transmit data in the form of light particles -- or photons -- that pulse through a fiber optic cable. The glass fiber core and the cladding each have a different refractive index that bends incoming light at a certain angle. When light signals are sent through the fiber optic cable, they reflect off the core and cladding in a series of zig-zag bounces, adhering to a process called total internal reflection. The light signals do not travel at the speed of light because of the denser glass layers, instead traveling about 30% slower than the speed of light. To renew, or boost, the signal throughout its journey, fiber optics transmission sometimes requires repeaters at distant intervals to regenerate the optical signal by converting it to an electrical signal, processing that electrical signal and retransmitting the optical signal.

Fiber optic cables are moving toward supporting up to 10-Gbps signals. Typically, as the bandwidth capacity of a fiber optic cable increases, the more expensive it becomes.

Types of fiber optic cables

Multimode fiber and single-mode fiber are the two primary types of fiber optic cable. single-mode fiber is used for longer distances due to the smaller diameter of the glass fiber core, which lessens the possibility for attenuation -- the reduction in signal strength. The smaller opening isolates the light into a single beam, which offers a more direct route and allows the signal to travel a longer distance. Single-mode fiber also has a considerably higher bandwidth than multimode fiber. The light source used for single-mode fiber is typically a laser. Single-mode fiber is usually more expensive since it requires precise calculations to produce the laser light in a smaller opening.

multimode fiber is used for shorter distances because the larger core opening allows light signals to bounce and reflect more along the way. The larger diameter permits multiple light pulses to be sent through the cable at one time, which results in more data transmission. This also means that there is more possibility for signal loss, reduction or interference, however. Multimode fiber optics typically use an LED to create the light pulse.

While copper wire cables were the traditional choice for telecommunication, networking and cable connections for years, fiber optics has become a common alternative. Most telephone company long-distance lines are now made of fiber optic cables. Optical fiber carries more information than conventional copper wire, due to its higher bandwidth and faster speeds. Because glass does not conduct electricity, fiber optics is not subject to electromagnetic interference, and signal losses are minimized.

Advantages and disadvantages

Fiber optic cables are used mainly for their advantages over copper cables. Advantages include:

Support of higher bandwidth capacities.
Light can travel further without needing as much of a signal boost.
They are less susceptible to interference, such as electromagnetic interference.
They can be submerged in water -- fiber optics are used in more at-risk environments like undersea cables.
Fiber optic cables are stronger, thinner and lighter than copper wire cables.
They do not need to be maintained or replaced as frequently.

However, it is important to note that fiber optics do have disadvantages users should know about. These disadvantages include:

Copper wire is often cheaper than fiber optics.
Glass fiber requires more protection within an outer cable than copper.
Installing new cabling is labor-intensive.
Fiber optic cables are often more fragile. For example, the fibers can be broken or a signal can be lost if the cable is bent or curved around a radius of a few centimeters.

Fiber optics uses

Computer networking is a common fiber optics use case due to optical fiber's ability to transmit data and provide high bandwidth. Similarly, fiber optics is frequently used in broadcasting and electronics to provide better connections and performance. Internet and cable television are two of the more commonly found usages of fiber optics. Fiber optics can be installed to support long-distance connections between computer networks in different locations.

Military and space industries also make use of optical fiber as a means of communication and signal transfer, in addition to its ability to provide temperature sensing. Fiber optic cables can be beneficial due to their lighter weight and smaller size.

Fiber optics is frequently used in a variety of medical instruments to provide precise illumination. It also increasingly enables biomedical sensors that aid in minimally invasive medical procedures. Because optical fiber is not subject to electromagnetic interference, it is ideal for various tests like MRI scans. Other medical applications for fiber optics include X-ray imaging, endoscopy, light therapy and surgical microscopy.

Reasons To Install A Valve Actuator

When I walked out into our Service Center last week, I was surprised to see 5 extremely large gate valves sitting on the floor. According to our valve technician, he was going to be adding actuators to control the isolation valves. Though opening and closing the valves could be achieved by using the hand wheels that came with the valve, it would be extremely time consuming, and exhausting. I was told the hand wheel would need to make 3 complete revolutions to move 1”. On a 30” valve, that’s 90 turns, and I saw the hand wheel. It was massive, and heavy. The valve actuators we were adding would close the valve in 8 minutes, at the push of a button.

As the need for more streamlined and efficient processes become more prevalent, engineers and plant managers must look for ways to leverage technology available. Valve automation is one way to do so. There are a number of benefits for employing valve actuators, time is just one of them. Here are the 5 most popular reasons we hear.

SAFETY

Being able to remotely control a valve allows operators to stay safe. They’ll keep their hands from extreme hot or cold temperatures, and be able to stay out of bad environments, such as those with noxious gases.

In emergency situations, valve actuators go to fail safe positions, whether that’s fail open or fail close. Pneumatic actuators will use a spring return, while an electric actuator has a backup battery to allow for fail safe positioning. Either way, a valve actuator takes one thing off your mind when emergencies occur.

RELIABLE OPERATION

Valve actuators allow for greater control and visibility of the system. If you’re using a PLC or DCS type system, it’s easy to communicate with the valves, and get a feedback signal from the valve to confirm it is in the position you need it to be. When valves are manual, the door to operator error is left open.

INACCESSIBLE OR REMOTE VALVE LOCATION

Valve actuators are great for those valves you just can’t get to. Whether the valve is located high above you, down in a pit, underground, or even 5 miles off-site, if it’s actuated, you can control it.

COST

There’s a great deal of cost savings to be had when a valve actuator is involved. A valve actuator is always in contact with its operator, ensuring the valve is open to just the right percentage. When manually adjusted, you run the risk of wasting materials, or ruined product due to operator error.

EXCESSIVE VALVE TORQUE

As you can imagine, large valves can be tough to close with a manual hand wheel. Fluid viscosity and velocity can have an impact on how much torque is needed to close the valve. Could every one of your operators close a 36” butterfly valve against rushing river water?

Setting your valve up with the appropriate valve actuators can make sure you have the right amount of force to turn or lift the valve every time.

If you’re looking to gain more control over your process, or are simply looking for ways to make it more efficient, you may want to take a closer look at valve actuators. With the right equipment in place, you can make what could be a time consuming, back-breaking, unpredictable chore, into a precise, reliable procedure.

Ultrasonic Vs. Magnetic Flow Meters

While selecting the proper flow meter technology for your system is critical, your ability to rely on the meter’s readings will depend more heavily on the application. Every meter technology will have its advantages and disadvantages, but it’s the nuances of your system and what is flowing through it that should garner the most attention.

Let’s talk about water applications, for example. For a simple application like water, there are a dozen different technologies that can work well. But, does the water contain bubbles or particles? Is it ionized? Answering these questions will make a big difference in the types of flow meters that would be ideal for your system. For water in many forms, magnetic and ultrasonic flow meters have become popular technologies. Let’s review their pros and cons…

Ultrasonic Flow Meters

Ultrasonic flow meters will detect and measure flow rates without invading the flow stream or using moving parts. To do so, they employ one of two following principles of operation.

Transit-Time Ultrasonic Flow Meters send a sound wave through the flow, relying on the difference in time between upstream and downstream times of flight. This difference in time is proportional to the velocity of the flow. Transit-time flow meters are not suited for water with heavy aeration or high concentrations of solids or suspended particles as this can obstruct the sound waves. They are more appropriately used for clean and ultra-pure flows.

Doppler Ultrasonic Flow Meters also send a sound wave into the flow, but contrary to transit-time technology, Doppler meters depend on suspended bubbles and particles in the water to reflect the sound waves providing a shift in the frequency. Any shift in the frequency of reflections is proportional to the flow velocity. Therefore, Doppler ultrasonic flow meters are obviously better suited for aerated or impure water applications (i.e. waste-water).

Pros:

By far, the best reason to use an ultrasonic flow meter of any kind is the lower costs associated with installation. Your system would not need to be shut down and your piping would not need to be altered.
Device will not obstruct flow or contaminate processes
Lack of moving parts means less maintenance
Flow range typically 100:1
Can be used with corrosive fluids
Zero pressure drop (Magnetic flow meters also provide no pressure drop if you are installing a meter the same size as the line size)
Operates on pipe diameters from 1/2” to 200” (may require 2 or 3 different sets of transducer depending on pipe size and range transducers cover)
Insensitive to changes in temperature, viscosity, density or pressure (Temperature will effect the transit time sensor selection requiring high temp sensors above 250F.)
Available in a wide variety of communication protocols (Transit Time)
Ability to register locally, remotely or to interface with an energy management system (Transit Time)

Cons:

Similar to many of the devices we examined in Not All Flow Meters Are Created Equal! Part 2, the accuracy of ultrasonic flow meters becomes much less dependable when the flow rate drops below 2 ft/s.
Any number of unknown internal piping variables can shift the flow signal and create inaccuracies
The scaling, pitting, and fouling that can occur over time in older piping systems can be problematic.
Accuracy may be affected by air space in the pipe
Accuracy may be affected by the size distribution of particles and any relative velocity between particles and the water (Doppler)

Magnetic Flow Meters

Magnetic flow meters (a.k.a magmeters) measure flow rates by employing Faraday’s Law of Electromagnetic Induction. A magnetic field is created by running current through a coil sounding the flow tube. The conductive media/liquid then creates a voltage as it passes through the flow tube and magnetic field of the meter. The electrodes sense and measure the voltage created as the liquid passes through the tube. The greater the velocity the higher the voltage, thus creating the proportional signal that is eventually converted to volumetric flow. Magnetic flow meters are specifically designed for systems that move conductive fluids like water, acids, caustic liquids, and slurries.

Pros:

No moving parts or flow obstructions
Almost zero pressure drop (Since the coefficient of friction for the liner materials (Teflon) may be lower than the actual piping material they may provide less of a pressure drop than the same length of piping material)
Accurate to +/-0.25% of reading
Flow range turn-down of 300 to 1 or better
Available for pipe diameters from 1/10” to 120”
Relatively unaffected by viscosity, temperature and pressure as long as the magmeter is selected based on the process conditions
Applicable to all flow profiles and does not require straight run (only the CMAG can make this statement.)
Can respond well to rapid changes in flow
Applicable to liquids with heavy particulates
Available in a wide variety of communication protocols
Ability to register locally, remotely or to interface with an energy management system
Service life of 75 years

Cons:

Water must contain a certain amount of Microsiemens (uS), giving it the power to conduct heat and/or electricity. Some magmeters can work down to 2-3 uS/cm, while other require 10 uS/cm or more.
Accuracy may be affected by air space in the pipe

Benefits of using Conductivity control Meters

Conductivity controllers are used to monitor and control conductivity in process water or wastewater. Exceptional capabilities of the Conductivity controllers:-

These are Programmable wide measurement range
These devices are computerized temperature repayment
Set factors on the front panel
Huge vibrant red LED display screen
Twin heavy-duty output relays

Conductivity Controllers are offered very high overall performance virtual indicating, dual set point, ON/OFF controllers for conductivity, that use a temperature compensated conductivity probe. The Conductivity Controllers have an ok=1.zero mobile consistent conductivity probe with the front panel cell adjustment potentiometer. The conductivity controller capabilities an analog voltage output of one mV/LSD for recorders, printers, laptop interfacing peripherals, etc. The conductivity controller's display is a big 0.fifty six inches high-performance vibrant purple LED.

The general conductivity indication and manage range for the Conductivity Controller is 0 to 2 hundred mS/cm, multiple levels can be selected thru internal DIP switches. Conductivity controller probe connectors are spade lug kind. All conductivity controllers are warmth cycled a hundred hours previous to cargo. Intelligent Level Controller is also used very useful in the general conductivity indication .You can find best quality products like SITRANS FM Electromagnetic Flowmeters, Wika Digital temperature transmitter with HART protocol, electromagnetic flow meter Suppliers, Siemens Electromagnetic, flow meter Suppliers In Delhi NCR at instronline, you can also find Best Price Electromagnetic Flow meters here

Benefits OF dependable Conductivity Controllers

Nowadays, industries are geared up with excessive-cease machinery and technologies to support clean and productive production processes. With using cutting-edge machinery and electric measuring devices help you to perform innovative sports and convey out the terrific best of the product. In truth, industrial measuring gadgets have attained vast vicinity in the industry as with this, you can measure and file uncertain parameters which could deliver hurdles within the production procedure. but, there are many technical and environmental restrictions, however, with the use of calibrating devices, you could carry out even the maximum complex sports without difficulty and perfection.

A Conductivity Meter is one of the widespread electrical measuring gadgets used to degree the supply of dissolved contaminants into the water body. Manufacturing industries and food and dairy manufacturing corporations need an excessive-intensive device to a degree water solution’s capacity to hold an electrical fee. With the use of this calibrating tool, you may without difficulty dealing with the water first-rate whether used for ingesting functions or for manufacturing any product. thru this tool, you may appropriately degree the presence of ions and salt content material in a liquor solution.

The shape of the tool makes it convenient and gives the measurement right away and easily to the user.A tool has two inbuilt sensors referred to as electrodes that assist in measuring the aqueous solution. these electrodes are immersed in a water body and calculate the supplied voltage. essentially, a conductivity meter is used to manipulate the availability of impurities in the form of business wastes, harmful chemical substances, and ions into the water body. In most of the producing industries, it will become essential to continuously take a look at the water great, used for the production methods.

A device permits the consumer to get the exact numbers with the help of digitized display. you could examine the size by the use of the digitized calibrating device that is to be had within the marketplace at a very competitive rate.

PROS AND CONS OF 2 CHECK VALVES TYPES

One of the most essential valves in water and wastewater pumping systems is the check valve. Its purpose is to automatically open while pumps are running, and return to the closed position to prevent reverse flow when the pumps are not in operation. These valves help minimize energy consumption and protect the pumping system from pressure surges and damage from reverse flow.

Selecting check valves for a process is like selecting hardware for new cabinets. Once you decide on a knob or a handle, there's a multitude of styles, colors, and price points to consider beyond that. Same with check valves. It's pretty clear the process you're working on requires a check valve, but which one? Each style of check valve is designed to meet a certain need. Here's the pros and cons of two different styles of check valves, the lift check and swing check.

Lift Check Valves

Lift check valves are commonly used in high-rise buildings, industrial and power plant applications, and water and wastewater applications. They have no external moving parts and are known to be economical and reliable. Over time, these types of valves can have high energy costs because the disc remains in the flow stream during operation.

Silent Check Valve

Silent check valves are known for their quiet closure. Flow pushes the disc to allow forward flow. When the pump is stopped, a compression spring pushes the disc into the seat before flow reverses, hence the silent closure.

This type of check valve is most commonly used in clean water applications with high head.

Nozzle check valves are very similar to the silent check valve, are meant for high pressure, industrial and power applications.

Ball Check Valve

Ball check valves are commonly used in water and wastewater applications. They have very simple operation, and are compact and economical too. These valves feature a rubber coated ball that moves in and out of the seat as flow moves forward and reverse.

Because the ball has a long way to travel when the pump shuts off, these valves have a high tendency to slam in high head applications.

Swing Check Valves

Swing checks are certainly some of the most common check valves used in water and wastewater pumping systems. They're readily available and relatively low cost. They're also automatic, requiring no external power source, guided only by the direction of flow.

These valves can come in a few different configurations, operating in the same basic way.

Dual-Disc

This check valve features a wafer body design and two D-shaped discs that rotate out of the way as flow enters the valve. It has good non-slam characteristics, but is not recommended for wastewater applications. It is also susceptible to vibration and wear.

Traditional Swing Check

Everyone knows this one, right? It's definitely the most common check valve in water and wastewater applications. This type of valve usually has metal or resilient seats and a 60-90 degree swing. This valve has a tendency to slam, however, due to the long stroke, friction in the packing, and inertia of the disc.

Air cushions are sometimes employed to help alleviate the slamming. Though some believe that a lever and spring is a better accessory as they allow the valve to close faster.

Tilted Disc Check Valve

The difference between the tilted disc check valve and the traditional swing check valve is that flow is allowed to pass on both sides of the disc. Because of this, it allows for extremely low head loss.

This valve is not recommended for wastewater applications because pins that extend into flow stream tend to collect debris. Clean water or treated effluent are best for this valve.

Do you have the right type of check valve for your application? Could there be a better one? Always discuss changes to your pumping system with an engineer who is well versed in all types of check valves. They may be able to help you find a valve that slams less or could even be more energy efficient.

5 THINGS YOU MUST KNOW FOR SIZING A PRESSURE REGULATOR, CORRECTLY!

A pressure reducing regulator is commonly used to manually control pressure of a liquid, gas or steam. Choosing the right regulator for your application can be challenging. There are 5 variables required to size any pressure regulator and properly calculate Cv: upstream pressure, downstream pressure, flow range, temperature and fluid type. We define each variable and talk about why it’s crucial to sizing a pressure regulator.

**Please note: Cv is a coefficient of flow for valve sizing. It’s used to quantify valve flow performance and can vary with both size and style of the valve or regulator. Once you calculate the required Cv range, you’ll know the valve or regulator is sized correctly to handle the actual flow.

1. UPSTREAM PRESSURE

Supply pressure or Inlet pressure. This is the pressure upstream of the regulator. This pressure could be coming off of a main header at 100 psi. If it is a higher pressure, such as 1,000 psi, and your goal is to regulate a much lower pressure, less than 100 psi, then a second regulator may be required to knock down the pressure in two stages: one high pressure regulator and one low pressure regulator.

2. DOWNSTREAM PRESSURE

Outlet or Control Pressure set point or range. This is the pressure downstream of the pressure reducing regulator. The pressure levels are what you are attempting to control. It could be a specific pressure point, like 30 psi, or a range of 5 to 20 psi. The difference between upstream and downstream pressure is called a “pressure drop” or “pressure differential”.

3. FLOW RANGE (minimum, maximum and normal)

It’s a good idea to size the regulator at a minimum of 3 separate points in order to get a range of flow requirement. This gives you a safety factor, so the regulator is not over or under-sized.

4. TEMPERATURE (minimum and maximum)

Temperature can affect the required Cv. Note that temperature does not affect Cv nearly as much as pressure and flow.

5. FLUID TYPE

Determine what fluid is going through the regulator. Is it liquid, gas or steam? What are its properties? Understand that sizing formulas are different for each type of fluid. For example, the formula for critical pressure drop is different than non-critical pressure drop for gases. For steam, you must know whether it’s saturated steam or super heated (higher temperature).

A regulator cannot be accurately sized without knowing these 5 variables. Understand that changing any of the above values could get you into a completely different regulator.

After sizing, the next step is to select your regulator by identifying the following criteria:

Line size
Material compatibility
Connection type
Accuracy required
Shutoff capability (metal seated vs. resilient seated)
Direct-operated vs. Pilot-operated

How does a solenoid valve work?

Solenoid valves are one of the most commonly used control valves in fluidics. They come in a range of designs, but each solenoid valve has the two same basic components that make it what it is. Have you ever wondered how a solenoid valve works? Read on to find out more about the working principle of the solenoid valve and discover our fantastic range of Maxseal solenoid operated valves.

What is a solenoid valve

Solenoid valves are electromechanically operated valves that convert electric energy into mechanical energy. Their main purpose is to regulate the movement of gas or liquid and eradicate the need for an engineer to manually control the valve, which will save the application both time and money.

Solenoid valves are used in fluid power systems, to control cylinders, fluid power motors or larger industrial valves and can be used for a wide array of industrial applications, including general on-off control, calibration and test stands, pilot plant control loops, process control systems, and various original equipment manufacturer applications.

As solenoid valves are used in the fluidic industry, their material must be compatible with fluid. Solenoid valves are therefore most commonly made out of brass, stainless steel, aluminum, and plastic.

How does a solenoid valve work?

Solenoid valves consist of two basic parts: a solenoid (or electromagnet) and the valve. The valve body is made up of two or more orifices/openings, whereas, the solenoid is home to several important parts, including a coil, sleeve assembly and plunger.

Solenoid valves work by employing the electromagnetic coil to either open or close the valve orifice. When the coil within the solenoid is energised, the plunger is lifted or lowered to open or close the orifice. This is what in turn controls flow, regulating the movement of gas or liquid.

Advantages & disadvantages of a solenoid valve

One of the main advantages of solenoid valves is their versatility. They can be used in an array of industries, for a wide variety of applications and are perfect for a broad range of liquids or gaseous media. They are also an extremely efficient way of controlling flow, as they require very little wiring, expense and effort compared to other valves.

A solenoid valve’s biggest flaw is its capability to handle dirty or contaminated fluids or gas. Foreign contaminants can collect in the solenoid valve’s parts and impede operation. It is also very important that the correct voltage is applied to these valves.

Maxseal solenoid operated valves

At Instronline, we supply a wide range of solenoid valves, including Maxseal solenoid operated valves. Maxseal’s valves are a range of top-quality stainless-steel solenoid valves that promote reliability and durability. Well known for performing immensely well in extreme and hazardous environments, Maxseal solenoid valves have been installed in plants all over the world for many years.

How do I choose an air filter regulator?

An air filter regulator is an essential tool for protecting sensitive downstream equipment. These innovative air preparation devices combine a filter and regulator in one space-saving unit to remove particulates and moisture from the air line and reduce air pressure to a setpoint. Here, Fluid Controls gives you our guide to choosing the right air filter regulator.

What is an air filter regulator?

Air filter regulators, or simply filter regulators, combine a filter and pressure regulator in one unit. Filter regulators are primarily used to maintain a safe supply of compressed air to pneumatic equipment. They do this by removing water and particulates from the air supply, whilst also providing accurate control of downstream pressure. The space-saving single unit design also minimises leaks due to fewer air connections.

How does a filter regulator work?

A filter regulator combines two primary functions. The filter cleans the air that travels from the compressor by straining and trapping any solid particulates, like dust and dirt, and separating liquids from the compressed air. Meanwhile, the regulator controls the speed and precision of the fluid’s flow. Filters are installed in the air line upstream of regulators, directional control valves, lubricators, and air-driven devices like cylinders.

How to choose a filter regulator

When choosing the right filter regulator for your application, it is worth asking yourself the following questions to aid your selection process:

What is the flow rate for the application? Once you have determined the flow rate, you can then select the correct port size.

What level of filtration is needed? In other words, how dry does your air supply need to be? General-purpose 40 micron filters typically remove up to 95% of water. The addition of a 5 micron filter will increase water removal further to around 99%.

What is the inlet and outlet pressure? It will be the job of the pressure regulator to regulate these parameters. Remember that there will be a noticeable pressure drop through the filter regulator.

You should also consider the following factors when choosing a filter regulator:

1. Ambient temperature

2. Filter drain

3. Materials

4. Pressure gauge

5. Self-relieving

6. Bowl capacity

Differences Between Barometers and Manometers

Manometers

A manometer is a device that measures pressure, typically atmospheric pressure. Manometers have been used for centuries and come in a variety of designs, from older glass tubes containing mercury or water to new digital devices.

Barometers

Like a manometer, a barometer also measures atmospheric pressure. In fact, a barometer is a type of close-end manometer. However, barometers are more limited in design and function than manometers. All barometers are manometers, but not all manometers are barometers.

Differences between Manometers and Barometers

Barometers

As a subdivision of manometers, barometers come in one basic design: a close-ended tube. Specifically, a traditional barometer is a glass tube with one open end and a vacuum at the other end. On the open end, atmospheric gases exert pressure on the liquid inside the tube. This liquid, usually mercury, will match the height of the pressure applied by the outside gases, as the vacuum on the closed end of the tube will not cause a change in the mercury’s height.

Close-ended barometers can either be U-shaped or well-shaped. In a well-shaped barometer, the tube of mercury stands upside-down or inverted in a larger well of mercury, so that the closed end with the vacuum is the tallest point and the open end is suspended in the liquid. Outside gases then press down on the well of mercury, which expands into the closed tube.

Differences Between Barometers and Manometers-1

Barometers can also be digital or aneroid today, which makes them portable – traditional glass barometers need to be attached to a table or left standing. Aneroid barometers, like those that can be found in cars, may have a digital or clock interface. These barometers have a series of cells filled with air that rise depending on the atmospheric pressure. This pulls levers attached to the cells, changing the dial on the barometer’s interface.

Manometers

Manometers can be open-ended, close-ended, or digital. An open-ended manometer is filled with a liquid like water or mercury, and the tube is U-shaped. Both tops of the U-shaped tube can be uncovered so that atmospheric gases apply pressure to each side. Open-ended manometers do not need to have equal-sized arms of their tubes, and can even have a well on one end.

In addition to the simple U-shaped open-ended manometer, many manometers have a bulb or some other attachment on one end that is filled with a high-pressure gas. This gas puts pressure on its end of the tube, while atmospheric gases do the same on the other end. Manometers can therefore measure different kinds of gaseous pressure.

Another more precise type of manometer is the inclined-tube manometer. This is an open-ended manometer that is typically inclined on a 1-inch vertical rise, with a well on the lower end. The incline allows for more precise measuring of low pressures.

In a close-ended manometer, one end of the manometer is attached to the high-pressure gas, and the other has a vacuum of gas instead of being open to the air. Barometers also fill this function, but measure only atmospheric gases.

Inner Liquid

Barometers

Barometers are usually filled with mercury. A heavy liquid is needed, or the barometer must be extremely tall in order to show the relatively large changes in atmospheric pressure. In a digital or aneroid barometer, there is no liquid – there are instead cells of air.

Manometers

Like barometers, glass manometers are generally filled with mercury or another heavy liquid. However, open-ended manometers can also be filled with lighter liquids that can show smaller changes in pressure. These liquids include water, oil, bromides, and benzenes. Using water or oil can fix the concerns with mercury, such as poisoning and toxicity.

Calculating Pressure

Barometers

Reading a mercury barometer is relatively straightforward. Because the open end is the only side affecting the mercury’s height, a user simply needs to read the marked height on the closed vacuum end. This should give the atmospheric pressure in millimeters or inches, which can be converted to torr. (For example, typical atmospheric pressure at sea level height on a mercury barometer should be 760 mmhg, or millimeters of mercury.)

Manometers

Atmospheric pressure in an open-ended manometer is read based on the difference in height between the liquid in each arm of the tube. On an open-ended manometer with atmospheric gas on both sides, the height difference is calculated in either millimeters or inches, which can be converted to hectopascals.

When the manometer is open on one end and also attached to a high-pressure gas, consideration must be given to which arm has more liquid. If the side open to air has more liquid, then the high-pressure gas is exerting more force, and the height should be added to the atmospheric pressure. If the opposite is true for the arms, then the height should be subtracted from the atmospheric pressure. This will give the pressure being exerted by the high-pressure gas.

If the manometer is closed on one end (creating a vacuum) and also attached to a high pressure gas, then, like a barometer, the pressure is simply the height of the closed arm.

Purpose

Barometers

The barometer’s close-ended vacuum is especially good for measuring atmospheric pressure. This has made the mercury barometer the traditional instrument for weather forecasting and meteorology, fields that depend on changes in atmospheric pressure to predict weather patterns.

Manometers

Other types of manometers besides barometers can be used to measure pressures both lower and higher than atmospheric pressure. By attaching a bulb or other device of high-pressure gas to a manometer, the pressure of that gas can be calculated. In some instances, a barometer may still be needed to gauge the baseline atmospheric pressure, however.

Fundamentals Of Pressure Measurement

Gauge Versus Absolute Pressure

Vacuum or negative pressures are normally expressed as inches or millimeters of mercury or water vacuum.

Nominal Versus Actual Pressure

The accuracy of the generated pressure is measured as the difference between the actual pressure produced by the pressure standard and a standard pressure to be used for the calibration of a secondary standard pressure measuring instrument. AMETEK deadweight testers are referred to “Nominal” or even unit pressures, such as 1000, 2000, 3000 PSIG etc.

Pressure standards manufactured by other manufacturers, Ruska, D.H., refer the output pressure to the actual output pressure as stated on the certification or computed by an equation included within the certification. AMETEK accuracy is therefore the difference between the output pressure and the nominal pressure stated in percentage of the reading.

AMETEK further states the ability of the instrument to repeat identical pressures with identical weights and piston as the percentage of “Repeatability”. Ruska, D&H accuracy as stated is the statistical ability of the instrument to repeat the identical pressure with the same weights and piston. This is comparable to AMETEK’s stated percentage for instrument repeatability.

Units of Pressure Measurement

Units of Mass Measurement

Gravity

Primary and Secondary Pressure Standards

WHICH PUMP MOTOR ENCLOSURE DO I NEED?

One of the most common questions we get at Crane Engineering is about motor enclosures. Maintenance personnel and engineers alike are uncertain which type is right for their application. They know it's critical to choose the right one, and for good reason. The wrong choice leaves pump motors vulnerable to adverse conditions and potential failure.

Which motor enclosure is right for my pump motor?

There are lots of options when it comes to motor enclosures. For instance, a common situation we run into is pumps in wash down applications. A water resistant motor enclosure is required if a pump is being cleaned and sanitized on a regular basis. In this case, Totally Enclosed Wash Down (TEWD) is most likely needed. This type of enclosure protect the motor from wet environments and high water pressure during wash downs.

Here's a few others we recommend for applications we see:

Open Drip-Proof (ODP) - Often selected for indoor, clean, dry locations. Air circulates through the windings, cooling the motor. This enclosure prevents water droplets from entering the motor within a 15 degree angle from vertical.

Totally Enclosed Non-Ventilated(TENV) - Used most often in environments where a fair amount of dirt or dampness exists. The enclosure is not air tight, but has no vent openings. It also has no cooling fan.

Totally Enclosed Fan Cooled (TEFC) - Like the Totally Enclosed Non-Ventilated enclosure, except it has a cooling fan. Used on pumps, compressors, fans, and other belt-driven and direct connected equipment.

Weather Protected Type 1 (WPI) - As you might expect, the Weather Protected Type enclosures are for outdoor use. Their purpose is to prevent debris, dust, rain, and rodents from entering the motor.

Weather Protected Type 2 (WPII) - This enclosure is utilized on pumps that need a high degree of protection. Ventilation air is routed in such a way that airborne particles will not enter the electric parts of the motor. Air velocity is also minimized so moisture and dirt also will not enter the electric parts of the motor.

Explosion Proof (Exp Proof) - These enclosures are designed for hazardous applications. The enclosure will withstand an explosion from inside the motor casing, preventing gases or hazardous air particles from igniting.

ASEPTIC VALVE OR HYGIENIC VALVE, WHAT’S THE DIFFERENCE?

From time to time I get the opportunity to sit in on product training's offered here at Crane Engineering. A couple weeks ago, I attended a session on sanitary valves, presented by Chris Johnson, one of our account managers. He demonstrated the function and features of each sanitary valve and discussed which were hygienic and which were aseptic. After the presentation, I asked Chris to help me understand what the difference is. Turns out, I wasn’t the first to ask.

What's aseptic?

The term aseptic means to be free from contamination caused by harmful bacteria, microorganisms, or viruses. When applied to valves, it means the materials and surface finish of the valve are optimized for exceptional clean ability. It also means each component of the valve that comes in contact with the process is hermetically sealed from the environment and atmosphere that surrounds the process. This is achieved by using a bellows on the valve stem to prevent harmful bacteria, ET AL, from getting into the process.

How hygienic and aseptic valves are similar

Hygienic and aseptic valves have a lot in common. They share similar materials of construction, and smooth surface finishes. Their design also requires there is no place for bacteria to hide within the valve. Despite their similarities, there are distinct differences between the two.

How’s hygienic different from aseptic?

While aseptic valves aim to prevent contamination from the environment, the focus of hygienic valve design is easy clean ability.

Parts of a hygienic valve will move in and out of the process, becoming exposed to the surrounding environment. For instance, a rising stem on a valve will come in contact with the process, and may also come in contact with the environment outside the process.

When do I use aseptic or hygienic valves?

Hygienic valves are common in food, beverage, and dairy manufacturing. They are found in processes where clean ability (CIP or COP) is extremely important.

Aseptic valves, are most often found in industries that require high levels of purity. These include manufacturers of injection drugs, cosmetics, microelectronics, and the like. Aseptic valves are used here to control processes and minimize contamination from environmental sources.

In sanitary applications, valve design matters! If you're unsure which valve is best for your process, talk to an engineer. They can help determine which valve will achieve your objectives for production and cleanliness.

LINEAR ACTUATOR USES: COMMON APPLICATIONS

Linear actuators offer a cost-effective solution to move loads in a straight line. The device comes in multiple forms, ranging from telescoping to twisted and coiled. You may be wondering, “What are the uses for a linear actuator?” Here are nine of the most common uses for a linear actuator to help you make the most of this invaluable tool.

What Is a Linear Actuator?

A linear actuator changes the rotational motion of a motor into a straight line. Conventional electric motors move in a circle, while linear actuators move forward and backward. The push and pull action allows the device to slide, tip, and lift items with the push of a button.

The design provides operators accurate and precise control over the production. The fluid movement means the linear actuator requires minimal maintenance over its lifespan and comes with natural energy efficiency. They are easier to install than their hydraulic or pneumatic counterparts, cost less, and take up significantly less room.

When to Use a Linear Actuator

Manufacturers leverage linear actuators in tools and industrial machines, such as printers, sprayers, computers, and valves. Choosing an actuator depends on the product, with hydraulic actuators powering hydraulic car jacks and pneumatic actuators often powering pistons and ignition chambers. Each of these devices offers an affordable, repeatable, and consistent motion because of the integration.

Most Common Uses for Linear Actuator

Material Handling

The many uses for a linear actuator have improved automation in the workplace. It streamlines manufacturing while lowering the cost of production. The electric linear actuators have transformed into a vital and necessary tool to achieve optimal material handling.

Linear actuators are responsible for moving loads from point A to point B. The electromechanical version has the added ability to stop the movement mid-stroke. Some of the other types of actuators in material handling include industrial, high-speed, and micro models.

Linear actuators enable safe, secure, and precise motion, primarily when operators use them in conjunction with sensors or other smart technologies. The combination allows workers to complete previously repetitive tasks with minimal manual intervention.

Some of the visible applications include sorting machines, feed systems, and clamps. One example is using pneumatic actuators along with conveyor belts. An electric actuator provides greater efficiency because it doesn’t slow down the control capabilities.

Robotics

Linear actuators make movement possible in robots. They allow robotic machinery to interact with its environment through wheels, clamps, arms, and legs. Some of the most popular linear actuators to get robots moving include:

Motorized threaded rods
Pneumatic cylinders
Scotch yokes
Solenoids
Pneumatic muscles

Imagine that a robotic arm has a gripper on the end. When the operator presses a button, a sensor communicates to the arm to clasp the box in position A. The clamp secures the package and moves it to position B, before releasing the box onto the conveyor belt or desired work surface.

The gripping mechanism works because of the linear actuator. It talks to the smart technology when the clamp reaches the appropriate constraints and maintains it, so the package doesn’t drop or shift during transit. A linear actuator presents a more consistent and reliable option than a hydraulic actuator, which uses hydraulic fluid for movement and control.

Food and Beverage Manufacturing

The industrial-scale of today’s food and beverage industry requires high levels of automation to meet demand. Manufacturers must streamline processing, treatment, packaging, and other processes to ensure timely distribution. Linear actuators play a crucial role in making these actions possible.

Each type of linear actuator has a distinct role in automation. Rod-style models clean production areas, which makes them a premier choice for dairy and beverage plants. Electric rod-style linear actuators offer versatility, thanks to multiple profile options, which makes them ideal for different types of food production tools.

Linear actuators improve efficiency while maintaining a sanitized environment, reducing the odds of contamination. Visit a food production facility, and actuators are visible in meat separators, toasters, de-boning devices, and food processors. They also exist in ubiquitous appliances, like conveyors and pouch machines.

Window Automation

Adjusting a window at ground level is straightforward but can be extremely difficult when it’s out of reach. The solution: linear actuators. They offer a practical solution that lets people easily open and close windows and enjoy the comforts of modern living.

Window automation marks one of the most common uses of a large linear actuator, also known as a push-rod motor. The device quietly and conveniently contracts or extends, even in extreme heat and cold. The best odds of seeing a large linear actuator at work in window automation include:

Shutters
Skylights
Casement windows
Top or bottom hung windows

The wide range of uses means linear actuators are visible in everything, from workshops to warehouses to waiting halls. A single installation replaces the need for manual operation while improving overall ventilation and airflow. A linear actuator also centralizes the control panel instead of having several different places.

Agricultural Machinery

Modern agricultural machinery has never been more reliable, in part, because of linear actuators. The devices assist farmers, workers, and other laborers in completing various agricultural tasks, on top of withstanding harsh weather conditions and exposure to herbicides, pesticides, and fertilizers.

Ground zero for linear actuators is in the fields. They give operators control for the height and angle of sprayers for thorough and consistent coverage. Actuators can aid in opening and closing hatches while simplifying the mechanisms to operate machinery.

Linear actuators exist inside tractors to improve work quality and reduce labor. An actuator ensures accurate steering wheel adjustments, toggles ventilation, and adjusts the rearview windows into the correct operating position. The straightforward integrations mean operators increase control of their tractors without sacrificing performance.

Many of these same mechanisms apply to seed drills and combine harvesters. Drills require pinpoint accuracy when planting seeds, so farmers can improve land usage and minimize waste. Combine harvesters benefit from seamless functionality through the integration of linear actuators in grain tank extensions, grain tank covers, and concave adjustments.

Solar Panel Operation

The push for alternative energy sources has coincided with an uptick in solar panel usage. Conventional panels use hydraulics or other similar devices, but recent innovations have made harnessing the sun’s power more efficient. Electric linear actuators give panels the ability to track the sun, moving with the sunlight to maximize the amount of direct absorption.

Installing linear actuators provides solar panel users the most bang for their buck. The useful machines absorb more solar energy while withstanding the hot and harsh working environment. Linear actuators can even withstand high-pressure jets, debris, and dust.

Cutting Equipment

Machines spare humans from as much danger as possible when cutting. They take over repetitive tasks or risky assignments that require more endurance and power than creative prowess. Linear actuators power these machines to ensure accurate cuts with every slice.

Common uses for a large linear actuator include wood, glass, metal, and paper cutting devices. The blade can cut straight lines or jigsaw patterns, based on the actuator’s configuration. The same applies to metal cutting, which requires copious mechanical strength.

Cleanliness stands out as one of the overlooked benefits of linear actuators in a cutting environment. Many people associate the desire for automated sanitation with food and beverage processing. The crisp cuts reduce the amount of debris and waste that can otherwise interfere with production.

Valve Operation

Today’s industry would not be possible without linear valve actuators turning electric, pneumatic, and hydraulic energy into a push and pull motion. The cost-effective product offers an attractive alternative to manual operation. It operates with a range of rising stem valves with optional features for integrated control.

The two primary models are diaphragm and piston actuators. The diaphragm version contains a section of rubber than encircles the edges of a cylinder or chamber. A connective rod at the center of the diaphragm moves whenever the device receives pressure, making it ideal for a low-pressure environment.

Piston actuators contain a piston that moves along the cylinder’s body. The rod translates force on the piston to the valve, which leads to opening and closing. Piston actuators can withstand higher pressure workloads, travel further, and have more substantial thrust than diaphragm actuators.

Non-Industrial Applications

The most common uses for a linear actuator lie in industrial automation, but those are far from the only applications. The device has become increasingly popular in residential settings where counterparts, like hydraulic and pneumatic actuators, are not feasible. Many people use linear actuators for automation as a way to create more space in a compact home.

SMALL LINEAR ACTUATOR CAN ACCOMPLISH BIG THINGS

What Is a Small Linear Actuator?

An actuator is the part of a machine that receives a signal from a control device and puts other pieces of equipment in motion. Sounds pretty important, right? Actuators are vital to make sure that each part of a machine fires in synchronization.

Let’s take a look at what actuators can accomplish and how to use them – particularly small, linear models.

Small Part, Big Results

A small, or micro, actuator operates on a precise scale. Some models may travel just millimeters and can be finely adjusted by fractions of nanometers to provide tight control. This type of small linear actuator – 12V or less may be all the power they need – keeps machines running precisely.

However, do not mistake small for weak or unimportant. A well-chosen small linear actuator can accomplish big things.

Straight-Line Motion

When we describe a micro actuator as linear, we mean that the part produces movement along a straight path. This type of motion is seen in pneumatic and hydraulic devices. The other main type of actuators provides rotary, or circular, action.

In a micro linear actuator, small nuts, covers, and sliding tubes create a smooth path for the machinery to function. You might find some of these parts described as a small electric linear actuator, small DC linear actuator, or small linear thermoelectric actuator, but they all provide smooth motion along a single path in a compact piece of equipment.

Micro Linear Actuator Maintenance and Replacement

Of course, to keep your equipment running smoothly, you need to keep an eye on your parts and perform regular maintenance, such as replacing fluids. Measure your machine performance to determine when parts may need to be serviced. Older equipment may need to be replaced periodically.

If you are building a new machine or looking for a replacement part, consider the following options. If you need more information, an experienced professional can help you choose the right tool for the job. Creative Motion Control has a team of engineers, researchers, and technicians who can help you select the most appropriate equipment.

What Types of Micro Linear Actuators Are Available?

Actuators can be powered by hydraulic pistons, pneumatics, thermal energy, magnets, mechanical force, and, recently, supercoiled polymers. These types of machines power everything from exercise equipment to prosthetic limbs to bus brakes.

However, with a micro linear actuator, small electronics are a more likely source of power. They can provide the necessary charge to move many times their weight while remaining small enough to fit in precise machinery. As an added benefit, electrical equipment is environmentally friendly, and your micro linear actuator will produce practically no carbon footprint.

Luckily, there is a bevy of options for the professional or hobbyist looking for a small electric linear actuator.

Small DC Linear Actuator

DC stands for direct current, a type of electrical power. A small DC linear actuator can be powered by little charge. For example, some models require as little as 6V and weigh around 10 to 15 grams.

Equipment of this size and weight is ideal for small spaces requiring precise movement. Roboticists, medical manufacturers, and aerospace engineers all use this type of small DC linear actuator. However, it’s also an attractive size for hobbyists who need equipment that can pack a punch while operating in tight spaces.

Small 12 Volt Linear Actuator

A small 12-volt linear actuator is a particular type of small electric linear actuator that deserves special mention. This size of equipment provides a good balance of compact size and power.

For example, a 12V linear actuator may measure less than one foot or up to two and a half feet (when fully extended). With weights of about one to two pounds, each small 12V linear actuator can support several times its own weight. An actuator of this size may be able to move a dynamic force of up to 15 pounds or support 30 pounds of static force.

Built to survive temperatures ranging from far below freezing to over 100 degrees Fahrenheit, a small linear actuator can pack a wallop in a tiny frame and is rugged enough to stand up in many pieces of equipment.

Small Linear Thermoelectric Actuator

Like most equipment that depends on magnetic force, a small linear thermoelectric actuator is usually built with shape memory alloys that move when heated. This provides a great deal of force in a relatively small package, and a small linear thermoelectric actuator can be an appropriate choice if selected with care.

Users should be careful with all small electric actuators around water and other conductive material. With a small linear thermoelectric actuator, users must also be careful about the ambient temperature. Very hot or very cold conditions may make the equipment less productive, or even hazardous, so when considering which micro linear actuator is right for the job, consider the environment (or environments) in which it will have to work.

Which Micro Linear Actuator is Right for Me?

When looking for the right micro linear actuator for your job, consider the following factors.

Power Source
Motion and Accuracy
Compatible Peripherals
Safety Concerns
Job Site
Size and Weight
Dependability
Capacity
Price

Let’s look at each in turn.

Power Source

We’ve focused on electrical equipment on this page because that’s a common power source for machinery pieces at this scale. In particular, we’ve discussed some benefits of a small 12-volt linear actuator, which offers a mix of a compact size with serious power.

However, another option may be more appropriate for the work you have in mind depending on your space and power demands.

Motion and Accuracy

This probably goes without saying, but double-check that you are not buying a rotary piece of equipment if you are looking for a micro linear actuator.

This is also a good opportunity to think about the accuracy of the device you have in mind. Actuator precision at this scale is measured in nanometers. Different manufacturers guarantee different amounts of accuracy, so try to determine your needs before you invest.

Compatible Peripherals

Does your micro linear actuator require an external control board or other separate equipment? You shouldn’t rule out an appropriate piece just because it depends on a secondary piece of machinery, but make sure it fits with your current set-up or factor the purchase of additional peripherals into your costs.

Safety Concerns

As previously discussed, it’s vital to be careful with electronic devices around water and other conductive material. Remember to consider all the places your machinery will have to function to determine the safest equipment.

If you’ll be taking your machinery on the road, you might consider a micro linear actuator specifically designed for travel.

Size and Weight

If you’re in the market for a micro linear actuator, you probably value a tight fit and light frame. Keep in mind that many products have several models under one name. Specific models may only vary by a few inches, but at this scale, that could make the difference between a piece of equipment that works and one that rattles around or can’t squeeze into place.

Dependability

To make sure you’re buying a dependable product, make your purchase from a reputable seller. Creative Motion Control specializes in rugged actuators built to last, with a unique oil lubrication system to keep your gear running smoothly for the long term. Anodized body parts protect equipment from dust and grime and make machinery easy to clean.

Capacity

Remember that actuators are measured by both their dynamic (moving) power and their static (holding) power. A wise buyer considers both numbers to choose a micro linear actuator that can withstand the toughest demands whether the equipment is in motion or supporting a static load.

Price

Some machine parts are built for aerospace engineers and biomedical researchers and may include features that a casual hobbyist doesn’t need. While all machines are important, buyers may be able to find a lower-cost micro linear actuator to suit their needs.

Of course, if you are shopping for all the bells and whistles, an experienced manufacturer can help you select the model that provides all the features you require.

Also, remember to factor the cost of any necessary peripherals into your budget if your chosen micro linear actuator requires additional equipment you don’t already own.

A Micro Linear Actuator Can Accomplish Big Things

When it comes to linear actuators, bigger is not always better. A small device can move many times its own weight while remaining light and compact enough to fit into tight spaces and make your machinery hum.

If you are looking for precise movement, consider purchasing a small electric linear actuator. With their small size, this gear allows highly accurate control over your machinery, whether you are a professional or a dedicated amateur.

Difference between contactors and relays

Constructional Features:

Operation of Relays and Contactors

-- Relays are switching devices used in any control circuit for checking a condition or multiplying the number of contacts available.

-- Contactors are switching devices used to control power flow to any load.

Difference between contactors and relays

RELAYS

-- Relays are switching devices used in any control circuit for checking a condition or multiplying the number of contacts available.

-- Relatively smaller in size

-- Used in circuits with lower ampacity. (Max 20A)

-- Mainly used in control and automation circuits, protection --- circuits and for switching small electronic circuits.

-- Consists of at least two NO/NC contacts

-- Relays do not have an arc suppression system built-in.

CONTACTOR

-- Contactors are switching devices used to control power flow to any load.

-- Larger when compared to Relays

-- Used in circuits with low and higher ampacity up to 12500A

-- Used in the switching of motors, capacitors, lights etc.

-- Consists of a minimum one set of three-phase power contacts and in some cases additional auxiliary contacts are also provided.

-- Normally, contactors have in- built arc chutes for suppression.

Pressure Switch Basics and Selection Tips

Pressure switches are commonly used in a wide variety of industrial and commercial applications. To meet the varying demands of these applications, numerous pressure switch designs are available. The key to selecting the best pressure switch for your application is understanding the differences in pressure switch designs.

Sensing Technologies

A pressure switch is simply a device capable of detecting a pressure change and, at a predetermined pressure, opening or closing an electrical switch.

Pressure switches are usually classified as either electromechanical or solid state.

Electromechanical pressure switches have a sensing element which responds to changes in pressure and mechanically operates a snap-acting switch in response to the pressure changes. Different types of sensing technologies are used in the design of electromechanical pressure switches. Diaphragm switches use an elastomeric or weld-sealed metal diaphragm which deflects with pressure changes; they act directly, or via a push-rod, on a snap-acting switch.

With a bellows or bourdon tube switch, the movement of the bellows, or sealed metal bourdon tube, is caused by pressure changes; this movement mechanically operates a snap-acting switch.

A piston switch design uses an O-ring sealed piston that moves in response to pressure changes, and directly or via a push-rod, actuates the electrical snap-acting switch.

Solid state pressure switches use the same technology found in analog pressure transmitters to sense changes in pressure. A weld-sealed metal diaphragm or O-ring sealed ceramic diaphragm with a piezoresistive strain gage-based sensing element is used to measure changes in pressure. Rather than harnessing the energy of the pressure changes to mechanically operate a switch (as with electromechanical pressure switches), solid state pressure switches electrically measure pressure changes and internal electronic circuitry is used to activate one or more solid state switched outputs.

Ranges, Setpoint, & Deadband

Both electromechanical and solid state pressure switches are commonly available to sense vacuum, positive pressures up to thousands of psi, and compound ranges of vacuum to positive pressure.

The predetermined point at which the pressure switch contact opens or closes is the setpoint.

Electromechanical switches are typically available with a factory setting, or with a blind adjustment capability set by the user relative to an external pressure reference such as a pressure gauge or known pressure value.

Electromechanical switch setpoints can be set to activate upon an increased or decreased pressure. Solid state switch setpoints are set either by calibrated dials, knobs, or entered digitally with a keypad and display.

When selecting the pressure range for a pressure switch, a general rule is that electromechanical setpoints should be in the middle of the operating pressure range to optimize both accuracy and switch life. With a solid state pressure switch, selecting the setpoint in the upper 25% of the operating range will provide the most accurate performance without compromising switch life.

Deadband is the difference in pressure between the switch setpoint and reset point. For example, if a pressure switch is set to activate at 100 psi on an increasing pressure, the switch will close when the pressure rises to 100 psi. When the pressure drops to the reset point of 90 psi, the switch will open. The deadband is 10 psi, the difference between the setpoint (100 psi) and the reset point (90 psi).

For electromechanical pressure switches, deadband can be adjustable but is typically a fixed value, or automatically increases linearly as the setpoint is increased through the adjustable setpoint range.

For solid state switches, the deadband is typically fully adjustable up to 100% of the full operating pressure range. As a general rule a narrow deadband is used in alarm circuits while a wider deadband is better suited for control circuit applications.

Proof and Burst Pressures

Over pressure ratings include proof and burst pressure specifications. Proof pressure is the amount of over pressure that can be applied to the pressure switch without causing damage. The pressure switch can be exposed to pressure reaching the proof pressure rating, and be expected to work properly when the pressure returns to within the rated operating pressure range.

Burst pressure is the amount of over pressure applied at which the pressure switch will certainly be damaged. Physical damage to the pressure switch may occur at any point between the proof pressure and burst pressure. Because proof pressure ratings are determined in a laboratory under controlled conditions including rate of pressure change and temperature, they should be considered a reference value. It is not uncommon for pressure switches in the field to experience pressure surges and spikes that cause damage if a switch with too low of a proof pressure rating was selected. Typically solid state switches have lower proof pressure ratings and are most sensitive to overpressure conditions. Electromechanical switches with a diaphragm generally have higher overpressure ratings than solid state switches. Piston design switches have very high overpressure ratings and are the most reliable when subjected to pressure surges or spikes, and applications where the normal working pressure is above the nominal range of the switch. If pressure surges or spikes are anticipated in an application, a pressure switch with a high proof pressure should be selected to avoid damage.

Installation of a pressure snubber can also help to dampen the effects of fast pressure spikes on a pressure switch.

Accuracy (Repeatability)

For an electromechanical pressure switch with a factory set or user adjusted setpoint relative to a known pressure reference, accuracy is a measure of the switch’s ability to repetitively operate at its adjusted setpoint under the same operating conditions. This is referred to as Repeatability in pressure switch specifications.

Because a solid state switch setpoint can be adjusted with calibrated dials, knobs, or a keypad and display, specifications will include both a setting accuracy value and a repeatability value. Pressure switches are typically available with accuracies from 0.25% to 2% and cost increases with accuracy. To avoid paying a premium for unnecessary accuracy, consider the needs of the application. An accuracy of 2% is probably sufficient for a simple alarming application, but controlling a critical process may call for a higher accuracy switch.

Chemical Compatibility

For both electromechanical and solid state pressure switches, determining the chemical compatibility of the pressure switch with the medium sensed is a critical element in the longevity of the pressure switch. Wetted parts are the parts of the pressure switch that actually come in direct contact with the medium being sensed, and their material composition is identified in pressure switch specifications. The wetted parts will include the pressure sensing port of the switch, the diaphragm, bellows, bourdon tube, or piston and any O-ring seals.

Chemical resistance charts and databases are readily available on the Internet and may be used to determine the compatibility of pressure switch wetted parts with the chemicals encountered in the measured medium.

A pressure switch with a brass pressure sensing port and elastomeric diaphragm (such as Buna N or Viton) may work well for some applications but will not last as long as a pressure switch with the chemical resistance of a weld-sealed stainless steel diaphragm and sensing port in many industrial applications.

Cycle Life and Cycle Rate

The number of times the pressure switch will be activated will have a direct impact on its longevity. Inherent in their design, electromechanical pressure switches have moving parts that are subject to fatigue affected by factors like magnitude of pressure changes and temperature. Diaphragm switches will typically provide >500k cycles. A piston design pressure switch can typically provide >1 million cycles and is more reliable than a diaphragm design when subjected to frequent large pressure excursions, pressure surges and spikes. With no moving parts, solid state pressure switch wear is reduced, typically allowing >50 million cycles.

The rate at which a pressure switch is cycled will also impact its longevity. An electromechanical pressure switch with a diaphragm works well for applications with a cycle rate of 25 per minute or less. Piston design mechanical switches are usually suitable for up to 50 cycles per minute. With no moving parts to wear out, a solid state switch should be selected for applications requiring rates that exceed 50 cycles per minute.

Electrical Characteristics

Electromechanical pressure switches harness the pressure of the medium being sensed to mechanically operate a snap-acting switch – no external power supply is required for the pressure switch to operate. Typically, electromechanical pressure switches are provided with SPDT or DPDT contacts rated for 3 to 15 amps and voltages from 120VAC to 480VAC. With solid state switches, an external power supply, usually 24VDC, is necessary to power the electronic circuitry inside the switch. The outputs of solid state switches are typically normally-open and normally-closed transistor switching outputs rated for about 500mA and 30VDC.

Advantages and Disadvantages of Pneumatic Instruments

The disadvantages of pneumatic instruments are painfully evident to anyone familiar with both pneumatic and electronic instruments. Sensitivity to vibration, changes in temperature, mounting position, and the like affect calibration accuracy to a far greater degree for pneumatic instruments than electronic instruments. Compressed air is an expensive utility – much more expensive per equivalent watt-hour than electricity – making the operational cost of pneumatic instruments far greater than electronic. The installed cost of pneumatic instruments can be quite high as well, given the need for special (stainless steel, copper, or tough plastic) tubes to carry supply air and pneumatic signals to distant locations. The volume of air tubes used to convey pneumatic signals over distances acts as a low-pass filter, naturally damping the instrument’s response and thereby reducing its ability to respond quickly to changing process conditions.

Pneumatic instruments cannot be made “smart” like electronic instruments, either. With all these disadvantages, one might wonder why pneumatic instruments are still used at all in modern industry. art of the answer is legacy. For an industrial facility built decades ago, it makes little sense to replace instruments that still work just fine. The cost of labor to remove old tubing, install new conduit and wires, and configure new (expensive) electronic instruments often is not worth the benefits.

However, pneumatic instruments actually enjoy some definite technical advantages which secure their continued use in certain applications even in the 21st century. One decided advantage is the intrinsic safety of pneumatic field instruments. Instruments that do not run on electricity cannot generate electrical sparks. This is of utmost importance in “classified” industrial environments where explosive gases, liquids, dusts, and powders exist. Pneumatic instruments are also self-purging. Their continual bleeding of compressed air from vent ports in pneumatic relays and nozzles acts as a natural clean-air purge for the inside of the instrument, preventing the intrusion of dust and vapor from the outside with a slight positive pressure inside the instrument case. It is not uncommon to find a field-mounted pneumatic instrument encrusted with corrosion and filth on the outside, but factory-clean on the inside due to this continual purge of clean air. Pneumatic instruments mounted inside larger enclosures with other devices tend to protect them all by providing a positive-pressure air purge for the entire enclosure.

Some pneumatic instruments can also function in high-temperature and high-radiation environments that would damage electronic instruments. Although it is often possible to “harden” electronic field instruments to such harsh conditions, pneumatic instruments are practically immune by nature.

An interesting feature of pneumatic instruments is that they may operate on compressed gases other than air. This is an advantage in remote natural gas installations, where the natural gas itself is sometimes used as a source of pneumatic “power” for instruments. So long as there is compressed natural gas in the pipeline to measure and to control, the instruments will operate. No air compressor or electrical power source is needed in these installations. What is needed, however, is good filtering equipment to prevent contaminants in the natural gas (dirt, debris, liquids) from causing problems within the sensitive instrument mechanisms.

Types of Bourdon Tube

Basically they are designed to follow the physical law that, within the elastic limit, stress is proportional to strain (Hooke’s Law), that is deflection is proportional to the pressure applied.

Types of Bourdon Tube

There are 3 main types of elastic elements for pressure measurement, namely

-- Bourdon Tubes,

-- Bellows, and

-- Diaphragm.

1. C-Type Bourdon Tube

This instrument is by far the most common device used to indicate gauge pressure throughout the oil gas industry.

A bourdon tube obey Hookes Law, that is within elastic limits. Its free end will experience a movement that is proportional to the fluid pressure applied. The measuring element named for bourdon is partially flattened metal tube formed in a 250° Arc. The tube is sealed at one end (the tip ) and connected to the pressure at the other end (socket).

Any pressure inside the tube exceeding the pressure on the outside cause the tube to become more circular in cross section. As a result, the tip moves in an arc. This movement is connected through a level, quadrant and pinion to a pointer which moves round a scale to indicate the pressure.

The amount of movement of the free end of the tube is directly proportional to the pressure applied ( providing the tube elastic limit is not exceeded ).

Where greater sensitivity is required, the bourdon tube may be constructed in the form of a Spiral or Helix.

2. Spiral Bourdon Tube

Spiral Bourdon Tube is made by winding a partially flattened metal tube into a spiral having several turns instead of a single C-bend arc.

The tip movement of the spiral equals the sum of the tip movements of all its individual C-bend arcs.

Therefore it produces a greater tip movement with a C-bend bourdon tube. It is mainly used in low- pressure application.

3. Helical Bourdon Tube

Helical is a bourdon tube wound in the form of helix. It allows the tip movement to be converted to a circular motion.

By installing a central shaft inside the helix along its axis and connecting it to the tip, the tip movement become a circular motion of the shaft.

Advantages of the Spiral and Helical Tubes over the C-Type Bourdon Tube

1. Both the spiral and helical tubes are more sensitive than the C-Type tube. This means that for a given applied pressure a spiral or helical tube will show more movement than an equivalent C-Type tube, thus avoiding the need for a magnifying linkage.

2. Spiral and helical tubes can be manufactured in very much smaller sizes than the equivalent C-Type tubes. Hence, they can be fitted into smaller spaces, such as inside recorders or controller cases where a C-Type would be unsuitable because of the size.

APPLICATION OF BOURDON TUBE ELEMENTS

Before using a Bourdon tube on a particular process application, a number of questions need to be considered. We need only to consider two here.

1. What is the maximum operating pressure likely to be encountered by the tube? Manufacturers recommend that the normal operating pressure should not exceed 60% of the maximum scale reading. For example, if the normal working pressure were 6 bar, we would select a bourdon tube instrument ( pressure gauge) having full-scale deflection of 10 bar.

2. Is the process fluid corrosive or non corrosive? Material for the bourdon tubes must be able to handle the process fluid. Therefore, selection of pressure gauge must take into account the corrosivity of the line fluid.

5 REASONS TO INSTALL A VALVE ACTUATOR

SAFETY

RELIABLE OPERATION

INACCESSIBLE OR REMOTE VALVE LOCATION

COST

EXCESSIVE VALVE TORQUE

Setting your valve up with the appropriate valve actuators can make sure you have the right amount of force to turn or lift the valve every time.

WHAT IS A PRESSURE SENSOR?

If you are reading this article, then you are probably wondering what exactly is a pressure sensor.

Today, we will hopefully cover all of the questions you may have about pressure sensors.

What is Pressure?

To understand pressure sensors, first, you need to understand the pressure. Pressure is an expression of force exerted on a surface per unit area.

We commonly measure the pressure of liquids, air, and other gases, amongst other things.

The standard unit for pressure is the “Pascal”. This is equivalent to one “Newton per meter squared”.

A pressure sensor simply monitors this pressure and can display it in one of the several units known around the world. This is commonly the “Pascal”, “Bar”, and “PSI” (Pounds per Square Inch) in the United States.

The pressure of the air in your tire is a great example of pressure and how it is measured.

As we air the tire up, the force it exerts on the tire increases, causing the tire to inflate. This is monitored with a pressure sensor inside the tire on newer vehicles.

How does Pressure Sensor Work?

In a nutshell, a pressure sensor converts the pressure to a small electrical signal that is transmitted and displayed.

These are also commonly called pressure transmitters because of this. Two common signals that are used is a 4 to 20 milliamps signal and a 0 to 5 Volts signal.

Most pressure sensors work using the piezoelectric effect.

This is when a material creates an electric charge in response to stress. This stress is usually pressure but can be twisting, bending, or vibrations.

The pressure sensor detects the pressure and can determine the amount of pressure by measuring the electric charge.

Pressure sensors need to be calibrated so it knows what voltage or milliamp (mA) signal corresponds to what pressure. This is a basic “Zero” and “Span” calibration or minimum and maximum which is a common job for maintenance personnel.

Most Common Types of Pressure

What are some of the common types of pressure that you can measure with a pressure sensor?

There are three common types that we use in the industry.

First being “Gauge Pressure”.

This is measured in reference to atmospheric pressure which is typically 14.7 PSI.

You will show a “positive” pressure when it is above atmospheric pressure and a “negative” when it is below atmospheric pressure.

The next type is “Absolute Pressure”.

Simply put, this is the pressure as measured against absolute vacuum. A full vacuum will have an absolute pressure of zero PSIa and increase from there.

If you need to read a pressure that is lower than atmospheric pressure, this is the type of sensor you would use.

The last type that is commonly monitored in the industry is “Differential pressure”.

This is exactly what it sounds like, the difference between two pressures, a pressure being measured and a reference pressure.

Industrial Applications of Pressure Sensors

1. Steam Systems

In industry, pressure sensors are used for a wide variety of processes. Some common uses are to measure the pressure of steam. Steam is commonly used to heat many processes in manufacturing facilities.

This pressure sensor on the steam system can serve multiple purposes though. First and most obvious is to observe and monitor the pressure.

Another purpose is to control when and where steam can flow and regulate its pressure.

Steam can build up a pressure in a vessel and become dangerous. We can use the pressure sensor as an input device to open and close a control valve to keep the pressure and steam flow regulated. This only requires simple programming in the PLC to achieve this.

2.Filters

Pressure sensors are also installed next to filters in many industrial processes.

If the filter begins to clog, the flow will decrease. As the flow of the liquid decreases, pressure can increase or decrease depending on which side of the filter is monitored.

If you monitor the pressure, it will give you a simple indication that the filter is clogged and needs to be cleaned or replaced.

3.Level Measurement

A common use that isn’t as obvious is the use of a pressure sensor as a level sensor.

In an open tank, you can use the hydrostatic pressure that is measured at the sensor. With a little math, using the size of the tank and specific gravity of the liquid, we can determine how much of that liquid is in the tank.

If the tank is closed, it isn’t as simple of an installation. It is still a viable option though. This will require at least two sensors to measure differential pressure.

The high-pressure sensor would be located at the bottom of the tank measuring the liquid pressure and the low-pressure sensor near the top measuring the air pressure inside. A calculation can then be performed to figure out how much liquid is in the tank.

What is an Orifice Meter?

An orifice meter is a conduit and a restriction to create a pressure drop. An hour glass is a form of orifice. A nozzle, venturi or thin sharp edged orifice can be used as the flow restriction. In order to use any of these devices for measurement it is necessary to empirically calibrate them. That is, pass a known volume through the meter and note the reading in order to provide a standard for measuring other quantities.

Due to the ease of duplicating and the simple construction, the thin sharp edged orifice has been adopted as a standard and extensive calibration work has been done so that it is widely accepted as a standard means of measuring fluids. Provided the standard mechanics of construction are followed no further calibration is required. An orifice in a pipeline is shown in figure 1 with a manometer for measuring the drop in pressure (differential) as the fluid passes thru the orifice. The minimum cross sectional area of the jet is known as the “vena contracta.”

How does it work?

As the fluid approaches the orifice the pressure increases slightly and then drops suddenly as the orifice is passed. It continues to drop until the “vena contracta” is reached and then gradually increases until at approximately 5 to 8 diameters downstream a maximum pressure point is reached that will be lower than the pressure upstream of the orifice. The decrease in pressure as the fluid passes thru the orifice is a result of the increased velocity of the gas passing thru the reduced area of the orifice.

When the velocity decreases as the fluid leaves the orifice the pressure increases and tends to return to its original level. All of the pressure loss is not recovered because of friction and turbulence losses in the stream. The pressure drop across the orifice increases when the rate of flow increases. When there is no flow there is no differential. The differential pressure is proportional to the square of the velocity, it therefore follows that if all other factors remain constant, then the differential is proportional to the square of the rate of flow.

BETA RATIO is the ratio of orifice plate bore divided by pipe I.D. is referred to as the Beta Ratio or d/D where d is the plate bore and D is the pipe I.D.

THE ORIFICE PLATE

The orifice plate bore can be made in many configurations to handle various flow measurement jobs. The flowing conditions should be checked to see which of the configurations is suitable for each measurement job.

a. The Thin Plate, Concentric Orifice

In the design and use of orifice plates, several basic factors must be followed to assure accurate and reliable measurement. The upstream edge of the orifice must be sharp and square. Minimum plate thickness based on pipe I.D., orifice bore, etc. is standardized. The plate should not depart from flatness along any diameter by more than 0.01 inch per inch of the dam height (D-d)/2. To conform with recommended practices, the orifice-to-pipe diameter ration d/D (called Beta ratio), must not exceed recommended limits.

b. Eccentric Orifice Plates

The eccentric plate has a round opening (bore) tangent to the inside wall of the pipe. This type of plate is most commonly used to measure fluids which carry a small amount of non-abrasive solids, or gases with small amounts of liquid, since with the opening at the bottom of the pipe, the solids and liquids will carry through, rather than collect at the orifice plate.

c. Segmental Orifice Plates

The opening in a segmental orifice plate is comparable to a partially opened gate valve. This plate is generally used for measuring liquids or gases which carry non-abrasive impurities such as light slurries or exceptionally dirty gases. Predictable accuracy of both the eccentric and segmental plate is not as good as the concentric plate.

d. Quadrant Edge Plate

The quarter-circle or quadrant orifice is used for fluids of high viscosity. The orifice incorporates a rounded edge of definite radius which is a particular function of the orifice diameter.

e. Conic Edge Plate

The conic edge plate has a 45° bevel facing upstream into the flowing stream. It is useful for even lower Reynolds numbers than the quadrant edge.

METER TAP LOCATION

a. Flange Taps

These taps are located one inch from the upstream face of the orifice plate and one inch from the downstream face with a + 1/64 to +1/32 tolerance.

b. Pipe Taps

These taps are located 2½ pipe diameters upstream and 8 pipe diameters downstream (point of maximum pressure recovery). Flange taps are almost universally used in the United States with some older meter stations still using pipe taps.

c. Vena – Contracta Taps

These taps are located one pipe diameter upstream and at the point of minimum pressure downstream (this point is called the vena-contracta). This point, however, varies with the Beta ratio and they are seldom used in other than plant measurement where flows are relatively constant and plates are not changed.Exact dimensions are given in appropriate tables.

d. Corner Taps

These taps are located immediately adjacent to the plate faces, upstream and downstream. Corner taps are most widely used in Europe, in line sizes less than 2 inches they are used with special honed flow meter tubes for low flow rates.

General Installation Recommendations

1. Meter manifold piping should always be installed to enable calibration as well as to protect the differential element against over range.

2. The meter should be installed as close as possible to the orifice fitting.

3. Always slope the manifold lines gently from the orifice fitting to the meter to eliminate any high or low points in the manifold lines.

4. Use condensate chambers or air traps to remove either liquid from a gas system or gas from a liquid system if lows or highs in the manifold piping cannot be avoided.

It is important when pressurizing or depressurizing differential measuring devices to apply or release pressure to or from the high and low meter chambers uniformly, so as not to impose excessive overange.

What Is Water Flow Meter And What Type Of Application Is Suited For It?

Water flow meters are used to measure the volume of water used in commercial and residential buildings. The water is supplied to homes and offices via a public water supply system. Water meters may also be used at water sources or throughout the water system to calculate the flow rate of a part of the system. Water flow meters may also measure the flow rate of slurries or fluids in closed pipes. The flow rate of water is measured in cubic metres (m3) or litres on an electronic or mechanical register.

Water flow meters can measure hot water, cold water, clean water, dirty water and slurries.

Two common methods are used in water flow meter measurement: velocity and displacement flow meters. Each type takes advantage of a variety of technologies.

Paddlewheel Sensors

The Paddle wheel sensor is a cost effective and most commonly used water flow meter. It may also be used to measure flow rates of water-like fluids. Many paddle wheel sensors are sold with insertion or flow fittings. Like turbine meters, they require a 10 pipe diameters of straight pipe on the inlet and 5 pipe diameters on the outlet. The rotor of the paddle wheel sensor is fitted perpendicular to the flow rate. It will make contact with a limited cross-section of the flow.

Positive Displacement Flow Meter

This type of flow meter is used in applications where a straight pipe is not available and if a paddle wheel sensor and turbine flow meter would experience too much commotion. Positive displacement flow meters are used for viscous liquids as well.

Magnetic Flow Meters

This type of flow meter does not have moving parts and used in wastewater applications or with dirty liquids that are conductive. Displays are an important part of this type of flow meter which can be used for data logging or remote monitoring.

Ultrasonic Flow Meters

This flow meter is used in applications where sewage and dirt are involved such as waste water, slurries and other dirty liquids. This type of water usually damages conventional flow meters. Ultrasonic flow meters operate on the principle that a frequency shift of the ultrasonic signal occurs when it is reflected by gas bubbles or suspended particles in motion. This is also known as the Doppler Effect.

If you are looking for perfect flow meters for your industry, no company can provide better products than Proteus Industries Inc. The company is committed to develop innovative and high quality flow management products to provide customer satisfaction.

The company features several types flow meters and switches to choose from keeping your requirements in consideration. The company offers a complete line of flow meter and management devices at the highest specifications in the industry.

The company assures world-class calibration capability that allows delivering flow meters with specialized temperature and fluid specific calibrations. The company’s flow meters monitors the cooling flow in industrial applications to ensure safety of all.

Pneumatic Actuator (Air Cylinder) Basics

There are thousands of industrial applications that require a linear motion during their operation sequence. One of the simplest and most cost effective ways to accomplish this is with a pneumatic actuator. Pneumatic actuators are also very clean operating because the operating fluid is a gas, which prevents leakage from dripping and contaminating the surroundings.

This section will discuss the basic construction and function of a pneumatic actuator, the relationship with a fluid power system and the selection guidelines for pneumatic actuators or air cylinders.

Basic Styles

Pneumatic actuators convert compressed air into rotary or linear motion. There are many styles of pneumatic actuators: diaphragm cylinders, rodless cylinders, telescoping cylinders and through-rod cylinders.

The most popular style of pneumatic actuator consists of a piston and rod moving inside a closed cylinder. Even so, there is a large variety of construction techniques and materials to fit a wide range of applications and user preferences. Body materials can be aluminum, steel, stainless steel and even certain polymers. Construction can be either non-repairable or repairable. This actuator style can be sub-divided into two types based on the operating principle: single acting and double acting.

Single-acting cylinders have a single port to allow compressed air to enter the cylinder to move the piston to the desired position. They use an internal spring or sometimes simply gravity to return the piston to the “home” position when the air pressure is removed. Single-acting cylinders are a good choice when work is done only in one direction such as lifting an object or pressing an object into another object.

Double-acting cylinders have a port at each end and move the piston forward and back by alternating the port that receives the high pressure air. This uses about twice as much energy as a single-acting cylinder, but is necessary when a load must be moved in both directions such as opening and closing a gate.

In a typical application, the actuator body is connected to a support frame and the end of the rod is connected to a machine element that is to be moved. A control valve is used to direct compressed air into the extend port while opening the retract port to atmosphere. The difference in pressure on the two sides of the piston results in a force equal to the pressure differential multiplied by the area of the piston. If the load connected to the rod is less than the resultant force, the piston and rod will extend and move the machine element. Changing the valve to direct compressed air to the retract port while opening the extend port to atmosphere will cause the cylinder assembly to retract back to the “home” position.

Pneumatic actuators are at the working end of a fluid power system. Upstream of these units, which produce the visible work of moving a load, there are compressors, filters, pressure regulators, lubricators, control valves and flow controls. Connecting all of these together is a network of piping or tubing (either rigid or flexible) and fittings.

Pressure and flow requirements of the actuators in a system must be taken into account when selecting these upstream system components to ensure the desired performance. Undersized upstream components can cause a pneumatic actuator to perform poorly or even make it unable to move its load at all.

Force

The above Figure shows a basic system to power and control a pneumatic actuator. When selecting an actuator it is important to properly match the cylinder to the job.

A typical pneumatic system configuration is shown in Figure 4C. The theoretical force available in the actuator is the piston area multiplied by the supplied air pressure. Spring force must be subtracted from this value for single-acting cylinders. The actual force of the actuator will be 3-20 percent less due to pressure losses in the system. A good rule to use when sizing an actuator is to select an actuator that has about 25% more force available than needed for the job,

Speed

When the cylinder force (F) is known, the bore diameter(d) can be found by the above formula. F is the force required (lbs) and P is the supply pressure (psi). Stroke length is determined by the required travel of the machine element driven by the actuator. The speed at which the cylinder can move a load is directly related to the rate that the compressed air can flow through the pneumatic system to the piston to make it move.

This can often be a little tricky to calculate, since as the flow rate increases, system resistance (basically friction of the air moving through pipes and components) will increase in a non-linear fashion. The result is a larger pressure drop from the supply (air compressor) to the cylinder. When the pressure drop is so large that the available pressure at the cylinder cannot move the load, the cylinder will stall. When speed is critical to a machine operation, it may require testing two or three combinations of valves, tubing and cylinders to get the desired performance.

Once the cylinder stops moving however, the friction losses go away and the pressure builds back up to 80 psi. This situation results in a jerky motion of the cylinder as it moves the load.

Several factors could overcome this problem:

-- System pressure can be increased to overcome friction losses

-- Larger tubing can be used to reduce friction losses

-- Different size cylinder could be tried that will reduce the flow

Mounting

The final bit of basic selection criteria is the cylinder mounting arrangement. There are many different configurations available from various manufacturers. The more common ones include rigid nose or tail mount, trunnion mount, rear pivot mount and foot mount. A study of the machine motion required usually will show which mounting configuration is the best choice.

Once the basic actuator size and configuration is known, other options such as end-of-stroke cushions, magnetic piston (for position detection switches) or special seals should be considered when making the final selection.

Cushions

Cushions do an excellent job of preventing a piston from banging into the end caps at the end of stroke. Flow control valves can prevent banging also, but at the expense of a slow travel speed. Cushions only slow the travel for about the last half inch of stroke. A cushion is very useful when the design requires a higher cycle rate or speed and also smooth starting and stopping.

Magnetic Pistons

Magnetic pistons allow simple magnetic proximity sensors to be mounted on a cylinder which can allow a control system to get feedback on the position of a cylinder. Since most cylinders are either extended or retracted, two proximity switches can monitor the operation of a cylinder. This can be very beneficial for machines that require a sequence of operations. Due to the nature of compressed air systems , the exact speed of a cylinder may vary slightly due to a number of factors outside of the control of the machine’s control system such as supply pressure variations, moisture content in the air or ambient temperature. Therefore, a control sequence that begins Step 2 once Step 1 is confirmed complete and so on is a much more robust design.

Temperature Extremes

When it comes to sealing a pneumatic system, remember that environmental conditions such as temperature extremes or corrosive materials may require special seal materials such as Viton. Most manufacturers offer these special seals as an option.

Since pneumatic actuators are at the working end of a fluid power system, producing the visible work of moving a load, pressure and flow requirements of the actuators must also be taken into account when selecting upstream components. Undersized upstream components can cause a pneumatic actuator to perform poorly or even make it unable to move its load at all.

Control electronics for proportional valves at Instronline

For simple and inexpensive control of a proportional valve, Wandfluh, based in Frutigen, Switzerland, has developed the PD3 digital amplifier electronics unit. The device can mount directly on a solenoid coil or connect to a standard solenoid coil with a cable.

The product has a standardized IO-Link interface. It permits digital communication, transmitting operating parameters, diagnostic data and commands to the valve control. With the IO-Link interface, the PD3 capable of handling IoT and Industry 4.0 functions.

If the design engineer prefers, valve control can be through an analog voltage or current signal, or via a digital frequency or PWM signal. The PD3 electronics is IP67-protected and has LEDs which indicate the status of the functional elements of the control.

Complementing the IO-Link option, the company’s widely used PASO software is also available for parameterization and diagnostics with the PD3. PASO engages the device via a wireless Bluetooth connection.

This intuitive Windows-based software and its graphical user interface make the entire signal flow clearly visible to operators and technicians. According to company officials, this lets users quickly parameterize the controls and set up diagnostic functions.

In addition, an oscilloscope option is available with which control signals can be selected and characteristics recorded synchronously. Finally, a new Wandfluh app is available that can also parameterize and provide diagnostic capabilities with the PD3.

What is an Orifice Flange ?

An Orifice Flange is used in combination with orifice meters to measure the flow rate of oil, gas and other liquids conveyed by the pipeline. Orifice flanges are manufactured to ASME B16.36 in multiple sizes and, material grades.

An orifice flange is used to measure the flow of the fluid conveyed by the pipeline via a flow nozzle positioned on the flange itself. Pairs of pressure tappings are machined onto the orifice flange, making separate tappings on the pipe wall unnecessary.

An Orifice flange is a disc – shaped flange, engineered with either a Raised Face or a Ring Type Joint facing.

The traditional orifice flange assembly consists of a pair of flanges, orifice plate, bolts, nuts, gaskets, jacking screws and plugs. Jacking screws ensure the easy removal of the primary flow element.

Orifice flanges are available in all ASTM forged grades (ASTM A105, ASTM A350, ASTM A694, ASTM 182 respectively for carbon, alloy and, stainless steel flanges), dimensions (combinations of nominal sizes and pressure ratings) and, in socket weld, threaded or weld neck shape (WN is the most used).

Purpose of an Orifice Flange

1. They are widely used with orifice meters to measure the flow rate of either liquid or gases, flowing through the pipe.

2. An orifice plate, a device measuring the flow of the inner fluid or gas, is secured between two orifice flanges, attached to the pipe.

3. The orifice plate contains a small hole; two pressure tap holes are drilled in each flange which helps in measuring the pressure built inside the pipe.

4. A ‘jack screw’ fitted between the two flanges, it enables to separate the flanges during inspection or replacement process.

Uses of an Orifice Flange

These flanges are used in the following industries:

-- Heavy and light chemicals

-- Steel

-- Paper

-- Nuclear

-- Petrochemicals

-- Sewage treatment

-- Water treatment and distribution

-- Power Generation

-- Oil production and refining

-- Gas Processing and transmission

What’s Wrong With Your Actuator? 5 Things to Check

About a year ago, we published a blog post called 40 Reasons Your Actuator Isn’t Working. Since then, the article has generated thousands of views, and it continues to get hundreds more every month.

While there may be 40 reasons valve actuators may stop working, there are really only a handful of components that can cause the problems. So, if you have an actuator on the fritz, here are the five things you need to check.

The valve

What manifests as an actuator problem may actually be a valve problem. Our service experts report that this is the case 7 out of 10 times they are called about a faulty actuator.

Some common valve issues that can cause actuator problems:

-- A worn out valve stem

-- Seized up packing

-- An obstruction

-- Too much torque

It doesn’t do any good to repair an actuator when the valve is what’s causing the trouble. On the contrary, it wastes both time and money — and leaves you back where you started.

So, before you start tearing apart your actuator, first put the unit into manual override and see if you can operate the valve manually (this is only possible for electric actuators). If the valve still doesn’t move, then the problem is most likely the valve. If the valve does operate in manual mode, then you may have an actuator problem.

Actuators only have four major components that can break down and require repair.

The center column drive

An actuator opens and closes a valve by acting on the valve stem. This is the job of the center column drive, and this drive can break. However, this is a very rare occurrence, and not the mostly likely cause of actuator issues.

The connection to the valve

Much more likely is that the connection to the valve — the drive nut — has failed. A worn out actuator drive nut will not move the valve stem properly. You can see this by removing the center column cover and looking down the center to the valve stem.

The contactor

The motor contactor is an electric actuator internal electrical part that tells the actuator to open or close the valve when given an input signal. If it fails, the actuator will not function. The contactor is also fuse protected, so check the fuses first!

The motor

On an electric actuator, the motor provides the torque to operate the valve. If the motor fails, the valve isn’t going anywhere. In this case, verify that the duty cycle and insulation class are sufficient for the application.

And that’s basically it! Everything else is bulletproof.

In terms of repair work, every circumstance is unique. If it’s possible to lock out the actuator electrically so there is no current, it may be possible to perform the repairs on-site. For example, if you need a new motor or contactor, a technician will often be able to replace the parts without shutting down the whole line.

On the other hand, for mechanical work like replacing the center column, you’ll likely need to remove the actuator from service before it can be repaired.

The extent of the repairs is also partially dependent on the type of valve the actuator is paired with. For example, to repair the actuator on a gate valve, you typically need to take the entire unit out of service and shut down the line.

Types of Sensors used in Vibration Measurement

BRIEF EXPLANATION OF VIBRATION SENSOR PRINCIPLES:

1. VELOCITY SENSORS

2. ACCELERATION SENSORS

3. PROXIMITY SENSORS

What Types of motors can be used with variable frequency drives?

The various types of industrial motors that can be used with variable frequency drives are:

Dc motor: dc motors are still in production although the number of active manufacturers has decreased considerably, specifically those that are still manufacturing large dc motors (> 1 MW).

Ac asynchronous squirrel cage motor: This type of motor is the most commonly used motor in industrial processes with variable frequency drives.

Ac synchronous motor with brush less ac or brushed excitation.

The most common electrical VFD used in industry today is the variable frequency drive using Voltage Source Inverter (VSI) typology and controlling asynchronous squirrel cage motors.

Types of Bourdon Tube

Basically they are designed to follow the physical law that, within the elastic limit, stress is proportional to strain (Hooke’s Law), that is deflection is proportional to the pressure applied.

Types of Bourdon Tube

There are 3 main types of elastic elements for pressure measurement, namely

-- Bourdon Tubes,

-- Bellows, and

-- Diaphragm.

1. C-Type Bourdon Tube

This instrument is by far the most common device used to indicate gauge pressure throughout the oil gas industry.

The amount of movement of the free end of the tube is directly proportional to the pressure applied ( providing the tube elastic limit is not exceeded ).

Where greater sensitivity is required, the bourdon tube may be constructed in the form of a Spiral or Helix.

2. Spiral Bourdon Tube

Spiral Bourdon Tube is made by winding a partially flattened metal tube into a spiral having several turns instead of a single C-bend arc.

The tip movement of the spiral equals the sum of the tip movements of all its individual C-bend arcs.

Therefore it produces a greater tip movement with a C-bend bourdon tube. It is mainly used in low- pressure application.

3. Helical Bourdon Tube

Helical is a bourdon tube wound in the form of helix. It allows the tip movement to be converted to a circular motion.

By installing a central shaft inside the helix along its axis and connecting it to the tip, the tip movement become a circular motion of the shaft.

Advantages of the Spiral and Helical Tubes over the C-Type Bourdon Tube

APPLICATION OF BOURDON TUBE ELEMENTS

Before using a Bourdon tube on a particular process application, a number of questions need to be considered. We need only to consider two here.

A brief guide on the types of automation

Automation is the trend today, everywhere universally. It is the changing the work efficacy to a great extent and also referred to as automatic control. It is being used in factories, automobile, paper, packaging industry, etc.

There are even some processes in which they are completely automated and did you know for a fact that there are several types of automation.

Some of its advantages include:

• Increased throughput or productivity: Automation helps in enhancement of production. More amount of work can be done in less time.

• Improved robustness of processes or product: There is a consistency in work. One need not worry about the process of the work being hampered or the product turning something else or in some weird shape

• Reduces human labor costs and expenses: As everything gets automated in this technological-driven field, labor costs and expenses are reduced. Though less labor, but the output is outstanding.

Below are the types of automation available in the world of automation

-- Industrial Automation

-- Numerically Controlled Machines

-- Industrial Robots

-- Flexible Manufacturing Systems

-- Computer-Aided Manufacturing

1. Industrial Automation

Industrial automation, this type of automation refers to the usage of control systems like computers, robots, and information technologies (IT) for managing diverse processes and machineries in an industry in order to replace a human being.

Typical purpose controllers for industrial processes comprise Programmable logic controllers, stand-alone I/O modules, and computers.

Some of the advantages include high safety, productivity, flexibility, quality, accuracy.

2. Numerically Controlled Machines

Numerical Control Machine can be defined as the machine that is controlled by the set of instructions called as program.

It is extensively used for a variety of metal machining processes like turning, drilling, milling, shaping etc. In this, the numerical forms are the basic program instructions for diverse types of jobs

The advantages of Numerically Controlled Machines are there are greater operator safety, lower tooling costs, less chances of human error, etc.

3. Industrial Robots:

Industrial robots are changing the scenario of manufacturing industry. They are mostly used for performing tasks that are dangerous or inappropriate for human workers.

It is apt for conditions which need high output and with no errors. It is a programmable robot and can be utilized for many purposes.

Some of them include packing, palletizing, welding, material handling, assembly applications, etc and they’re sorted based on their number of axes, structure type, size of work envelope, payload capability and speed.

Few of the advantages of this type of automation are: it reduces waste, decreases production cost, increases safety, attracts more customers, etc.

4. Flexible Manufacturing Systems

A flexible manufacturing system in short referred as FMS is a way for producing goods that is readily adaptable to modifications in the product being manufactured, in which machines are capable of manufacturing parts and in the capacity to handle differing levels of production.

Some of the advantages of FMS are it reduces manufacturing cost, lowers cost per unit produced, there is a greater labor productivity, greater machine efficiency, improved quality, etc

5. Computer-Aided Manufacturing

Computer-aided manufacturing in short referred to as CAM is a type of automation which utilizes software to control machine tools and related items in the manufacturing of work pieces.

Some of the advantages are the work is done solely on the computers (so manual work is required), is faster and efficient, etc.

Water flow meter: the most important types and applications

All water flow meter types have unique working principles, specific benefits, and costs. A water flow meter measures the amount of water flowing through a pipe. There are several working principles to choose from, depending on the application, maintenance needs, and budget.

The four most common water flow meter types are turbine (also called mechanic), vortex, ultrasonic, and electromagnetic. This article will tell you everything you need to know about them and help you choose one for your application.

If you would like to see our selection, take a look at our water flow meter page.

Water flow meter types

Turbine water flow meter

The most popular and cheapest way to measure water flow, a turbine flow meter, measures the speed of the water running through a pipe with a rotating turbine or piston in it, usually in a propeller, shunt, or paddle wheel design. The volumetric flow rate of the water is proportional to the speed of the rotating blades. Sadly, these meters can clog in dirty or chunky water, such as process water, which increases maintenance costs, so for those applications, we recommend electromagnetic process flow meters. They also don’t work well with low flow.

Vortex water flow meter

Vortices are the “swirls” that form as a fluid moves past an object, like river water around a rock or air currents across a wing. In a vortex flow meter, a sensor tab flexes from side to side as each vortex flows past, producing a frequency directly proportional to the volumetric flow rate. Multivariable vortex meters measure up to five process variables with one connection: volumetric flow rate, mass flow, density, pressure, and temperature. Insertion vortex meters work well on very large pipes since you can insert them by hot tapping with a retractor.

Ultrasonic water flow meter

Ultrasonic water flow meters use ultrasound to measure flow. A transit-time ultrasonic meter sends one signal downstream and another upstream. Then the meter compares the travel time for both signals to find the flow velocity. Finally, it uses this calculation to find the volumetric flow rate. You can also measure energy and temperature using the differences between the hot and cold legs.

Clamp-on ultrasonic meters measure water from outside the pipe by sending signals through the pipe walls. This feature makes them ideal for measuring flow in large pipes and a wide range of other processes.

Electromagnetic water flow meter

Last but not least, electromagnetic water flow meters use a magnetic field and Faraday’s law of induction to measure flow. Liquid flowing through a magnetic field creates a charge. So when the fluid flows faster, it creates more voltage, proportional to the movement of the water. The flow meter then processes the voltage into the flow rate.

Electromagnetic water flow meters don’t have great accuracy, so you can’t use them for custody transfer. They also don’t work on pure water because it has no ions to measure, so they can only be called water flow meters with a qualification.

Depending on the brand, you can also have a confusing range of liners to choose from. You need to know the chemical compatibility, flow velocity, and potential abrasion in your application. So this information will factor into your choice of the best liner for your application.

Water makes for a simple flow application because you don’t need a special liner material. For pure water, you can go with a simple liner like hard rubber or polyurethane, but if you anticipate corrosive chemicals or process water, you will need something else. If you are unsure what to choose, give us a call and our experts will be happy to help.

Electromagnetic process flow meter

Electromagnetic flow meters are especially suited to measure process water flow since chunky liquids can clog turbine or vortex flow meters.

Keep in mind that your process water dictates the equipment you use. Some chemicals may attack your flow meter and shorten its lifespan. If your process water contains chemicals, you’ll need a Teflon liner to prevent corrosion. Otherwise, just go with polyurethane or hard rubber liners.

Conclusion

The ideal water flow meter type is determined by the details of your application because some flow meters work better than others in certain situations. You can save a lot of time and energy by making an informed choice,

Clamp-on ultrasonic flow meter: types, advantages, and applications

Clamp-on ultrasonic flow meters are portable metering devices that measure volume flow in industrial applications from outside the pipe wall, without breaking the line, using ultrasound. Most flow meters have to be mounted inside the pipe (inline), which takes more time and requires the machinery to be dismounted and the work paused.

Portable flow meters

Portable flow meters can be installed, removed, and transported easily. This makes them an ideal choice for industrial applications that are already running, or that only require occasional flow measurement. In the latter case, an engineer can use the same portable flow meter to measure flow in multiple places by removing and transporting the device after each measurement.

Clamp-on ultrasonic flow meters are among the most popular types of flow measurement today. They are installed on closed pipes, and most often used to measure the flow of liquids.

— IMG of portable EM flow meter

Doppler vs Transit time

Ultrasonic flow meters calculate the flow rate from the frequency shift of the ultrasound waves that result from travelling through the measured material. There are two main ways types of ultrasonic flow meters: transit time and doppler flow meters. While they both use ultrasound, there are some crucial differences in their working principles, which make them ideally suited for measuring different types of materials.

Doppler clamp-on ultrasonic flow meter

Doppler clamp-on ultrasonic flow meters use the doppler effect, a frequency shift in sound waves emitted by a moving source.

The transducer creating the ultrasound waves is mounted on one side of the pipe, and the sound waves are reflected back to the sensor from particles or bubbles present in the flowing material. The flow meter then measures the doppler effect in the returning sound waves and calculates the flow rate.

Doppler flow meters only work on materials that contain particles or bubbles that will reflect sound waves, like sludge or wastewater. They also require the material to flow fast enough for the particles or bubbles to be suspended.

Transit time clamp-on ultrasonic flow meter

Transit time clamp-on ultrasonic flow meters use two transducers (usually on the same side in the case of clamp-on flow meters): one sends out the ultrasound waves, which bounce back from the opposite wall of the pipe, and are intercepted by the second transducer.

When the material is flowing, the sound will travel more quickly in the direction of the flow and slowly against the flow. Flow rate is calculated from this shift in the transit time of the ultrasound waves, hence the name.

Transit time ultrasonic flow meters work best on clear materials, such as water or gas, which let the waves travel unobstructed in both directions.

If you would like to know more about the difference between transit time and doppler ultrasonic flow meter,

The benefits of clamp-on ultrasonic flow meters

Clamp-on ultrasonic flow meters are versatile devices with many advantages:

Accuracy: Some clamp-on ultrasonic flow meters are very accurate, measuring flow from as low as 0.03 ft/second. This is enough to detect leaks.

Easy installation: Clamp-on flow meters are easy to install and very portable, which can save work hours and resources.

Less maintenance: Clamp-on devices are not in contact with the measured material and have no moving parts, which greatly increases their lifetime. They are also immune to sensor buildup and can be used on hazardous or corrosive materials without any extra precautions.

Easy calibration: Because of how easy it is to remove them, clamp-on devices can be recalibrated relatively quickly. This leads to even lower maintenance costs and more reliable measurements.

Portability: Clamp-on devices can be moved around in a factory, so they can replace multiple flow meters in some cases and even used to validate other flow measurements.

No pressure loss: Installing the meter on the outside of the pipe wall eliminates the problem of pressure loss, which can occur with inline measurements.

Clamp-on ultrasonic flow meter installation

Clamp-on ultrasonic flow meters are installed using metal chains, straps, or mounting rails to fix the device to the pipe. Usually, a coupling paste is applied underneath to ensure an acoustically conductive connection.

If the surface of the pipe is very rough, some filing or cleaning may also be required. In some cases, multiple clamp-on flow meters are installed on a single pipe in order to ensure higher measurement accuracy.

Installing the meter should be quick and easy for a trained engineer.

Applications

Clamp-on ultrasonic flow meters can be used in any industrial application where a regular ultrasonic flow meter would do. However, they are especially suited for the following materials:

-- Gas

-- Oil

-- Water and other clear liquids

-- Sewage and wastewater

-- Slurry

-- Process water

-- Air or Oxygen

Conclusion

Clamp-on ultrasonic flow meters are versatile devices with many advantages. They can save a lot of work hours and resources if used well, and often replace multiple devices.

Principle, Limitations, Calibration and configuration of Ultrasonic Level Transmitter

Measurement principle

Continuous non‐contacting ultrasonic level measurement is based on the time of flight principle.

An ultrasonic level instrument measures the time between sound energy transmitter from the sensor, to the surface of the measured material and the echo returning to the sensor.

As the speed of sound is known through the travel medium at a measured temperature, the distance to the surface is calculated. Level can be calculated from this distance measurement.

Echo Processing built in to the instrument can allow the instrument to determine the material level of liquids, solids or slurries even in narrow, obstructed or agitated vessels.

Limitations

Ultrasonic is seldom used in upstream hydrocarbon process stream for level measurement; it might be used in atmospheric utilities applications. In applications which are susceptible to vapour density variation, compensation reference pin should be used.

Maximum measurement distance should be checked against the technology (above 30 m the reflectivity may be reduced and might cause a measurement error/problem).

Ultrasonic sensors have, as physical limitation, a blocking distance (close to the sensor) where they cannot measure reliably, e.g. 0.25 metres.

Vessel pressure limitation should approximately be, e.g. 0.5 bar or less. Higher pressure may introduce uncertainty in the level measurement.

Vapour, vacuum or temperature gradients can influence the speed of sound and consequently can cause incorrect measurements.

Presence of foam or heavy turbulence on the surface of the measured material can cause unreliable measurement.

Selection

As ultrasonic is non‐contacting, even abrasive or aggressive materials can be measured. Vessel height and head room should be considered to select an instrument with suitable minimum and maximum range.

Design

Ultrasonic sensors should be made of a material suitable for the measured medium (e.g. PVDF or ETFE) Solid construction and a self‐cleaning action on the face of the sensor provide a reliable, low maintenance product.

Performing an initial or ‘empty calibration’: In this principle, ‘enter’ the distance E from the sensor face to the minimum level (zero point). It is important to note that in vessels with parabolic roofs or bottoms, the zero point should not be more distant than the point at which the ultrasonic wave reflects from the tank bottom.

When possible, a flat target plate that is parallel to the sensor face and directly below the sensor mounting position should be added to the bottom of the vessel for best empty tank performance.

Once the empty distance has been set, the high calibration point or 100% full point can be set. This is done either by setting the distance from the sensor face to the 100% full level or by entering a span (level) from the 0% or low calibration point to the 100% full level.

During commissioning, ensure that the 100% full or high calibration point does not enter the ‘blocking distance’ or ‘blind zone’ of the respective sensor. This will vary from sensor to sensor. Blocking distances or blind zones can be extended to avoid false high level reflections caused by obstructions, but they can only be reduced to a certain distance due to the physical limitations of the sensor itself. The minimum level (distance E/zero point) should be configured. This zero point should be above any dished boiler heads or conical outflow located at the bottom of the tank/vessel.

The maximum level (distance F/full span) should be configured. This distance F should take into account both BD ‘blocking distance’ and SD ‘safety distances’.

Where BD represents a dead zone in which the wave cannot make any measurement and SD corresponds to a warning or an alarm zone.

Where are manifolds used?

Manifolds are used in my many fluid power applications, depending upon the application. Manifolds are used in hydraulics as well as pneumatics, and can be used to mount valves or to consolidate plumbing. When used for mounting valves, they are the interface between the valves and the ports to be plumbed into.

With industrial style hydraulic valves, such as ISO valves mounted on D03 or D05 patterns, for example, the valves terminated with plain ports surrounded by O-rings, and cannot be plumbed directly into a hydraulic system. The manifold is a block, or series of adjoining blocks, which has an interface for the valve(s) to mount to, ports for the fluid to travel, and then ports to plumb the manifold to the rest of the circuit. The pressure passage can be parallel to the valve pressure ports, or in series, joining the tank to pressure port of subsequent valves.

Pneumatic valves use various manifold mounted systems, which can be ISO standards or manufacturer specific. Just as with hydraulic valves, one long block, or various small adjoining blocks, have directional valves mounted to the manifold(s). The manifold will have common pressure ports feeding the DCV’s, and return ports are combined into the manifold and usually exhausted to air.

The advantage of manifold mounted valve systems is in their modularity; standard valves of various, easily exchangeable iterations can be mounted to a manifold to customize the circuit and its number of actuators. As well, a standard valve series can be mounted to manifolds employing any type of port, such as NPT, Metric or ORB, rather than producing every valve with every version of port, saving manufacturing and inventory costs.

Manifolds can be used outside of valving, as well. A manifold can simply be a chamber with two or more ports joined in series to reduce plumbing. For example, a return line manifold with six smaller ports joining to one large tank port will save the need for a series of expensive tee’d together fittings, reducing both cost and the chance of leakage. A manifold can be used less commonly in pressure lines as well, cleaning up plumbing and improving appearance as well.

Advantages and Disadvantages of Pneumatic Instruments

What are the Orifice Plate Flow Requirements?

The orifice flow meter is a well-established flow measurement method. The sizing, dimension, and installation requirement is dictated by the ISO 5167-1 & ISO 5167-2.

Basically, the orifice sizing is involving a coefficient that was determined from the empirical test. This coefficient is the coefficient of discharge. During the test, the fluid flow is required to be a fully developed flow condition which means a fluid flow that is not a swirl-flow.

This requirement is proved to be effective enough to produce the lowest uncertainty of coefficient of discharge which can lead to an accurate flow measurement reading. If the fluid flow isn’t fully developed, it is proved also that the uncertainty of the coefficient of discharge is high which can lead to an in-accurate flow measurement reading.

The swirl flow itself can be caused by an elbow, control valve, or any other equipment in the upstream and downstream of the orifice plate.

There are two methods to establish the swirl-free conditions, by putting a certain straight run pipe length and by using an additional flow straightener or flow conditioner to reduce the straight run requirement.

ISO 5167-2 has already specified the requirement of this straight run with or without a flow conditioner. The straight run on that standard was determined experimentally and give a practical number that shall be followed to get the required flow meter uncertainty.

What is a PID Controller?

A PID controller is an instrument used in industrial control applications to regulate temperature, flow, pressure, speed and other process variables. PID (proportional integral derivative) controllers use a control loop feedback mechanism to control process variables and are the most accurate and stable controller.

PID control is a well-established way of driving a system towards a target position or level. It's a practically ubiquitous as a means of controlling temperature and finds application in myriad chemical and scientific processes as well as automation. PID control uses closed-loop control feedback to keep the actual output from a process as close to the target or set point output as possible.

What is a PID Temperature Controller?

A PID temperature controller, as its name implies, is an instrument used to control temperature, mainly without extensive operator involvement. A PID controller in a temperature control system will accept a temperature sensor such as a thermocouple or RD as input and compare the actual temperature to the desired control temperature or set point. It will then provide an output to a control element.

What is a Digital PID Controller?

A digital PID controller reads the sensor signal, normally from a thermocouple or RTD and connects the measurement to engineering units, such as degree Fahrenheit or Celsius, that are then displayed in a digital format.

History of PID Controller

The first evolution of the PID controller was developed in 1911 by Elmer Sperry. However, it wasn't until 1933 that the Taylor Instrumental Company (TIC) introduced the first pneumatic controller with a fully tunable proportional controller. A few years later, control engineers went eliminate the steady state error found in proportional controllers by resetting the point to some artificial value as long as the error wasn’t zero. This resetting “integrated” the error and became known as the proportional-Integral controller. Then, in 1940, TIC developed the first PID pneumatic controller with a derivative action, which reduced overshooting issues. However, it wasn’t until 1942, when Ziegler and Nichols tuning rules were introduced that engineers were able to find and set the appropriate parameters of PID controllers. By the mid-1950’s, automatic PID controllers were widely adopted for industrial use.

What is a Coriolis Flow Meter and how does it work

A Coriolis flow meter is a type of mass flow meter. It is designed differently and works differently than thermal or differential mass flow meters. The first industrial Coriolis patents date back to the 1950s with the first Coriolis mass flow meters built in the 1970s.

How Does a Coriolis Flow Meter Work?

A Coriolis mass flow meter measures mass through inertia. Liquid or a dense gas flows through a tube which is vibrated by a small actuator. This acceleration produces a measurable twisting force on the tube proportional to the mass. More sophisticated Coriolis meters employ dual curved tubes for higher sensitivity and lower pressure drop.

In this article the design and evolution of the Coriolis flow meter is explained in more details.

Coriolis meters, while considered the most accurate flow meters, are susceptible to errors when bubbles are present in the liquid. The bubbles can create “splashing” within the tube, generate noise, and change the energy needed for tube vibration. Large cavities increase the energy needed for tube vibration inordinately and can lead to complete failure.

Common Applications for Coriolis Flow Meters

Coriolis mass flow meters are used predominately in scientific applications where they measure both corrosive and clean gases and liquids. They are also used in:

Pulp and paper processing

-- Petroleum and oil

-- Chemical processing

-- Wastewater handling

Coriolis flow meters with a straight tube design are more easily cleaned so are preferred for food and beverage applications as well as pharmaceuticals. They can also handle the slurries typically found in mining operations.

Why is Industrial Automation Important?

Over the past years, there has been a positive growth in the global industrial automation industry. According to a report, industrial automation market is expected to reach USD 153.83 Billion by 2022, growing at a CAGR of 5.10% between 2017 and 2022. Moreover, usage of automation techniques is on the rise and is expected to continue rising for the foreseeable future.

These expectations showcase that global industrial automation companies are preferring automation to reduce manual labor inputs and decrease costs. It further eliminates the requirement for many low-paying offshore jobs and allows the companies to increase the need for high-skilled activities.

The major advantages of using automation are:

• Reduced direct human labor costs and expenses

• Increased productivity

• Enhanced consistency of processes or product

• Delivery of quality products

Why is industrial automation so important?

The industrial world is facing many technological changes which increased the urgent demand for the premium quality products and services that can only be supplied by a high level of productivity. This requirement needs process engineering systems, automated manufacturing, and industrial automation.

Hence, industrial automation plays a key role in solving the requirements of companies. It is extremely significant to face the tasks of:

Globalization – Global industrial automation market demands superior, practical services.

Productivity – Automation companies want to enhance their productivity by producing a higher level of Automation. The key factors include costs, time and quality.

On the other hand, industrial automation is all about working smarter, faster, and proficiently. This makes automation more powerful and that’s why customers are looking for pioneering, end-to-end technologies with open, modern architecture and new data from new connections. As the industrial automation industry comprehends the advantages of the Internet of Things (IoT), it is becoming essential that organizations adopt these technologies.

Industrial Automation Becomes a ‘Solutions’ Business:

Industrial automation is important as it becomes a solution business. Let us check how it becomes a solutions business:

Industrial automation refers the categorization of software and hardware and a mechanism that combines them (hardware & software). Moreover, it involves the process of rolling out new features using advanced technology in business to reduce limitations. Automation can be achieved by installing automated devices or embedded systems as well as automation software performing the logical tasks and control the operation processes.

Implementation of these devices, software, and hardware will be the ‘Solution’ to deliver the operation to be automated. These solutions are widely used nowadays to enhance efficiency and productivity of businesses.

Using Android is not feasible in industrial Automation:

Using Android in industrial automation is not feasible due to various reasons. Here are some of them:

• Future expansion as Android is not modular

• Ruggedness and environmental factors

• Android cannot handle sizable and complex systems

• Not reliable

• You cannot guarantee the safety of the process

Future of Industrial Automation:

Industrial Automation is moving towards exceptional productivity spurred by superior energy efficiency, rigorous safety standards, and better design. Instrumentation and controls have always been a source of new products such as amplifiers, displays, control elements etc.

Automation has been using everywhere nowadays. SCADA, DCS, Process Instruments etc have made automation more reliable and powerful.

All You Need to Know About Ball Valves

What are Ball Valves?

Ball valves are quarter-turn valves that use a hollow, perforated, and pivoting ball to control the flow of materials from one opening to the next. The valve can be open, closed, or partially open to allow gasses, liquids, and slurry materials pass through it. Ball valves are used in applications where tight shut-off is required.

Ball valves are extremely versatile as they can handle pressures up to 1000 bars and temperatures up to 400 degrees. Their sizes range from 0.5 cm to 121 cm and they are easy to operate and repair. Ball valves are designed to allow only a 90-degree rotation for opening and closing the valve. This means the valve locks fully when the handle is turned. Ball valves are popular in industrial use because of the air-tight seal they provide when fully closed.

What are the Different Components of a Ball Valve?

Ball valves can be made of metal, plastic, or metal fused with ceramic. The ball in the valve is usually chrome plated for durability. Just like other industrial valves, ball valves also feature certain moving parts. Here are the components of a ball valve:

Body or Shell

The body of a ball valve houses all other components of the valve. It also serves as the first pressure boundary of the valve. This is because it provides the first line of resistance against the flow of materials through pipes connected to the valve. The body of a ball valve provides the main framework of the valve. It protects the other components and also holds them together.

Bonnet

The bonnet of a ball valve covers the opening of the valve’s body. It is usually bolted or screwed to the body making sure it stays intact. Bonnets form the second pressure boundary of the valve as they reinforce the strength of the body in countering the pressure of materials flowing through the pipes connected to the valve. The bonnet of a ball valve is usually made of the same material as the body of the valve to make it stronger and durable.

Trim

The trim of a ball valve features all the moving parts of the valve. This includes the ball (disk), seat, stem, and sleeves. The ball in the valve acts as its disk. This hollow sphere is placed in the center of the valve and it turns to allow materials to pass through. The ball acts as the third pressure boundary of the valve as it comes in direct contact with the materials flowing inside the pipes connected to the valve. The stem of the ball valve connects the ball to the actuator. As the actuator is turned, the stem moves as well, in turn, rotating the ball. The stem connects the ball to the actuator through welded joints. The seat of the ball valve is where the ball is placed. The seat is also known as ‘seal ring’ as it nestles the ball inside and provides a snug fit when the valve is closed.

Actuator

The actuator of the ball valve is what we use to open and close the valve. Hand wheels, levers, motors, solenoids, pneumatic operators, and hydraulic arms are all examples of ball valve actuators. Most ball valve manufacturers produce ball valves where the actuator is mounted over the bonnet through a yoke.

Packing

As the name suggests, packing prevents any leaks through the stem. Ball valve packing can be found in the space between the stem and the bonnet. It is usually made of fibrous materials like flax or Teflon. Packing provides protection to the internal parts of the valve and it forms a seal over them to prevent any leakages.

How Does a Ball Valve Work?

Ball valves are shut-off valves that use a ball to start or stop the flow of materials through the valve. The ball in the valve performs the same function as the disc in other valves. The ball is hollow and features a hole that is also known as the bore. When the actuator is moved, the ball rotates to a point where part or the entire bore is in line with the valve body inlet and outlet. This allows the materials to flow through the valve.

To close the valve, the actuator is moved again. The ball rotates to a point where the bore is perpendicular to the flow path. This causes the flow to stop. Most ball valves require a 90-degree turn of the actuator to fully open or close. The valve can be partially opened but that causes damage to the ball valve. This is the reason why ball valves do not belong to valves recommended for throttle applications. They are most suitable for applications where tight shutoff is necessary for example to control the flow of gas.

Ball valves can be unidirectional, bidirectional, or multi directional depending on the number of valve seats and ports. For example, a two-way ball valve with a single seat will be unidirectional with flow direction indicated on the valve. The same valve with two seats will be bidirectional. In this valve, one seat will be on the upstream side while the other will be on the downstream side of the ball. Three-way, four-way, and five-way multi port ball valves can be unidirectional if the flow is entering through a designated port. Ball valves with multiple ports allow flow in more than one direction eliminating the need for several valves.

What Types of Ball Valves are Used in Piping?

Ball valves don’t have a complicated mechanism. They are easy to install and simple to use. Their simple design makes them versatile, they can be used in many different industrial applications. There are many types of ball valves depending upon their body construction and function.

Types Based on Body Configuration

Ball valve manufacturers categorize these valves on the basis of their body configuration. There are four types of ball valves based on their construction.

Top Entry Ball Valve

As the name suggests, top entry ball valves allow access to the internal parts of the valve by removing the bonnet cover on the top. These valves can be easily assembled and disassembled. Easy access allows repair and maintenance without having to disengage the ball valve from the pipeline.

End Entry Ball Valve

These ball valves have a single-piece body. The connections on the valve are flanged or screwed. The ball is inserted from one end and is kept in place by a screwed insert. End entry ball valves are usually smaller in size and used for applications requiring less pressure.

Split Body Ball Valve

In split body ball valves, the body of the valve is divided into two or three pieces that are bolted together like flanges. One part of the body is always larger than the rest and that is what holds the ball. The stuffing box is constructed around the larger body part. Split body ball valves are usually larger in size, though you can find smaller ones as well. They are easy to inspect and maintain.

Welded Body Ball Valve

In welded body ball valves the bonnet is welded to the body of the valve. This makes the valve safe from any kind of leakages. The valve’s internal parts cannot be accessed or maintained. Welded body valves are suitable for underground applications, submarine pipelines, and for regulating the flow of hazardous materials.

Types Based on Ball Movement

Ball movement indicates how a ball valve functions. There are three types of ball valves based on ball movement.

Floating Ball Valve

In this type of valve, the ball is attached only to the stem of the valve. It is kept in place by the compression of two elastomeric seats against the ball. But the ball has some space to freely float between the seats. When upstream pressure is generated in the valve, the ball gets pressed against the downstream seat producing a tight seal. This type of valve can thus provide bi-directional shut-off.

Trunnion Ball Valve

Floating ball valves are difficult to operate in high pressure. That problem is remedied in trunnion mounted ball valves. In this type of ball valve, the ball is supported by a shaft or trunnion on its vertical rotation axis. The trunnion absorbs the pressure from the flow so the contact between the ball and seats is not overly stressed. This, in turn, reduces the operating torque. Trunnion ball valves are suitable for high pressure, large scale applications.

Rising Stem Ball Valve

Seal rubbing is one of the primary causes of valve failure. Rising stem ball valve eliminates that problem by incorporating tilt-and-turn operations. In this ball valve, a stem is inserted in the seal that prevents any direct contact between the seal and the seats. When the valve is closed, the stem wedges against the set, ensuring a tight shut-off. When the valve is open the stem tilts away from the seat so the flow can easily pass through.

Types Based on Bores

Bore is the internal diameter of the balls used in ball valves. There are three basic types of ball valves based on bores.

Full-Port Ball Valve

The full-port ball valve is named so because the diameter of the bore in this valve matches the diameter of the connected pipeline. This means there is no restriction to flow through the valve. Full-bore or full flow ball valves are ideal for situations where pigging may be required. They are used widely in chemical, petrochemical, and refining industries.

Reduced-Port Ball Valve

As the name suggests, a reduced port valve has an internal bore diameter that is one or two nominal sizes lower than the internal diameter of the connected pipeline. The flow path is restricted which results in higher energy losses. A reduced port valve is used mostly in the oil and gas industry.

V-Port Ball Valve

V-port ball valve features either a ‘v’ shaped ball or a similarly shaped seat. This ball valve is used in applications where the flow velocity needs to be maintained at a certain level. This is why v ball valve is also called a control valve.

Types Based on Number of Pieces

Ball valves can be housed in one, two, or three-piece structures.

One-Piece Ball Valve

This is the cheapest ball valve because it features a single piece of housing that is welded or forged to the body of the valve. One-piece ball valves cannot be opened so cleaning, maintenance, or replacement of parts is impossible. This ball valve is suitable for small scale industrial applications and materials like gases that do not require valve maintenance.

Two-Piece Ball Valve

This ball valve is made of two pieces of housing that are threaded together. Two-piece valves can be disassembled for cleaning and maintenance but that requires the valve to be disengaged from the pipeline.

Three-Piece Ball Valve

Three-piece ball valve features three different pieces of housing that are bolted together. The valve can be easily cleaned and maintained. The internal parts can also be replaced without disengaging the valve from the pipeline. Three-piece ball valves are more expensive than the other two types of valves in this category.

What are the Applications of Ball Valves?

Ball valves provide reliable leak protection which makes them perfect for a number of industrial applications. They have a low-pressure drop and can open and close quickly which makes them great for liquid and gas applications. Ball valves are extremely versatile so they can be used for subsea, underground, and cryogenic services.

Ball valves can be used for air, gas, and liquid applications that require bubble-tight service. They can also be used in low-point drains and high-point vents for liquid, gas, and other fluid applications. Cooling water and feed water systems can be regulated using ball valves and they can also be used for steam services.

Ball valves can be used at turbine skids, gas feed lines, compressor skids, crude oil plants, generator skids, polymer plants, separator skids, LNG plants, field gas plants, industrial gas processing plants, tank farms, oil refinery feedstock lines, hydrocarbon processing, and automated process applications. Stainless steel ball valves can be used in petroleum refining, desalination, and brewing.

Ball Valve vs. Gate Valve: Which One is Better For Your Application?

Valves are an important component of any kind of piping system. They help start, stop, and regulate the flow of materials and prevent leaks and unwanted flow. Valves are vital to the operations of many machinery and equipment across various industries and applications. It is hard to imagine a set-up where valves are not involved. However, not all valves are the same.

While there are many different types of valves available in the market ball valves and gate valves are two of the most common types of valves used in almost all industries. Though both of these valves perform more or less the same function, there are structural differences between the two that make them suitable for different applications. It can be confusing to choose which one is suitable for your needs. That is where this guide can help you. Read on to find out how gate and ball valves work, what makes them different from each other, and how you can choose which one is best for your application.

What are Ball Valves?

Ball valves are ‘shut-off valves’ in that they help prevent the flow of materials through the piping system. They are called ball valves because of their structure and function; each valve features a small sphere or ball inside. The ball has a hole in its center called a bore, it is the position of this bore that indicates whether a ball valve is open or closed.

Ball valves are normally controlled by a lever. This lever can rotate 90 degrees, when it is rotated perpendicular to the pipe, the ball valve is opened. The bore of the valve aligns with the pipe and allows materials to flow through. Rotate the lever again bringing it parallel to the pipe to stop the flow. The bore of the valve now becomes perpendicular to the pipe and stops any flow.

Ball valves have a simple design and are easy to turn on and off quickly. They are durable, rarely freeze, provide reliable service, and can be used across multiple industries and applications. They are mostly used in oil and gas applications, marine applications, pharmaceuticals, and more. Ball valves are compact in size and require very little space to install.

What are Gate Valves?

Gate valves get their name because they feature a flat closure element that moves up and down to start or stop the flow of materials. This closure element, also called a gate, is connected to the stem of the valve. The stem is in turn connected to the actuator, which in case of manual gate valves, is a handwheel. When you rotate the handwheel, the gate slides up, removing any barrier for the materials in the pipe and they are free to flow. Rotating the handwheel counter clockwise, slides the gate back in place, stopping the flow of materials.

Gate valves are sturdy and durable. They are used in on/off applications where the valve is used infrequently. You can find gate valves in the oil and gas industry, pharmaceuticals, manufacturing, automobile industry, and marine applications. Gate valves prevent pressure drop due to flow of materials. That is why they are great for high pressure and high temperature applications as well.

Gate valves come in many different shapes and sizes. They are extremely versatile both in terms of design and application. They are bi-directional which means you can use them to regulate flow of materials in any direction. They also require very little maintenance and can last for ages.

What are the Differences Between Ball Valves and Gate Valves?

Now that you know what ball and gate valves are and how they work, let’s take a look at what makes them different from each other. As both valves perform basically the same function, it can be confusing to choose which one is right for your needs. Here are some main differences between ball valves and gate valves.

Structure

Ball and gate valves may work in similar ways, but they have different structures. While ball valves feature a small sphere attached to a stem, gate valves have a round or rectangular gate that is attached to the stem and is used to regulate the flow of materials. Because of the way they are structured, ball valves offer immediate shut-off, which is not possible for a gate valve to do.

Gate valves don’t provide quick shut-off, but they do give you more finely tuned control over the flow of materials and the pressure of the flow. For example, gate valves are great in situations where there’s high water pressure potential. In similar situations, a ball valve would likely form a water hammer, while a gate valve makes sure that doesn’t happen.

Ball valves may in smaller is size than gate valves, but they require more space for actuation. Manually operated ball valves require their lever to be turned at 90 degrees to work. The lever requires more space to work. While a manual gate valve is operated through a handwheel. So even if the gate valve is larger in size, it may take less space than a ball valve to operate.

Another structural consideration is that gate valves are more prone to corrosion than ball valves. The valve opens and closes with a screw handle attached to the gate. The handle is in constant contact with the material flowing through the valve and can easily corrode. This hampers the performance of the valve. You can choose a material like stainless steel and brass for handle construction to counter this problem.

Ports

The inlets and outlets of a valve are called ports. Gate valves are bi-directional, this means they have only two ports. The ports can be threaded, soldered, or flanged depending upon the type of gate valve and the application.

Ball valves on the other hand, can have two or more ports. These ports may be threaded, soldered, or flanged based on the valve’s application and type. Ball valves with three ports are used for mixing and diverting the flow of materials. In addition to their number, the size and function of ports in valves also plays a role. A full-port ball valves features a ball with a bore size that is the same as the diameter of the pipeline the valve is attached to. A reduced-port ball valve features a ball that has a smaller bore size than that of the pipeline.

Flow Characteristics

Gate valves can function in either fully open or fully closed states. If a gate valve is partially open, it causes throttling which can damage the valve and affect its function. Also, a partially opened gate valve is not proportional to the motion of the closure element. This means you cannot use gate valves for active control of media flows. Gate valves are more suitable for shutoff of materials flowing in linear direction. They are used in piping situations where flow needs to be regulated infrequently like when isolating equipment or sections of pipes.

Ball valves are designed so that the flow of materials is closely proportional to the rotation of the closure element or ball. This causes a flow characteristic called the ‘modified equal percentage’. Ball valves are thus suitable for active control of media flows. Ball valves seal very well, better than gate valves in most instances. That is why they are great for regulating the flow of gasses and other light materials that are prone to leakages. Ball valves have a quick shut-off so they are mostly used in applications where you need to start or stop the flow completely and frequently.

Actuation

Gate valves are usually used for isolation of general purpose flows and for high-pressure and high temperature applications that require manual operation. This is the reason why most gate valves are actuated using a handwheel. The handwheel offers more control over opening and closing the valve. However, it is more difficult to operate as it requires great strength especially during high-pressure operations. Also, since handwheels need to be rotated for the valve to turn on or off, it is difficult to actually ‘see’ whether the valve is open or closed. This problem is eliminated when using mechanical, electric, or pneumatic gate valves.

Ball valves are used for active control of material flow so they can be manually, electrically, or pneumatically actuated. Manual ball valves are more frequently used in industries as they are cheaper and they offer greater control over the flow of materials. Another advantage of manual ball valves is that the lever needs to be held perpendicular to the pipeline for the valve to be opened and turned back when closed. This makes it easy to ‘see’ just from the position of the lever whether the valve is open or closed.

Cost

Comparing the cost of gate and ball valves is like comparing apples and oranges, since both of them are used for different purposes and applications. However, if all things are kept the same, ball valves are generally more expensive than gate valves. This is because they offer more features and are more versatile than gate valves. Also, ball valves are more durable than gate valves as they are less prone to corrosion. So the slight increase in price more than makes up for the years of use you’ll get out of ball valves.

How to Choose the Right Valve for Your Application?

Choosing between a ball valve and gate valve comes down to a number of factors. Here are some considerations you need to make to see which valve is better for your application:

The type of medium that you need to control can dictate the type of valve you need. Gate valves are better with liquids and viscous liquids like oils as they are more prone to leakages than ball valves. Knife gate valves can help you regulate the flow of slurry materials. Ball valves can be used with liquids and gasses as they provide a firmer seal.

The size of the space you have can also help you decide between a ball and gate valve. Ball valves are smaller is size but manually actuated ball valves need more space. Gate valves are normally larger in size.

The kind of application you require is also important when choosing a valve. Gate valves are more suitable for high-pressure, high-temperature, infrequent applications. Whereas, ball valves are more suitable for active control of media flow.

The cost of valves is another consideration. Ball valves are generally more expensive than gate valves but they offer a more reliable operation as well.

Conclusion

Both ball and gate valves are used frequently in many different kinds of industries and across different applications. Choosing the right valve for your needs can be easy when you break down the operation you need the valve to perform. No matter which valve you choose, make sure to buy from a trusted valve manufacturer and get valves that have proper warranties. At SIO we offer a great deal of attention to design, manufacture, pack, and deliver valves that are of the highest quality. We use state-of-the-art testing equipment and software to make sure our valves are safe to use and provide reliable operation for years.

Learn more about our products here. Browse through our catalogue to find the best gate valves and ball valves for your needs.

Types of Sensors Used in Industrial Automation

A Sensor is a device that identifies the progressions in electrical or physical or other quantities and in a way to deliver a yield as an affirmation of progress in the quantity. In simple terms, Industrial Automation Sensors are input devices which provide an output (signal) with respect to a specific physical quantity (input).

Sensors used in Automation:

In the industrial automation, sensors play a vital part to make the products intellectual and exceptionally automatic. These permit one to detect, analyze, measure and process a variety of transformations like alteration in position, length, height, exterior and dislocation that occurs in the Industrial manufacture sites.

These sensors also play a pivotal role in predicting and preventing numerous potential proceedings, thus, catering to the requirements of many sensing applications.

The following are the various types of sensors used in automation:

Temperature Sensors

Pressure sensors

MEMS Sensors

Torque Sensors

Let’s discuss about these different Types of industrial automation sensors in detail to understand their scope of use:

Temperature Sensors :

A temperature sensor is a device that collects information concerning the temperature from a resource and changes it to a form that can be understood by another device. These are commonly used category of sensors which detect Temperature or Heat and it also measures the temperature of a medium.

Digital Temperature Sensors and Humidity & Temperature Sensors are few of the main temperature sensors used in automation.

Digital Temperature Sensors:

These Digital Temperature Sensors are silicon-based temperature- sensing ICs that provide accurate output through digital representations of the temperatures they are measuring. This simplifies the control system’s design, compared to approaches that involve external signal conditioning and an analog-to digital converter (ADC).

Humidity & Temperature Sensors

The Temperature & Humidity sensors attribute a temperature & humidity sensor complex with a measured digital signal output. By utilizing the technique and temperature & limited digital-signal-acquisition humidity sensing technology, it ensures high consistency and exceptional long-standing stability.

Applications of Temperature Sensors:

They are weatherproof & designed for continuous temperature measurement in air, soil, or water

Exceptional accuracy and stability

For measurements in complex industrial applications

For measurements under rough operating conditions

Pressure Sensors:

The Pressure Sensor is an Instrument that apprehends pressure and changes it into an electric signal where the quantity depends upon the pressure applied.

Turned parts for Pressure Sensors and Vaccum Sensors are few of the major pressure sensors used in Industrial automation.

Turned parts for Pressure Sensors

These Pressure sensors are widely used in Industrial and hydraulic systems, these are high pressure industrial automation sensors also used in climate control systems.

Vaccum Sensors

Vaccum Sensors are used when the Vaccum pressure is below atmospheric pressure levels and it can be difficult to sense through mechanical methods. These sensors generally depend on a heated wire with electrical resistance correlating to temperature. When vaccum pressure increases, convection falls down and wire temperature up rises. Electrical resistance increases proportionally and is calibrated adjacent to pressure in order to give an effective measurement of the vaccum.

Applications of Pressure Sensors:

Used to measure pressure below than the atmospheric pressure at a given location

Used in weather instrumentation, aircrafts, vehicles, and any other machinery that has pressure functionality implemented

Pressure sensors can be used in systems to measure other variables such as fluid/gas flow, speed, water level, and altitude

MEMS Sensors (Micro-electro-mechanical Systems)

These MEMS industrial automation sensors convert measured mechanical signals into electrical signals.

Acceleration and Motion MEMS are few important sensors used in industrial automation.

Acceleration sensors

Micro-electro-mechanical Systems (MEMS) Acceleration Sensors are one of the main inertial sensors; and are dynamic sensor competent of have a greater range of sensing capabilities.

Motion sensors

Micro-electro-mechanical system (MEMS) motion sensors use data processing algorithms designed on a motion interaction platform which integrates numerous low-cost MEMS motion sensors with ZigBee wireless technology to carry personified interactions while working together with machines. Sensor signal processing systems mainly solve noise cancellation; signal smoothing, gravity influence partition, coordinate system alteration, and position information recovery .Widely used in the automotive Industry in ABS technology.

Applications of MEMS Sensors:

These have numerous applications ranging from industry, entertainment, sports to education. For example, triggering airbag deployments or monitoring of nuclear reactors

Used to measure static acceleration (gravity), tilt of an object, dynamic acceleration in an aircraft, shock to an object in a car, vibration of an object. Cell phones, washing machines or computers

Used to detect motion

Torque sensors

The torque sensors complete with essential mechanical stops, raise overload capacity and offer additional guard during mounting and operation.

Rotating Torque & Torque Transducers are few important sensors used in industrial automation.

Rotating Torque Sensors

This Rotating Torque industrial automation sensors used for measuring reaction of rotating torque. These torque meters complete with essential mechanical stops increase surplus capacity and offer extra safety during mounting and operation.

Torque Transducers

These torque transducers utilize superior strain gage technology to indulge the most challenging necessities for static and dynamic applications of sensors.

Applications of Torque Sensors:

Used to Measure the speed of rotation and maintenance necessities

Used to measure Mass and mass moment of inertia

The amount of the torque to be calculated, from the point of vision of quasi-static process

Used to measure the highest speed of rotation, oscillating torque

Conclusion:

All these above mentioned sensors are increasingly utilised in the automation industry. The recent surge in commercial demonstration of these sensor systems highlights their unique capabilities.

Guidelines For Selecting Right Valve For Your Industrial Application

Industrial valve selection criteria

Basic knowledge on the industrial performance requirements, is an important factor which is going to make your valve selection procedure easier. It is advisable to keep the following five points in mind, before starting the valve selection procedure, to ensure that you exactly know what you are looking for:

1. Valve Size and Type

It is to be noted that, a valve within an industrial set up performs more than one functions. This includes shut off flow, divert flow, mix flow, pressure relief, backflow prevention, and adjust flow. For example, in water supply pipelines stop valve is used for giving away connections for inserting and controlling the flow of the water. For 16 inch pipeline, full line size butterfly valves is used. The maximum velocity through valves normally limited to 12 feet per second, and should not exceed 20 feet per second.

2. Materials for Manufacture

Check the chemical compatibility requirements for your industrial unit, before getting into valve selection procedure. The materials used for the construction of valves should be compatible with the gases and other materials flowing through it. For example, valves made up of copper alloys are a popular pick by the industrialists who are into oil and gas manufacturing. Plastic valves usually resist harsh and corrosive conditions along with chemicals better than metal valves.

In a review of the selections of 8,061 engineer and other technical user search selections (2009 – 2013) using SpecSearch valve search forms, it was found that 80 percent selected corrosion resistant materials such as stainless (27.2 percent), brass or bronze (24.1 percent) or plastic (18.2 percent).

3. Performance Requirement

Pressure and temperature requirements play an important role in making valve selection procedure easier for manufacturers. Industries which generate high temperatures and pressures, metal alloys are generally advisable for them. Metal valves are also best suited for pressurized gases.

4. Check Valves have Special Requirements

Check valves most of the times perform as expected. It is still suggested to keep a check on the response time needed as well as the cracking pressure required to open the valve.

Some categories of check valves require positive downstream pressure to open. These are generally referred as closed check valves in the market, and the second category require a positive backpressure to close, and are called as open check valves. A proper choice between the two based on the industrial requirements, improves the check valve reliability.

It is suggested to make a decision for selecting this category of valve, by checking which one is more closed or open during normal system operations.

5. Maintenance

Always consider your resources you have to keep a tap on the maintenance of the valves which are functioning within your industrial unit. This is important for both valve reliability and application stability.

For example, ball valves resist clogging, jamming and malfunctioning. But at the same time, they are not suitable to adjusting flow. Installing these valves in units to control flow can lead to leaking or premature failure.

Valve connection types affects the functioning of systems and processes. Each of the connection type has its own advantages and disadvantages.

Valve Selection Guide

If you are tech savvy, and understand numbers online valve selection guide is certainly a boon for you. The online guide offers you directory of types of valves, along with its measurements and the industries in which it can be used.

One can also get their handbook on valve selection guide ordered home, by calling up any best listed valve company online or by any manufacturer in the industry.

A Guide For Selecting Industrial Transmitters For Manufacturing Industry

In terms of pressure and temperature, the industrial transmitters are types of electronic devices, that are designed to provide accurate measurements. The usage of transmitters allows for the monitoring and control of applications, thus ensuring stability, reliability, and safety of processes. Moreover, the industrial transmitters are designed with additional reset and calibration options. This would allow the transmitters to adjust the measurement range while ensuring a complete output signal. Depending on the process application, the transmitters can be segregated in several types. The transmitters are broadly divided into three groups- type, signal production, and process instrumentation. The industrial transmitters can be divided into the following products, based on these groups-

-- Electronic: Subdivided into two types i.e. Analog and digital

-- Pneumatic

The industrial transmitters mentioned above are those classified as broad types and signal production, whereas the transmitters that are utilized for process instrumentation purposes are four types. All the transmitters have multiple common types that are used for various industrial applications.

Flow - ultrasonic flow sensors, differential pressure flow sensors, and velocity flow sensors

Temperature - Thermocouple type, RTD Type

Pressure - Absolute Transmitter, Gauge Transmitter, Differential Transmitter

Level - Point Level, Continuous Level, Ultrasonic Level, Conductive Level, Pneumatic Level, Capacitance

FLOW TRANSMITTER

Why Use A Flow Transmitter?

With a flow transmitter, one can measure and indicate flow. The flow sensor and transmitter are combined in one piece. The changes in flow in the actual process are represented by the flow signal from the flow sensor that is utilized by the transmitter to generate a 4-20mA output. Many customers often just want to know the rate at which a gas or liquid is flowing through a pipeline. In such cases, a simple flow indicator available at a fraction of the cost of the simplest flowmeter will usually suffice. These instruments are simple and easy to install. It requires no external power and can be used to provide local indication of flow.

How To Select/Choose A Flow Transmitter?

When it comes to selecting or choosing a flow meter, the cheapest is by no means best. Even though, it might seem the best way to save money in the short term, considering the lower cost solution may potentially result in problems later down the line. The most-effective installation will be the one where the supplier can provide good technical back-up, an established track record, independently traceable test facilities, and a reputation for high-reliability products based on development and sound-research. There are a few considerations when selecting a flow meter.

A) Purpose and application of the flow meter - What exactly do you want the flow meter to accomplish? What are the requirements of the job at hand? What is the application type?

B) Flow profile of the flow meter - What are the flow rates and characteristics of the liquids or gases for your application? Have you identified the minimum and maximum flow rates for your application? What do you know about the performance qualities of the specific flow meter?

C) Flowmeter performance and capabilities - What size flow meter will be sufficient for your needs? Does the flow meter material or construction have any impact on the fluids of gases that you are moving to? What about the pressure and temperature of the fluids and gas - how will that affect the performance of the flow meter or accuracy of measurement?

D) External factors - What real-life conditions may contribute to equipment downtime? Are their local environment or government regulations that might affect your operations? What about vendor selection?

E) Budget - What is the cost of the flow meter and related equipment? What about installation and maintenance costs? What are the costs of operations? Have you considered the expected lifespan of the flow meter or depreciation values?

What Are The Different Types Of Flow Transmitters?

To measure the flow, various technologies are used in flow transmitters. These include ultrasonic flow sensors, velocity flow sensors, and differential pressure flow sensors.

TEMPERATURE TRANSMITTER

Why Use A Temperature Transmitter?

Temperature transmitters convert the thermocouple or Resistance Temperature Detector (RTD) signal to a 4-20 mA output signal and are the ultimate solution for many remote temperature measurement applications. Moreover, 4-20 mA transmitters have specific advantages over conventional temperature measuring devices. However, it must be selected with caution to avoid "ground loop" problems. The temperature of a remote process must be monitored in many cases. The common sensing devices such as the thermocouples and RTD's produce very fewer signals. A two-wire transmitter would be connected to these sensors that will amplify and condition the small signal. This signal can be transmitted through ordinary copper wire once conditioned to a usable level, and used to drive other equipment such as data loggers, computers or controllers, meters, and chart recorders.

How To Select/Choose A Temperature Transmitter?

When selecting a temperature sensor, there are several considerations.

A) Type of application - What is the device to be measured? Is there ambient temperature in a room or enclosure? Is it an electronic component with plastic or metal packaging that may or may not have high voltages present? Or a bulk of glowing steel? Maybe some parts of an automobile engine such as exhaust port or an intake?

B) Range of expected measured temperature - What process are we measuring the temperature? When exactly should you use an RTD or a thermocouple? Are there applications where a thermocouple is more suitable than an RTD or vice versa? Does the accuracy level of application determine which sensor to use? What could be the ambient temperature range around the measurement point?

C) Temperature display - Is It desirable to have a local display of the temperature? Are you monitoring temperature trend or an actual controlled valve? What is the temperature range of the application? What is the control point? What is the maximum and minimum temperature required for the application?

D) Temperature sensor type - Do you have an established plant or company preferences that may influence your choice of temperature sensor? Are there any specific temperature senor types in your inventory? What is the stability and control precision requirement? Any particular speed of response to the temperature change requirement?

E) Costs and Safety Concerns - What costs are associated with temperature management failure? Is the temperature measurement part of the Safety Instrumented System?

What Are The Different Types Of Temperature Transmitters?

Different types of transmitters utilizing various temperature measurement technologies are available to be used in the process industries. The most common types include thermocouple type temperature transmitter and RTD type temperature transmitter.

PRESSURE TRANSMITTER

Why Use A Pressure Transmitter?

With pressure transmitters, the low-level electrical outputs from pressure-sensing elements are converted to higher-level signals that can be transmitted over a long distance for further processing and usage in various systems. A pressure transmitter has been designed to measure pressure in liquids, fluids, or gases. And for this, various sensing technologies have been utilized. The main purpose of deploying a pressure transmitter is to measure the pressure transmitter of different points of interest and to express the values in different units.

How To Select/Choose A Pressure Transmitter?

Selecting an appropriate pressure transmitter for a correct application can be a tedious task and failure to do so can make the operation of the equipment ineffective and possibly risky. The operating conditions (environment) and performance requirements are the two primary areas to focus on when selecting a pressure transmitter.

A) Operating conditions - What will be the operating conditions of the transmitter? How to choose the transmitter case and wetted materials to extend its service life? How to select on the basis of the medium being measured? Are the parts exposed to the medium compatible with or can withstand its particular characteristics? How to ensure that the appropriate type of enclosure/seal is selected? How can we choose between a gauge and an absolute pressure transmitter?

B) Performance Requirements - Is the pressure range being measured in the vacuum or positive scale of measurement? Is every point of measurement stand-alone or are the differences between the two points being measured? How can we determine the minimum and maximum process temperatures?

What Are The Different Types Of Pressure Transmitters?

The pressure transmitters are divided into three types- absolute, gauge, and differential transmitters that are essentially used in measuring various types of process pressures.

LEVEL TRANSMITTER

Why Use A Level Transmitter?

The level transmitters are mainly used to measure the level of liquid or solid material within a vessel or space. These are the only such type of transmitters that can measure level continuously or at determined points. They provide continuous level measurement and can be used to determine the level of a given liquid or bulk-solid at any given time.

How To Select/Choose A Level Transmitter?

The process of selecting the optimal level transmitter for industrial and commercial processes is affected by many variables. Normally, the selection criteria include physical considerations, including:

Phase (liquid, solid or slurry)

Temperature

Pressure or vacuum

Chemistry

Dielectric constant of medium

Density (specific gravity) of the medium

Agitation (action)

Acoustical or electrical noise

Vibration or mechanical shock

Tank size and shape

While a few of the application constraints are:

Price, accuracy and response rate

Ease of calibration or programming

Physical size and mounting of the instrument

Control or monitoring of discrete (point) or continuous levels.

What Are The Different Types Of Level Transmitter?

The seven types of level transmitters used in industries are - point level, continuous level, ultrasonic level, conductive level, pneumatic level, capacitance level, and hydrostatic based.

Control electronics for proportional valves at Instronline

WHAT IS A PRESSURE SENSOR?

If you are reading this article, then you are probably wondering what exactly is a pressure sensor.

Today, we will hopefully cover all of the questions you may have about pressure sensors.

What is Pressure?

To understand pressure sensors, first, you need to understand the pressure. Pressure is an expression of force exerted on a surface per unit area.

We commonly measure the pressure of liquids, air, and other gases, amongst other things.

The standard unit for pressure is the “Pascal”. This is equivalent to one “Newton per meter squared”.

The pressure of the air in your tire is a great example of pressure and how it is measured.

As we air the tire up, the force it exerts on the tire increases, causing the tire to inflate. This is monitored with a pressure sensor inside the tire on newer vehicles.

How does Pressure Sensor Work?

In a nutshell, a pressure sensor converts the pressure to a small electrical signal that is transmitted and displayed.

These are also commonly called pressure transmitters because of this. Two common signals that are used is a 4 to 20 milliamps signal and a 0 to 5 Volts signal.

Most pressure sensors work using the piezoelectric effect.

This is when a material creates an electric charge in response to stress. This stress is usually pressure but can be twisting, bending, or vibrations.

The pressure sensor detects the pressure and can determine the amount of pressure by measuring the electric charge.

In the RealPars video “What is Sensor Calibration and Why is it Important?” we described the sensor calibration in detail.

Most Common Types of Pressure

What are some of the common types of pressure that you can measure with a pressure sensor?

There are three common types that we use in the industry.

First being “Gauge Pressure”.

This is measured in reference to atmospheric pressure which is typically 14.7 PSI.

You will show a “positive” pressure when it is above atmospheric pressure and a “negative” when it is below atmospheric pressure.

The next type is “Absolute Pressure”.

Simply put, this is the pressure as measured against absolute vacuum. A full vacuum will have an absolute pressure of zero PSIa and increase from there.

If you need to read a pressure that is lower than atmospheric pressure, this is the type of sensor you would use.

The last type that is commonly monitored in the industry is “Differential pressure”.

This is exactly what it sounds like, the difference between two pressures, a pressure being measured and a reference pressure.

Industrial Applications of Pressure Sensors

1. Steam Systems

This pressure sensor on the steam system can serve multiple purposes though. First and most obvious is to observe and monitor the pressure.

Another purpose is to control when and where steam can flow and regulate its pressure.

2.Filters

Pressure sensors are also installed next to filters in many industrial processes.

If the filter begins to clog, the flow will decrease. As the flow of the liquid decreases, pressure can increase or decrease depending on which side of the filter is monitored.

If you monitor the pressure, it will give you a simple indication that the filter is clogged and needs to be cleaned or replaced.

3.Level Measurement

A common use that isn’t as obvious is the use of a pressure sensor as a level sensor.

If the tank is closed, it isn’t as simple of an installation. It is still a viable option though. This will require at least two sensors to measure differential pressure.

Take a Look Back at what we learned!

Pressure is an expression of force exerted on a surface per unit area.

The standard units are the Pascal, Bar, and PSI or pounds per square inch.

Pressure sensors convert the pressure into an electrical signal that can be transmitted and displayed. This is why many sensors are referred to as transmitters.

These sensors commonly measure Gauge Pressure, Absolute Pressure, and Differential Pressure.

Gauge pressure is measured against the atmospheric pressure, absolute is measured against a vacuum, and the differential pressure is the difference between two pressures.

Pressure sensors are commonly used to monitor pressures in different processes.

A common thing to monitor is steam pressure. That pressure sensor can be used to control a valve to keep steam pressure at a constant level.

Another common but lesser known use is to monitor the level of a liquid in a tank.

Filter clogs are a common use of differential pressure monitoring. By knowing the pressure before and after the filter, you can determine if it is clogged.

I hope you learned about Pressure Sensors. Check back soon to find out how to choose a pressure transmitter!

Got a friend, client, or colleague who could use some of this information? Please share this article.

5 REASONS TO INSTALL A VALVE ACTUATOR

SAFETY

RELIABLE OPERATION

INACCESSIBLE OR REMOTE VALVE LOCATION

COST

EXCESSIVE VALVE TORQUE

Setting your valve up with the appropriate valve actuators can make sure you have the right amount of force to turn or lift the valve every time.

BASICS OF VALVE POSITIONERS

There are a lot of different types of valve positioners out there. How do you know if you need a pneumatic, electric or electro-pneumatic positioner? In this post, we'll cover the basics of valve positioners in general, as well as an overview of the different valve positioner types.

A valve positioner is a device that adjusts the valve actuator’s position based on a control signal. These positioners are best used in control applications because of their precision.

Valve positioners are usually mounted on the yolk or top casing of a pneumatic actuator for linear control valves, or near the end of the shaft for rotary control valves. For either configuration, the positioner is connected mechanically to the valve stem or valve shaft. This allows for the valve’s position to be compared with the position requested by the controller. When a control signal differs from the valve actuator’s position, the valve positioner sends the necessary feedback to move the actuator until the correct position is reached.

We came up with 10 Reasons to Install a Valve Positioner so you can discover ways that a positioner could improve your control process. Here is a quick summary of reasons to use a valve positioner on your rotary or linear control valves:

Ability to have fine control over a precise process.
Increase the speed of response to change in process, allowing for faster loading and venting.
Allow for split ranging (one controller for two valves).
Overcome seating friction in rotary valves.
Allow for increased usage of 4 – 20mA electronic signal.
Minimize valve stem packing friction effects and the resulting hysteresis. This is particularly important for high temperature packing materials like graphite.
Negate flow-induced reactions to higher pressure drops and compensates for internal force imbalances.
Allow the use of characteristic cams in rotary valves.

There are a few different types of valve positioners available. Depending on the type of positioner, it either uses air or electricity to move the actuator. Let’s discuss some of the popular options.

Pneumatic positioners receive pneumatic signals (usually 3-15 psig). The positioner then supplies the valve actuator with the correct air pressure to move the valve to the required position. Pneumatic positioners are intrinsically safe and can provide a large amount of force to close a valve.

Electric

Electric valve positioners receive electric (usually 4-20 mA) signals. They perform the same function as pneumatic positioners do, but use electricity instead of air pressure as an input signal. There are three electric actuation types: single-phase and three-phase alternating current (AC), and direct current (DC) voltage.

Electro-Pneumatic

Electro-pneumatic valve positioners convert current control signals to equivalent pneumatic signals. It uses a mix of both electricity and air, as implied by the name.

Digital

Digital or “smart” positioning devices use a microprocessor to position the valve actuator while monitoring and recording data. They function very similarly to an analog-type positioner, except the electronic signal conversion is digital rather than analog. Smart positioners are very accurate, use less air than analog positioners, and allow for online digital diagnostics. For more information, read our blog post about Reducing Air Loss with Smart Valve Positioners.

Pneumatic Actuator (Air Cylinder) Basics

Basic Styles

Force

The above Figure shows a basic system to power and control a pneumatic actuator. When selecting an actuator it is important to properly match the cylinder to the job.

Speed

Once the cylinder stops moving however, the friction losses go away and the pressure builds back up to 80 psi. This situation results in a jerky motion of the cylinder as it moves the load.

Several factors could overcome this problem:

-- System pressure can be increased to overcome friction losses

-- Larger tubing can be used to reduce friction losses

-- Different size cylinder could be tried that will reduce the flow

Mounting

Cushions

Magnetic Pistons

Temperature Extremes

Pressure Switch Basics and Selection Tips

Sensing Technologies

A pressure switch is simply a device capable of detecting a pressure change and, at a predetermined pressure, opening or closing an electrical switch.

Pressure switches are usually classified as either electromechanical or solid state.

With a bellows or bourdon tube switch, the movement of the bellows, or sealed metal bourdon tube, is caused by pressure changes; this movement mechanically operates a snap-acting switch.

A piston switch design uses an O-ring sealed piston that moves in response to pressure changes, and directly or via a push-rod, actuates the electrical snap-acting switch.

Ranges, Setpoint, & Deadband

Both electromechanical and solid state pressure switches are commonly available to sense vacuum, positive pressures up to thousands of psi, and compound ranges of vacuum to positive pressure.

The predetermined point at which the pressure switch contact opens or closes is the setpoint.

Proof and Burst Pressures

Overpressure ratings include proof and burst pressure specifications. Proof pressure is the amount of overpressure that can be applied to the pressure switch without causing damage. The pressure switch can be exposed to pressure reaching the proof pressure rating, and be expected to work properly when the pressure returns to within the rated operating pressure range.

Burst pressure is the amount of overpressure applied at which the pressure switch will certainly be damaged. Physical damage to the pressure switch may occur at any point between the proof pressure and burst pressure. Because proof pressure ratings are determined in a laboratory under controlled conditions including rate of pressure change and temperature, they should be considered a reference value. It is not uncommon for pressure switches in the field to experience pressure surges and spikes that cause damage if a switch with too low of a proof pressure rating was selected. Typically solid state switches have lower proof pressure ratings and are most sensitive to overpressure conditions. Electromechanical switches with a diaphragm generally have higher overpressure ratings than solid state switches. Piston design switches have very high overpressure ratings and are the most reliable when subjected to pressure surges or spikes, and applications where the normal working pressure is above the nominal range of the switch. If pressure surges or spikes are anticipated in an application, a pressure switch with a high proof pressure should be selected to avoid damage.

Installation of a pressure snubber can also help to dampen the effects of fast pressure spikes on a pressure switch.

Accuracy (Repeatability)

Chemical Compatibility

Cycle Life and Cycle Rate

Electrical Characteristics

Selecting Motors for Industrial Applications

Mechanical and environmental considerations are on the list, as is the application and operation. All of these factors are important, but the application is where the selection process should start.

Selecting Motors

The application defines the motor load, speed, acceleration, deceleration and duty cycle of the motor. This all feeds into the horsepower and torque requirements. Control of motor speed and position also determines the type motor used, and defines whether the motor load is constant or variable horsepower and torque.

Applications Drive Motor Loads

Applications drive the type of motor load, and there are four main types in industrial automation:

-- variable horsepower and constant torque

-- variable torque and constant horsepower

-- variable horsepower and variable torque

-- positional control or torque control

Gear pumps, cranes and conveyors are examples of variable horsepower and constant torque applications. Constant speed AC and DC motors work well in these applications where the horsepower requirements may vary, but the load remains constant.

A web unwind or rewind machine is an example of a variable torque and constant horsepower application because the load increases with the diameter of the roll and vice versa. DC motors and servo motors work well here, and AC motors with closed loop drives are another option. Consider regenerative power in this case to increase efficiency.

Centrifugal pumps, fans and mixers/agitators require variable horsepower and variable torque. When speed increases, so does the motor load. Variable frequency drives (VFDs) are often used in these situations.

Motion control applications with linear motion slides and actuators often require accurate positional control, and some presses and tension control systems use torque control. Feedback is usually required, and servo and stepper motors are often a good choice.

Pick a Motor

You only need to choose between two classifications of motors, AC and DC, but there are over three dozen motor types used in industrial applications. Fortunately, looking through the Instronline Control and Motors online catalogs, you’ll find solutions for most motor applications using servo systems, stepper systems, general purpose and inverter duty AC motors—or general purpose DC motors and gearmotors.

The selection of motors and drives listed and pictured about should cover most industrial automation motor applications.

Some applications need a gearbox to increase torque. To help with motor, drive and gearbox sizing, Instronline has online product selectors and configuration utilities for Sure Servo Complete Systems, AC Motors, SureGear Gearboxes and more. With application and environmental information in hand—it’s possible to calculate load inertia, torque and speed—along with mass and size of the load.

Application Types

Three common motor speed/torque control applications include constant speed, variable speed and torque (or position) control.

Constant Speed Applications

Many applications only require the motor to run at constant speed with no need for acceleration and deceleration ramps. Simple on-off control using branch circuit protection fusing, contactor and overloads are all that is needed to turn the motor on an off. Motor starters, manual motor control or soft starter are also often used.

Common AC and DC motors are suitable in these applications. Both are simple and efficient designs and require minimal maintenance.

Variable Speed Applications

Precisely controlling the speed of fans, centrifugal pumps, mixers/agitators, conveyors and other loads can greatly increase energy efficiency. The ability to control acceleration and deceleration may also help handle product better, such as on a conveyor, and reduce mechanical issues by being gentler on the motor and drivetrain of the system. Coarse positioning of product can also be accomplished with variable speed control using slowdown and stop photoeyes.

DC and AC motors work well in most variable speed applications. DC drives have been around for over 100 years, and variable speed drives for AC motors have been in use for about 30 years.

DC motors are common used on conveyors and other fractional horsepower applications because they provide full torque at low speeds, with torque remaining constant throughout much of the speed range. Many DC motors use brushes which require maintenance, so keep that in mind or spend a little more money for brushless DC motors, or switch to AC motors and drives.

An AC induction motor with a VFD is the popular choice today. If it is a fan or pump application, this is often the best option, especially if motor loads are over 1 HP.

Position Control Applications

Beyond simple constant speed and variable speed applications is motion control. Executing precise position control, and implementing motion profiles with closed loop control, often requires a servo or stepper system. Dispensing applications and moving a linear slide or actuator are examples.

At the low speed end of the precision scale, a stepper system, open or closed loop, is a good choice, especially since the stepper has full torque at zero speed. As speeds and accuracy requirements increase, a servo system is a good choice because it handles dynamic loads and complex motion profiles better than a stepper.

There is a wide choice of AC, DC, stepper and servo motors available for your applications. Identify whether it is a constant speed, variable speed or position control application—and then size and select appropriately using online guidance from Instronline.

Difference between contactors and relays

Constructional Features:

Operation of Relays and Contactors

-- Relays are switching devices used in any control circuit for checking a condition or multiplying the number of contacts available.

-- Contactors are switching devices used to control power flow to any load.

Difference between contactors and relays

RELAYS

Relays are switching devices used in any control circuit for checking a condition or multiplying the number of contacts available.
Relatively smaller in size
Used in circuits with lower ampacity. (Max 20A)
Mainly used in control and automation circuits, protection circuits and for switching small electronic circuits.
Consists of at least two NO/NC contacts
Relays do not have an arc suppression system built-in.

CONTACTOR

Contactors are switching devices used to control power flow to any load.
Larger when compared to Relays
Used in circuits with low and higher ampacity up to 12500A
Used in the switching of motors, capacitors, lights etc.
Consists of a minimum one set of three-phase power contacts and in some cases additional auxiliary contacts are also provided.
Normally, contactors have in- built arc chutes for suppression.

Tips for Specifying Variable Frequency Drives(VFD'S)

For well over 30 years, variable frequency drives (VFD) have been controlling the speed of three-phase alternating-current (AC) induction motors. In addition to saving energy, there are many things to consider for maximum efficiency, control, operation and motor life when using VFDs.

A VFD’s speed control is necessary for applications where variable torque and horsepower are needed such as centrifugal pumps, blowers, fans, mixers and agitators. Operating at lower speed offers significant energy savings. Other key features included variable acceleration and deceleration, non-emergency motor start-stop control and overload protection.

To realize the benefits of VFDs in variable speed motor applications, let’s look at the top ten tips in the Table.

Table: Top Ten Tips for Specifying and Using VFDs

1. Understand and use benefits and features

2. Size based on loads

3. Select braking options

4. Interface to the VFD

5. Understand digital communication options

6. Apply the right control mode

7. Define the motion profile

8. Outline installation requirements

9. Specify operation parameters

10. Handle noise and harmonics

Reducing motor speed saves energy in a variety of fan, blower and pump applications. Reduced inrush current when starting a motor along with controlled acceleration and deceleration are also big benefits. Features on the VFD, such as a keypad or potentiometer, allow manual adjustment of parameters, including speed and torque. Automatic adjustment of these parameters is also possible using a PLC or other controller.

When it comes to sizing the VFD, don’t just match the horsepower of the motor. Review of the operating profile is important as changing loads, and continuous running or frequent starts and stops, changes torque and peak current demands.

Peak current demands may create temporary overload conditions, yet the VFD must provide adequate current for proper motor performance. In an application, such as a conveyor with a heavy load, high breakaway torque may demand power and torque, requiring an oversized VFD. The additional headroom provided by a larger drive is worth the small increase in price and extra required panel space.

When decelerating a motor, a VFD can provide approximately 20% of the available torque for braking. For heavy loads and frequent start-stop applications, adding a braking resistor can significantly increase braking torque.

Interface, Communication and Control

Typical run, jog and speed control functions in a VFD are selected using discrete or analog outputs signals from a controller.

Often a combination of discrete, analog and preset control is used. For example, a controller sends an analog speed signal to a drive, and discrete signals to control run and jog functions, with acceleration and deceleration parameters hardcoded.

To reduce or eliminate hardwiring, digital communication such as Modbus RS-232/RS-485, EtherNet/IP or other protocols can be used to control the drive and set parameters. This type of communication also enables monitoring of the drive status, such as speed and current, and may also enable remote configuration capability.

Some drive control modes require specific types of AC drives. Volts-per-Hertz (V/Hz) drives are most common, and work well for pump and fan applications. As speed accuracy requirements increase, open-loop sensorless-vector drives, and closed-loop VFDs with encoder feedback, provide accurate speed regulation for web handling, paper mills, printing presses and converting applications.

Understand Motion, Installation and Operation

Before setting a drive’s parameters, be sure to understand the motion profile required. What speed is needed; and can the motor accelerate slowly or must it start quickly, are just some of the questions to be answered. VFD parameters must also be understood for optimum drive setup and control.

VFDs create heat during operation that may need to be vented out of the control cabinet, particularly if there are frequent starts and stops. Running a motor at low speeds for extended periods also adds heat and usually requires an inverter-duty rated motor, which includes a built-in fan.

The AC drive manual covers many installation requirements. An important installation note is to not use a contactor or disconnect switch at the AC drive input for run-stop control, but only to remove power from the drive input under an emergency stop condition. Use discrete signals or digital communication for non-emergency start and stop functions during normal operation.

Noise and harmonics generated by a VFD can damage connected motors and nearby equipment. Passive harmonic filters such as AC line reactors and chokes are often installed to reduce these problems. Check the drive installation manual and use these filters to reduce harmonics and protect the VFDs from transient overvoltage. Active harmonic filters can also be used to reduce noise generated by the VFD.

What is a Pneumatic System?

In machine automation a pneumatic system provides a simple and cost-effective means to move, clamp, rotate, grind and screw.

A pneumatic system is a collection of interconnected components using compressed air to do work for automated equipment. Examples can be found in industrial manufacturing, a home garage or a dentist office. This work is produced in the form of linear or rotary motion. The compressed air or pressurized gas is usually filtered and dried to protect the cylinders, actuators, tools and bladders performing the work. Some applications require a lubrication device that adds an oil mist to the closed pressurized system.

Pneumatics is an application of fluid power—in this case the use of a gaseous media under pressure to generate, transmit and control power; typically using compressed gas such as air at a pressure of 60 to 120 pounds per square inch (PSI). Hydraulics is another form of fluid power, which uses a liquid media such as oil but at a much higher pressure with a typical range of 800 to 5000 PSI.

A big reason pneumatics are used is due to simplicity. With little experience, on-off control of machines and equipment can be designed and assembled quickly using pneumatic components such as valves and cylinders. With proper air preparation, pneumatics systems are also reliable, providing a long service life with little maintenance needed.

Be Efficient

While a design using pneumatics is simple, there are some techniques to help make a better, more efficient system. It’s important to eliminate leaks. Any signs of an air leak should be addressed immediately. Related to this is tube length. Shorter tube lengths minimize system volume that must be pressurized and wasted each cycle, in turn minimizing air use. A valve mounted directly to a cylinder is an extreme example, providing the quickest pneumatic system response as well.

When selecting pneumatic components, be sure to not oversize them. This includes cylinders, valves, hose and tubes. Use online pneumatic air consumption tools to assist with this. Basically, determine the force needed to perform the work, calculating cylinder bore size based on this and the pressure available. With the pressure and cylinder bore known, calculate the valve air volume in cubic feet per minute (CFM), using the pressure, bore, stroke length and time for stroke.

While the cylinder is performing work, during clamping for example, a suitable design pressure of 60 to 80 PSI is common. However, retracting the clamps at a lower pressure uses less energy, so consider using a low pressure return or homing pressure.

Pneumatic System Components

There are many components connected to create a complete pneumatic system. Nearly all pneumatics systems consist of these items:

A method of generating compressed air to power the system. This is usually a plant air compressor and often includes pressure tanks, for reserve air, and distribution piping to machines and equipment.
A method of conditioning the compressed air, both at the compressor and locally, at the machine. All pneumatic motion requires clean and dry air with enough flow and pressure to perform the work. The process of filtering, regulating and lubricating compressed air is known as air preparation, or air prep. Manufacturing plants include air prep at centralized compressors, and additional air prep is beneficial at each machine’s point- of-use. This includes a manual shutoff, a filter to remove dirt, oil and water as needed, a regulator to control the system pressure, and possibly a lubricator to lubricate the air when needed for air tools or similar. A “soft start / exhaust dump” valve is also often included for operator safety to shut off upstream pressure and quickly relieve motion causing downstream pressure (pneumatic energy) when de-energized during a safety event.
A method of controlling the directional flow of air. These are typically one or more types of valves. A good choice in machine control would be a 5-way, 3-position, center-exhaust valve where the center off position dumps air from both sides of the cylinder when an emergency stop is pressed, and power is removed. This valve typically operates using two 24 VDC solenoids. Energizing individual solenoids extends or retracts its corresponding cylinder.
One or more air-driven work devices. These can be linear or rotary actuators (cylinders), grippers, motors, air nozzles, etc.
A collection or fittings and piping to connect all the components of a pneumatic system. These include rigid pipe and tubing or flexible tubing or hoses. Most cylinders include flow controls to both ports, to limit the cylinder speed by restricting air as it leaves the cylinder.

Pneumatic systems are common in industrial machine automation. Be sure to supply, prepare and distribute the air properly. When correctly selected, assembled and installed, pneumatic devices and actuators will have a long, efficient life with limited maintenance required.

WHY CHECK VALVES SLAM AND WHAT TO DO ABOUT IT

Check valves are simple valves. They use forward flow to open the valve, then automatically close when flow stops, preventing reverse flow from making its way back through the valve. They don’t require power to function, and they don’t require a whole lot of attention or maintenance. They do get a lot of attention, however, when they slam.

What causes the slam?

A check valve relies on gravity and/or reverse flow to close completely. Opportunity for check valves to slam frequently occurs at pump shutdown. When a pump stops, gravity and reverse flow slam the check valve shut. Because fluid is non-compressible, it creates a pressure or shock wave (water hammer). The fluid continues to flow back and forth until friction losses cause the wave to settle.

Slamming check valves cause serious pressure surges in a system that rattle pipes and damage equipment. Some people assume that’s just what check valves do. "No matter what, they’re going to slam." But that’s just not the case. Usually, the real cause of these problems stems from poor sizing and selection, not the type of valve itself.

Minimizing Slam Through Proper Sizing

Oftentimes check valves are selected based on the pipe size and the desire for the largest Cv possible. (CV stands for “coefficient of flow” for valves and demonstrates a valve’s capacity for liquid to flow through it.) Of course you want the ability to put as much fluid through the valve as possible, right? Makes sense, except this completely disregards the fact that flow conditions determine the internal performance of a check valve because the disc is directly in the flow path.

If there is not enough flow to keep the valve fully open with the disc reaching the ceiling of the check valve, the disc will move up and down, resulting in pre-mature wear, potential for failure, and a higher pressure drop.

For proper check valve selection, consider the following:

-- Line sizing

-- Application data (fluid characteristics, including
temperature and pressure)

-- Seat type

-- Installation (horizontal or vertical)

-- End connection

-- Valve rating

-- Material compatibility with the medium

-- Envelope dimensions

-- Leakage requirements

Selecting a valve of the proper size will have an impact on the amount of water hammer felt by the piping system.

Selecting the right type of check valve

Another solution to slamming check valves is to look at the type of check valve used in the application. Silent, ball, and resilient hinge are alternatives to the traditional swing check valve. They each carry different characteristics with varying degrees of pressure drop and closure speed.

Silent Check Valves

Silent or spring –assisted check valves do not rely on gravity or reverse flow to close. Instead, the spring closes in about one-tenth of a second, the valve before reverse flow has an opportunity to slam the valve shut. It is able to close quickly because it has a shorter distance to travel than the flap on a traditional check valve.

Ball Check Valves

Ball check valves are economical and very simple valves. They sometimes utilize a rubber coated ball that floats up and out of the way while flow passes through the valve, and seats when flow stops. This particular valve closes slowly, so the potential for slamming is high.

There are other styles of ball check valves that work similarly to silent or in-line check valves. These are called cone check valves.

Resilient Hinge Check Valves

Resilient hinge check valves are very similar to the traditional swing check valve. The major difference is that a rubber molded disc flexes up and out of the way when fluid flows through the valve. The flap does not rotate around a hinge pin.

It has a shorter stroke than a traditional swing check valve, reducing the closing time of the valve and minimizing the potential for water hammer to occur.

Conclusion

Each of these valves have different characteristics, features and benefits that should be carefully selected for just the right fit into a system. If you’re experiencing issues with a check valve or need to select a new one for your process, talk to an engineer experienced in selection/sizing of these valves. Doing so will help your system perform at its highest efficiency while reducing slam and requiring less maintenance.

Working Mechanism of pneumatic cylinder

A pneumatic cylinder can be found in many different types, like single-acting cylinder, double acting cylinder, rotary air cylinder, rod-less air cylinder and telescoping cylinder. These cylinders are preferred for many reasons that include noise-free operation and elimination of the need to store liquids, as in the case of hydraulic cylinders. An air-based pneumatic cylinder is also clean and environment-friendly as any leakage from it doesn’t pollute the surroundings.

Pneumatic actuators are the tools consisting of parts like pneumatic cylinder, piston and valves and are used in the applications like oil refining and chemical industries. Another popular category is that of pneumatic drills which is widely preferred over those based on electric motors these days. Grinders, wrenches and sanders are other popular tools based on pneumatics. Some of the other categories gaining popularity with the manufacturing and other industrial units include air compressors, air brakes, pneumatic bladder, pressure sensor and pressure regulator.

Shopping for an air cylinder may quality like a unproblematic and quick task when you look at it from the external. But the moment that you go to buy one of these you will detain that all has distorted right before your eyes. When air cylinder comes time to make a business decision you have to get on the right way or option individual left out in the dark without the item that you need. Usefully, if you know what goes into buying an air cylinder you can make the nearly everyone of the procedure and finally get the excellent one?

What are you using it in maintain of?

Will you need any pneumatic accessories to go beside with it, such as a pneumatic air typical? It is one thing to know who sells air cylinders, but one more entirely to get the one that is right for your use. Which might require a high pressure cylinder, while others are using them to make some sort of relaxation item? In fact, your use is going to have a lot to say about the type of air cylinder that you end up purchasing.

When you pay money for any range of air cylinders you need to make sure that the analysis you make is one that you can live with now and into the future. Do you think you have the information just before buy the right unit sometime in the near opportunity? If you have ever made a purchase in the past you possibly know to convention. If this is new to you make sure you take your time. Business an air cylinder should be a perfect system. In the end, if you made the right purchase you will know it.

These devices differ from their hydraulic or electrical counterparts based on the kind of driving force they use. Unlike the hydraulic or electrical tools, it is far cheaper to work with pneumatic tools as they make use of air to operate which is available in plenty. Moreover, they are highly efficient in carrying out different functions which is why most people prefer working with them.

These devices have a simple working principle that makes it fairly convenient to work with them. Stored gas or air consists of potential energy which gets converted into the kinetic energy under the force of compression. The compressed gas or air will invariably try to expand, thus forcing the piston of the device to shift with a significantly large force. This force derived from pressurized gases actually forms the ultimate basis of the operation of pneumatic tools. The simplest device that makes the use of this working principle is a pneumatic cylinder. Different types of pneumatic cylinders are filled with gases like CO2 or air is connected to other pneumatic devices to carry out desired functions.

How do you select a gerotor motor?

When selecting a gerotor motor, there are many items to consider, including performance, quality, reliability and cost. Choosing the wrong one could lead you down a path of frustration. Before selecting your motor, let’s discuss the basics of gerotor motors.

The gerotor motor, or generated rotor motor, has been around for decades. In fact, the first gerotor motor in Eaton’s portfolio was manufactured more than 65 years ago. Soon after, the company invented the Geroler motor to meet the needs of the market and improve upon performance and reliability.

These two motor types use what is termed as the orbit principle, which is what gives the motors their tremendous power density and compact size. A gerotor motor star has six teeth and seven lobes. The spaces among them are pressure chambers. Pumped fluid flows into these pockets, creating high pressure in one chamber and low pressure in another. This creates an imbalance of forces, which causes the gerotor motor star to rotate, or orbit. A gerotor motor star orbits multiple times, Figure 1, typically six to eight times depending on the specific star and ring geometry—for each complete single revolution within the outer ring. Geroler motors use the gerotor principle, but use rollers instead of lobes. This reduces friction and wear—and improves low-speed performance, extending the motor’s life.

Gerotor and Geroler motors deliver from 10 to 50,000 in.-lb of torque and can operate at speeds up to 2,000 rpm. Because of their simple design and compact size, they can be used in both mobile and industrial applications. However, they are well-suited for mobile applications—especially agriculture, material handling and construction—because of their incredible power density.

The speed and torque requirements of the application will determine the size of motor. This will point users into what displacement (how much fluid is needed to turn one revolution) is needed. Speed and torque can be determined with the following basic motor equations. These are the starting points for finding the properly sized motor.

Theoretical torque (in.-lbs) = in.3/rev x pressure differential/(2Pi)

Theoretical speed (rpm) = gpm x 231 / in.3/rev

Here are five things to consider when deciding on the right gerotor or Geroler motor for your needs:

Performance:

– Ask for mechanical and volumetric efficiency data, and make sure the test data is over an extended period of time. Some manufacturers may tune performance to peak in the first few hours of operation, but then degrade quickly. Performance that degrades quickly will not do your machine justice.

– Compare apples to apples; hydraulic motor performance data is not standardized. Be wary of ratings and test data that do not include all of the performance test parameters.

Quality:

– Does the manufacturer have a history of consistent quality? Ask for the quality data.

– Motor grinding is not all the same. Grinding star profiles outside the capabilities of the form grinding machine will cause inconsistent results.

– Look for high-quality materials and ensure that inferior materials (with processes like heat treating and form grinding) are not being used.

– Compare the warranty options.

–

Reliability:

– Reliability is quality over time. Look for a product with a track record—history is the best predictor of the future.

Support:

– Investigate the options for additional support. Would you benefit from CAD modeling support or the creation of a custom solution? Remember that this can differentiate your machine from the competitor.

– Do you just want a part or do you want a system of solutions? Some manufacturers can provide a custom system of solutions for your machine, while others specialize in providing a singular part.

Cost:

– Obviously cost is very important, but it is really a function of all the previous items. Sacrificing the above items can provide a lower cost, but consider what will happen to your machine (and your customer) when issues arise.

– Some companies try to keep costs low by having a “one size fits all” approach to their motor portfolio. This may work for some, but make sure the solution you choose really works the way it should on your machine.

WHICH PUMP MOTOR ENCLOSURE DO I NEED?

Which motor enclosure is right for my pump motor?

Here's a few others we recommend for applications we see:

Weather Protected Type 1 (WPI) - As you might expect, the Weather Protected Type enclosures are for outdoor use. Their purpose is to prevent debris, dust, rain, and rodents from entering the motor.

5 THINGS YOU MUST KNOW FOR SIZING A PRESSURE REGULATOR, CORRECTLY!

1. UPSTREAM PRESSURE

2. DOWNSTREAM PRESSURE

3. FLOW RANGE (minimum, maximum and normal)

It’s a good idea to size the regulator at a minimum of 3 separate points in order to get a range of flow requirement. This gives you a safety factor, so the regulator is not over or under-sized.

4. TEMPERATURE (minimum and maximum)

Temperature can affect the required Cv. Note that temperature does not affect Cv nearly as much as pressure and flow.

5. FLUID TYPE

A regulator cannot be accurately sized without knowing these 5 variables. Understand that changing any of the above values could get you into a completely different regulator.

After sizing, the next step is to select your regulator by identifying the following criteria:

Line size
Material compatibility
Connection type
Accuracy required
Shutoff capability (metal seated vs. resilient seated)
Direct-operated vs. Pilot-operated

ASEPTIC VALVE OR HYGIENIC VALVE, WHAT’S THE DIFFERENCE?

What's aseptic?

How hygienic and aseptic valves are similar

How’s hygienic different from aseptic?

While aseptic valves aim to prevent contamination from the environment, the focus of hygienic valve design is easy clean ability.

When do I use aseptic or hygienic valves?

Hygienic valves are common in food, beverage, and dairy manufacturing. They are found in processes where clean ability (CIP or COP) is extremely important.

VALVE SIZING: WHAT ARE SAFETY FACTORS?

When sizing a valve for an application, you may have heard engineers talk about safety factors. What is a safety factor, and why is it necessary to have it factored into the valve's size?

A safety factor is essentially a measure of protection against a change in process conditions. It ensures that the valve will still operate as required, even if the process conditions change and are outside the parameters originally designed for the valve. The safety factor frequently oversizes the valve. A valve that is oversized is far more manageable and safer than a valve that has been undersized.

Safety factors are are applied as an engineer reviews the following criteria:

Flowing Conditions

Typically valves are sized anywhere from 60-80% of valve open. Should flow exceed this, extra capacity will be available in the upper flow range. Not having a safety factor here will restrict flow through the valve, causing a higher pressure drop, potentially starving the downstream equipment of the flow and pressure required.

Pressure and Temperature Ratings

Pay careful attention that the pressure – temperature ratings of a particular valve are well within the requirements of the service. This also applies to the packing and gasket materials as this may limit the rating of the valves.

Valves are rated for pressures, i.e. class #150, #300, #600 and so on. When sizing a valve for pressures you also need to take the temperature of the process as a factor. For example water on a class #150 carbon steel valve at 100°F service temperature is rated for up to 285 PSIG operating pressure. Likewise a class #150 carbon steel valve at 1000°F is only rated to 20 PSIG. This is the rating on the body only not the rest of the valve materials like the packing and seats. Those also need to be looked at.

Different materials of construction offer different pressure and temperature limits. Though we only spoke here of high temperatures, it's just as important to consider lower temperatures. Standard carbon steel is only rated to -20°F and would require different materials below -20°F.

Process Media

Water is pretty straight forward. Special process media like a syltherm or Dow therm require special attention to not only the body material, but also the type of end connections for process sealing of the piping. Some users prefer using #300 flanged connections on a class #150 pipe line because they can make tighter connections. PTFE would be trouble for syltherm at -50°F as it can crack the PTFE and cause leaking. This would be true for both seats and seals.

Need help sizing or selecting a valve? Ask us about it! We gladly provide technical assistance to businesses

WHEN CAN BUTTERFLY VALVES BE USED AS CONTROL VALVES?

I’ve seen rumblings across a few valve forums about the ability of a butterfly valve to be used as a control valve. Some people say it’s fine to use, others say it’s just a way of cheaping out on the process, that there’s no way a butterfly valve can deliver the control one would need. Who’s right?

To get the answer, I called up one of our Senior Application Engineers for valves, Ralph Lechner.

I explained to him the things I had read, and asked “So when is it appropriate to use a butterfly valve in a control application?” He responded with “It’s always appropriate! A butterfly valve can be used in control applications, BUT… you must first weigh your expectations against the valve’s capabilities in the process conditions set forth.”

Butterfly Valves – An Economical Choice

Butterfly valves are a great (and less expensive) alternative to globe and other control valves in applications where 1-2% accuracy is acceptable. Process conditions will dictate whether a resilient seated or high performance butterfly valve should be selected.

A resilient seated butterfly valve is the most economical choice. If pressures and temperatures are not extreme, this type of valve should work just fine. If pressure and temperature exceed the limits of a resilient seat, a high performance butterfly valve is necessary.

Getting Maximum Control of Butterfly Valves

Other control valves have linear flowing characteristics. A butterfly valve’s design does not allow it to have linear flow characteristics (due to the shape of the disc and its relationship to the pipe), thus making it more difficult to control.

Consider adding instrumentation and a positioner to the valve to help gain more precise control of the valve. Also, make sure operating process conditions are ideal for proper control. Excessive temperatures and high velocities always need to be considered.

Though the butterfly valve isn’t the right choice for processes that require precise control, like mixing paints or food flavors, don’t throw it out of contention. It still has a place in the control valve category. Ralph recommends looking to the butterfly valve first for control applications.

Not sure what to select for a control valve? Ask us about it! We gladly provide technical assistance for valve selection to businesses.....

What are the Pros and Cons of Mass Air Flow Sensors?

This can be observed in multiple automotive applications, where calculating the best air/fuel ratio needs the mass of the gas irrespective of its environment, not only its volume.1 Although, there are also different approaches for alternative devices, for example manifold pressure sensors or speed density measurements for engines.

For applications where volumes and temperatures are expected to maintain consistency, a flow meter may be a beneficial proxy for mass flow rates. This article will discuss some of the main benefits and weaknesses of the use of mass air flow sensors for various applications.

Pros

A Large Number of Design Options

Mass air flow sensors are available in a variety of sensor types and designs. Hot-film or hot-wire sensors are the most popular, and it is possible to include extra characteristics for example silicon layers or membranes 2 to create true mass flow readings that are able to cope with turbulent conditions and back flow.

For example, micro machined mass air flow sensors, also known as MEMS sensors, are commonly used in medical applications, where their compact, small, and chip-based design makes them simple to integrate into devices for artificial ventilation.3,4

Utilizing further electronics, it is also comparably simple to build in amplifiers to maximize the signal levels from the sensors where only slight variations in mass flow rate are expected.

Along with there being several types of mass airflow sensor, it is also a possibility to tailor their performance characteristics by tuning parameters, for example the outlets on the housing and the gas intake.

Various housing designs can also be employed to decrease turbulence in the air intake, which can enhance performance. Furthermore, inlet sizes can be made greater so that the mass air flow sensor does not limit the intake of air.

Robust Measurements

As mentioned before, a flowmeter could possibly be considered as an alternative to a mass air flow sensor in particular environments. Although, given the volume dependence on temperature and the of gases, flow meter readings are highly sensitive to changes in environmental conditions.5

The option to adjust mass air flow sensors to perform under back flow and make true mass air flow readings makes measurements much more hardy for applications such as automotive analysis and gas chromatography inlets, where the chemical composition of the gas is essential.

Low Cost

In mass air flow sensors, the lack of moving parts makes them more dependable and simpler to maintain and, for thermal mass air flow sensors especially,makes them relatively low cost. MEMS-based sensors commonly have very low draws of power, which decreases the related costs of running the sensor.

These devices are easy to produce in the masses, which helps to keep manufacturing costs low, making mass air flow sensors an inexpensive solution for mass air flow measurements.

Cons

Easily Contaminated – Leading to Sensor Malfunctioning and Failure

The introduction of self-cleaning hot-film and hot-wire sensors has decreased the issues related to sensor contamination but has not totally eliminated them. A high current is utilized to enhance the temperature of the wire and ‘burn off’ any debris to self-clean the wires.

Badly performing mass air flow sensors as a result of contamination are one of the most frequent sources of engine issues. While relatively simple to correct, any tiny amount of trace material that adjusts the resistivity of the wires can lead to inaccurate results in the sensor measurements.

Cleaning also increases the risk of breaking the fragile wires in hot-wire type sensors or harming the surface of the film, which would both render the sensor useless.

Thermal Mass Air Flow Sensors Require Calibration

To analyze the mass flow, thermal sensors are reliant upon temperature changes between the metal surface vulnerable to the airflow and a shielded reference wire. As various gases have alternate thermal characteristics, the heat loss and increase of current in the exposed wire will be changeable dependant on the composition of the gas.

As this current change must be calibrated against a mass flow rate for the sensor to perform and carry out the conversion correctly, this means that calibration is only beneficial for one kind of gas.

Reduced Air Intake and Performance

Although mass air flow sensors can be produced with an inlet to decrease the restriction of air entering the sensor and ultimately the device, even the most recent hot-wire devices do impact air intake slightly.

This is more challenging in older sensor designs where the air flow restrictions were increased, and the sensors were incapable of coping with back flow issues. These problems frequently resulted in fueling problems while accelerating and starting the engine, where the air intake was at its most turbulent and, as a consequence, fuel mixtures that were too rich were being used.

What are solenoid valves?

Solenoid valves are electrically activated valves, typically used to control the flow or direction of air or liquid in fluid power systems. Used in both pneumatic and hydraulic fluid power functions, the spool or poppet design of most solenoid valves makes them perfect for various functions and applications.

The spool or poppet of the valve connects to a ferrous metal plunger, which is typically spring centered or spring offset, but may be detented instead. The plunger slides within a core tube of non-ferrous metal, itself surrounded by a coil of electrical windings. The coil exists with any range of voltage from 12-48 Vdc to 110-220 Vac. When power is sent through the coil, a magnetic field is created, which pushes or pulls the plunger, shifting the valve.

The most basic solenoid valves are two-way, two-position poppet valves, which simply open and close, modifying their flow path when their coil is energized. They are available as “normally-open” and “normally-closed” versions, which means normally-flowing and normally-blocked, respectively. Normally-open in fluid power contradicts normally-open in electronics, which stands for the switch or contact open and not flowing electrons.

Three-way, two position poppet valves are also common, diverting flow from one channel to another. Two 3/2 valves in parallel can be used to control a cylinder bidirectionally. Although construction varies depending on the use, this type of valve can be used for either pneumatics or hydraulics, but is more common to pneumatic systems.

Spool solenoid valves consist of a machined spool which slides within a machined valve body. One or both ends of the spool are acted upon by a plunger, and when activated by either coil, pushes the spool one way or the other, allowing three positional envelopes. The 4/3 hydraulic solenoid valve is one of the most popular, allowing for bidirectional control of a cylinder or motor from a single valve body. The “ways” of a solenoid valve refer to how many ports it contains, and the “positions” of a solenoid valve refer to how many discrete states in which it operates. A three-position valve employs a spring centered neutral state along with two actuated positions.

For bidirectional motor or cylinder control, pneumatic valves are machined with five ports, and are referred to as 5/3 valves as common practice. The “ways” of a pneumatic valve also include its exhaust ports, to which there are usually two. Occasionally these same valves are described as 4-way, 3-position valves, even though close inspection reveals the two exhaust ports bisecting the pressure port.

Solenoid valves for either hydraulic or pneumatic applications are available as manifold-mounted modular units, such as the pneumatic or hydraulic ISO valves. These valves contain standard mounting and porting patterns, permitting valves from any manufacturer to be installed upon the same manifold. Most often, these valves are also quite economical, and readily available “off-the-shelf.”

The electrical coils of a solenoid valve are optioned with either DIN connectors, lead wires, Deutsch connectors, central connection or any other popular form of electrical connection used in fluid power and automation. Most solenoid valve coils are field replaceable, making repair and maintenance easy for technicians. Coils also have a wide range of application and purpose. Some are intended for the industrial environment, where atmospheric conditions are consistent. Mobile environments are much more demanding and command coils to handle both extreme temperature ranges and exposure to road film and salt, for example.

The evolution of dual cylinder actuation

When should you use stainless steel cylinders?

Stainless steel air and hydraulic cylinders are used in applications where corrosion resistance is the utmost priority. Standard cylinders are made from combinations of alloy steel, such as 1018, 1045 and 4140, which are all susceptible to oxidation and rust in humid or wet applications. Even when epoxy painted, carbon steel cylinders exposed to surface abrasion, dents or harsh chemicals can wear away any paint, leaving exposed steel to corrode.

Marine environments often require the usage of stainless steel cylinders, both onshore and offshore. Saltwater is especially damaging to standard alloy steel, which will rust rapidly when exposed to saline. Maritime cylinders used for cranes, boat lifts, davits or other machinery do well when made from stainless steel alloys.

Offshore oil rigs are especially prone to aqueous corrosion, and although special construction and coatings can mitigate some oxidation, the nature of pneumatic and hydraulic cylinders makes them more prone to corrosion. Manufacturing cylinders in 316-grade stainless steel produces an especially resistant raw material for offshore applications.

Stationary marine applications are only half of the equation when it pertains to the effectiveness of stainless steel. Shipbuilders use stainless actuators in locations most prone to corrosion, such as trim actuators, steering components or life craft hoists. An onshore crane failure will just be annoying and time-consuming to repair, but the failure of a steering cylinder could be deadly, so all precautions must be taken to encourage reliability. Stainless actuators are often the best answer.

Environments containing caustic or corrosive chemicals will make do with stainless steel cylinders as well. Although poor for marine applications, 304 stainless steel works well in the metals industry where chemicals like sodium hydroxide are used in the cleaning process. Another tough environment requiring the use of stainless cylinders are pulp and paper mills. The black liquor by-product is extremely corrosive to steel, so 304 stainless comes to the rescue once again, extending the life of linear actuators in demanding applications. That being said, even stainless cylinders will eventually corrode when exposed to black liquor, showing you how demanding the environment is.

Sometimes a cylinder must not only resist the damaging effects of its ambient environment, but it must also aid in the protection and safety of that environment as well. Food grade applications often require stainless steel air and hydraulic cylinders. Indeed, they excel here because food applications are often damp or altogether wet. A bottling plant, for example, uses stainless steel extensively, not just for extended life of the machinery, but to prevent corroding or rusting machinery from contaminating the product.

Because stainless steel is less likely to rust, its surface finish remains true for longer periods of humid exposure. A clean, smooth surface prevents the adhesion and accumulation of food particles and bacteria, which is clearly the top concern for food and beverage production.

Food grade cylinders are manufactured to different standards compared to “off-the-shelf” cylinders, with features added to reduce the accumulation of bacteria. For example, a quality stainless air cylinder used in food and beverage might have a polished surfaced to prevent bacterial adhesion, rounded corners to reduce burrs and welded or threaded construction to eliminate cavities or pockets. Typical tie-rod cylinders, for example, provide hiding spaces under the tie rod locations, making washdown less effective.

Food grade applications can be so extreme as to eliminate externally adjustable cushions, which provide a pocket for food and bacteria to reside. Cushions may still exist but will be the non-adjustable type without any exterior cross drillings. Even the rod wiper may be manufactured from food grade polymers to prevent cross-contamination. Although stainless steel cylinders are more costly than standard steel alloys, some applications absolutely require their superior corrosion resistance properties.

Where is bar stock used?

The term bar stock is often used in fluid power settings, but it can refer to either one of two quite different things. It can mean piston rod bar stock, the metal rods used in cylinders, or the metal used for manifolds, subplate mounts, and plumbing. This section will examine all of these uses.

Piston rod bar stock

Hydraulic cylinders are the essence of fluid power motivation. However, their simplicity often leads us to discount their subtleties of manufacture, often assuming they’re constructed of identical stock. You’d be surprised, then, to discover the devil is in the details, and not all cylinders are fabricated equally. One factor often overlooked is the bar stock used for piston rod construction. To help with the finer points of bar stock, we employed the help of Adam Hart, plant manager at Higginson Equipment in Burlington, Ontario.

Piston rod stock is nearly as varied as what is produced from the steel industry, but some are more common than others.

“The most common bar stock material by far, is 75 kpsi 0.0005-in. (1/2 thou) chrome plated steel bar,” said Hart. “There are also many other options. With a steel piston rod, you can increase the tensile strength … up to 100 kpsi, and the chrome can be increased to 0.001.” He is describing the tensile strength and the chrome plate thickness of the bar stock, which is important because most cylinders spend half their time pulling. Additionally, thicker chrome results in superior corrosion resistance.

Other techniques are employed to strengthen the rod stock.

“Most large diameter piston rods are induction hardened, which helps improve impact resistance,” said Hart. “If an end user keeps breaking male rod threads, sometimes this stronger material can help improve the longevity of the cylinder.”

Regarding cylinder finish treatments, in extreme conditions, such as corrosive or salinated fluid exposure, rod stock can be further upgraded to stainless steel.

“Some end users require corrosion resistance for their process, which is where stainless steel steps in,” said Hart. “Most grades of stainless steel can have a chrome finish.” However, stainless steel is not the only finish available. “Aside from chrome, the only other common finish treatment for piston rods is nitride. This is an extremely durable finish. It is a chemical process that hardens and darkens the material, which provides wear and corrosion resistance.”

Hart revealed what he wishes engineers and end-users would consider when designing and applying a cylinder application.

“I would like engineers and end-users to keep in mind, wherever there may be misalignment issues, a female rod thread with a stud may decrease downtime. If you break the attachment off the end of a rod, it is a relatively simple to replace the stud and attachment without the need of replacing the entire rod,” he said.

Bar stock for manifolds

Bar stock may be used either as a mounting for other valve systems or simply for consolidation of plumbing. The bar stock itself is typically an alloy of either aluminum or ductile iron, and is manufactured in billets suitable for machining finished product. The most popular use is the bar stock manifold, which is a block of varying length drilled with passages, ports and bolt holes for mounting valve systems.

Aluminum is a popular choice for bar stock material when system pressure is 3,000 psi or less. It is easier to work with than ductile iron, and is also lower in physical mass and overall cost. However, when working pressure is higher than 3,000 psi, iron is required to withstand the additional stress. Ductile iron, such as Dura-Bar, is a continuous cast (iron) that is less brittle than standard cast iron and is pressure rated to 6,500 psi. Ductile iron is a compound with a highly controlled microstructure, improving strength and machinability. Although forged steel is another option for bar stock, it is rarely used on less than the most extreme applications.

Whatever name you know them by best—ISO, cetop, NG6, D03—the industry standard modular stackable valves are the most common system of circuit construction, and they all require a manifold to interface with. A manifold for a D03 valve, for example, is around 3 in. tall and 3 in. deep, but can be as long as needed to mount any number of valve stacks. The manifold most often has pressure and tank drillings running its length. Each “station” of the manifold, where the valve mounts with four bolts, has four drillings mating up with the pressure and tank passages, as well as mating up with the work ports, which are drilled on the side of the manifold in a vertical arrangement. Bar stock manifolds can be drilled as either parallel or series circuits, depending on the application.

Bar stock can be cut into smaller slices and drilled in similar arrangements to bar manifolds to create subplate mounts. The subplates allow one valve to mount atop, with four ports on each of the four sides. Bottom-ported subplates are also available, but are rarely used, because of their tricky mounting, and ports all on one surface, making plumbing difficult. Bar manifolds have plenty of material to enable the addition of a relief valve cavity, but subplates have no such luxury of real estate. Both manifolds and subplates are available in sizes from D02 to D08, and many manifold accessories are available to help complete the hydraulic circuit, such as tapping plates, cover plates and gauge blocks.

Bar stock can also be used to clean up plumbing on machines by reducing the need for adapters and fittings. By drilling ports into a bar, a header or manifold can provide a junction to common feed or return lines, so that each tube or hose plumbs neatly into the same source. Manifolds and headers can reduce leak points, but also add a look of professionalism compared to a mess of tees and adapters. Bar stock is great for mounting components, such as test points, transducers or pressure switches. The bar material can also be anodized any color, or even just treated for corrosion resistance by clear anodizing for aluminum or nickel plating for ductile iron. Lastly, because bar stock is so commonly used in various applications, it is readily available through every fluid power distributor in North America.

What is a flow meter calibration system?

What is calibration and why is it so important?

What are some standard best practices of flow meter calibration?

Flow meter calibration has best practices, which help to ensure accuracy. These are:

Calibration should occur under conditions that are similar to the flow meter’s actual operation.

Calibration of a flow meter is necessary to obtain accurate measurements.

The Most Important Things About Electric Contact Pressure Gauge

General specification of Electric Contact Pressure Gauge:-

A manipulate unit is usually had to carry out these contracts. Touch pressure gauges with inductive alarm touch can be applied in probably explosive atmospheres, supplied that the proper policies are complied with. .if you are looking for Food Process Industries / Hygienic Applications then find best electromagnetic flow meter Dealers which has the good information about Water treatment plants, Iron and Steel Industries, General Mechanical Engineering Industries, Rubber Molding / Processing Plants, Chemical process industries.They will help you out in choosing best Temperature Transmitter Suppliers and Temperature Transmitter Exporters.

EP model contact pressure gauges with electrical contacts are suitable for controlling and regulating process sequences. The contact opens and closes electrical circuits in relation to the position of the pointer on the pressure gauge. Contact pressure gauges with bourdon tube system are used at process pressures of approximately 1 kg/sq.cm and upwards. The materials used to make the gauges are suitable for chemically aggressive gases or liquids, although these may not be too viscous or be susceptible to crystallization which long lasting and very easy to use. The tried and tested bourdon tube system coupled with modular contacts provides a very reliable contact pressure gauge. Electrical alarm contacts which are used for magnetic snap action contacts, especially in harsh industrial conditions which are very tough, the high contact pressure and the choice of different electrical contact materials enables high currents to be switched reliably. If the electric switching capacities of the contacts are exceeded or now not reached, a relay is for use to provide the appropriated contemporary rating. If you are looking products dealers like Diaphragm pressure gauge dealer in Noida Best Pressure Transmitter Suppliers, Pressure Transmitter exporter, Pressure Transmitter supplier in Delhi NCR.

The benefit of Using Electric Pressure Gauge:-

1. The Modular construction system ensures high reliability and long service life.

2. Due to stainless steel design here is Chemical resistance Very good.

3. The Contact Accuracy of every class is near about 1,6 % of FS standard and Casing, Stainless Steel 304 standard.

4. Stainless Steel Measuring System which is very good looks wise.

5. Up to four-alarm contact possible as an option which is more comfortable.

6. This is well suitable for the programmable controller.

Area of Application:-

Widely used in Petroleum industries m, Thermal / Hydro Power Stations, Hydraulics and Pneumatics systems.

See Believe Power Genex Positioner, Electropneumatic Positioner

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The See Believe Power Genex positioner is adjusted from the other pneumatic positioner. This reduced and durable unit is intended for most extreme execution in a wide range of situations. The See Believe Power Genex positioner is accessible in Standard, Intrinsically Safe and Explosion Proof renditions. A measured input unit takes into consideration the option of breaking point switches and/or position transmitters, without extra mounting sections.

Different components include: Replaceable channel, gage ports, dampers, tapped fumes port for venting of supply media, outside zero change and totally fixed spread. ATEX; CSA and FM endorsements. The electro-pneumatic positioner is utilized as a part of Control Valves with pneumatically worked actuators. The valve is worked by method for electrical controller or Control Systems With a control sign of 4 to 20 mA or split scopes of 4~12/12~20 mA.

The See Believ Electro-Pneumatic Positioner changes over this control signal into a pneumatic yield in extent to the lift of the control valve. The Instronline is the best See Believe Electropneumatic Positioner supplier in NCR that contains the best ElectroPneumatic positioned with actual data required for the establishment and uses of this gear. It is tended to in fact qualified and prepared individual or having significant information of instrumentation and control innovation. It must be utilized as a part of the path depicted in this manual. Effective safe operation of this gear is reliant upon the correct taking care of, establishment, operation and upkeep.

What are the Types of Sensors Used in Industrial Automation?

As industry, and society in general, moves towards the next industrial revolution - Industry 4.0 - we are moving towards an age of industrial automation. This automation will manifest itself in many different processes within industry, to not only monitor processes better and improve efficiencies, but also to predict when an issue may occur.

Industrial automation is only possible due to advances in big data analysis methods, artificial intelligence (AI) algorithms and the Internet of Things (IoT), as these advanced data manipulation methods enable large data sets to be analyzed and predicted to a much greater degree than ever before. The ability to analyze data and detect trends and anomalies against historical data is why industrial processes can now be automated with high accuracy and precision.

Before these advanced algorithms can do their thing, data must be collected. Sensors provide a way to capture and measure the local environment in the form of data points. There are various different sensors used in the automation of industrial processes, ensuring that the various points along the manufacturing line are running smoothly and will continue to do so in the future (and predicting potential downtime if not).

The sensors mentioned here exist as part of the average manufacturing line. If the production plant in question produces more complex materials, such as a chemical plant, then more sensors will be required, such as those which measure complex fluid flows, the presence of certain chemicals and their risks, and material/chemical exposure to the occupational environment. Of course, many more sensors are used around the whole plant, as they can be used to detail and analyze almost every aspect of an industrial plant.

Temperature and Humidity Sensors

Temperature and humidity sensors are often coupled together as high temperature in the presence of water can cause water molecules to vaporize, increasing humidity. Temperature sensors are used in manufacturing lines to measure the temperature of machinery and equipment as a safeguard against overheating and breaking downs, as well as to check the temperature of products along the line (if required).

For the most part, they are used to ensure that no breakdowns occur along the line, especially in manufacturing processes that utilize heat to create products. Similarly, the water present in high humidity environments can damage the electronics in the manufacturing line, so it must be monitored as well.

Depending on the specific medium and environment being sensed, there are a number of different temperature sensors, with the most common being thermocouples, thermistors, resistant temperature detectors (RTDs), infrared sensors and thermometers. The data algorithms in automated processes can detect if there is any overheating occurring and take appropriate action to stop the overheating without human intervention (although warnings can be sent to the personnel).

Pressure Sensors

Pressure sensors are used in manufacturing environments where high pressures are required to create a product. The generation of high pressures can be dangerous, so the levels must be measured to ensure the manufacturing process remains safe. The data from these sensors can be analyzed via the data software to detect when the pressure is reaching dangerous levels. The process can then be stopped or modified accordingly, and personnel can be notified about the automated response.

Turned parts and vacuum sensors are the most commonly used sensors. As well as detecting high pressures, they can also be used to detect if the pressure drops below the atmospheric pressure level at any location within the plant and measure other parameters that are important in the manufacturing of products, such as fluid and gas flows, speed and water levels.

All of these data points can be used to ensure that these parameters in the manufacturing process (if they are applicable) are optimal, and in these certain cases the automated systems can tweak the parameters to ensure that the efficiency and output are as high as possible (this is often in conjunction with other sensors that detect the various manufacturing operational parameters).

Torque Sensors

Torque sensors are used in different pieces of machinery along a manufacturing line to offer extra protection when the machinery is taking a load, and can be used in many cases to raise the overload capacity of a piece of machinery as the levels at which equipment fails can be better determined. They do this by measuring the speed of rotation (and highest potential speed of rotation), mass and mass moment of inertia, which are used to determine the torque.

Automated processes can take all this data to provide the most optimal loads for each piece of machinery, as well as determine when maintenance is required or downtime is imminent. The two most common torque sensors are rotating torque sensors and torque transducers.

What are Encoder Sensors?

Encoder sensors are a type of mechanical motion sensor that create a digital signal from a motion. It is an electro-mechanical device that provides users (commonly those in a motion control capacity) with information on position, velocity and direction. There are two main types of encoder: linear and rotary. Here, we look at encoder sensors in more depth.

Encoder sensors have become a widely used class of sensors where feedback information from a moving mechanical system is required. It is a device that can provide precise information on the speed, direction and positioning of a piece of mechanical equipment. In recent years, encoders have become a lot more sensitive and tough with higher resolutions at a lower cost, and as a result are now widely used in many industries.

From an industry perspective, encoder sensors are used across the automotive, consumer electronics, medical, military, manufacturing and scientific instrument industry sectors. In terms of specific applications, encoder sensors can be found in printers, food processing, robotics, material handling, axis controllers, medical scanners, dispensing pumps, military-grade antennas, drilling machines and telescopes, to name but a few.

The difference between the two different types of encoder is the way in which they respond to motion in a given area, and the clue is in their names. Linear encoder sensors measure a motion along a linear path, whereas a rotary encoder sensor responds to rotational motion. Both types often employ magnetic principles (a magnetic scale or magnetic field) to detect any changes. The sensor will either detect changes in the magnetic field or magnetic position and this provides an output which represents a speed, position or directional change.

Each class of sensor can be further broken down into absolute and incremental sensors. Absolute encoders use a series of pulses to measure the position and speed of the equipment, whereas an absolute encoder uses bit configurations to directly track positions. So, the type of equipment being analyzed, and how it moves, determines what type of encoder sensor is needed.

Linear Encoders

In a linear encoder a magnetic sensor passing over a magnetic scale. As the sensor moves along this scale, it detects changes in the magnetic field which are proportional to the measuring speed and the displacement of the sensor. As linear sensors only detect changes in the magnetic field, external factors such as light, debris or oil have no effect on the sensing capabilities, and as a result they are often used in harsher environments. Optical linear encoders are not as widely used, but use parallel beams of light on a glass scale to generate sinusoidal wave outputs that are detected using a photodetector.

There are many key components to linear encoder sensors, including the scanning unit, sensor unit, transducer and a transmissive/reflective scale. Overall, the linear encoder converts the motion into either a digital or analog signal and this can be used to determine the positional change over time.

Rotary Encoders

Rotary encoders can be magnetic or non-magnetic in nature. In a magnetic rotary sensor, the sensor is passed over a rotating disc of alternating (north and south) magnetic regions. The sensor detects the smalls changes in the magnetic field either via the Hall effect (change in voltage compared the deflection of the electrons in the magnetic field) or the magneto resistive effect (a change in resistance caused by the magnetic field).

Electronic rotary encoder sensors are a little more complex and are typically controlled via the rotation of a shaft which is connected to the circuitry of the encoder. The shaft is connected to the encoder via a part known as the hub. When the shaft rotates, it causes the disc (which contains both solid and transparent lines) to rotate across the circuitry of the encoder. The circuitry contains light-emitting diodes (LEDs) that can be spotted using a photodiode. The speed of the rotation is dependent upon the speed of the shaft attached to the encoder. Each concentric ring in the rotary encoder has its own light source to identify each line in the rotating disc. The signal from the detectors is then converted into an output that provides feedback on the position or velocity of the sensor.

What is Thermal Flow Meter ?

However, if there is even a slight breeze of air moving past your body, your body will come into contact with more cool (unheated) air molecules than it would otherwise, causing a greater rate of heat loss. Thus, your perception of the surrounding temperature will be cooler than if there were no breeze.

We may exploit this principle to measure mass flow rate, by placing a heated object in the midst of a fluid flowstream, and measuring how much heat the flowing fluid convects away from the heated object. The “wind chill” experienced by that heated object is a function of true mass flow rate (and not just volumetric flow rate) because the mechanism of heat loss is the rate at which fluid molecules contact the heated object, with each of those molecules having a definite mass.

The simplest form of thermal mass flowmeter is the hot-wire anemometer, used to measure air speed. This flowmeter consists of a metal wire through which an electric current passes to heat it up.

An electric circuit monitors the resistance of this wire (which is directly proportional to wire temperature because most metals have a definite temperature coefficient of resistance). If air speed past the wire increases, more heat will be drawn away from the wire and cause its temperature to drop.

The circuit senses this temperature change and compensates by increasing current through the wire to bring its temperature back up to setpoint. The amount of electrical power required to maintain the hot wire at a constant elevated temperature is a direct function of mass air flow rate past the wire.

In other words, the computer needs to know how many air molecules are entering the engine per second in order to properly meter the correct amount of fuel into the engine for complete and efficient combustion. The “hot wire” mass air flow sensor is simple and inexpensive to produce in quantity, which is why it finds common use in automotive applications.

Industrial thermal mass flowmeters usually consist of a specially designed “flowtube” with two temperature sensors inside: one that is heated and one that is unheated. The heated sensor acts as the mass flow sensor (cooling down as flow rate increases) while the unheated sensor serves to compensate for the “ambient” temperature of the process fluid.

Thermal Flow Meter

A typical thermal mass flowtube appears in the following photographs (note the swirl vanes in the close-up photograph, designed to introduce large-scale turbulence into the flowstream to maximize the convective cooling effect of the fluid against the heated sensor element):

Thermal mass flowmeters lend themselves well to “insertion” style probes, sensing the passage of fluid molecules at one point within the flowstream.

An example is shown in the next two photographs, where a thermal mass flowmeter (manufactured by Sage) senses the amount of gas sent to a flare. The insertion probe appears in the left-hand photo (mounted in the vertical flare pipe) while the transmitter head appears in the right-hand photo (located inside of a weather-sheltered building):

The simple construction of thermal mass flowmeters allows them to be manufactured in very small sizes.

The following photograph shows a small device that is not only a mass flow meter, but also a mass flow controller with its own built-in throttling valve mechanism and control electronics.

To give you a sense of scale, the tube fittings seen on the left- and right-hand sides of this device are 1/4 inch, making this photograph nearly full-size:

Some substances have much greater specific heat values than others, meaning those substances have the ability to absorb (or release) a lot of heat energy without experiencing a great temperature change.

Fluids with high specific heat values make good coolants, because they are able to remove much heat energy from hot objects without experiencing great increases in temperature themselves.

Since thermal mass flowmeters work on the principle of convective cooling, this means a fluid having a high specific heat value will elicit a greater response from a thermal mass flowmeter than the exact same mass flow rate of a fluid having a lesser specific heat value (i.e. a fluid that is not as good of a coolant).

This means we must know the specific heat value of whatever fluid we plan to measure with a thermal mass flowmeter, and we must be assured its specific heat value will remain constant.

For this reason, thermal mass flowmeters are not suitable for measuring the flow rates of fluid streams whose chemical composition is likely to change over time. This limitation is analogous to that of a pressure sensor used to hydrostatically measure the level of liquid in a vessel:

in order for this level-measurement technique to be accurate, we must know the density of the liquid and also be assured that density will be constant over time.

Thermal mass flowmeters are simple and reliable instruments. While not as accurate or tolerant of piping disturbances as Coriolis mass flowmeters, they are far less expensive.

Disadvantages of Thermal mass Flow Meters

In many industrial applications, however, this limitation is severe enough to prohibit the use of thermal mass flowmeters. Industrial applications for thermal mass flowmeters include natural gas flow measurement (non-custody transfer), and the measurement of purified gas flows (oxygen, hydrogen, nitrogen) where the composition is known to be very stable.

It is a well-known fact in fluid mechanics that turbulent flows are more efficient at convecting heat than laminar flows, because the “stratified” nature of a laminar flowstream impedes heat transfer across the fluid width.

Therefore, a change in flow regime (from turbulent to laminar, and vice-versa) will cause a calibration shift for this design of thermal mass flowmeter.

What is an Orifice Flange ?

An Orifice flange is a disc – shaped flange, engineered with either a Raised Face or a Ring Type Joint facing.

Purpose of an Orifice Flange

1. They are widely used with orifice meters to measure the flow rate of either liquid or gases, flowing through the pipe.

2. An orifice plate, a device measuring the flow of the inner fluid or gas, is secured between two orifice flanges, attached to the pipe.

3. The orifice plate contains a small hole; two pressure tap holes are drilled in each flange which helps in measuring the pressure built inside the pipe.

4. A ‘jack screw’ fitted between the two flanges, it enables to separate the flanges during inspection or replacement process.

Uses of an Orifice Flange

These flanges are used in the following industries:

Heavy and light chemicals
Steel
Paper
Nuclear
Petrochemicals
Sewage treatment
Water treatment and distribution
Power Generation
Oil production and refining
Gas Processing and transmission

CAN A BALL VALVE BE USED AS A CONTROL VALVE?

If you have basic valve knowledge, you are probably familiar with ball valves – one of the most common types of valves available today. A ball valve is typically a quarter-turn valve with a perforated ball in the middle to control flow. These valves are known for being durable with excellent shutoff, but don’t always offer very precise control. Let’s talk about when it’s okay to use a ball valve as a control valve.

Even though ball valves aren’t the best device to control flow, they are still commonly used because of their cost effectiveness. You can get away with using a ball valve in an application that doesn’t require precise adjustability and control. For example, a ball valve should have no problem keeping a large tank filled at a certain level within a few inches.

As with any equipment, you will need to take the complete process conditions into consideration before selecting your valve. This includes the product or material, size of piping, flow rate, etc. If you are trying to control an expensive material that you are worried about wasting, you might not want to rely on a ball valve.

Ball valves aren’t very precise because their adjustment isn’t proportionate to the large amount of flow that the open hole provides. There is also ‘slop’ or ‘play’ in between the stem and ball that hinders precise control. Lastly, the amount of torque required to adjust ball valves doesn’t allow for fine adjustment near the “closed” and “open” position.

When you need precise control over your application, a globe valve will be more accurate than a ball valve. Globe valves are considered the industry standard for control valves because they are good at regulating flow, whereas ball valves are better for on/off control without pressure drop.

If you must use a ball valve to control your process, you might want to consider different types of ball valves depending on your application. A trunnion or v-port ball valve will perform better and allow for more accurate adjustability in certain scenarios.

Trunnion ball valves have an additional mechanical anchoring of the ball at the top and bottom. They use a splined or keyed stem connection that eliminates any play between the ball and stem. V-port ball valves have a ‘V’ shaped ball instead of the standard round hole. This allows for more control because of the tapered opening, allowing for more linear flow.

If you're located in Wisconsin or Upper Michigan and need help deciding which valve is best suited for your application, reach out to one of our engineers. Otherwise if you enjoyed this article, you might want to check out our post about when to use soft-seat ball valves vs. metal-seat ball valves.

What’s Wrong With Your Actuator? 5 Things to Check

The valve

What manifests as an actuator problem may actually be a valve problem. Our service experts report that this is the case 7 out of 10 times they are called about a faulty actuator.

Some common valve issues that can cause actuator problems:

-- A worn out valve stem

-- Seized up packing

-- An obstruction

-- Too much torque

It doesn’t do any good to repair an actuator when the valve is what’s causing the trouble. On the contrary, it wastes both time and money — and leaves you back where you started.

Actuators only have four major components that can break down and require repair.

The center column drive

The connection to the valve

The contactor

The motor

And that’s basically it! Everything else is bulletproof.

On the other hand, for mechanical work like replacing the center column, you’ll likely need to remove the actuator from service before it can be repaired.

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Speak to us today about our complete range of Norgren pressure switches and fittings by email us at info@instronline.com

4 Benefits of Digital Valve Positioners

What if I told you there was one simple plant upgrade you could make to be more competitive?

This isn’t a hypothetical exercise. By upgrading your valve positioners from analog to digital, you will be able to maximize your plant productivity and increase your standing in today’s competitive market.

Here are four advantages of digital valve positioners.

Better control valve reliability and performance

Whatever industry you’re in — energy, industrial processing, manufacturing, etc. — you likely face constant pressure to improve productivity and efficiency. It’s easy to overlook your control valves, but they can play a huge role in this effort.

According to Flow Control, “A poorly performing $3,000 control valve can cause significant losses because of shutdowns, lost production, reduced efficiency, and unsafe events.” Digital valve positioners help protect against all of these consequences by improving control valve reliability and performance.

More accurate calibration for more accurate control

The level of process control a positioner provides depends on how accurately it can be calibrated. Here, digital positioners have a large advantage because they have fewer moving parts than analog positioners and they automatically self-calibrate. An analog positioner requires a seasoned touch to adjust the cam manually. With smart digital positioners, just about anyone can push the right button to calibrate the valve correctly the same every time.

More accurate control reduces process variability, which leads to higher operating profits.

Advanced diagnostics for predictive maintenance

If you have an analog positioner, your control valve may be performing poorly, but you won’t know it until the time comes to service that valve. By then, you could already have accumulated hundreds of thousands, or even millions, of dollars in productivity losses. You might even have had to shut down your operations for emergency repairs.

Digital positioners monitor your valves many variables — valve travel and thrust, air consumption, temperature, valve friction, and more — and provide real-time data so you can identify and fix any performance problems before they balloon into emergencies.

The biggest advantage of digital positioners is the real-time data and diagnostics they provide.

Easy setup for reduced commissioning costs

Finally, it’s much easier to setup and install digital valve positioners than analog ones. This is because the digital devices can be calibrated and configured electronically with a the local push buttons, smart handhelds or a laptop. Not only does this mean you can get your control loops up and running faster during the commissioning process, but, again, the risk of human error is significantly decreased.

Tips for Upgrading to Digital Valve Positioners

Are you ready to take your plant productivity to the next level by upgrading to digital positioners for your control valves? Your plant managers, your maintenance staff, and your bottom line will thank you.

If you’re just starting out, the digital transformation process can be daunting. But moving from analog to digital positioners doesn’t have to be difficult. These tips will help you ease the transition.

Partner with a trusted supplier

The first step in upgrading to digital positioners is to make sure you have a trusted supplier — someone who can advise you on the proper positioners for your applications, as well as provide the installation and service required to get the most out of your positioners and the valves they control.

Consider your plant infrastructure

Going digital requires more than just purchasing and installing the positioner. In this article for Flow Control, Sandro Esposito identifies some plant infrastructure factors to keep in mind, including the following:

Power: Digital positioners may have different power requirements than older legacy analog ones.

Wiring: Proper wiring is required for fast communication.

Loop tuning: You’ll likely need to adjust the tuning of your control loop to account for the digital positioner’s increased speed and accuracy.

Your supplier can help you assess these factors and make appropriate recommendations.

Make sure your employees get the training they need

Fear is one of the biggest obstacles to technology adoption. Fortunately, fear has an easy antidote: knowledge.

Before installing new positioners, make sure everyone who will need to interact with the devices gets proper training so they can do their work with confidence. When you purchase a Masoneilan SVI II AP from us, we can host a training session, such as a lunch and learn, to go over the options, diagnostics, and setup requirements for the device.

Don’t try to do it all at once

In an article for CEP Magazine, Janine McCormick and Steve Hagen recommend establishing a valve monitoring program as a way to get more out of your smart positioners. But, they also warn against doing it all at once:

“Do not try to start the program with every control valve in your facility. Turning on all the alerts in all your smart positioners at once is a good way to overwhelm your operations and program teams. Instead, make a list of a handful of critical valves to be monitored. It is easier to work out the process on a few valves and then expand the program slowly.”

This is sound advice for introducing any new technology into your plant. Start small, work out the process and make sure people are comfortable with it, and then ramp up once you’ve worked out all of the kinks.

Identify the data that’s most valuable to you

Just like it’s not a good idea to replace every positioner in your facility all at once, you probably don’t want to turn on all of the diagnostics at once either.

Remember that data on its own doesn’t mean anything — it only becomes valuable when you turn it into meaningful, actionable information. For each valve with a digital positioner, determine what information you need to make better decisions and take appropriate actions. Start by collecting and analyzing just that data. You can always expand the system later.

What is a Digital Positioner and Why Should You Use One?

A valve positioner is a device mounted on the actuator that exerts or reduces air pressure as necessary to make sure the valve achieves the correct position.

When there is no positioner, the control signal goes directly to the actuator. When a positioner is installed, it intercepts this signal and then outputs a different signal to the actuator.

Essentially, a positioner ensures that the final control element in a loop exerts optimal control.

There are three types of positioners:

Pneumatic positioners. These devices receives a pneumatic (air) signal from the controller and output a pneumatic signal to the actuator.

Analog, or electro-pneumatic, positioners. Here, the input signal is electrical, rather than pneumatic.

Digital, or smart, positioners. These positioners also receive an electrical signal, but it’s digital as opposed to analog.

Digital positioners came on the scene about 20 years ago, but they only really started gaining popularity recently as automation has started to take off in plants and along pipelines.

For example, the Siemens SITRANS VP300 digital positioner allows you to:

Auto tune the positioner in minutes, as opposed to the hours analog positioners can take

Get diagnostic information about the health and performance of your control valves

Identify potential problems before they happen

Integrate the positioner with other control systems so all of your data is in one place

What this all boils down to is higher valve productivity, decreased downtime, and overall better plant performance.

How accurate can a Coriolis Flow Meter be?

Mass flow measurement is the basis of most recipe formulations, material balance determinations, and billing and custody transfer operations throughout industries that need to measure flow. With these being the most critical flow measurements in a processing plant, the reliability and accuracy of mass flow detection is very important.

In the past, mass flow was often calculated from the outputs of a volumetric flow meter and a densitometer. Density was either directly measured (Figure 5-1A), or was calculated using the outputs of process temperature and pressure transmitters. These measurements were not very accurate because the relationship between process pressure or temperature and density are not always precisely known--each sensor adds its own separate error to the overall measurement error, and the speed of response of such calculations is usually not sufficient to detect step changes in flow.

One of the early designs of self-contained mass flow meters operated using angular momentum (Figure 5-1B). It had a motor-driven impeller that imparted angular momentum (rotary motion) by accelerating the fluid to a constant angular velocity. The higher the density, the more angular momentum was required to obtain this angular velocity. Downstream of the driven impeller, a spring-held stationary turbine was exposed to this angular momentum. The resulting torque (spring torsion) was an indication of mass flow.

These meters all had moving parts and complex mechanical designs. First developed for the measurement of aircraft fuel, some are still in use. However, because of their complex nature and high maintenance costs, they are gradually being replaced by more robust and less maintenance-demanding designs.

Mass flow also can be measured by batch weighing or by combining an accurate level sensor with a densitometer. Another method is to mount two d/p transmitters on the lower part of an atmospheric tank at different elevations. In this case, the output of the top d/p cell will vary with the level in the tank, while the lower one will measure the hydrostatic head over a fixed elevational distance. This pressure differential yields the density of the material in the tank. Such systems have been used to measure the total mass flow of slurries.

Interferences

The effect of the Coriolis force on the vibrating tube is small. Full-scale flow might cause a deflection of only 0.001 inch. To obtain a flow rangeability of 100:1, sensors must be able to detect deflections to an accuracy of 0.000001 inch in industrial environments where the process pressure, temperature, and fluid density are all changing, and where pipe vibration interferes with measurement.

The elasticity of metal tubes changes with temperature; they become more elastic as they get warmer. To eliminate the corresponding measurement error, the tube temperature is continuously measured by an RTD element and is used to continuously compensate for variations in tube elasticity.

Coriolis mass flow meters usually are calibrated on water, because the constants are valid for all other liquids. Calibration for density is usually done by filling the tubes with two or more (stagnant) calibration fluids of known densities.

Accuracy & Rangeability

Coriolis meters provide 0.1-2% of rate inaccuracy over a mass flow range of up to 100:1. In general, curved tube designs provide wider rangeability (100:1 to 200:1), while straight-tube meters are limited to 30:1 to 50:1 and their accuracy is lower. Overall meter error is the sum of base inaccuracy and zero-shift error, the error attributable to the irregular output signal generated at zero flow conditions. Zero-shift error becomes the dominant portion of total error at the lower end of the flow range, where the error is between 1% and 2% of rate. Some manufacturers state the overall accuracy as a percentage of rate for the upper portion of the flow range and as a percentage of span for the lower portion, while others state it as a percentage of rate plus a zero-shift error. There is a fair amount of "specmanship," and one must read sales literature carefully when comparing different devices.

When used for density measurement, the typical error range of a Coriolis measurement is 0.002-0.0005 g/cc.

Errors are caused by air or gas pockets in the process fluid. In the case of homogeneously dispersed small bubbles, more power is required to vibrate the tubes, whereas, if the gas phase separates from the liquid, a damping effect on tube vibration (and, consequently, error) develops. Small voids also cause noise because of the sloshing of the process liquid in the tubes. Larger voids will raise the energy required to vibrate the tubes to excessive levels and may cause complete failure. Because the flowtube is subjected to axial, bending, and torsional forces during meter operation, if process or ambient temperature and pressure fluctuations alter these forces, performance may be affected and re-zeroing of the meter may be required.

Variations in the density of the process fluid can affect the frequency transfer function of mechanical systems, necessitating the re-zeroing of older designs to protect them from degraded performance. Because of their tube configurations, newer designs are unaffected by density changes over wide ranges of specific gravity variations.

Sizing & Pressure Drop

Because of the wide rangeability of Coriolis flow meters (30:1 to as high as 200:1), the same flow can be measured by two or three different sized flow tubes. By using the smallest possible meter, one will lower the initial cost and reduce coating build-up, but will increase erosion/corrosion rates and head loss, increasing pumping and operating costs.

Downsizing (using a meter that is smaller than the pipe) is acceptable when the pipe is oversized, and the process fluid is clean with a low viscosity. On corrosive, viscous, or abrasive slurry services, downsizing is not recommended. A list of acceptable flow tube sizes and corresponding pressure drops, inaccuracies, and flow velocities can be obtained from software provided by the manufacturer.

Different Coriolis meters incur different pressure drops, but in general, they require more than traditional volumetric meters, which usually operate at less than 10 psid. (The yearly electricity cost of pumping 1 GPM across a differential of 10 psid is about $5 U.S.). This higher head loss is due to the reduced tubing diameter and the circuitous path of flow. Besides pumping costs, head loss can be of concern if the meter is installed in a low-pressure system, or if there is a potential for cavitation or flashing, or if the fluid viscosity is very high.

The viscosity of non-Newtonian fluids is a function of their flowing velocity. Dilettante fluids, for example, increase their apparent viscosity (resistance to flow) as their velocity is increased. This apparent viscosity can be drastically higher than their viscosity when stagnant. In order to provide suppliers with data on the flowing viscosity in a particular pipe, head loss per foot of pipe (used in pump sizing calculations) can be used as an approximation.

Tuning a PID Controller

Heat treatment processes exemplify the need for PID control. To ensure consistent product quality the temperature inside an oven or furnace must be kept within narrow limits. Any disturbance, such as when a product is added or withdrawn or a ramp function is applied, must be handled appropriately. Although simple in concept, the mathematics underpinning PID control is complex and achieving optimal performance entails selecting process-specific values for a range of interacting parameters.

The process of finding these values is referred to as “tuning.” When tuned optimally, a PID temperature controller minimizes deviation from the set point, and responds to disturbances or set point changes quickly but with minimal overshoot.

This White Paper from OMEGA Engineering discusses how to tune a PID controller. Even though many controllers provide auto tune capabilities, an understanding of PID tuning will help in achieving optimal performance. Individual sections address:

-- Basics of PID Control

-- PID Controller Tuning Methods

○ Manual Tuning

○ Tuning Heuristics

○ Auto Tune

Common Applications of PID Control

Basics of PID Control

PID control is based on feedback. The output of a device or process, such as a heater, is measured and compared with the target or set point. If a difference is detected a correction is calculated and applied. The output is measured again and any required correction recalculated.

PID stands for proportional-integral-derivative. Not every controller uses all three of these mathematical functions. Many processes can be handled to an acceptable level with just the proportional-integral terms. However, fine control, and especially overshoot avoidance, requires the addition of derivative control.

In proportional control the correction factor is determined by the size of the difference between set point and measured value. The problem with this is that as the difference approaches zero, so too does the correction, with the result that the error never goes to zero.

The integral function addresses this by considering the cumulative value of the error. The longer the set point-to-actualvalue difference persists the greater the size of correction factor calculated. However, when there is a delay in response to the correction this leads to an overshoot and possibly oscillation about the set point. Avoiding this is the purpose of the derivative function. This looks at the rate of change being achieved, progressively modifying the correction factor to lessen its effect as the set point is approached.

PID Controller Tuning Methods

Every process has unique characteristics, even when the equipment is essentially identical. Airflow around ovens will vary, ambient temperatures will alter fluid density and viscosity, and barometric pressure will change from hour to hour. The PID settings (principally the gain applied to the correction factor along with the time used in the integral and derivative calculations, termed “reset” and “rate”) must be selected to suit these local differences.

In broad terms, there are three approaches to determining the optimal combination of these settings: manual tuning, tuning heuristics, and automated methods.

Manual Tuning

With enough information about the process being controlled, it may be possible to calculate optimal values of gain, reset and rate. Often the process is too complex, but with some knowledge, particularly about the speed with which it responds to error corrections, it is possible to achieve a rudimentary level of tuning.

Manual tuning is done by setting the reset time to its maximum value and the rate to zero and increasing the gain until the loop oscillates at a constant amplitude. (When the response to an error correction occurs quickly a larger gain can be used. If response is slow a relatively small gain is desirable). Then set the gain to half of that value and adjust the reset time so it corrects for any offset within an acceptable period. Finally, increase the rate until overshoot is minimized.

Tuning Heuristics

Many rules have evolved over the years to address the question of how to tune a PID loop. Probably the first, and certainly the best known, are the Zeigler-Nichols (ZN) rules.

First published in 1942, Zeigler and Nichols described two methods of tuning a PID loop. These work by applying a step change to the system and observing the resulting response. The first method entails measuring the lag or delay in response and then the time taken to reach the new output value. The second depends on establishing the period of a steady-state oscillation. In both methods these values are then entered into a table to derive values for gain, reset time and rate.

ZN is not without issues. In some applications it produces a response considered too aggressive in terms of overshoot and oscillation. Another drawback is that it can be time-consuming in processes that react only slowly. For these reasons some control practitioners prefer other rules such as Tyreus-Luyben or Rivera, Morari and Skogestad.

Auto Tune

Most process controllers sold today incorporate auto-tuning functions. Operating details vary between manufacturers but all follow rules similar to those described above. Essentially, the controller “learns” how the process responds to a disturbance or change in set point, and calculates appropriate PID settings. In the case of a temperature controller like OMEGA’s CNi8 series, when “Auto Tune” is selected the controller activates an output. By observing both the delay and rate with which the change is made it calculates optimal P, I and D settings, which can then be fine-tuned manually if needed. (Note that this controller requires the set point to be at least 10°C above the current process value for auto tuning to be performed).

Newer and more sophisticated controllers, such as OMEGA’s Platinum series of temperature and process controllers, incorporate fuzzy logic with their auto tune capabilities. This provides a way of dealing with imprecision and nonlinearity in complex control situations, such as are often encountered in manufacturing and process industries, and helps with tuning optimization.

Common Applications of PID Control

Ovens and furnaces used in industrial heat treatment are required to achieve consistent results regardless of how the mass and humidity of material being heated may vary. This makes such equipment ideal for PID control. Pumps used for moving fluids are a similar application, where variation in media properties could change system outputs unless an effective feedback loop is implemented.

Motion control systems also use a form of PID control. However, as the response is orders of magnitude faster than the systems described above these require a different form of controller to that discussed here.

Understanding PID Tuning

PID control is used to manage many processes. Correction factors are calculated by comparing the output value to the set point and applying gains that minimize overshoot and oscillation while effecting the change as quickly as possible.

PID tuning entails establishing appropriate gain values for the process being controlled. While this can be done manually or by means of control heuristics, most modern controllers provide auto tune capabilities. However, it remains important for control professionals to understand what happens after the button in pressed.

How to Maintain and Determine Calibration Frequency of Equipment

A lot of different variables determine how frequently your instruments should be calibrated or re-calibrated. Let us look at some of them:

Manufacturers’ Recommendations:

Annually or Biannually:

After a Damaging Incident:

As Demanded by Projects:

Before or After a Major Project:

Semiannually, Quarterly or Monthly:

Keeping your instruments calibrated will ensure that all your projects and tests are accurate and that high quality is maintained throughout.

Temperature Effects on Pressure Gauges

Effects of Temperature

Changes in ambient temperature affect the accuracy of gauges in several ways. Range shift is caused by the change in modulus of elasticity of the bourdon. This effect increases proportionately as the pressure increases. As a general rule, the loss of accuracy will be an additional 1% of full scale reading for every 50°F change in temperature. Zero shift is created by the change in physical dimensions of the various components brought about by the temperature change. This shift is constant over the entire scale and does not vary with applied pressure.

Minimizing Temperature Effects on Pressure Gauge

Maximum Temperature Limits

To ensure the longest possible life and accurate readings, pressure gauges that have soft-soldered pressure joints (General Equipment gauges with brass internals) should not be exposed to process or ambient temperatures over 120˚F. This is especially true of pressure gauges with liquid filled cases, due to the expansion of the case fill fluid. Long term exposure to temperatures in excess of 120˚ F may cause discoloration of dials and fill fluids, as well as hardening of the case seals and possible fill leakage. Gauges with silver soldered or welded pressure joints (gauges with SST internals / Process Gauges) should not be exposed to process or ambient temperatures over 190˚F.

Accuracy

High and low temperatures affect accuracy on indication. A general rule of thumb for dry gauges is 1% of full scale change for every 50˚F change from 75˚F. This allowance should be doubled for gauges with liquid filled cases.

Steam Service

In order to prevent live steam from entering the bourdon tube, a siphon filled with water should be installed between the gauge and the process line. Siphons should also be used on any application whenever condensing, hot vapors (other than steam) are present.

Capillary Lines

When a gauge is installed on a process line containing hot liquid or gas, one solution is to simply include a length of capillary tubing between the hot line and the gauge. The slow rate of heat transfer through the added capillary and dead-ended process fluid will generally protect the gauge from damage.

Diaphragm Seals

Diaphragm seals with filled, flexible line assemblies are another good solution to the problem of hot liquid and gas lines.

Cold Service

The minimum recommended operating temperature for all gauges is –40˚F. Gauges filled with silicone oil will provide the most resistance to the effects of operating in freezing conditions.

Fill Fluids

The effective operating temperature of Glycerin Fill Fluid is 40˚F to 140˚F and for Silicone Fill Fluid -40˚F to 190˚F.

How to choose pneumatics in food and beverage processing

Recently, a food processing OEM was designing and installing a new line of extremely high-speed filling machines intended to deliver higher performance with a smaller shop floor footprint. Redesigning the pneumatic valve system in the OEM’s machinery using collective wiring and stainless-steel filter-regulators cut the size of the overall footprint nearly in half and minimized both build and installation times. By relying on a supplier that understood their overall processes and helped them choose the right components, the OEM was able to realize a variety of bottom-line advantages:

They halved the size of machine’s control panel.
Their costs for components decreased by almost $1,000 per machine.
Each machine required one hour less wiring time and one hour less plumbing time.
There was an operating cost savings of $2,200 per machine ($22,000 per year).

The combination of timely advice and intelligently chosen pneumatic components is critical to the ultimate success of systems like these. For any given application, selecting the optimal pneumatic component depends on understanding two main issues:

The required operating performance and parameters
The operating environment.

For example, when considering the operating performance requirements for pneumatic cylinders, design engineers first must determine parameters such as available air pressure, desired speed and cylinder power, and maximum theoretical force. This force must be 50-100% greater than the basic force required, to account for effects such as friction, potential lateral loads on the piston rod and braking effects at the end of the stroke. These values are typically included on the manufacturers’ datasheets; if not, the manufacturer can offer guidance on calculating them.

Standard pneumatic cylinders have an end cover, cylinder, piston, piston rod and front gable, along with a piston rod bearing and scraper seals. Their general design adheres to ISO standards. In most applications, the cylinder and end caps are made of aluminum, to provide the level of strength required without adding excessive weight; chrome-plated steel or stainless steel are often used for the piston rod.

Pneumatic cylinders’ performance characteristics are often specified for an operating temperature range of ‑20° to 80° C; however, more challenging applications require cylinders that can exceed these limits. To meet these demands, a growing number of pneumatic cylinder manufacturers have developed products designed for environments as low as -40° or as high as 150° C, which can require the use of higher performance lubricants and special sealing materials.

All too often, the operating environment is overlooked in the process of selecting a pneumatic cylinder or accessory. Environmental factors may include ambient temperature, vibration, operating media/chemicals and other fluids or materials present. However, a variety of other aspects of the operating environment should also be considered. For example, in humid operating environments or those that pose a risk of salt spray, all external cylinder surfaces need to be coated, and the piston rod should be made of stainless steel.

Requirements for cleanliness

Applications in food and beverage production typically require specific certification of the pneumatic cylinder and other associated equipment and special clean design features that minimize entrapment points for bacteria. Multiple national and international standards must be taken into account. For example, 3‑A Sanitary Standards Inc. is dedicated to advancing hygienic equipment design for the food, beverage, and pharmaceutical industries.

An online database simplifies identifying vendors of components that comply with 3-A certification. Other important standards and guidelines are published by NSF (National Sanitation Foundation) International, the International HACCP Alliance, the American National Standards Institute (ANSI), and the Safe Food Alliance.

Food production environments necessitate frequent wash-downs of the work area, which can lead to damage to static and dynamic gaskets and seals. Constant exposure to damp and the caustic sprays of hydrogen peroxide and other cleaning materials used in wash-down cycles can eat away at unprotected materials. These environmental challenges have made stainless steel the most commonly used material for all food processing applications. Although stainless steel is more expensive and more costly to machine than aluminum, it can resist the steam, high pressure water, and caustic cleaners often used in food and beverage production. This makes it easier for designers to meet stringent requirements for hygiene and corrosion resistance, which justifies the higher initial investment for many machine designers.

Fortunately, however, some new, less costly alternatives to stainless steel pneumatic cylinders are available for food and beverage processing applications, Figure 1. They feature cylinder barrels and end covers made of anodized aluminium, with stainless steel piston rods, piston rod nuts, and end cover screws. Pistons, piston bearings, and piston rod bearings made of polyoxymethylene, an FDA-approved thermoplastic with high stiffness, low friction, and excellent dimensional stability. Polyurethane scraper rings, piston seals and cushion seals are used to seal in keep the transparent food-grade grease.

No matter which component is being specified, it’s critical to understand the details of the food processing application and what is required—such as pressure, temperature, flow, and port sizes, configurations, and locations. Too often, filters or valves are chosen based on cost or size alone, forcing maintenance personnel to spend extra time on maintenance as a result of the system designer’s less than optimal choice. Longevity and repeatability are basic requirements for any good pneumatic solution. Choose components that have been thoroughly tested and designed to withstand the toughest conditions for operation, vibration, and impact.

In food processing applications that involve sub-freezing temperatures, specify products designed to withstand these conditions without sacrificing performance or reliability, Figure 2. In a filter-regulator, for example, the air must be dry enough to avoid ice formation. If temperatures reach 32° F or lower, performance will be degraded because liquid particles become gelatinous or frozen.

When specifying pneumatic cylinders, take a careful look at the ingredients to which they may be exposed; for example, ice, sugar crystals or dough can form deposits on piston rods that will interfere with their operation. To alleviate this problem, choose options that allow installing metal scraper rings (rather than rubber or plastic ones) with the piston rod seal to remove the residue before it can damage the cylinder assembly.

Watch out for water

The accessories and options for pneumatic components are frequently neglected, so it’s important to ensure the entire product can withstand the environment where it will operate to avoid forcing maintenance personnel to waste time replacing parts. For example, the adjustment knob or T-handle of a typical regulator is made of a composite material. The caustic chemicals used in wash-down can corrode many types of plastic, so in addition to a stainless steel regulator, the knob should be made of stainless steel or other compatible material.

Filter-regulator options such as tapped manual drains or automatic stainless-steel drains are widely used to get rid of excess liquid and prevent water from draining onto the floor. Look for non-relieving regulators that do not release gases or liquid into the atmosphere. Whenever possible, select pre-lubricated or lubrication-free mechanisms that use food-grade grease and don’t require periodic lubrication.

Although some pneumatic valves meet NEMA protection standards or IEC/IP ratings, most are designed to be mounted in an enclosure to protect them during wash-downs. Check the design of this enclosure for any crevices between the valves and subplate or manifold bases and other non-smooth surfaces that can harbor bacteria. For those who use serial communications with their valves, these electronics also require protection.

Components that require lubricated compressed air or periodic manual lubrication should be avoided when working in food processing to minimize the risk of product contamination. Lubricant in the compressed air can collect near exhaust ports, and manually applied lubricant can spill onto or collect on multiple components.

Using dry air in non-lubricated applications is critical; condensation can corrode system components, increasing maintenance costs and reducing system efficiency. Also, unless distribution air lines are made of stainless steel, aluminum, or high-strength plastic, water can create pipe scale that can work its way into components and cause malfunctions. Water is a poor lubricant; when emulsified with residual compressor oils, it becomes a milky substance that must be drained away. Depending on the amount of liquid produced, this can lead to problems with OSHA. In addition, there should never be any contact with synthetic emulsions in food processing. Dry, filtered, non-lubricated air usually eliminates these issues.

Making smarter choices

Over and above issues related to a component’s required performance and the environment in which it must operate, food processing OEMs are increasingly demanding systems that can connect seamlessly and communicate intelligently with other systems within the facility.

For example, IO-Link smart control of pneumatic valve manifolds makes process data easily accessible and allows monitoring by PLC. This point-to-point communication technology for sensors, actuators and control devices can be built into most PLC configurations or incorporated into most existing industrial Ethernet and fieldbus networks. IO-Link technology can be especially beneficial for machine applications that require frequent changeovers; both reconfiguration time and unplanned downtime can be reduced significantly.

Although the choice of pneumatic components for any industrial application is often a matter of making tradeoffs to work within budget restrictions, system designers can prevent future frustration and ensure optimal equipment performance by resisting the temptation to cut corners on corrosion resistance, cleanliness issues, and long-term maintenance costs while laying the groundwork for additional expansion and enhanced system communication.

What is a pressure gauge?

A pressure gauge is a fluid intensity measurement device. Pressure gauges are required for the set-up and tuning of fluid power machines, and are indispensable in troubleshooting them. Without pressure gauges, fluid power systems would be both unpredictable and unreliable. Gauges help to ensure there are no leaks or pressure changes that could affect the operating condition of the hydraulic system.

The hydraulic system is designed to work in a set pressure range so the gauge must be rated for that range. Hydraulic pressure gauges are available to measure up to 10,000 psi, although maximum hydraulic pressure is typically in the 3,000 to 5,000 psi range. Hydraulic gauges are often installed at or near the pump’s pressure port for indication of system pressure, but can be installed anywhere on the machine where pressure needs to be monitored—especially if sub-circuits operate at a pressure rate different from pump pressure, such as after a reducing valve. Often, pressure-reducing valves have a gauge port to tap into, allowing you to directly monitor its downstream pressure setting.

Pressure gauges have been used in fluid power systems for well over a hundred years, so it might be a surprise that pressure gauge designs continue to evolve. The evolution of pressure gauges for fluid power applications has, generally, been an increase in application specific features. For instance, pressure gauges are now more routinely designed with hydraulic friendly pressure connections (such as SAE/Metric straight threads) to prevent system leaks. Analog gauges with custom scales are more common and digital pressure gauges with customizable firmware allow process measurement of pressure-based measurement of leaks or other parameters like torque, load, force and hardness.

Pneumatic and compressed air systems are also rife with gauges, as pressure is also measured in many locations throughout the system. Pressure is measured at the receiver(s), as well as at every FRL or stand-alone regulator in the system. Sometimes pressure is measured at pneumatic actuators as well. Typically, pneumatic pressure gauges are rated for not much more than 300 psi, although typical systems run around 100 psi.

Pressure is measured in three ways—absolute, gauge and vacuum. Absolute pressure is a measure of actual pressure including ambient air, which is zero-referenced with a perfect vacuum, but can be as high as 14.7 psi at sea level. Absolute pressure readings are considered in applications interacting with ambient air, such as the compression ratio calculation for flow (cfm) requirements. Gauge pressure is zero-referenced against ambient pressure and is used in most applications operating in, but not with, ambient air, such as in fluid power systems. Disconnected from equipment, gauge pressure will read zero. Finally vacuum “pressure” is expressed in Torr, or referenced against ambient pressure, as with “in.-Hg” (inches of mercury) units, which measures pressure below ambient.

The hydraulic gauge can withstand different pressure ranges based on what type of gauge style it is and what material it is made out of. Because of this, the gauge style and the material make up two of the most important selection criteria for gauges.

They are many types of gauge styles, the most common being Bourdon tubes and bellow gauges. Bourdon tubes function by taking the pressure and converting it into mechanical energy. This energy moves a dial in the gauge, displaying the current amount of pressure in the system. Bourdon tube gauges are currently some of the most common gauges and have different configurations such as curved, helical and spiral. The different style of tubing, the size of the tube and the material it is made out of all vary based on the pressure range. One important characteristic to note is the cross section of the tubing changes with increasing pressure. Generally, as the working pressure of the gauge increases, the shape of the cross section of the tube’s design will gradually change from an oval shape to a circular shape.

Bourdon tube operation is simple. They consist of a semicircular and flat tube of metal, fixed at one end and attached to a sensitive lever mechanism at the other. As pressure increases inside the tube, the force of the fluid attempts to straighten out the curved tube. The tube then pulls away from the lever, which being connected to the needle on the display, shows the pressure at the fluid port.

While bellow gauges function similarly to Bourdon tubes, they differ in the fact that they use a spring to judge the amount of energy to push the dial. The spring is expanded and compressed by the pressure in the tubes and the energy created by that movement is transferred into gears that move the pressure dial.

The pressure range at which the gauge will be working is a primary selection factor for the type of material used to make the gauge. Gauges operating at higher pressures generally tend to be made of materials such as steel; when operating at lower pressures, they tend to be made of bronze.

Most pressure gauges in North America come with a 1⁄4-in. NPT male, but SAE thread is gaining popularity. The use of test-point adapters at various locations on the hydraulic system allows for measurement during troubleshooting without having to purchase dozens of pressure gauges. The test-point fitting attaches to the gauge, which can be screwed onto the test points throughout the circuit, allowing you to connect under pressure to measure at various points in the system. Most gauges are 21⁄2 in. in diameter, and can be either top-mount or panel-mount styles, but gauges are available in every size, material and construction imaginable.

Whether used for testing equipment or operating machinery, the right pressure gauge helps reduce costly downtime. In mechanical gauge applications for hydraulic systems, the common threats to gauge reliability are vibration, pulsation and pressure spikes. Therefore, it’s best to look for gauges designed specifically for hydraulic applications. These features include: a forged brass case to prevent resonant frequencies from destroying internal components; a liquid-filled case to protect the gauge from vibration and extreme pressure cycles; and a restrictor to prevent damage to the gauge from pressure spikes. Although the liquid used in the gauge varies from application to application, glycerin is commonly used and performs well in many conditions. The higher the viscosity of the liquid, the more it dampens the vibrations. When choosing between a dry, water- or glycerin-filled gauge, it is also important to consider the following: temperature range, needle response time required, changes in pressure and the amount of vibration expected from the application.

Finally, depending on the demands of the application, gauge accessories, such as specialized restrictors, piston snubbers or even diaphragm seals, may be needed to prevent premature gauge failure.

Which Types of Flow Meters Are Best for Industrial Use?

Several distinct features in liquid flow meters differentiate them on the basis of their functionality and accuracy. To help select the best model for a particular use without overspending, consider the options below for volume-based meters.

Coriolis Meters

Coriolis meters use two designs to provide true mass flow measurement; one is a single tube design, and the other uses two parallel tubes. They operate with an oscillation developed in the tube at a reference frequency based on Newton’s Second Law of Motion and dependent on mass flow rate.

Among the most precise technologies, Coriolis meters are well suited for a broad and developing range of liquid and gas applications. It provides multiparameter data about temperature, density, and mass. Coriolis meters are commonly utilized in nuclear facilities, pharmaceutical manufacturing, wastewater treatment facilities, natural gas measurement and custody transfer.

Differential Pressure Flow Meters

Differential pressure flow meters gauge variations in pressure to identify the speed of flow. It features a flow-restrictive orifice, or laminar flow element, which measures the drop in pressure through the restriction. The points for a drop in the pressure from upstream to downstream are proportional to the rate of flow. At times when no moving parts are required or when a prompt response time is needed, a differential pressure flow meter is the best choice. It is usually found in industrial applications to calculate the output of fuels, in specialty chemical manufacturing, or plain water measurement testing. Differential pressure flow meters are also used in laboratories for calculation and control of the flow of gases while mixing them or separating them with the help of chromatography.

Gear Meters (Positive Displacement)

Positive displacement gear meters use oval, counter-synchronized gears linked to rotate with the flow of liquid. The volume of liquid being transferred through these oval gears is well controlled, giving the meters a great amount of precision. It is designed in a relatively simple and rugged manner, making it well suited for installation in even the harshest situations. Gear meters are well suited for high viscosity liquids. These are utilized in hydraulics and further applications that involve extremely viscous liquids. Gear meters also work extremely well with fuel or oil transfers as well as in manufacturing and pulp and paper industry. Because the gears in the meters are made of stainless steel, they are the best choice for petrochemical industries or any further application which involves light to heavy oils.

Paddle Wheel Meters

Paddle wheel meters come in several forms with oscillating disks, propellers, and rotating paddle wheels. The rotating components of a paddle wheel meter provide a pulse when passing through either a magnetic or optical sensor. The frequency of this pulse is proportional to the velocity of the liquid at either point of the channel or pipe. The design of this meter provides a high precision at a low cost. This meter is usually seen in rural areas for the purpose of irrigation, in water and wastewater treatment, on aqua farms, and in plain-water measurement. Paddle wheel meters function with viscous liquids at a turbulent flow, making them well suited for use in utilities and the oil and gas industries.

Magnetic Meters

Magnetic meters come in two variants: namely, insertion and full-bore. Magnetic meters use coils to develop their magnetic field. When a conductive fluid passes through the field, it produces a voltage proportional to the flow, through an electrode in the wall of the meter or insertion probe. Magnetic meters function by calculating the electrical content of the liquid. This magnetic technology contains no moving parts, and the full-bore design secures the liquid flow from any intrusion. This is a relatively high-end liquid flow meter and is used in the petrochemical, chemical manufacturing, mining, pulp and paper manufacturing, water purification, and food and beverage industries. However, a magnetic meter must not be used with a low conductivity fluid such as de-ionized water.

Based on the above analysis, magnetic flow meters are normally considered to be the most suitable liquid flow meters for industrial operations. These meters can accurately measure any type of conductive liquid flow, whether dirty or clean. Most of the industries use chemicals or water in various forms. They require an accurately measured inflow and outflow. Therefore, it is always necessary to have a full pipe for the accurate measurement of the liquid.

The benefits of solenoid valves

Solenoid valves are used widely in pneumatic as they allow fast responses, automated actuation and are ideal for fail-safe systems due to their immediate reaction to a cut in the energy source.

What are pneumatic solenoid valves?

A solenoid valve is an electromechanically controlled valve. Its main feature is an electromagnet consisting of a single coil of wire in the shape of a tube. When electricity is passed through the coil it produces a magnetic field at right angles to the current flow. By placing a ferrous metal bar within the coil and applying a current, the electrical energy is converted to mechanical energy; the bar is propelled in linear motion by the resultant magnetic field. Solenoids are used in many applications where automated switching and valves are a feature.

A pneumatic control valve applies the linear motion generated in the solenoid to a piston or actuator within a valve. This allows electronic flow control of liquids or gases. Pneumatic solenoid valves require a constant flow of current to remain open as without the current, the electromagnetic field disperses and the valve returns to its original position. This means that pneumatic control valves are useful in situations where you require automated actuation, fast valve response times or in fail-safe systems.

Solenoid pneumatic flow control valves can be used in any application that requires the flow control of a gas (usually air). Industries that use pneumatic solenoid valves can be from industrial hydraulics, pneumatics to household plumbing and heating.

What are the key pneumatic solenoid valve types?

The two-way valve is the most common pneumatic solenoid valve type. A two-way valve has two ports. In terms of operation, pneumatic solenoid valve types are classified by whether they are direct acting valves or pilot-operated (indirect) valves.

Direct acting valves

Direct-acting pneumatic solenoid valves have a coil which magnetically opens the valve without the need for outside pressure. That is, when electricity is applied to the electric coil surrounding the plunger, the valve is opened (or closed, depending on its resting position). The flow rate and operating pressure directly relate to the diameter of the tube through which the media flows, and therefore direct-operated pneumatic solenoid valves do not require a minimum operating pressure or pressure difference.

Pilot-operated valves

Pilot-operated pneumatic solenoid valves, or indirect solenoid valves, have two connected chambers and use a pilot hole in a diaphragm (or cover) to indirectly control the pressure of the media. Once the solenoid valve is energised, the pressure difference controls the lift of the membrane and allows the gas to flow in a single direction. These types of pneumatic control valves are suitable for a high flow rate at high pressures with lower power consumption. A minimum pressure differential is required across the valve to keep them either open or closed.

Pneumatic solenoid valves from Fluid Controls

It is important to select the correct pneumatic solenoid valve for the right application. The type of pneumatic control valve required will depend on the purpose of the system and the media used within it. Fluid Controls has a wide range of pneumatic solenoid valves; we are bound to have one in stock that suits your requirements; please contact us if you need guidance in making your selection.

What Is a Vibration Sensor | Types of Vibration Sensors?

In this article, we are going to talk about the different types of vibration, the different types of vibration sensors, and how to choose a vibration sensor based on parameters.

For optimum performance of the machines, it is necessary to continuously monitor the parameters like speed, temperature, pressure, and vibration.

Monitoring changes in any parameter could solve any downtime and/or machine damage which results in financial loss. Among these parameters one of the best operating parameters to judge dynamic conditions is vibration.

Vibration Types and Definitions

First, we need to have a definition of vibration before we get too far into our discussion.

Vibration can be defined as the mechanical oscillation about an equilibrium position of a machine or component or simply the back and forth motion of a machine or component.

Vibration in industrial equipment is sometimes part of the normal operation but sometimes it can be a sign of trouble.

In machine monitoring we are dealing with two types of vibration;

– Axial (Thrust) Vibration

– Radial Vibration

1. Axial (Thrust) Vibration

“Axial” Vibration is a longitudinal shafting vibration or parallel to the shaft of a motor. For example, a shaft misalignment could cause axial vibration.

2. Radial Vibration

“Radial” Vibration occurs as a force applied outward from the shaft. Radial vibration would occur if there is a heavy spot in the motor as it rotates.

If there is a deformed fan blade, as the fan spins, the deformed fan blade would pull outwardly on the shaft of the motor causing radial vibration.

Types of Vibration Sensor

Now that we know what vibration is, let’s look at the different types of sensors to monitor vibration.

First, we will talk about an accelerometer.

1. Accelerometer

Accelerometers are devices that measure the vibration, or acceleration of motion of a structure.

They have a transducer that converts mechanical force caused by vibration or a change in motion, into an electrical current using the piezoelectric effect.

There are two types of piezoelectric accelerometers,

– High Impedance

– Low Impedance

1.1. High Impedance Accelerometer

High impedance accelerometers produce an electrical charge which is connected directly to the measurement instruments.

They require special accommodations and instrumentation so they are found in research facilities or high-temperature applications.

1.2. Low Impedance Accelerometer

Low impedance accelerometers have a charge accelerometer as its front end as well as a built-in micro-circuit and transistor that converts that charge into a low impedance voltage.

This type of accelerometer easily interfaces with standard instrumentation which makes it commonly used in the industry.

2. Strain Gauge

Next, let’s talk about a strain gauge type of vibration sensor.

Just like it sounds a strain gauge measures the strain on a machine component.

A strain gauge is a sensor whose resistance varies with applied force; It converts force, pressure, tension, weight, etc., into a change in electrical resistance which can then be measured.

When external forces are applied to a stationary object, stress and strain are the results.

When there is a strain applied to any metallic wire, the length of that wire increases and the diameter decrease.

This increase in length and decrease in diameter will change the resistance of the wire which will give us our measurement of strain on our machine component.

3. Eddy-Current

The last type of vibration sensor we will discuss is an Eddy-Current or Capacitive Displacement sensor.

Eddy-Current sensors are non-contact devices that measure the position and/or change of position of a conductive component. These sensors operate with magnetic fields. The sensor has a probe which creates an alternating current at the tip of the probe.

The alternating current creates small currents in the component we are monitoring called eddy currents.

The sensor monitors the interaction of these two magnetic fields.

As the field interaction changes the sensor will produce a voltage proportional to the change in the interaction of the two fields.

When using Eddy-Current sensors it is important for the component to be at least three times larger than the sensor diameter for normal operation; otherwise, advanced calibration would be required.

How to Choose a Vibration Sensor

When choosing a vibration sensor for your application it is important to look at factors such as;

– Range and accuracy

– Environment conditions

– The shape of the measuring surface

Out of the three sensors that we have discussed the accelerometer is the most common because it has a good range of frequency, meaning it can sense slow and fast applications.

Along with the frequency, accelerometers are priced affordably and are durable. They do have to be mounted directly to the machine which is common for vibration sensors.

Eddy current or capacitive sensors have medium accuracy and are not optimal for high-resolution applications. They are very durable making them a good option for dirty environments.

Just like the accelerometers, they have to be directly mounted to the machine being monitored.

Lastly, strain gauges are both versatile and accurate while still suitable for hazardous environments.

Unfortunately, they can be hard to install correctly and to get proper data your application will need amplifiers which can drive up the price.

Improving Performance of Industrial Equipment Using Pressure Transducers

Used to convert fluid pressure into electrical signals which can monitor and control systems, pressure transducers have become an invaluable tool for the protection and optimization of industrial equipment.

Innovative Construction Methods

The sophisticated design and resilience are the result of highly innovative and carefully controlled construction methods, such as the advanced strain gauge technologies of chemical vapor deposition (CVD) and sputtered thin films.

CVD is a particularly effective method for the manufacture of strain gauge sensors, which utilize a pressure diaphragm to detect movement, and convert this information into electrical signals. Devices produced using CVD are generally compact and can provide high accuracy and excellent hysteresis characteristics. These sensors are fabricated on wafers in large batches and use polysilicon deposited onto a stainless-steel substrate, with chemically milled strain gauge patterns.

As well as CVD processes, sputtered thin films have also been integral to the success of recent pressure transducers. During the sputtering process, a solid target of the desired material is bombarded by energized particles, resulting in the release of atoms from the target.

Sputtered thin film deposition uses these released atoms to form a thin film. Using the sputtered thin film process in the manufacture of pressure transducers provides a sensitive and robust diaphragm, suitable for direct contact with almost all oils, liquids, and gases.

These innovations in the chemical manufacture of pressure sensors have been partnered with equally important advances in electronics, greatly enhancing the capabilities of transducers. For example, supplying electronic packages with pressure transducers in recent years has enabled each individual sensor to be tuned, in order to meet the exact requirements of each customer.

Advanced ASIC Technology

These electronic packages apply advanced ASIC (application specific integrated circuits) technology, which can enhance functionality and performance. They can also be customized, providing an effective and convenient option that cuts costs in cases where complex and costly control technology is not required.

The economic advantage from the introduction of ASIC has been significant. In combination with improvements in volume manufacturing techniques, ASIC’s introduction has reduced the unit cost of transducers by a factor of 10 in many instances. As a result, manufacturers have been able to sell sensors offering a level of performance previously associated with units that sold for £300, for as little as £30 a sensor.

Combining sputtered thin film and CVD technology with ASIC electronics packaging, a powerful combination of accuracy and reliability can be offered to the growing number of engineers who choose to investigate the advantages of pressure transduction technology.

The wide range of sensor products currently available will allow engineers to apply transducers across ever more challenging environments, as will the modular nature of components, which increases the variety of available options in the accommodation of transducers.

Pressure sensors will provide a greater level of data acquisition and system control as they continue to improve and develop, which will be applied both within the many industries currently utilizing them, and within those that aim to adopt them in the future.

pressure transducers Series

Instronline pressure transducers provide a wide range of pressure ports, outputs, and electrical connections, with pressure ranges between 15 and 200 psi, and with operating temperatures of -40 °C to +125 °C.

These sensors have a long operating life and can provide excellent resistance to mechanical vibration and pressure shocks, while the application of high temperature vacuum brazing of the stainless-steel components during their production offers a structure which is both strong and corrosion resistant, with low hysteresis and creep.

This information has been sourced, reviewed and adapted from materials provided by Instronline Instrumentation & Tools.

For more information on this source, please visit Instronline Instrumentation & Tools.

What is a pressure transducer, what does it measure, and how does it work?

Some people think that “pressure transducer” and “pressure transmitter” mean the same thing, but they don’t. All pressure transmitters have pressure transducers and some even have more than one. As a matter of fact, some have more than one.

What is a pressure transducer?

A pressure transducer converts the pressure on the sensor into an analog signal. Sometimes it does that from inside a transmitter. And that’s how it gets confusing.

Transducers work great for small spaces, and the output usually ranges between 0 and 100 millivolts. More often than not we use them with amplifiers. Pressure transducer sold without amplifiers are often called “bare” transducers.

However, in case we try to find a pressure transducer for an application, regarding the output you should study these three possibilities that are the most used.

Millivolt Pressure Transducers

The output is nominally around 30mV. The output value is directly proportional to the pressure that the received in the transducer.

Because the output signal is so low, the transducer should not be located in an electrically “noisy” areas. Another fact that must take it into account is the resistance of the cable. Long distances will affect accuracy.

Voltage Pressure Transducers

These transducers include an amplifier (signal conditioning) which provide a much higher output than a millivolt transducer. Normally 0-5Vdc or 0-10Vdc.

The main advantage for these transducers is that are not as susceptible to electrical noise as millivolt transducers and can, therefore, be used in more application areas.

4-20 mA Pressure Transducers

Also known as pressure transmitters. The current output 4-20mA is less affected by electrical noise and resistance in the signal wires, this output is the best to be used when the signal must be transmitted “long” distances.

We know that there are many things to know before choosing a pressure transducer for your application, but you don’t have to be worried, contact us and we will quote you the right device for your application.

DIFFERENCE BETWEEN ABSOLUTE AND INCREMENTAL ENCODERS?

In this article, we will discuss the various types of encoders and which encoder may be used for which function.

we are going to discuss the difference between Absolute and Incremental encoders and which one may be used for which function.

Encoder Types and Technologies

There are many types of encoders but they basically fall into two main sensing techniques. Those being:

– Linear

– Rotary

Within those categories, there are differing encoder measurement types such as:

– Absolute

– Incremental

There are also various electromechanical technologies such as:

– Magnetic

– Optical

– Inductive

– Capacitive

– Laser

There is a plethora of information regarding Encoders and it may seem hard to wrap your head around.

Descriptions like rotary or linear, optical and magnetic, absolute and incremental.

We touch on a few basics to help you understand what’s what and why.

Let’s first break these categories down a little and explain a couple of the many configurations.

1. Linear Encoder

First, the Linear Encoder uses a transducer to measure the distance between two points. These encoders can use a rod or a cable that is run between the encoder transducer and the object that will be measured for movement.

As the object moves, the transducer’s data collected from the rod or cable creates an output signal that is linear to the object’s movement.

As the distance is measured, the Linear Encoder uses this information to determine the position of the object.

An example of where a Linear Encoder may be used is for a CNC milling machine where precise movement measurements are required for accuracy in manufacturing.

Linear Encoders can be “Absolute” or “Incremental”. We will touch on Absolute and Incremental measurements a little later in this article.

2. Rotary (Shaft) Encoder

A Rotary Encoder collects data and provides feedback based on the rotation of an object or in other words, a rotating device.

Rotary Encoders are sometimes called “Shaft Encoders”. This encoder type can convert an object’s angular position or motion based on the rotation of the shaft, depending on the measurement type used.

“Absolute Rotary Encoders” can measure “angular” positions while “Incremental Rotary Encoders” can measure things such as distance, speed, and position.

Rotary Encoders are employed in a wide variety of application areas such as computer input devices like mice and trackballs as well as robotics.

Rotary or Shaft encoders, as previously stated, may be “Absolute” or “Incremental”.

3. Position Encoder

The next encoder, which is a “Position” Encoder, is used to determine the mechanical position of an object. This mechanical position is an “absolute position”.

They may also be used to determine a change in position between the encoder and object as well. The change in position in relation to the object and encoder would be an incremental change.

Position Encoders are widely used in the industrial arena for sensing the position of tooling and multi-axis positioning.

The Position Encoder can also be Absolute or Incremental.

4. Optical Encoder

“Optical” Encoders interpret data in pulses of light which can then be used to determine such things as position, direction, and velocity.

The shaft rotates a disc with opaque segments that represent a particular pattern. These encoders can determine the movement of an object for “rotary” or “shaft” applications while determining exact position in “linear” functions.

Optical encoders are used in various applications such as printers, CNC milling machines, and robotics.

Again, these encoders may be Absolute or Incremental.

After explaining the main groups, you may be seeing a pattern.

All the encoders basically do the same thing, produce an electrical signal which can then be translated to position, speed, angle, etc.

Absolute Encoder vs. Incremental Encoder

Now that we have broken down the main groups, let’s discuss the difference between Absolute and Incremental measurements.

To discuss the difference between absolute and incremental measurements, we will use the Rotary Encoder type as an example.

In a Rotary “Absolute” measurement type encoder, a slotted disc on a shaft is used in conjunction with a stationary pickup device. When the shaft rotates, a unique code pattern is produced. This means that each position of the shaft has a pattern and this pattern is used to determine the exact position.

If the power to the encoder was lost and the shaft was rotated, when power is resumed, the encoder will record the absolute position as demonstrated by the unique pattern transmitted by the disc and received by the pickup.

This type of measurement is preferred in applications requiring a great degree of certainty such as when safety is a primary concern. Because the encoder knows, at all times, its definitive position based on the unique pattern produced.

Absolute measurement encoders can be

– Single-turn

– Multi-turn

“Single-turn” encoders are used for measurements of short distance while “multi-turn” would be more suitable for longer distances and more complex positioning requirements.

For incremental measure encoders, the output signal is created each time that the shaft rotates a measured amount. That output signal is then interpreted based on the number of signals per revolution.

The incremental encoder begins its count at zero when powered on. Unlike the absolute encoder, there are no safeguards regarding the position.

Because the incremental encoder begins its count at zero in startup or power disruption, it is necessary to determine a reference point for all tasks requiring positioning.

Encoders in Counting Applications

In the previous article, when describing the use of an encoder for the purpose of counts, that example is a good example of an incremental encoder.

Assume that the power has not been disrupted and you have turned on the conveyor, and placed the machine in setup mode.

As the encoder is turning, the controller is receiving counts. Let’s say the count range is 0 to 10000.

This is an incremental encoder so the absolute position is not known, we just know that a full revolution of the shaft registers a count of 10000.

We’ll place the object on the conveyor and, as soon as the entrance photo-eye sensor detects the object, the current encoder count is captured. Let’s say that number is 5232.

We will then capture the count with the object exiting and being detected by the exit photo-eye. We’ll say that the number is 6311. So to determine the count of the full travel, we will subtract 5232 from 6311 and determine that the object travel is 1079 counts.

By this example, it is obvious that we do not know the absolute location of the object, we just know that the travel count from the entrance to exit is 1079.

That doesn’t tell us that the object is three inches from the exit, just entering, etc.

we just know that the object will enter, a count will be captured, and the object will exit and again, the count captured.

In the event that we did not see the object exiting within the allowable travel count, plus or minus a deadband, the machine will fault and the process will stop.

There are many, many encoder variations out there and we could go on for hours about the varying types.

Hopefully, we have given you a basic understanding of what’s out there and when you may want to choose one particular type over the other.

Thank you so much for reading the blog.

Information About Ultrasonic Flowmeter

Ultrasonic flowmeters use sound waves to determine the velocity of a fluid flowing in a pipe. At no flow conditions, the frequencies of an ultrasonic wave transmitted into a pipe and its reflections from the fluid are the same. Under flowing conditions, the frequency of the reflected wave is different due to the Doppler effect. When the fluid moves faster, the frequency shift increases linearly. The transmitter processes signals from the transmitted wave and its reflections to determine the flow rate.

Transit time ultrasonic flowmeters send and receive ultrasonic waves between transducers in both the upstream and downstream directions in the pipe. At no flow conditions, it takes the same time to travel upstream and downstream between the transducers. Under flowing conditions, the upstream wave will travel slower and take more time than the (faster) downstream wave. When the fluid moves faster, the difference between the upstream and downstream times increases. The transmitter processes upstream and downstream times to determine the flow rate. They represent about 12% of all flowmeters sold.

Plusses and Minuses

This technology can be very accurate and is used for custody transfer (meaning accounting accurately for an expensive fluid) of natural gas and petroleum liquids. High turndown (can read low as a percentage of the full scale or top reading), handles high pressures, is repeatable (consistent), handles extreme temperatures, can be used clamped to the outside of a pipe without penetration, is low maintenance, highly reliable and self –diagnosing. Disadvantages can include high cost, sensitivity to stray process vibrations, problems with pipe diameter change due to buildup and clamp-on units have lower accuracy.

Ultrasonic flowmeters do not obstruct flow so they can be applied to sanitary, corrosive and abrasive liquids. Some ultrasonic flowmeters use clamp-on transducers that can be mounted external to the pipe and do not have any wetted parts. Temporary flow measurements can be made using portable ultrasonic flowmeters with clamp-on transducers. Clamp-on transducers are especially useful when piping cannot be disturbed, such as in power and nuclear industry applications. In addition, clamp-on transducers can be used to measure flow without regard to materials of construction, corrosion, and abrasion issues. However attractive, the use of clamp-on transducers introduces additional ultrasonic interfaces that can affect the reliability and performance of these flowmeters. In particular, if not properly applied and maintained, attenuation of the ultrasonic signal can occur at the interfaces between the clamp-on transducers and the outside pipe walls, and between the inside pipe walls and the fluid.

Ultrasonic flowmeters are available in sizes to 72 inches and larger.

How to Use Ultrasonic Flowmeters

Ultrasonic flowmeters are commonly applied to measure the velocity of liquids that allow ultrasonic waves to pass, such as water, molten sulfur, cryogenic liquids, and chemicals. Transit time designs are also available to measure gas and vapor flow. Be careful because fluids that do not pass ultrasonic energy, such as many types of slurry, limit the penetration of ultrasonic waves into the fluid. In Doppler ultrasonic flowmeters, opaque fluids can limit ultrasonic wave penetration too near the pipe wall, which can degrade accuracy and/or cause the flowmeter to fail to measure. Transit time ultrasonic flowmeters can fail to operate when an opaque fluid weakens the ultrasonic wave to such an extent that the wave does not reach the receiver.

Industries Where Used

The industries in order of higher to lower are oil and gas, water and wastewater, power, chemical, food and beverage, pharmaceutical, metals and mining, and pulp and paper.

Application Cautions for Ultrasonic Flowmeters

For transit time ultrasonic flowmeters, be sure that the fluid can adequately conduct ultrasonic waves, because the flowmeter will not measure when the ultrasonic waves cannot penetrate the flow stream between the transducers. Similarly, ultrasonic waves must be able to penetrate the fluid for Doppler flowmeters to operate accurately. When the fluid is relatively opaque and does not penetrate the fluid, Doppler flowmeters tend to measure the velocity of the fluid at or near the pipe wall, which can cause significant measurement error and/or cause the flowmeter to fail.

For Doppler ultrasonic flowmeters, be sure that the fluid adequately reflects ultrasonic waves, because the flowmeter will not operate without a reflected ultrasonic signal. Depending upon design, reflections can occur due to small bubbles of gas in the flow stream or the presence of eddies in the flow stream. If not already present in the flowing stream, generating these sources of reflection can be difficult in practice. Fortunately, some combination of bubbles of gas and/or eddies are present in most applications.

The velocity of the solid particles in slurry can be different than its liquid carrier fluid. Be careful applying ultrasonic technology when the solid particles can become concentrated in one part of the flowing stream, such as in a horizontal pipe flowing at a relatively low velocity. Be careful when applying Doppler ultrasonic flowmeters in slurry applications because the solid particles can produce strong signals that can cause the Doppler flowmeter to measure the velocity of the solids and not the velocity of the liquid.

Avoid fluids that can coat wetted transducers or coat the pipe wall in front of non-wetted transducers because the flowmeter will not measure when the ultrasonic waves cannot enter the flow stream. Be sure to maintain reliable clamp-on transducer connections to the pipe wall because the flowmeter will not measure when the ultrasonic waves are not able to reach the fluid.

Be sure to understand the process and apply these flowmeters properly. For example, a periodic cleaning process upstream may cause the flowmeter to stop working because the dirt may not allow ultrasonic energy to pass through the fluid. Further, if the dirt coats wetted transducers, the flowmeter may fail to operate until it is cleaned.

What is a Tachometer?

A tachometer is a sensor device used to measure the rotation speed of an object such as the engine shaft in a car, and is usually restricted to mechanical or electrical instruments. This device indicates the revolutions per minute (RPM) performed by the object.

The device comprises of a dial, a needle to indicate the current reading, and markings to indicate safe and dangerous levels. The word comes from the Greek ‘tachos’ meaning speed and ‘metron’ meaning measure so tachometer and speedometer have become interchangeable and essentially both measure speed.

Historically, the first mechanical tachometers were designed based on measuring centrifugal force: an inertial force directing away from an axis of rotation that acts on all objects as viewed from a rotating frame of reference. In 1817, it was adapted to be used for measuring the speed of machines and since 1840, it has been predominantly used to measure the speed of vehicles; specifically locomotives.

Advanced tachometers have novel uses. For example, in the medical field, a haematachometer placed in an artery or vein can estimate the rate of blood flow from the speed at which the turbine spins. The readings can be used to diagnose circulatory problems like clogged arteries.

Types of Tachometers

The types of tachometers commonly found are:

Analog tachometers - Comprised of a needle and dial-type of interface. They do not have provision for storage of readings and cannot compute details such as average and deviation. Here, speed is converted to voltage via use of an external frequency to voltage converter. This voltage is then displayed by an analog voltmeter.

Digital tachometers - Comprised of a LCD or LED readout and a memory for storage. These can perform statistical operations, and are suitable for precision measurement and monitoring of any kind of time-based quantities. Digital tachometers are more common these days and they provide numerical readings instead of using dials and needles.

Contact and non-contact tachometers – The contact type is in contact with the rotating shaft and uses an optical encoder ot magnetic sensor. The non-contact type is ideal for applications that are mobile, and uses a laser or optical disk. Both of these types are data acquisition methods.

Time and frequency measuring tachometers – Both these are based on measurement methods. The time measurement device calculates speed by measuring the time interval between the incoming pulses; whereas, the frequency measurement device calculates speed by measuring the frequency of the incoming pulses. Time measuring tachometers are ideal for low speed measurements and frequency measuring tachometers are ideal for high speed measurements.

Working Principle

The working principle of an electronic tachometer is quite simple. The ignition system triggers a voltage pulse at the output of the tachometer electromechanical part whenever the spark plug fires. The electromechanical part responds to the average voltage of the series of pulses and it shows that the average voltage of the pulse train is proportional to engine speed. The signal from the perception head is transmitted by standard twin screened cable to the indicator.

The tachometers are temperature compensated to be able to handle operations over an ambient temperature range of – 20 to +70°C (-4 to +158°F).

The tachometer in a vehicle enables the driver to select suitable throttle and gear settings for the driving conditions as prolonged use at high speeds can cause insufficient lubrication which will affect the engine. It enables the driver to prevent exceeding speed capability of sub-parts such as spring retracted valves of the engine, and overheating, thereby causing unnecessary wear or permanent damage and even failure of engines.

Applications

The following are the key application areas of tachometers:

Automobiles, airplanes, trucks, tractors, trains and light rail vehicles

Laser instruments

Medical applications

Analog audio recording

Numerous types of machinery and prime movers

To estimate traffic speed and volume.

WHAT IS A VFD?

Today you will learn about VFD. Specifically, what it is and when do we use it with automation and PLCs.

So what exactly is a VFD? Well, it stands for Variable Frequency Drive.

They are used for running an AC motor at variable speeds or let them ramp up their speed to give them a smooth startup.

Some people simply call them drives.

VFDs work by adjusting the frequency of the motor to adjust the rpms.

To do this, a VFD will actually convert the voltage twice:

1) First, it converts our three-phase AC to DC. This is accomplished with diodes.

2) Then it cleans the DC with a capacitor.

3) Next, it will convert the DC to AC. This is accomplished with transistors acting as switches.

Utilizing these “switches” is what allows the VFD to adjust the frequency that the VFD supplies to the motor. This, in turn, controls the speed of the motor.

Now I know this is a lot of information to take in. Let me compare the internal workings of the VFD with a simple plumbing system.

First, let’s look at the diodes that convert the AC to DC. This operates like a check valve in a water system.

A check valve, like a diode with electricity, only allows water to flow in one direction.

The capacitor acts as a water filter to keep everything clean and useable.

The transistors act like valves. They turn the flow on and off when needed. This allows the VFD to adjust the frequency to the motor.

Now that we have an understanding of how a VFD works, let’s see what they are used for.

One very common use in industry is to control the speed of a water pump in a water treatment facility.

A water treatment plant typically has a constant flow of water coming in to the plant. However, if the water demand exiting the plant is lower than the supply entering the plant, then the operator will need to slow down the supply.This is achieved by using a VFD on the AC motor.

The operator can monitor water flow and manually adjust the VFD accordingly.

Another great thing about VFDs is the fact that they can be controlled with a PLC. Using basic communication protocols that have been covered in previous videos, such as RS232 and RS485, PLCs can monitor and control motor speeds using the VFD.

This helps make a process like water treatment that much easier and more efficient. This setup can be used in any situation that would benefit from automation.

Let’s look back at what we now know. VFD stands for Variable Frequency Drive. They are used for controlling the speed of an AC motor.

They are also used for ramping up a motor for a smooth startup, or to prevent a heavy load from straining the motor on startup.

This is accomplished by adjusting the frequency delivered to the motor. A setup of an AC to DC converter, then DC to AC converter.

VFDs are used throughout industry. A common example is to regulate water flow entering a water treatment plant. VFDs allow the operator to control the flow of the pump manually or automatically with a PLC.

There are many different brands and features available. If you are looking at using a VFD just be sure to do your research!

I hope this blog post has helped you get a feel for VFDs. They really can make any automation or industrial process operate more smoothly.

As always, be sure to check back soon for more RealPars videos and blog posts!

Thanks for reading and sharing our blog posts with your friends and colleagues.

The 7 Best Vortex Flow Meters On The Market

Vortex flow meters are broad spectrum flow meters one can use in areas of metering, measuring and control of liquid, gas or mostly steam flow. Many prefer these devices due to their high stability, the versatility of medium and their high reliability.

As such, the petroleum and chemical industries, as well as metallurgy, food, paper, urban pipeline heating, and other coal and gas industries widely use these flowmeters. This article discusses seven vortex devices that are useful in the area of flowmeters.

How does the vortex work?

It follows the principle of von Karman effect, stating that the fluid generates vortices alternately on either side when the steam encounters the bluff or bar-like obstruction.

When it attains a particular flow rate, a series of vortices is caused downstream of the bluff body. Zones of high and low-pressure vortices are formed, and these differences in pressure exactly match the frequency of the vortices. A mechanical sensor of the flow meter senses and measures this. It is primarily to measure the mass, volume, density and other parameters of the flowing fluid.

Proline Prowirl F 200

The Prowirl F 200 has a lot of tricks. As per the interface is concerned, we can see it has the same interface as a level radar from Endress+Hauser, which means we don’t have to figure out a new layout. That also equals same set up and same logic behind the buttons!

As a loop-powered device, the Prowirl uses the same cable for power and communication at the same time. No more tangles! We also have a ton of options for variables like volume, mass flow, energy flow, temperature, and more.

It has a great measuring range too. We can get anywhere from 2 to 32 166 meters cubed per hour on steam at 180 degrees Celsius and 10 bar of pressure. And your error margin in volume flow maxes at +- 1 percent and in mass flow at + – 1.7 percent (steam, gas). That’s tight!

Siemens: SITRANS FX300 Vortex Flow meter

The FX300 provides accurate volumetric and mass flow of fluids with integrated temperature and pressure compensation. It gets a local LC display with two lines and ten characters per line spacing and multiple language options.

It comes in different variants, such as a single or dual transmitter versions. One also has integral mount choices of flange and sandwich options, suitable for measuring industrial conductive and non-conductive liquids.

The FX300 is deployed in an operating temperature range of -40 to +240°C at an accuracy of +/-0.75% for liquids, +/-1% for steam and gases for the standard version. As for the pressure and temperature compensated version, it has an accuracy of +/-0.75% for liquids, and +/-1.5% for gases at repeatability of +/-0.1%.

There is nothing notable about its output option and communication, other than 4-20 mA and HART digital protocol. Other exciting features include the hazardous approvals it gets from ATEX and FM. It gets a degree of protection of IP67, which makes the device dust-tight and semi water-resistant.

Furthermore, it gets a wide range of wetted material options- 1.4404, 1.4435, Hastelloy C22, and many more. In short, the FX300 is the one you need to look for if your applications have a wide variety of conductive and non-conductive fluids that you need to measure accurately.

Yokogawa: DigitalYEWFLO Series Vortex Flow Meter

The digitalYEWFLO comes with a ton of features like the multivariable, reduced bore and cryogenic options. Its unique Spectral Signal Processing (SSP) means that it provides high accuracy and stability in harsh process conditions.

The Multivariable option has a built-in temperature sensor that performs temperature measurement. The Reduced Bore gets a reduced bore with concentric piping for fluids with lower flow range. The Cryogenic version is for fluids with a process temperature as low as -196°C. Lastly, it has a high-temperature option with a process range of -29 to +450°C.

With powerful electronics such as SSP, the device can automatically select the optimum adjustment for its applications. It features self-diagnostics, such as high vibration of the piping and pulsating flow automatically. As for the output option, the device gets Foundation Fieldbus, BRAIN and HART protocol. The device receives a degree of protection of IP67, which is dust-proof and decently water resistant.

Furthermore, it gets 316L stainless steel for wetted material which is rust-proof and chemical resistant. It gets a housing made of Polyurethane coated with a corrosion-resistance layer. As for the accuracy, the device has a flow rate of +/-0.75% of reading in liquids and a +/-0.5 to +/-1% reading in gas or steam applications.

Additionally, the device also has Ex- certification from ATEX, CSA, FM, TIIS, and IECEx. To sum up, the digitalYEWFLO series is best suited for cryogenic application and in hazardous flow meter applications!

ABB: VortexMaster FSV450 Vortex Flow Meter

The FSV450 gets multiple integral mount options, such as flange and wafer including dual sensor capability. The FSV450 vortex flow meter measures the flow of vapor, liquid, steam or gas with integrated binary output. It also has optional temperature measurement and compensation and flow computer bifunctionality.

With a degree of protection of IP67, the device is dust-proof and resistant to high-pressure water jets. Also, with wetted materials such as 316L and Hastelloy C, the device is resistant to abrasion, rust, and corrosion as.

The device has a process temperature range of -55 to 280°C and a high-temperature range of -55 to 400°C. As for the accuracy, the device gets a 0.65% reading in liquids and 0.9% reading for gas/steam application. Also, it gets a temperature accuracy of ±1 °C or 1 % of reading. Not only that, but the device also has approvals for hazardous applications from ATEX, IECEx, cFMus, and NEPSI too.

Additionally, the device features an operating mode of biogas. It gets a standard LCD indicator with four push buttons for operation and navigation. As for output options, it gets a 4-20 mA analog, HART protocol (HART 7) and Modbus RS485. In conclusion, if you are looking for a flowmeter with good accuracy and hazardous approvals, the FSV450 is for you!

Schneider Electric: Foxboro Model 84S Vortex Flow Meter

The Foxboro Model 84S is a high-performance sanitary vortex flowmeters for use in pharmaceutical sanitary liquid services and CIP systems. The device gets a 4-20 mA, and HART communication protocol for remote configuration and calibration.

The device has an LCD indicator for local configuration along with navigation keys for operation. The 84S has features like the ActiveTuning algorithm that corrects real time Reynolds number, compensates for piping effects and also performs adaptive filtering and signal conditioning.

Foxboro also offers another interesting feature- FlowExpertPro program that ensures that the user has selected the proper flowmeter type for the application. The FlowExpertPro also provides a meter selection tool as a free website to all users.

The device has a process temperature range of -18 to 177°C for liquid, gas and steam applications with an accuracy of +/- 0.5% of reading in liquids and +/- 1.0% of reading in gas and steam. With approval from 3A, the 84S comes with no moving parts. It gets wetted materials such as 316/316L SS and finished to 25 microinch sanitary standards.

Another notable feature is the DirectSense technology. It measures pressure pulses from vortex shedding directly without mechanical linkages. It also provides increased measurement sensitivity for broader range ability and greater immunity to pipe vibration. To sum up, the Model 84S is a viable choice for hygienic and sanitary applications.

Kobold: DVE Multi-Parameter Vortex Flowmeter

The Kobold DVE series comes with many variants (V, T, P, E) that offer distinct possibilities. The DVE integrates output capability with single line penetration. It also simplifies system complexity and helps reduce initial equipment cost, installation, and maintenance costs.

The DVE-V provides cost-effective volumetric flow monitoring solution for low-viscosity liquids. The DVE-T incorporates temperature sensing to provide compensated mass flow reading of saturated steam. The DVE-P delivers mass flow, temperature, pressure, and density readings. As for the output options, the DVE gets analog, limit switches, HART and Modbus protocols.

The device gets a LCD indicator with alphanumeric 2-line (16 characters) with six push buttons for configuration. Additionally, it gets 316L stainless steel for wetted material which is rust-proof and chemical resistant. Also, the device receives a standard temperature range of -200 to 260°C. For the high-temperature option, it gets a range of -200 to 400°C.

As for the accuracy, the device has a volumetric flow rate of +/-1.2% and +/-1.5% of reading in liquids and gas, a mass flow rate of +/-1.5% and +/-2.0% of reading in liquids and gas, a density accuracy of +/-0.3% and +/-0.5% for reading.

Furthermore, it also gets hazardous protection approvals from ATEX and IECEx. If you are looking for a low-cost vortex flowmeter for hazardous applications, the DVE and its variants is an apt choice for you.

Omega: FV-505C Vortex Flow meters

The Omega FV505C is the right flowmeter option if you are looking to measure the flow of low viscosity fluids and other conductive liquids. It gets a clear parallel two-line LCD that displays simultaneous flow rate and total flow rate along with process diagnosis. Similarly to Yokogawa digitalYEWFLO series, the Omega FV505C also utilizes the technology of Spectral Signal Processing.

The device gets a ton of features that can find a lot of uses for your flow meter applications. It receives a process temperature range of -40 to 260°C for the general variant, and a variety of -40 to 450°C for the high temperature variant with an accuracy of ±0.75% of reading liquids. It also has ±1% of reading for gas/steam respectively with a repeatability of ±0.2% of reading.

Also, it has different mounting options, such as flange and wafer. The wetted material is Duplex stainless steel. As for the functions, it can deliver self-diagnostics, Reynolds number correction, Gas Expansion Correction, Data security during power failure, and Downscale or Upscale Burn. To make a long story short, the Omega FV505C is a fine vortex flowmeter that offers high accuracy with significant repeatability and stability!

What do you need to know about control valve positioners?

So far, we’ve talked about control valves as basically body and actuator. Depending on the application, you may need some accessories to beef it up. Today, let’s review one of the most important, valve positioners.

What’s a valve positioner?

Valve positioners translate signals from the control system to send the right pressure to an actuator. In a nutshell, it tells the actuator to move the valve to a certain position based on the input data.

Valve positioners come in different types. Some use a pneumatic input signal to send pressure for opening or closing the valve. Some use analog signals to do the same thing. And now, we have smart positioners changing analog to digital to control your valves. Let’s take a closer look at these valve positioners.

Pneumatic positioner

This type uses the flapper/nozzle system. We have an article that discusses this working principle here. It requires compressed air to make everything work correctly and uses a signal of 3-15 pounds per square inch to receive the data from the controller.

The input tells the bellows to expand or compress, depending on the signal. The bellows moves the flapper assembly and the beam that measures the valve stem feedback through the cam.

In all this movement, the flapper will move closer or further from the nozzle. Thus the relay will increase or decrease the air output to the valve actuator. When the valve stem moves, it sends feedback through the beam. Then the air output will decrease or increase again, to position the valve properly based on the input signal.

Electro-pneumatic positioner

The working principle for this one resembles the pneumatic positioner. But rather than a pneumatic signal, you get an analog signal, usually 4-20 milliamps.

However, the signal works differently internally. It creates an electromotive force (EMF) based on the electrical signal applied to a coil. Basically, this force moves the flapper and increases or decreases the air to the valve actuator. You also have feedback from the valve stem and positioner to decrease or increase the output to the valve actuator if needed.

Smart positioner

Smart valve positioners bring a lot of benefits to the end user. They provide more flexibility for setup, plus they make it easier to get diagnostics. And these diagnostics can increase the life of your valve, reducing maintenance and unscheduled downtime.

You have different types of working principles that vary by vendor. So you can find Hall-effect positioners, devices with potentiometers, and more. Best of all, these smart positioners use loop power and offer a handful of field protocols for you to choose from.

Electro Pneumatic Positioner? How It's Works ?

The electro -pneumatic positioner is used in Control Valves with pneumatically operated actuators. The valve is operated by means of electrical controller or Control Systems With an control signal of 4 to 20 mA or split ranges of 4~12/ 12~20 mA.

Electro-Pneumatic Positioner converts this control signal into a pneumatic

output in proportion to the lift of the control valve.

FEATURES OF ELECTRO PNEUMATIC POSITIONER :-

There is no change in performance in the range of 5-200Hz of Vibrations.
Can be Used for Split Range Application
Easy to adjust zero and span & calibrate to the required travel of the valve.
Easy to convert from ATO (Air to Open) to ATC (Air to Close) action or vice versa.
Easy Feedback connection.
Fast and accurate response.
Low air consumption

This equipment works on the force balance principle and uses a flapper/ nozzle & set of springs to bring the forces under equilibrium at the required valve position with respect to the signal/command given to it.

When the input signal from the controller is applied to the torque motor, the armature receives torque in counter clock wise direction, due to this torque the counter weight/ flapper moves towards left side and the clearance between the Nozzle & the Flapper increases, due to which, the back pressure in the Nozzle decreases.

As a result of the above, the exhaust valve of the Pilot Valve moves towards right and the Inlet Valve “A” opens, thereby the supply air goes to the actuator through port OUT1. The valve Spindle will move up or down depending up on the actuator configuration (ATO/ATC) and the Feedback Spring will lengthen or shortens by the movement of Feedback Lever.

When there is a force balance between Feedback Spring tension and the Torque generated by the Torque Motor, the valve Spindle stays in it’s position.

Where Are Manifolds Used?

How Needle Valve Works ?

Needle valves are designed to allow precise flow control. Its name is derived from the sharp pointed disc and matching seat. They are extensively used for continuous blow-off or chemical feed control services.

The stem threads are finer than usual so that considerable movement of the hand wheel is required to increase or decrease the opening through the seat. Usually, these valves have a reduced seat diameter in relation to the pipe size.

Needle Valve Works

A variation on the stem-guided globe valve design is the needle valve, where the plug is extremely small in diameter and usually fits well into the seat hole rather than merely sitting on top of it.

Needle valves are very common as manually-actuated valves used to control low flow rates of air or oil.

A set of three photographs shows a needle valve in the fully-closed, mid-open, and fully-open positions (left-to-right):

Uses of Needle Valve

Needle valves are usually used in flow-metering applications, especially when a constant, calibrated, low flow rate must be maintained.

Since flow rates are low and many turns of the valve stem are required to completely open or close, needle valves are not used for simple shutoff applications.

Since the orifice is small and the force advantage of the fine-threaded stem is high, needle valves are usually easy to shut off completely, with merely “finger-tight” pressure. The spindle and/or seat of a needle valve, especially one made from brass, are easily damaged by excessive turning force when shutting off the flow.

Interesting Facts about Liquid Flow Meters and Sensors

Liquid Flow Meter

A liquid flow meter is a device, which is utilized to gauge the flow of a liquid. A liquid flow meter is also a useful device when it comes to gauge the volume of liquid that flows through the pipes. A liquid flow meter is commonly deployed in most of the industrial as well as domestic areas in order to deliver the accurate measurement of liquid flow. It can also provide assistance in identifying a leakage in the pipes. Fundamentally there are two broad categorizations of the liquid flow meters namely displacement water meter and the velocity water meter. An additional variety of liquid flow meter is compound meter. It is an innovative blend of both velocity and displacement meters. Moreover, there are further different variants of these two categories of liquid flow meters based on their different features and prices.

Liquid flow meters can measure liquid volume in either cubic feet or inches by using a totalizer, which vary according to its specifications. There are straight and circular registers, which show the readings. Each of these registers contain a sequences of numbers, which can be used to determine the usage of liquid quite conveniently. Every kind of liquid flow meter operates on the basis of a specific technique. Accurate measurements of the supply flow are obtained by deploying the liquid flow meters closer to the feed lines. The liquid stream is gauged precisely by the liquid flow meters and measured outcomes are transferred to the database or exhibited on the display area of the meter.

The velocity flow meter mainly calculates the speed and converts in into the process rates such as Gallons or Litres per minute of the liquid. The information gathered and received by a velocity flow meter may be converted into volume using a number of techniques. There are a wide range of velocity flow meters, which include propeller, ultrasonic, magnetic, multi-jet and turbine meters. Velocity flow meters are specifically the most effective type for the measurement of the flow rate of large water streams. For the similar reason, they have been utilized in large industrial settings and plants.

A further remarkable variant of the liquid flow meter is the positive displacement meter that calculates the liquid flow by comparing it to the capacity of chamber to hold the liquid. The total number of times the chamber is filled and emptied assists to analyze the flow of liquid. A positive displacement meter may utilize a piston mechanism to gauge and record the information. It is most suitable to calculate a lower liquid flow, which is why a positive displacement meter is mainly used for homes, hotels, apartments and office buildings.

Liquid Flow Sensors

Although there are now digital liquid flow meters in use that offer a greater magnitude of accuracy and effectiveness, analog liquid flow meter are still being used. However, digital liquid flow meters utilize a wide range of techniques in order to gauge and measure the flow of liquids. Among the most widely used digital liquid flow meter include the ones based on magnetic and ultrasonic sensors that can accurately measure the flow of liquids. In order to manage mass flow measurement in the process industries, the use of liquid flow sensors is extremely significant. The liquid flow sensors are used for gauging mass flow, flow velocity or a volumetric flow rate of a liquid. Accurate measurement of liquid flow and control products are the key to become successful in a particular field of work. With the rise in the needs of such products, there are certain fact that needs to be realized related to the type of liquid flow sensor, its functionality and its capability to deliver exact calculations.

Flow sensors can measure various liquids such as semiconductor processing fluids, light oils, fuels, inks and other transparent or translucent liquids. Viscosity plays an important role as a sensor will not work with liquids that are too dense. Because optical liquid flow sensors operate using an infrared light emitter that use the absorption or reflection of light to capture precise measurements of the fluid, the transparency of the liquid passing through is also important. For example, if the liquid absorbs all of the light from the emitter, then the flow sensor will not work. Hazardous chemicals can also pose a problem to the flow sensor as the chemicals can damage sensitive parts of the device such as the fittings or O-rings. Fortunately, there are alternative materials available that offer greater resistance to liquid types. Some other options available are brass, stainless steel or PTFE fittings that may be used in the sensor’s body depending on the liquid. Among the wide range of liquid flow meters, it will be more convenient to select one with a range of distinctive features such as strength and ability to endure climatic changes.

Which Types of Flow Meters Are Best for Industrial Use?

Coriolis Meters

Among the most precise technologies, Coriolis meters are well suited for a broad and developing range of liquid and gas applications. It provides multi parameter data about temperature, density, and mass. Coriolis meters are commonly utilized in nuclear facilities, pharmaceutical manufacturing, wastewater treatment facilities, natural gas measurement and custody transfer.

Differential Pressure Flow Meters

Gear Meters (Positive Displacement)

Paddle Wheel Meters

Magnetic Meters

What is HART, Foundation Fieldbus & Profibus ?

HART stands for ‘Highway Addressable Remote Transducer’ and is a standard originally developed as a communications protocol for control field devices operating on a 4-20 mA control signal.

HART is probably the most widely used digital communication protocol in the process industries, and:

Is supported by all of the major suppliers of process field instruments.
Preserves existing control strategies by allowing 4-20 mA signals to co-exist with digital communication on existing 2-wire loops.
Is compatible with analogue devices.
Provides important information for installation and maintenance, such as Tag-IDs, measured values, range and span data, product information and diagnostics.
Can support cabling savings through use of multidrop networks.
Reduces operating costs via improved management and utilisation of smart instrument networks.

What is PROFIBUS ?

At sensor/actuator level, signals of the binary sensors and actuators are transmitted via a sensor/actuator bus. Data are transmitted purely cyclically.

What is Foundation Fieldbus?

Device interoperability

Pressure Gauges : Common Causes for Failures and Their Effective Solutions

Pressure or vacuum gauges, if get damaged or don’t function properly can lead to leaks and emissions which may result in contamination of workplace or in some cases a fire explosion. Such unfortunate incidents not only cost lives of those working with and around the pressure gauges, but also major financial loss to the Company.

One of the fail-safe ways to avoid such undesirable situations is to periodically check the pressure gauges. These inspections can reveal the reasons which trigger breakdown in the gauges and thus can help you take necessary preventive measures in time. We have listed below some such causes observed during Quality Assurance checks to help you maintain the gauges better:

Temperature: Varying temperature levels can be a valid reason for failure of pressure gauges. Very high temperatures can lead to the loosening of metal joints and finally cracking. This can result in bigger issues. In such cases, you must set up a fully welded diaphragm seal in the pressure gauge. Another solution is to use cooling substances to bring down the high temperatures.

Vibration: This can cause a two-fold negative effect. If the gauge is vibrating, the user cannot get accurate reading. And continuous vibration can set the pointer off-mark and therefore providing faulty readings. In such cases, the source of vibration should be eliminated and calibration services must be employed to set right the pressure gauge.

Steam: In certain cases, the pressure gauges are continuously exposed to steam or hot air. This can affect their functioning to a large extent. The solution to this problem is to set up a mini-siphon having an internal chamber or a full siphon fitted with a coil for horizontal uses. When the pressure gauge is placed vertically, you can choose a pigtail siphon.

Corrosion: Another factor negatively impacting the smooth functioning of pressure gauges is corrosion. That is why only pressure gauges with non-corrosive parts are widely used by companies. Another popular solution is using a diaphragm seal, which will offer additional protection to the inner portions of the pressure gauge. This diaphragm seal is usually made of corrosion-resistant material.

Pulsation: Fast, erratic movements within a pressure system can cause substantial alterations to the pressure gauge. In such a situation, the gauge will be unable to give an accurate reading. If this continues for a prolonged period, the pressure gauge will break down in no time. To avoid such problems, companies set up a restrictor and liquid-filled case to suppress pulses on the gauge. A direct-drive gauge without gears and linkages is another effective solution.

Clogging: Clogging also hinders the smooth functioning of pressure gauges in systems. If there are suspended viscous/crystalline particles, they will definitely clog the pressure system and eventually affect the pressure gauge readings. The way out is to set up a diaphragm seal attached with a clog-preventing barrier.

Mishandling: While the above mentioned causes are instrument-related, human errors like mishandling can also cause the pressure gauge to malfunction. It is one of the most common issues faced by companies when it comes to faulty gauges. Such human errors usually occur either during installation, inspections or recalibrations. Pressure gauge calibration must always be done in a manner so as to not leave any room for errors.

With so many issues plaguing pressure gauges, it is highly important that periodic inspections are scheduled and followed without fail. They can help you ensure that your pressure gauges perform optimally. Also, regular and appropriate pressure gauge calibration is unavoidable for their perfect functioning.

Which are the available configuration levels for pressure sensors?

The various possible configuration levels for a pressure measurement solution are not defined conceptually in any standard. At WIKA we have chosen the following terminology:

Pressure sensor (pressure transmitter)

A pressure sensor (also pressure transmitter) delivers a standardised, processed signal within a housing with commonly available pressure connection and electrical connection. Typically, it can be coded and ordered as a catalogue product and thus provides the customer with a plug-and-play solution. Nevertheless, customised versions are possible when backed up with a corresponding “business case”.

Pressure sensor module

A pressure sensor module is designed for OEM applications. It delivers a standardised and calibrated signal, but can be customised with regard to connections and size. EMC protective measures must be arranged in the customer application.

Sensor elements and their assemblies

Sensor elements and their assemblies deliver an uncalibrated signal in mV/V and can be designed to suit the customer through corresponding modifications of the pressure connection or addition of a case etc. Here the customer is responsible for the calibration and thus for the accuracy achieved.

When to use a Diaphragm Seal ?

Process measurement sensors are not indestructible. Not even the most rugged device is fully immune to the chemical nature of process media or the kinetic impact associated with fluid composition and movement.

Balancing degrees of protection, usually to increase the useful life of the device, with sensor response and accuracy is a frequent challenge in the process measurement and control field.

Industrial processes commonly are associated with corrosive or toxic fluids, often at extreme pressure or temperature and containing various levels of solids.

Any of these traits can pose substantial risk to process performance and uptime. Operations that process fluids will employ pressure measurement devices to monitor process performance and maintain system safety levels.

There are many instances where characteristics of the process and its media are not compatible with pressure measurement devices.

Here are some potentially problematic scenarios for pressure measurement instruments:

Corrosive media that will prematurely deteriorate the pressure sensing element.
Viscous or fibrous media, also those that may crystallize or polymerize, posing a risk of clogging channels, tubes, and orifices of pressure measurement devices.
Media temperature that is beyond the rated range for the pressure measurement device has a potential to damage the instrument or cause error in the pressure reading.
A measuring point that is remotely located from where a technician may need to observe the reading. Also conceivable, the pressure measurement device needs to be located away from other potentially damaging environmental conditions.
The process requirements dictate specific hygienic requirements that are cause for the measurement device to be isolated from the medium.
Toxic or otherwise hazardous media that must be contained.
Excursions of system pressure may exceed the acceptable range of the instrument, potentially damaging the device.
A solution which can provide protection from the items listed above, while still maintaining instrument response and accuracy is a diaphragm seal. Seals are placed between the pressure measurement device and the process media. The space between the diaphragm, which is flexible, and the sensor is filled with a fluid that will hydraulically transfer the pressure condition on the process side of the diaphragm to the sensor. The diaphragm serves as a physical barrier between the potentially damaging media and the instrument. Diaphragm seals are available in a wide variety of configurations to accommodate any media type or connection requirement.

Seal selection involves specifying the connections and form factor to properly mate the diaphragm with the instrument and the process, then selecting the diaphragm material that will be compatible with the media.

The best way to achieve a positive solution is to share your requirements with a qualified assembler.

They can help select the right diaphragm seal and mate it up with a pressure gauge, providing a complete assembly that is ready to be installed in your process.

Types of Sensors used in Vibration Measurement

DIFFERENT SENSOR TYPES USED FOR VIBRATION MEASUREMENTS

1. VELOCITY SENSORS

2. ACCELERATION SENSORS

3. PROXIMITY SENSORS

What is Keyphasor ? How does Keyphasor works ?

A transducer that produces a voltage pulse for each turn of the shaft, called the Keyphasor. This keyphasor signal is used primarily to measure rotating shaft speed and serves as a reference for measuring vibration phase lag angle.

It is an essential element in measuring rotor slow roll bow or runout information.The Keyphasor transducer is typically a proximity probe (recommended for permanent installations in which the probe observes a physical gap change event), an optical pickup (used for temporary installations in which the pickup observes a change in reflectivity event) or a magnetic pickup.

Keyphasor is a Trademark owned by the Bentley Nevada Company. The system includes a proximity probe, extension cable and proximitor sensor. Convention recommends that the prime keyphasor event is located on the driving unit.

The keyphasor measurement required a coupling keyway or an elongated notch that can provide a once per turn event trigger for the signal pulse.

The keyphasor signal is a once per turn voltage pulse provided by a transducer, normally an eddy current proximity measurement.

Keyphasor is an electric pulse, or trigger, which is derived from a point on a rotating shaft, it serves as a zero phase reference for determining where imbalance is on a rotor.

The keyphasor in turbo machines are necessary to find phase angle of unbalance mass at the time of dynamic balancing.

You can monitor the machine health with vibration probes alone but if you want to analyze the cause of failure of the machine you need three dimensional graph showing/analyzing the vibrations at any point of time when machine is running. If you don’t install the keyphasor you will come to know that there are vibrations in the machine but you will not point out at what direction, at what point, at what angle.

The Keyphasor signal is used by monitoring, diagnostic, and management systems to generate filtered vibration. Amplitude, phase lag, speed and variety of other useful information.

Phase is a critical part of this information. Without phase information overall machine condition and machine faults would often be very difficult.

The Keyphasor is used as a reference point of the shaft, 0 to 360 degrees. When analysis are performed , the viewing of the 1X and 2X signals are important, X is defined as the running speed of the machine. The monitors read overall vibration signals at all frequencies, the Keyphasor is used to determine the speed.

Let’s say a machine is running at 5,000 RPM, with a Key phasor, the instrument can filter the frequency to 5,000 rpm or 83.33 Hz. With this signal, one can view the shaft behavior or orbit inside the bearing. The phase is calculated as from the time the Keyphasor triggers to the first positive peak of the vibration signal.

Keyphasor in turbomachines are necessary to find phase angle of unbalance mass at the time of dynamic balancing. Balancing of turbine rotor is essential.

Manufacturers at their shop can balance the rotors with some other means even if keyphasor is not present. But when rotor is to be balanced at user’s site, keyphasor is required for balancing of Turbine rotor is essential.

Advantages :

The Keyphasor is signal is used to generate more than one third of the information regarding the condition of the machine.

Shaft crack detection
Rub Detection
Shaft Balancing
Shaft /Structural resonance detection.

With the installation of the keyphasor, one can find out the direction the vibrations, at which point the vibrations are there, at which angle the shaft is vibrating.

Mass Flow Meters

Many traditional flowmeter technologies respond to the volumetric flow rate of the moving fluid. Velocity-based flowmeters such as magnetic, vortex, turbine, ultrasonic, and optical generate output signals proportional to the speed of fluid molecules and nothing else. This means that if the fluid flowing through one of these flowmeter types were to suddenly become denser (while still flowing by at the same number of volumetric units per minute), the flowmeter’s response would not change at all.

The information provided by a volumetric flowmeter may not be what is actually best for the process being measured, however. If the flowmeter in question happens to be measuring the flow rate of feed into a chemical reactor vessel, for example, what we’re really concerned with is how many molecules per unit time of feed is entering that reactor, not how many cubic meters or how many gallons. We know that changes in temperature will cause gases and liquids alike to change density, which means each volumetric unit will contain a different number of molecules after a temperature change than before. Pressure has a similar influence on gases: increased pressure means more gas molecules occupying each cubic foot (or other volumetric unit), all other factors being equal. If a process requires an accounting of molecular flow rate, a volumetric flowmeter will not provide relevant information.

In steam boiler control systems, the flow rate of water into the boiler and the flow rate of steam coming out of the boiler must be matched in order to maintain a constant quantity of water within the boiler tubes and drums. However, water is a liquid and steam is a vapor, so flow measurements based on volume are meaningless: a cubic foot of steam will never contain the same number of molecules as a cubic foot of water. The only reasonable way for the control system to balance both flow rates is to measure them as mass flows rather than volumetric flows. No matter what form (phase) the H2O molecules take, every kilogram going into the boiler must be matched by a kilogram coming out of the boiler in accordance with the Law of Mass Conservation: every H2O molecule entering the boiler must be matched by one H2O molecule exiting the boiler in order to maintain an unchanging quantity of H2O molecules within the boiler. This is why boiler feedwater and steam flowmeters alike are typically calibrated to measure in units of lbm (pounds mass) per unit time.

A similar problem arises in instances where the flowmeter is used for custody transfer. This term denotes scenarios where a particular material is being bought and sold, and where accuracy of flow measurement is a matter of monetary importance. Again, in such instances, it is usually the number of molecules being bought and sold that really matters, not how many cubic meters or gallons those molecules occupy. Here, as with the chemical reactor feed flow application, a volumetric flowmeter does not provide the most relevant information. We know from the study of chemistry that all elements have fixed mass values: one mole of any element in monatomic form (single, unbound atoms) will have a mass equal to the atomic mass of that element. For example, one mole of carbon (C) atoms has a mass of 12 grams because the element carbon has an atomic mass of 12. Similarly, one mole of oxygen (O) atoms is guaranteed to have a mass of 16 grams because 16 is the atomic mass for the element oxygen. Consequently, one mole of carbon monoxide (CO) molecules will have a mass of 28 grams (12 + 16), and one mole of carbon dioxide (CO2) molecules will have a mass of 44 grams (12 + 16×2). These molecule/mass relationships are fixed regardless of how dense or sparse the substances are: one mole of CO2 will have a mass of 44 grams regardless of pressure or temperature conditions affecting the density of that gas sample. The relationship between molecule count and mass for any given chemical compound is fixed, because mass is an intrinsic property of matter. If our desire is to account for the number of molecules passed through a pipe, and we happen to know the chemical composition of those molecules, measuring the mass of the fluid passing through is the most practical way to do it.

Dimensional analysis confirms this relationship. Volumetric flow is always measured in volume units (m3, ft3, cc, in3, gallons, etc.) over time, whereas mass flow is always measured in mass units (g, kg, lbm, or slugs) over time. To use a specific example, a mass flow rate in pounds (mass) per minute will be obtained by multiplying a mass density in pounds per cubic foot by a volumetric flow rate in cubic feet per minute:

For example, a volumetric flow rate of 1000 cubic feet per minute of water is equivalent to 62400 pounds (mass) per minute, or 1040 lbm/s, with water having a density of 62.4 lbm/ft3.

With modern sensing and computational technology, it is possible to combine pressure, temperature, and volumetric flow measurements in such a way to derive a measurement of mass flow. This is precisely the goal with AGA3 flow measurement (orifice plates), AGA7 flow measurements (turbines), and AGA9 flow measurement (ultrasonic): “compensating” the fundamentally volumetric nature61 of these flow-measuring elements with pressure and temperature data to calculate the flow rate in mass units over time.

However, compensated flowmeter systems require much more calibration effort to maintain their long-term accuracy, not to mention a significant capital investment in the multiple transmitters and flow computer required to gather all the necessary data and perform the mass flow calculations. It would be much simpler if there existed flowmeter technologies naturally responsive to the mass flow rate of a fluid! Fortunately, such flowmeter technologies do indeed exist, which is the subject of this section.

For each of the following mass flowmeter technologies, it should be clearly understood that the instrument in question naturally responds to mass flow rate. To use our hypothetical example of a fluid stream whose density suddenly increases while the volumetric rate remains constant, a true mass flowmeter will immediately recognize the increase in mass flow (same volume rate, but more mass per unit volume) without the need for additional compensating measurements or computer calculations. True mass flowmeters operate on principles directly related to the mass of the fluid molecules passing through the meter, making them fundamentally different from other flowmeter types.

In the case of the Coriolis flowmeter, the instrument works on the principle of inertia: the force generated by an object when it is accelerated or decelerated. This basic property of mass (opposition to change in velocity) forms the basis of the Coriolis flowmeter’s function. The inertial force generated inside a Coriolis flowmeter will thus double if the volumetric flowrate of a constant mass fluid doubles; the inertial force will likewise double if the density of a constant volumetric flow of fluid doubles. Either way, the inertial force becomes a representation of how fast mass is moving through the flowmeter, and so the Coriolis flowmeter is a true mass flow instrument.

In the case of the thermal flowmeter, the instrument works on the principle of convective heat transfer : heat energy extracted from a hot object as cooler molecules pass by. The ability for fluid molecules to transport heat is a function of the specific heat of each molecule and the number of molecules moving past the warmer object. So long as the chemical composition of the fluid remains unchanged, the convective transfer of heat is a function of how many fluid molecules pass by in a given time. The heat transfer rate inside a thermal flowmeter will thus double if the volumetric flowrate of a given fluid doubles and all else remains constant; the heat transfer rate will likewise double if the density of a given fluid doubles and all else remains constant (i.e. twice the number of molecules passing by with each time interval). Either way, the convective heat transfer rate becomes a representation of how many molecules of fluid are moving through the flowmeter, which for any given fluid type is proportional to the fluid’s mass flow rate. This makes the thermal flowmeter a true mass flow instrument for any (calibrated) fluid composition.

Some older, mechanical technologies exist for measuring true mass flow, but these are being supplanted by Coriolis and thermal mass flowmeter technologies. Coriolis and thermal mass flowmeters are also fast becoming the technology of choice for applications formerly the domain of compensated orifice plate (e.g. AGA3) and turbine (e.g. AGA7) flowmeters.

Coriolis Mass Flow meter as a Multi Variable Transmitter

The tubes within a Coriolis flowmeter are shaken at their mechanical resonant frequency to maximize their shaking motion while minimizing electrical power applied to the force coil.

The electronics module uses a feedback loop between the sensor coils and the shaker coil to maintain the tubes in a continuous state of resonant oscillation.

This resonant frequency changes with process fluid density, since the effective mass of the fluid-filled tubes changes with process fluid density (Note 1) , and mass is one of the variables influencing the mechanical resonant frequency of any elastic structure.

Note 1 : If you consider each tube as a container with a fixed volume capacity, a change in fluid density (e.g. pounds per cubic foot) must result in a change in mass for each tube.

Note the “mass” term in the following formula, describing the resonant frequency of a tensed string:

A fluid-filled tube is a close analogue to a tensed string, with tube stiffness analogous to string tension and liquid density analogous to unit mass. So long as the spring constant (tube stiffness) is known, the resonant frequency of the tubes’ vibration serves to indicate the unit mass of the tubes, which in turn represents fluid density given the known internal volume of the tubes.

Temperature changes have the potential to interfere with this density measurement, because temperature affects the elasticity of metal (Young’s modulus) as well as the tubes’ physical dimensions.

This is why all Coriolis flowmeters are equipped with RTD temperature sensors to continuously monitor the temperature of the vibrating tubes. The flowmeter’s microprocessor takes this tube temperature measurement and uses it to compensate for the resulting elasticity and dimensional changes based on a prior modeling of the tube metal characteristics.

In other words, the flowmeter’s microprocessor continuously updates the force variable (FT ) representing tube stiffness in the resonant frequency equation so that the frequency will always be a reliable indicator of unit mass (fluid density).

This temperature measurement happens to be accessible as an auxiliary output signal, which means a Coriolis flowmeter may double as a (very expensive!) temperature (Note 2) transmitter in addition to measuring mass flow rate and fluid density.

Note 2 : An important caveat is that the RTD sensing tube temperature in a Coriolis flowmeter really senses the tubes’ outside skin temperature, which may not be exactly the same as the temperature of the fluid inside the tube. If the ambient temperature near the flowmeter differs substantially from the fluid’s temperature, the tube skin temperature reading may not be accurate enough for the flowmeter to double as a fluid temperature transmitter.

The ability to simultaneously measure three process variables (mass flow rate, temperature, and density) makes the Coriolis flowmeter a very versatile instrument indeed. This is especially true when the flowmeter in question communicates digitally using a “fieldbus” standard rather than an analog 4-20 mA signal.

Fieldbus communication allows multiple variables to be transmitted by the device to the host system (and/or to other devices on the same fieldbus network), allowing the Coriolis flowmeter to do the job of three instruments!

Types of Level Gauges

Level gauge is a device which is used to show the level of fluids in fields. Depending on the type of application used, the type of level gauge should be selected. Level gauge is a direct method for measuring the level.

Level gauge consists of a metal body, machined to have an internal chamber and one or more front windows. On each window a special high resistance glass is used with sealing joint and metal cover plate hold by bolts and nuts.

Level devices operate under three main different principles:

The position (height) of the liquid surface
The pressure head
The weight of the material

Types of Level Gauge:

There are commonly 3 types of level gauges used:

Reflex level gauge
Transparent level gauge
Magnetic type level gauge

Reflex level gauge:

Reflex glass level gauges working principle is based on the light refraction and reflection laws.

Reflex glass level gauges use glasses having the face fitted towards the chamber shaped to have prismatic grooves with section angle of 90°. When in operation, the chamber is filled with liquid in the lower part and gases or vapors in the upper part.

The liquid level is well-known by different brightness of the glass in the liquid and in the gas/vapor zone. The reflex level gauges do not need a specific illumination. The day light is enough for seeing the level.

LIQUID ZONE :

This zone appears dark when the gauge is in operation the light ray’s incident on the external face of the glass are quite perpendicular to said face and, therefore, not deviated by the glass. These rays reach the glass/liquid interface with an inclination of approx. 45°. The critical angle glass/liquid is always superior to 45°.

Therefore the rays incident within the critical angle are refracted within the liquid and, since the internal walls of the gauge chamber are not reflecting, the rays cannot be seen from the outside. In fact the zone will appear dark, nearly black, to the observer.

GAS/VAPOR ZONE :

This zone appears silver bright to the observer. As for the liquid zone, the light rays reach the glass/gas-vapor interface with an angle around 45°.

Since this angle is greater than glass/gas-vapor critical angle, the rays are not refracted, but totally reflected making 90° turn, thus reaching the nearest glass/gas-vapor interface again with angle of 45°. For same reason they will be reflected and turned by 90° towards the observer, to whom the zone will appear silver bright.

Applications :

Reflex glass level gauges can be used in most of the fluids and applications.

Reflex level gauges cannot be used in certain cases as for example:

1. when the separation level between two liquids has to be
read (interface)

2. when the process fluid is high-pressure water steam, since
in this case the glass must be protected from the solvent
action of the boiler water by using mica shields

Transparent Level Gauge:

Transparent level gauges are always fitted with two plate transparent glasses between which the fluid is contained. The fluid level is indicated as the result of the different transparency of the two media.

To protect glass surfaces from corrosive action of the process fluid, Transparent Level Gauges can be fitted with Mica shields. The transparent level gauge is particularly recommended for applications where the glass needs to be protected from corrosive fluids and high temperatures.

Applications:

In corrosive fluid.
The observation of interface
the observation of the liquid color
for steam with an operating pressure > 20 bar
If repeated thermal shocks comes

Mica Sheet use in transparent level gauge: Mica sheet are widely used in visual liquid level to protect the glass surface from the corrosive effects of hot alkaline or acidic solutions. Mica shields are also commonly used in steam water applications to prevent etching and the weakening of the glass

Magnetic Level Gauge:

The Magnetic Level Gauge is used to preventive security against leakage, environmental safety, sure and trouble free application with chemically aggressive, pollutant, harmful or poisonous, inflammable or explosive, optically similar fluid interface.

The magnetic level gauge works based on some elementary physical principles:

The principle whereby the liquid in communicating vessels is always at the same level
Archimedes’s principle according to which a body immersed in a liquid receives a buoyancy equal to the weight of displaced liquid
The principle of attraction between North and South poles of two permanent magnets and that of repulsion between like poles.

There is a float in a pipe chamber which is movement with level and up and down accordingly. A flag flower is clamped with chamber. The individual flags or the follower contain an alignment magnet that couples with the float magnets as the float moves up or down within the piping column.

Float movement rotates the flags and changes their color, the position of the follower, or point at which the flags change color, represents the true level.

According to the orientation of each magnet each cylinder will show externally half of its surface of one colour or the other. The indicating scale will be of one colour over the chamber area taken up by gas, or steam phase contrasting with the other colour (e.g. red) over the chamber area taken up by liquid phase.

Applications :

Chemically aggressive fluid
Pollutant to environment
Inflammable or explosive fluid

How to change a level glass of a Level gauge :

Following steps to be taken to change the glass:

Isolate the level gauge from process from HP and LV valve.
Drain the level gauge process fluid from drain isolation valve.
Insure no leakage occurred from HP and LP valves.
Remove the all U-Clamp bolt and removed the glass and gasket and make smooth the surface of chamber and cover flange surface.
Fix the sealing gasket after some grease applied on chamber window surface. By applying the grease it is easy net time to remove the gasket on next time.
Fix the mica sheet in case of transparent glass.
Fix the glass then fix cover flange and cushion gasket then fix the U-Clamp and bolt .
Tighten the bolt in cross direction. Never tighten the bolt in one direction if tight the glass one direction then possibility to break the glass.
Tighten the all U-clamp bolt equally.

How to taken in line of level gauge in steam service:

To take the level gauge in line first open the LP valve slightly ½ or 1 turn and heat the glass with continuous draining the steam for some time.

It is necessary because if we taken level gauge directly then a temperature difference occurred and glass may be break and incident may occur.

After this isolate the drain valve then open the HP and LP valve and taken the level gauge in line and checked the leakage.

One point always remember that process person think that slide valve work as a normally isolation valve but this is not an isolation valve. Always kept slide valve in middle.

Metal Seated Valves and Soft Seated Valves : Differences

Metal Seated Ball Valves

Engineered to excel in the most demanding industrial settings where valve deficiencies can endanger safety, plant efficiency and reduce profitability, metal seated ball valves stand out.

These long-lasting valves are perfect for the oil and gas industries, refining and power generation.

Metal Seated Valves vs. Soft Seated Valves

Deciding on the right seat material can be a difficult decision when it comes to ball valves because you’ll have several options.

Having a complete understanding of the process conditions should be the starting point when it comes to choosing seated valves.

Does your situation require a bubble tight shut off?
Is the fluid corrosive?
Does it contain abrasive particulates?
Will it be under high pressure or temperatures?

Once you have a firm grasp on these factors, the choice will be apparent.

Advantages of Metal Seated Ball Valves

The key advantage of metal seated valves when compared to soft seated valves is that they can withstand high temperatures and severe service conditions.

Another important factor is that metal seats can be hardened by specialized coatings.

Soft Seated Ball Valves

The valves also work for longer time periods than soft seated valves. These durable valves can basically handle the majority of abrasive applications.

Metal Seated Valves Coating Options

With metal to metal seating, and depending on the service conditions, applying various coatings make it possible for ball and seat rings to be hard faced on sealing locations.

Metal-Seated Ball Valve Costs

Even though metal seated valves are more expensive, the cost of downtime resulting from failure, coupled with the replacement of soft seated valve break downs, should be factored in.

The efficiency and longevity of metal seated ball valves will pay off and counteract the higher price.

Bottom line, metal seated ball valves are the best, long lasting, economical options for critical applications.

Installation

The installation of metal seated valves can comply with shut off standards which include ANSI/FCI 70-2-1976 and designed for allowed leakage.

The most frequently specified leakage classes include Class V and VI. Class VI is often misinterpreted as “bubble tight.”

The Valtorc offers best metal seated ball valves with unique features. The below are the details of their product.

The Series 370 Metal Seated Valve

When it comes to metal seated ball valves, the Series 370 is a good example. This series is offered in sizes that range from 1/4″ to 4”, with threaded (NPT) or flanged connection ends.

Manufactured from premium quality 316 stainless steel, this metal valve also has pressure ratings as high as 2000PSI. Another important aspect is that it provides the ISO 5211 mounting pad intended for actuation.

The metal seated ball valves include the following characteristics.

Available in flanged or threaded connection ends, in sizes that range from 1/4″ to 4″.
For this configuration, the service temperature limitation is 450°F (232.2°C).
Configurations include metal seat with body seals polymeric seat seals, stem packing.
The body seal is spiral wound flexible/SS316 graphite (flexible/die-formed graphite).
Intended usage is in erosive and/or abrasive applications in which higher temperatures aren’t a concern.
The polymeric seals incorporated in this metal seat configuration are replaced with flexible, die-formed graphite seat seals with stem packing.

Recognizing your process condition is critical when it comes to choosing the appropriate seat for your specific application.

If you determine that the best solution is metal seated ball valves you’ll find them to be long lasting, cost effective solutions for critical applications.

What is a Paddlewheel flow meter ?

A variation on the theme of turbine flow measurement is the paddle wheel flowmeter, a very inexpensive technology usually implemented in the form of an insertion-type sensor. In this instrument, a small wheel equipped with “paddles” parallel to the shaft is inserted in the flow stream, with half the wheel shrouded from the flow.

A surprisingly sophisticated method of “pickup” for the plastic paddle wheel shown in the photograph uses fiber-optic cables (optional) to send and receive light. One cable sends a beam of light to the edge of the paddle wheel, and the other cable receives light on the other side of the paddle wheel. As the paddle wheel turns, the paddles alternately block and pass the light beam, resulting in a pulsed light beam at the receiving cable. The frequency of this pulsing is, of course, directly proportional to volumetric flow rate.

The external ends of the two fiber optic cables appear in this next photograph, ready to connect to a light source and light pulse sensor to convert the paddle wheel's motion into an electronic signal:

A problem common to all turbine flow meters is that of the turbine “coasting” when the fluid flow suddenly stops. This is more often a problem in batch processes than continuous processes, where the fluid flow is regularly turned on and shut off. This problem may be minimized by configuring the measurement system to ignore turbine flowmeter signals any time the automatic shutoff valve reaches the “shut” position. This way, when the shutoff valve closes and fluid flow immediately halts, any coasting of the turbine wheel will be irrelevant. In processes where the fluid flow happens to pulse for reasons other than the control system opening and shutting automatic valves, this problem is more severe.

Another problem common to all turbine flow meters is lubrication of the turbine bearings. Friction less motion of the turbine wheel is essential for accurate flow measurement, which is a daunting design goal for the flowmeter manufacturing engineers. The problem is not as severe in applications where the process fluid is naturally lubricating (e.g. diesel fuel), but in applications such as natural gas flow where the fluid provides no lubrication to the turbine bearings, external lubrication must be supplied. This is often a regular maintenance task for instrument technicians: using a hand pump to inject light-weight “turbine oil” into the bearing assemblies of turbine flow meters used in gas service.

Process fluid viscosity is another source of friction for the turbine wheel. Fluids with high viscosity (e.g. heavy oils) will tend to slow down the turbine’s rotation even if the turbine rotates on friction less bearings. This effect is especially pronounced at low flow rates, which leads to a minimum linear flow rating for the flowmeter: a flowrate below which it refuses to register proportionately to fluid flow rate.

What is a Differential Pressure Flow meter?

Differential pressure meters work on the principle of partially obstructing the flow in a pipe. This creates a difference in the static pressure between the upstream and downstream side of the device. This difference in the static pressure (referred to as the differential pressure) is measured and used to determine the flowrate.

Differential-pressure meters are hugely popular and it is estimated that at least 40% of industrial flow meters in use at present are differential-pressure devices, with the orifice plate being the most popular. Differential-pressure devices have been used to meter a wide variety of different fluids from gases to highly viscous liquids.

The popularity of differential-pressure flow meters is in part due to their simple design and low cost. By reading this guide you will have a much clearer idea of the benefits, viable metering options and applications for using differential-pressure meters.

How a Δp flow meters works

The concept of using the pressure drop caused by a fluid flowing through a restriction in a pipe as a measurement of flow rate dates back to the 18th Century, when it was discovered by Bernoulli.

The basic principle of how a Δp flowmeter operates is described in the figure below.

The differential pressure principle. Manometer tubes measure the difference in static pressure upstream and downstream of the restriction

When a fluid flows through a restriction, it accelerates to a higher velocity (i.e. V2 > V1 ) to conserve the mass flow and, as a consequence of this, its static pressure drops. This differential pressure (Δp) is then a measure of the flowrate through the device.

In simple terms for a given size of restriction, the higher the Δp, the higher the flowrate.

The relationship between the differential pressure and flowrate is derived from Bernoulli’s equation. Using Bernoulli’s equation, and conservation of mass , it can be shown that the differential pressure generated is proportional to the square of the mass flowrate, Qm (kg/s)

Many of the Δp meters available work on this principle of measuring the difference in pressure between upstream and downstream but there are some meters which use the differential pressure in other ways, for example, variable area meters.

What are the different types of Δp meter?

The most common types of differential pressure meter are:

Orifice plates
Venturi tubes
Cone meters (e.g. V-cones)
Nozzles
Low loss meters (e.g. Dall tubes)
Variable area meters
Inlet flow meters
Venturi cones
Venturi nozzles
Drag plates

Advantages and disadvantages of Δp meters

There are a number of general advantages common to most Δp meters. These include:

• They are simple to make, containing no moving parts

• Their performance is well understood

• They are cheap – especially in larger pipes when compared with other meters

• They can be used in any orientation

• They can be used for most gases and liquids

• Some types do not require calibration for certain applications

The main disadvantages to Δp meters are:

• Rangeability (turndown1 ) is less than for most other types of flowmeter

• Significant pressure losses may occur

• The output signal is non-linear with flow

• The discharge coefficient and accuracy may be affected by pipe layout or nature of flow

• They may suffer from ageing effects, e.g. the build-up of deposits or erosion of sharp edges

Common terminology

The diameter ratio or beta (sometimes referred to as the beta ratio) is the ratio between the diameter of the orifice or throat of device to that of the pipe.

Often Δp meters are described in terms of their beta value and diameter to fit a certain pipeline size, for example, a 4-inch β= 0.6 Venturi tube.

To state that a Δp meter has a low beta ratio, for example β = 0.2, means the plate has a small hole or restriction size. This causes the pressure loss across the Δp meter to be higher, which may mean that a pump with a higher discharge pressure (hence more expensive) or compressor will be needed to overcome the increased pressure loss and maintain a flowrate achievable with a larger beta Δp meter. On the other hand a higher differential pressure can generally be measured more accurately than a lower one.

Effect of using different values of beta

The effect of using larger values of beta include:

an increase in the discharge coefficient uncertainty
a lower differential pressure being measured across the orifice plate (and this can be more difficult to measure)
longer lengths of upstream straight pipe being required to ensure the velocity profile of the flow through the orifice plate is stable and symmetrical
the flow profile of the flow through the orifice being more affected by the roughness of the pipe walls

There are a number of sizing packages for orifice plates available, which will calculate the dimensions of the plate required. The software uses empirical formulae based on actual testing. Most of the results are available for beta values of 0.3 to 0.7.

Advantages:

Low cost
Ease of installation
Availability of comprehensive standard (ISO 5167-2)
No requirement for calibration – value of C from the standard
Availability of different designs, e.g. for viscous fluids, bi-directional flows, suspended solids

Disadvantages:

Low turn down (can be improved with dual range Δp cells)
High pressure loss (35 to almost 100% of measured Δp depending on beta)
Errors due to erosion / damage to upstream edges
Errors due to high sensitivity to upstream installation (especially large beta devices)

Discharge coefficient (C)

The discharge coefficient, C, is a parameter that takes account of non-ideal effects, for example energy losses due to friction, when using Δp meters. The discharge coefficient is basically the ratio of the actual to the measured mass flowrate.

The discharge coefficient can either be:

1. determined from a standard

provides good flow measurement at a reasonable price
is especially suitable where repeatability is more important than accuracy

2. determined by calibration

provides lower uncertainties on the flow measurement.

In nozzles and Venturi tubes the flow follows the boundary of the tube closely and the value of C is usually close to one. However, for orifice plates C has a value of approximately 0.6. Values of C can be obtained from the standard (ISO 5167) for nozzles, Venturi tubes and orifice plates that are manufactured to the specified tolerances of the standard.

Fundamentals of Valves and their Types

Valves are mechanical devices. They are basic elements with which the flow of fluids and pressure within a system can be regulated. They are mainly used to control the direction of fluid flow as well regulate the amount fluid flowing through a particular system or a process.

Valves perform any of the following functions.

Starting and stopping or isolating fluid flow. This corresponds to on and off functions.
Controlling or varying (throttling) the amount of fluid flow by change of direction or restriction. This corresponds to volume functions.
Checking the flow or controlling the direction of fluid flow and preventing backflow. This corresponds to directional functions.
Regulating downstream system or process pressure
Relieving component or piping over pressure

Fundamental of valves and their Types

There are many valve designs and types that satisfy one or more of the functions identified above. A multitude of valve types and designs safely accommodate a wide variety of industrial applications.

Regardless of type, all valves have the following basic parts: the body, bonnet, trim (internal elements), actuator, and packing.

Valves work by creating a partial or complete obstruction in the flow of fluids. The formation of obstruction can be formed manually or by injecting automatic elements in the system. A manual valve is generally controlled by handles, pedals or levers.

An automatic valve is generally driven by pressure changes (pneumatic valves), although there can be other versions as well, where they are driven by electrical signals (solenoid valves). Automatic valves are more common nowadays, except for operations which require human judgement.

The regulation is accomplished by the varying resistance that the valve introduces into the system as the valve is stroked. As the valve modulates to the closed position the system pressure drop shifts to the valve and reduces the flow in the system.

Because of the diversity of the types of systems, fluids, and environments in which valves must operate, a vast array of valve types have been developed. Isolating valves also called ‘block valves’. Possible valve choices for isolating service are gate valves, ball valves, butterfly valves and plug valves. Possible choices for control and regulating service are globe valves, butterfly valves, ball valves and plug valves. Under check valves swing check are most common.

Many globe valves can be made ‘stop check’ or non-return types. Safety and pressure relief valves are special on/off valves. They are designed to open and relieve excess pressure, re-close after normal conditions are restored, and function when normal operating controls fail. They are not designed to control normal operating pressure.

These valves are most critical valve in pressurized systems and they are often referred to as PRVs (pressure reducing valves). Other common types of valves are the diaphragm valve, and pinch valve. Each type of valve is normally designed to meet specific needs.

Some valves are capable of throttling flow while other valve types can only stop flow. There are valves which work well in corrosive systems while some other valves handle high pressure fluids.

Each valve type has certain inherent advantages and disadvantages. Understanding these differences and how they affect the valve’s application or operation is necessary for the successful operation of a facility.

Although all valves have the same basic components and function to control flow in some fashion, the method of controlling the flow can vary dramatically. In general, there are four methods of controlling flow through a valve as given below.

Move a disc, or plug into or against an orifice (for example, globe or needle type valve).
Slide a flat, cylindrical, or spherical surface across an orifice (for example, gate and plug valves).
Rotate a disc or ellipse about a shaft extending across the diameter of an orifice (for example, a butterfly or ball valve).
Move a flexible material into the flow passage (for example, diaphragm and pinch valves).

Each method of controlling flow has characteristics that make it the best choice for a given application of function.

Types of valves

Some of important types of valves are described below.

Gate valves

They are generally used in systems where low flow resistance for a fully open valve is desired and there is no need to throttle the flow. Gate Valves are designed to operate either in fully open or fully closed position.

Because they operate slowly they prevent fluid hammer, which is detrimental to piping systems. There is very little pressure loss through a gate valve.

In the fully closed position, gate valves provide a positive seal under pressure. However, under very low pressure, i.e. at 0.35 kg/sq cm light seepage is not be considered abnormal with this kind of valve.

Globe valves

These valves are used in systems where good throttling characteristics and low seat leakage are desired and a relatively high head loss in an open valve is acceptable.

Globe valves, as is the case with all valve designs, have both advantages and disadvantages. Like a gate, they close slowly to prevent fluid hammer. These valves can throttle the flow and they will not leak under low pressure when they are shut off. Flow and pressure control valves as well as hose bibs generally use the globe pattern.

The disadvantage of this design is that the ‘Z’ pattern restricts flow more than the gate, ball, or butterfly valves.

Ball valves

These valves allow quick, quarter turn on-off operation and have poor throttling characteristics. These valves are also designed to be operated fully open or fully closed with any liquid containing particles that could scratch the ball. Many people use them successfully for throttling clear water.

Ball valves have low pressure drops, open and close quickly, are simple, and are trouble free. With the development of Teflon seals, ball valves have grown in popularity. Opening or closing a ball valve too quickly can cause fluid hammer.

Plug valves

These valves are often used to direct flow between several different ports through use of a single valve. Like the gate valve, a plug valve has an unobstructed flow, yet requires only a 90 degree turn to open it. It also requires very little headroom. Stem corrosion is minimal because there are no screw threads.

Almost all plug valves are now furnished with an elastomer coated plug. These valves seals off drip tight. Plug valves are available in much larger sizes than ball valves and are highly suitable for use in wastewater plants.

Butterfly valves

These valves provide significant advantages over other valve designs in weight, space, and cost for large valve applications. Butterfly valves, like ball valves, operate with a 1/4 turn. These valves have center-hinged swinging disc. Low pressure and low temperature designs are resilient seated, usually rubber lined.

These valves can be used for blocking or regulating. High performance types of valves are metal seated. These valves are often double and triple ‘offset’ to reduce closure torque.

They are generally used for handling large flows of gases or liquids, including slurries, but should not be used for throttling for extended periods of time. They are also very compact relative to flanged gate and ball valves. These valves are relatively expensive to repair.

Diaphragm valves

Diaphragm valves are linear motion valves that are used to start, regulate, and stop fluid flow. The name is derived from its flexible disk, which mates with a seat located in the open area at the top of the valve body to form a seal.

These valves are used in systems where it is desirable for the entire operating mechanism to be completely isolated from the fluid.

Pinch valves

The relatively inexpensive pinch valve is the simplest in any valve design. It is simply an industrial version of the pinch cock used in the laboratory to control the flow of fluids through rubber tubing.

Pinch valves are suitable for on-off and throttling services. However, the effective throttling range is usually between 10 % and 95 % of the rated flow capacity. Pinch valves are ideally suited for the handling of slurries, liquids with large amounts of suspended solids, and systems that convey solids pneumatically.

Because the operating mechanism is completely isolated from the fluid, these valves also find application where corrosion or metal contamination of the fluid might be a problem.

Check valves

These valves are automatically open to allow flow in one direction. Check valves are designed to prevent the reversal of flow in a piping system. These valves are activated by the flowing material in the pipeline.

The pressure of the fluid passing through the system opens the valve, while any reversal of flow will close the valve. Closure is accomplished by the weight of the check mechanism, by back pressure, by a spring, or by a combination of these means. The general types of check valves are swing, tilting-disk, piston, butterfly, and stop.

A stop check valve is a combination of a lift check valve and a globe valve and incorporates the characteristics of both.

Needle valves

Needle valves are used to make relatively fine adjustments in the amount of fluid flow. The distinguishing characteristic of a needle valve is the long, tapered, needle like point on the end of the valve stem.

This ‘needle’ acts as a disk. The longer part of the needle is smaller than the orifice in the valve seat and passes through the orifice before the needle seats.

This arrangement permits a very gradual increase or decrease in the size of the opening. Needle valves are often used as component parts of other, more complicated valves. For example, they are used in some types of reducing valves.

Safety and relief valves

These are used to provide automatic over pressurization protection for a system. Relief and safety valves prevent equipment damage by relieving accidental over pressurization of fluid systems. The main difference between a relief valve and a safety valve is the extent of opening at the set point pressure.

A relief valve gradually opens as the inlet pressure increases above the set point. A relief valve opens only as necessary to relieve the over-pressure condition. A safety valve rapidly pops fully open as soon as the pressure setting is reached.

A safety valve will stay fully open until the pressure drops below a reset pressure. The reset pressure is lower than the actuating pressure set point. The difference between the actuating pressure set point and the pressure at which the safety valve resets is called blow down.

Blow down is expressed as a percentage of the actuating pressure set point. Relief valves are typically used for incompressible fluids such as water or oil. Safety valves are typically used for compressible fluids such as steam or other gases.

Safety valves can often be distinguished by the presence of an external lever at the top of the valve body, which is used as an operational check.

Control Valves Theory

Ball Valves

Ball valves offer very good shut-off capabilities. A simple quarter-turn (90°) completely opens or closes the valve. This characteristic minimizes valve operation time and decreases the likelihood of leakage due to wear from the gland seal.

Ball valves can be divided into two categories: reduced bore and full bore. In reduced bore valves, the valve opening is smaller than the diameter of the piping; in full bore valves, the valve opening is the same size as the diameter of the piping. Full bore ball valves are often valued because they minimize the pressure drop across the valve.

Balls valves are usually only recommended for use in the fully open or fully closed position. They are not suited to regulate flow by being kept partially open because ball valves make use of a ring-shaped soft valve seat.

When used in the partially open position, pressure is applied to only a portion of the valve seat, which can cause it to deform. If the valve seat deforms, its sealing properties are impaired and it will leak as a result

Butterfly Valves

In butterfly valves, the flow is regulated through a disc-type element held in place in the center of the valve by a rod. Similar to ball valves, valve operation time is short because the valving element is simply rotated a quarter turn (90°) to open or close the passageway.

Butterfly valves are characterized by their simple construction, lightness in weight, and compact design. Their face-to-face dimension is often extremely small, making the pressure drop across a butterfly valve much smaller than globe valves.

Materials used for the valving element and sealing can limit their applications at higher temperatures or with certain types of fluids. Butterfly valves are often used on applications for water and air, and in applications with large pipe diameters.

Globe Valve

The globe valve is suitable for use on a wide variety of applications, from flow rate control to open/close operation.

In this type of valve, flow rate control is determined not by the size of the opening in the valve seat, but rather by the lift of the valve plug (the distance the valve plug is from the valve seat).

One feature of globe valves is that even if used in the partially open position, there is less risk of damage to the valve seat or valve plug by the fluid than with other types of manual valves.

Among the various configurations available, needle type globe valves are particularly well suited for flow rate control.

Another point to consider about globe valves is that the pressure drop across the valve is greater than that of many other types of valves because the passageway is S-shaped.

Valve operation time is also longer because the valve stem must be turned several times in order to open and close the valve, and this may eventually cause leakage of the gland seal (packing).

Furthermore, care must be taken not to turn the valve shaft too far because there is a possibility it could damage the seating surface

Gate Valves

The construction of a gate valve is similar to that of a floodgate: flow is controlled by raising or lowering the valving element, which is generally available in three different types: solid (plain), flexible, and split. The latter two types help prevent the valving element and body from being deformed due to various operating conditions.

Like ball valves, gate valves are not usually used to regulate flow. One of the reasons for this is because the valving element can be damaged when in the partially open position.

Similarly, they also limit the pressure drop across the valve when fully open. However, setting the valve to the fully open or closed position requires the handle to be turned many times, which generally makes these valves have the longest operating times among those valve types mentioned here

Diaphragm valves

Diaphragm valves use a ‘pinching’ method to stop the valve flow using a flexible diaphragm. They are available in two types: weir and straight-way. The most commonly seen of the two is the weir-type. This is because the straight-way type requires additional stretching of the diaphragm, which can shorten the diaphragm’s life-span.

One of the major advantages of using diaphragm valves is that the valve components can be isolated from the process fluid. Similarly, this construction helps prevent leakage of the fluid without the use of a gland seal (packing) as seen in other types of valves.

One the other hand, the diaphragm becomes worn more easily and regular maintenance is necessary if the valve is used on a regular basis. These types of valves are generally not suited for very high temperature fluids and are mainly used on liquid systems

Note: There exists a valve for steam systems that goes by a similar name. It is an automated valve with a diaphragm type actuator. This is often shortened to just ‘diaphragm valve’, so when a valve is referred to by this name, care must be taken to verify which type of valve it is.

Types of Valve Actuators

Valve actuators are devices used to position valves. They can be used to fully open and shut a valve, or in an application that requires constant and precise control, such as regulating the flow of fuel to a gas turbine, modulate the position of the valve.

There are many applications that call for the use of actuators, such as:

Automating a process
Positioning valves that require large amounts of torque to operate
Instantaneous operation of systems used to protect personnel and equipment from dangerous conditions
Use in controlling areas where manual operation is impractical or impossible
Continually adjusting systems that must maintain desired parameters

Types of Valve Actuators

There are three basic types of automatic valve actuators: those that are controlled by pressurized air, by electrical power, or by hydraulic force.

Selecting the proper actuator is based on the following considerations:

The valve application
The means available to power the actuator
The speed at which the valve needs to operate
The amount of force required to operate the valve
The type of valve to be operated
The cost versus the benefit for using each type of actuator

Pneumatic Actuator

Pneumatic actuators use pressurized air to operate a valve. They do this by applying the force of the air to a piston or a diaphragm attached to the valve stem.

Pneumatic actuators are used to provide automatic or semi-automatic valve operation, and are the most popular type in use due to their dependability and simplicity of design.

The advantages of pneumatic actuators include:

Dependability and simplicity of design
Fast stroking speeds
Low fire risk
Low costs
Pressurized air can be stored, so the valves can be operated when power is lost

The disadvantages of pneumatic actuators include:

Poor performance at slow speeds
Compressibility of air, which can lead to inconsistent speeds of shaft movement
Impossible to precisely control position, unless fully open or shut

Due to their simple design, high reliability, and low cost, pneumatic diaphragm actuators are used in many industrial applications. For example, pneumatic diaphragm actuators are often used to control cooling water flow in power plants.

Electrical Actuator

Electric actuators include electric motors and solenoid-actuated valves. Electric motors can be used to open, close, and position a valve manually, automatically, or semi-automatically.

The motor operates in both directions and drives the valve stem by means of gear couplings. Solenoid valves use electric power to attract a magnetic slug attached to the valve stem and are used in automatic open-close applications.

The advantages of electric actuators include:

No source of pressurized air or fluid required
Useful where low temperatures could cause freezing of condensation in air supply lines
Capable of producing very large amounts of torque
Capable of producing consistent and adjustable operating speeds
Electric cables are easier than piping to route to an actuator

The disadvantages of electric actuators include:

More expensive and complex than other types of actuators
Slower comparative operation speeds
Susceptible to a loss of power
Potential fire hazard

When a facility is located in a cold enough climate, any moisture trapped in pneumatic control lines can freeze, removing control of that valve. In conditions such as this, many facilities will rely on electric motor actuators for reliability and efficiency during extreme temperatures.

Hydraulic Actuator

Hydraulic actuators use a pressurized fluid to control valve movement. The hydraulic fluid used is either water or oil and is fed to either one or both sides of a piston to cause movement.

Hydraulic valves provide for automatic and semi-automatic valve operation.

The advantages of hydraulic actuators include:

More powerful than a pneumatic actuator of the same size
Precise control of valve position
Capable of converting a small input pressure into a large output pressure
Incompressibility of the fluid, which means very little energy is lost during operation

The disadvantages of hydraulic actuators include:

External hydraulic pump required
Efficiency can be influenced by changes in temperature
More expensive and complex than pneumatic actuators
Can leak, causing a potential fire hazard

Hydraulic actuators are often used to operate the main stop and control valves for high-pressure steam turbine piping. The actuator’s ability to operate the valve against the high-pressure steam, as well as the ability to quickly shut the valve on the loss of control oil, makes hydraulic actuators well suited for this task.

Functions of Valve Actuator

All actuators must be capable of the following functions:

Move the closure mechanism (ball, disc, or plug). Actuators must have the appropriate directing controls and provide enough torque/thrust to move the closure mechanism in both mild and severe conditions.
Hold the valve closed in directed position. Actuators mush have the necessary spring, fluid power, or mechanical stiffness to hold the valve closed even in throttling applications wherein fluids provide excessive torque against it.
Properly seat the valve. For example, butterfly valves are considered properly seated when their disc has been positioned in the resilient seat or liner.
Have a sound failure mode. In the event of a disaster of system failure, valve actuators must be equipped to be fully opened, closed, or stay as-is, depending on the application.
Capable of rotating the rotation needed. Most valves will require either 90 or 180 degrees of rotation. Part of selecting the right valve actuator will depend on knowing the required rotational travel for use.
Capable of operating under required speed. The cycle speed is how the valve actuator is regulated.

Important Factors for Thermocouple Selection

It would be difficult to chart a career course in the industrial process control field without being exposed to thermocouples. They are the ubiquitous basic temperature measuring tools with which all process engineers and operators should be familiar.

Knowing how thermocouples work, how to test them, is essential. Sooner or later, though, you may be in charge of selecting a thermocouple for a new application. With no existing part in place for you to copy, what are the selection criteria you should consider for your process?

Thermocouple sensor assemblies are available with almost countless feature combinations that empower vendors to provide a product for every application, but make specifying a complete unit for your application quite a task. Let’s wade through some of the options available and see what kind of impact each may have on temperature measurement performance.

Thermocouple Type: Thermocouples are created using two dissimilar metals. Various metal combinations produce differing temperature ranges and accuracy. Types have standard metal combinations and are designated with capital letters, such as T, J, and K. Generally, avoid selecting a type that exhibits your anticipated measurements near the extremes for the type. Accuracy varies among thermocouple types, so make sure the accuracy of the selected type will be suitable.

NIST Traceability: This may be required for your application. The finished thermocouple assembly is tested and compared to a known standard. The error value between the thermocouple shipped to you and the standard are recorded and certified. The certified sensor assembly will be specially tagged for reference to the standard.

Junction Type: If your sensor will be contained within a tube or sheath, the manner in which the actual sensor junction is arranged is important. The junction can be grounded to the sheath, electrically insulated from the sheath (ungrounded), or protruded from the sheath (exposed). If your process environment may subject the sensor assembly to stray voltages (EMF), it may be wise to stay away from a grounded junction, even though it provides fast response to a change in temperature. Exposed junctions provide very quick response, but are subjected to potential damage or corrosion from surrounding elements. The ungrounded junction provides protection within the enclosing sheath, with a slower response time than either of the other two junction types. When using ungrounded junctions, keep the mass and diameter of the sheath as small as might be practical to avoid overdamping the sensor response.

Probe Sheath Material: This applies to assemblies installed in a tube or sheath which houses and protects the sensor junction and may provide some means of mounting. Material selections include a variety of stainless steel types, polymers, and metals with coatings of corrosion resistant material to suit many applications. Make sure the sheath material, including any coatings, will withstand the anticipated temperature exposure range.

Probe Configuration: Sheath tube diameter and length can be customized, along with provisions for bends in the tube. Remember that as you increase the mass around the junction, or increase the distance of the junction from the point of measurement, the response time will tend to increase.

Fittings and Terminations:There are innumerable possibilities for mounting fittings and wiring terminations. Give consideration to ease of access for service. How will the assembly be replaced if it fails? Are vibration, moisture, or other environmental factors a concern? What type of cable or lead wires would be best suited for the application?

Your options are so numerous, it is advisable to consult a manufacturer’s sales engineer for assistance in specifying the right configuration for your application. Their product knowledge and application experience, combined with your understanding of the process requirements, will produce a positive outcome in the selection procedure.

How to Select Right Thermocouple & Thermowell ?

To select an ideal thermocouple first we need to understand the need of measurement application and requirement.

Factors affecting temperature change

Accuracy required- impact of sensor accuracy on overall
measurement accuracy.

Length of deployment

Thermocouple material selection

Selection of the Measuring Junction

Durability

Range of temperature which is to be measured.

Determine the maximum and minimum range in which you want to measure the temperature and select the thermocouple with higher Maximum temperature range.

Check whether the linearity of thermocouple meets the range requirement.

Environmental Consideration

Select the correct sheath material to resist chemical reaction.

Perfect isolation to resist noise protection.

Thermocouple should withstand vibration and abrasion.

Appropriate connectors and cables to be used between thermocouple and measuring instruments.

Appropriate measuring instrument should be used to give an accurate result.

How to select right Thermowell for your application?

Select the thermowell material according to the temperature range and the environment (corrosive, oxidizing etc.) in which it is to be used.

These wells can be made from different materials like SS304, SS316, HRS446, Inconel, Monel, Ceramic, etc.

According to the construction of Thermowell (Steeped Shank, Straight Shank, Tapered Shank)

Steeped Shank- Provide faster response time and lower drag force.

Straight Shank- Extremely strong, but response time is slower and drag force on the fluid flow is high.

Tapered Shank- Provide good response time and strength.

Thermowell Insertion Length

For best temperature measurement accuracy, the “U” dimension should be long enough to permit the entire temperature-sensitive part of the measuring instrument to project into the medium being measured.

Liquid temperature measurement: One inch or greater.

Gas temperature measurement: three inches or greater.

Resistance to vibration.

Fluid flowing past the well forms a turbulent wake (the Von Karman Trail), which has a definite frequency based on the diameter of the well and the velocity of the fluid.

The thermowell must have sufficient stiffness so that the wake frequency will never equal the natural frequency of the thermowell itself. If the natural frequency of the well were to coincide with the wake frequency, the well would vibrate to destruction and break off.

To avoid the Thermowell failures caused by excessive pressure, drag forces, high temperature, corrosion, vibrations, it is recommended to run thermowell calculations based on your applications:

Maximum or operating temperature

Maximum or operating pressure

Fluid(gas or liquid) velocity

Fluid Density.

Working Principle of Hydraulic Actuators

Hydraulic actuators use liquid pressure rather than instrument air pressure to apply force on the diaphragm to move the valve actuator and then to position valve stem.

Nearly all hydraulic actuator designs use a piston rather than a diaphragm to convert fluid pressure into mechanical force.

The high pressure rating of piston actuators lends itself well to typical hydraulic system pressures, and the lubricating nature of hydraulic oil helps to overcome the characteristic friction of piston-type actuators.

Given the high pressure ratings of most hydraulic pistons, it is possible to generate tremendous actuating forces with a hydraulic actuator, even if the piston area is modest.

For example, an hydraulic pressure of 2000 PSI applied to one side of a 3 inch diameter piston will generate a linear thrust exceeding 14000 pounds (7 tons)!

In addition to the ability of hydraulic actuators to easily generate extremely large forces, they also exhibit very stable positioning owing to the non-compressibility of hydraulic oil.

Unlike pneumatic actuators, where the actuating fluid (air) is “elastic,” the oil inside a hydraulic actuator cylinder does not yield appreciably under stress. If the passage of oil to and from a hydraulic cylinder is blocked by small valves, the actuator will become firmly “locked” into place.

This is an important feature for certain valve-positioning applications where the actuator must firmly hold the valve position in one position.

Some hydraulic actuators contain their own electrically-controlled pumps to provide the fluid power, so the valve is actually controlled by an electric signal.

Other hydraulic actuators rely on a separate fluid power system (pump, reservoir, cooler, hand or solenoid valves, etc.) to provide hydraulic pressure on which to operate.

Hydraulic pressure supply systems, however, tend to be more limited in physical span than pneumatic distribution systems due to the need for thick-walled tubing (to contain the high oil pressure), the need to purge the system of all gas bubbles, and the problem of maintaining a leak-free distribution network.

It is usually not practical to build a hydraulic oil supply and distribution system large enough to cover the entirety of an industrial facility. Another disadvantage of hydraulic systems compared to pneumatic is lack of intrinsic power storage.

Compressed air systems, by virtue of air’s compressibility (elasticity), naturally store energy in any pressurized volumes, and so provide a certain degree of “reserve” power in the event that the main compressor shut down. Hydraulic systems do not naturally exhibit this desirable trait.

Hydraulic Actuators

A hydraulic piston actuator attached to a large shut-off valve (used for on/off control rather than throttling) appears in the next photograph.

Two hydraulic cylinders may be seen above the round valve body, mounted horizontally.

Like the pneumatic piston valve shown earlier, this valve actuator uses a rack-and-pinion mechanism to convert the hydraulic pistons’ linear motion into rotary motion to turn the valve trim:

A feature not evident in this photograph is a hydraulic hand pump that may be used to manually actuate the valve in the event of hydraulic system failure.

Advantages and Disadvantages of Valve Actuators

A valve actuator is the mechanism for opening and closing a valve. Manually operated valves require someone in attendance to adjust them using a direct or geared mechanism attached to the valve stem. Power-operated actuators, using air pressure, hydraulic pressure or electricity, allow a valve to be adjusted remotely, or allow rapid operation of large valves.

These valve actuators may be the final elements of an automatic control loop which automatically regulates some flow, level or other process. Actuators may be only to open and close the valve, or may allow intermediate positioning; some valve actuators include switches or other ways to remotely indicate the position of the valve.

Valve Actuators

Advantages and Disadvantages of Valve Actuators like Spring and diaphragm Actuators, Pneumatic piston Actuators, Electric Actuators, Hydraulic Actuators.

Spring and diaphragm Actuators

Spring and diaphragm pneumatic actuators can be “direct-acting”, meaning that air to the diaphragm casing pushes the actuator stem downward. This “air-to-close” action compresses the spring, which in turn pushes the actuator stem back up when the supply pressure is decreased or lost.

Additionally, spring and diaphragm pneumatic actuators can be “reverse-acting”, meaning that air to the diaphragm casing causes the actuator stem to move upward. This “air-to-open” action compresses the spring, which in turn causes the actuator stem to move downward when supply pressure is decreased.

Advantages:-

-- Lowest cost

-- Ability to throttle without positioner Simplicity

-- Inherent failure-mode action

-- Low supply-pressure requirement

-- Adjust ability to varying conditions

-- Ease of maintenance

Disadvantages:-

-- Limited output capability

-- Large size and weight

High-pressure spring and diaphragm Actuators

Spring-based actuators hold back a spring. Once the command was sent to the valve, or power is lost, the spring is released, then it will operate the valve.

Advantages:-

-- Compact, light weight

-- No spring adjustment needed

-- Costly cast components not needed

-- Inherent fall-safe action

-- No dynamic stem seals or traditional stem connector block
needed

-- Design can include integral accessories

Disadvantages:-

Requires high supply pressure 40 psig (2.8 bars) or higher

Positioner required for throttling

Pneumatic piston Actuators

A pneumatic control valve actuator converts energy (typically in the form of compressed air) into mechanical motion. The motion can be rotary or linear, depending on the type of actuator.

A Pneumatic actuator mainly consists of a piston which develops the motive power. It keeps the air in the upper portion of the cylinder, allowing air pressure to force the diaphragm or piston to move the valve stem or rotate the valve control element.

Advantages:-

-- High force or torque capability

-- Compact, light weight

-- Adaptable to high ambient temperatures

-- Fast stroking speed

-- Relatively high actuator stiffness

Disadvantages:-

-- Fall-safe requires accessories or addition of a spring

-- Positioner required for throttling

-- Higher cost

-- High supply-pressure requirement

Electric motor Actuators

An electric actuator is powered by a motor that converts electrical energy into mechanical torque. The electrical energy is used to actuate equipment such as multi-turn valves.

Advantages:-

-- Compact

-- Very high stiffness

-- High output capability

-- Supply pressure piping not required

Disadvantages:-

-- High cost

-- Lack of fail-safe action

-- Limited duty cycle

-- Slow stroking speed

Electro-Hydraulic Actuators

Hydraulic systems work because of Pascal’s law, which states that an increase of pressure in any part of a confined fluid causes an equal increase of pressure throughout the container. If force is applied to one part of a hydraulic system, it travels through the hydraulic fluid to the rest of the system.

Advantages:-

-- High output capability

-- High actuator stiffness

-- Excellent throttling ability

-- Fast stroking speed

Disadvantages:-

-- High cost

-- Complexity and maintenance difficulty

-- Fail-safe action only with accessories

Short Notes on Differential Pressure Flow Meters

Types of Differential Pressure Flowmeters

What is a Variable Area flowmeter

An variable-area flowmeter is one where the fluid must pass through a restriction whose area increases with flow rate. This stands in contrast to flowmeters such as orifice plates and venturi tubes where the cross-sectional area of the flow element remains fixed.

The simplest example of a variable-area flowmeter is the rotameter, which uses a solid object (called a plummet or float) as a flow indicator, suspended in the midst of a tapered tube:

As fluid flows upward through the tube, a pressure differential develops across the plummet. This pressure differential, acting on the effective area of the plummet body, develops an upward force (F = PA). If this force exceeds the weight of the plummet, the plummet moves up. As the plummet moves farther up in the tapered tube, the area between the plummet and the tube walls (through which the fluid must travel) grows larger. This increased flowing area allows the fluid to make it past the plummet without having to accelerate as much, thereby developing less pressure drop across the plummet’s body.

At some point, the flowing area reaches a point where the pressure-induced force on the plummet body exactly matches the weight of the plummet. This is the point in the tube where the plummet stops moving, indicating flow rate by it position relative to a scale mounted (or etched) on the outside of the tube.

The following rotameter uses a spherical plummet, suspended in a flow tube machined from a solid block of clear plastic. An adjustable valve at the bottom of the rotameter provides a means for adjusting gas flow:

The same basic flow equation used for pressure-based flow elements holds true for rotameters as well:

However, the difference in this application is that the value inside the radicand is constant, since the pressure difference will remain constant (Note) and the fluid density will likely remain constant as well. Thus, k will change in proportion to Q. The only variable within k relevant to plummet position is the flowing area between the plummet and the tube walls.

Note : If we know that the plummet’s weight will remain constant, its drag area will remain constant, and that the force generated by the pressure drop will always be in equilibrium with the plummet’s weight for any steady flow rate, then the relationship F = PA dictates a constant pressure. Thus, we may classify the rotameter as a constant- pressure, variable-area flowmeter. This stands in contrast to devices such as orifice plates, which are variable-pressure, constant-area.

Most rotameters are indicating devices only. They may be equipped to transmit flow information electronically by adding sensors to detect the plummet’s position in the tube, but this is optional.

Rotameters are very commonly used as purge flow indicators for pressure and level measurement systems requiring a constant flow of purge fluid. Such rotameters are usually equipped with hand-adjustable needle valves for manual regulation of purge fluid flow rate.

What is Shutdown Valve ?

A shutdown valve (also referred to as SDV or Emergency Shutdown Valve, ESV, ESD, or ESDV) is an actuated valve designed to stop the flow of a hazardous fluid upon the detection of a dangerous event.

Shutdown Valve

Types of valve

Types of Actuation

As shutdown valves form part of a SIS. It is necessary to operate the valve by means of an actuator.

These actuators are normally fail safe fluid power type.

Typical examples of these are:

Pneumatic cylinder

Hydraulic cylinder

Electro-hydraulic actuator

In addition to the fluid type, actuators also vary in the manner in which the energy is stored to operate the valve on demand as follows:

Single acting cylinder – Or spring return where the energy is stored by means of a compressed spring

Double acting cylinder – Energy is stored using a volume of compressed fluid

Measuring Performance

Proof test – A manual test that allows the operator to determine whether the valve is in the “as good as new” condition by testing for all possible failure modes and requires a plant shutdown

Difference between Fieldbus, Profibus and HART Protocols

The method of representing, encoding, and transmitting the data is called the protocol.

At the field level, the dominant protocols for process instruments are HART, FOUNDATION Fieldbus H1 and PROFIBUS PA.

Difference between Fieldbus, Profibus and HART Protocols

Foundation Fieldbus is an all-digital, serial, two-way communications system that serves as the base-level network in a plant or factory automation environment.

The FOUNDATION Fieldbus specification is uniquely different from other networking technologies. Foundation Fieldbus is not only a communications protocol but also a programming language for building control strategies.

In FF, one of the possibilities that a standard programming language and powerful communications features enable is the ability to perform control that is distributed into the field devices rather than a central controller

For example, it is common for the Fieldbus valve positioner to act as a controller for the loop as it is part of. PID controller can implement in DCS system ( also called as Host or Remote systems). In fieldbus devices, PID controller function can also implement in fieldbus device configurations (also called as local system). So, for fieldbus devices we can implement the PID function either in DCS system or in fieldbus device or at both places.

In fieldbus, It executes the PID function block but only for its own loop, not for other loops. This new architecture based on field device capability is called Field Control System (FCS) and is an alternative to DCS.

Foundation Fieldbus was originally intended as a replacement for the 4-20 mA standard, and today it coexists alongside other technologies such as Modbus, Profibus, and Industrial Ethernet.

A typical fieldbus segment consists of the following components.

H1 card – fieldbus interface card (It is common practice to have redundant H1 cards, but ultimately this is application specific)

PS – Bulk power (Vdc) to Fieldbus Power Supply

FPS – Fieldbus Power Supply and Signal Conditioner (Integrated power supplies and conditioners have become the standard nowadays)

T – Terminators (Exactly 2 terminators are used per fieldbus segment. One at the FPS and one at the furthest point of a segment at the device coupler)

LD – Linking Device, alternatively used with HSE networks to terminate 4-8 H1 segments acting as a gateway to an HSE backbone network.

And fieldbus devices, (e.g. transmitters, transducers, etc.)

The HART protocol does allow several devices to be multi-dropped on a single pair of wires, but this is a capability infrequently explored because of the low update speed, typically half a second per device.

For a vast majority of installations HART devices are connected point to point, that is, one pair of wires for each device and a handheld connected temporarily from time to time for configuration and maintenance.

Both FOUNDATION Fieldbus H1 and PROFIBUS PA are completely digital and even use identical wiring, following the IEC 61158-2 standard.

Communications Subsystem Differences

The communications interfaces required by a host are different for the pure digital communication in FOUNDATION Fieldbus and PROFIBUS on the one hand and for the hybrid of analog and digital for HART on the other.

For PROFIBUS and FOUNDATION Fieldbus a single integrated network architecture is used for I/O as well as for asset management.

The HART and PROFIBUS technologies do not have a control strategy programming language. FOUNDATION Fieldbus has a standard function block language and publisher/subscriber communication.

FOUNDATION Fieldbus has a number of useful communication features not offered by HART protocol. These include automatic device detection and address assignment for Plug-and-Play installation and time synchronization.

As HART communication speed is low it relies on the analog 4-20 mA signal for real-time process I/O and a HART device is therefore connected point to point.

In most systems, the 4-20 mA only connects to conventional I/O modules via individual wires, and any communication with the device is performed with a temporarily connected portable hand communicator. Field devices, and host, are integral parts of the system.

PROFIBUS has PROFIsafe for communication between instruments in safety- related systems, which FOUNDATION and HART do not offer

Basic Network Differences

It is technically possible to use FOUNDATION Fieldbus or PROFIBUS PA technology in any kind of system architecture. Systems based on conventional architecture can also benefit from the wire reduction made possible by field-level networks.

Summary

Fieldbus systems are complex, more training is needed, HART systems are easily understandable.

Field bus test devices are more complex.

Price of field bus devices are higher than HART enabled.

How to Select a Rotameter ?

Applied extensively in industrial process measurement and control, a rotameter is an instrument that uses a float of given density to establish, for any measurable flow rate, an equilibrium position within the fluid stream where the force of the flowing fluid equals the force of gravity.

Let’s break that down a little. A rotameter has a tapered tube with a float inside. As the measured fluid flows upward through the tube, it pushes the float upward along the length of the tube. As the float rises in the tube, the cross sectional area of the tube increases and more fluid can bypass around the float. At some point, the upward force of the fluid flow acting on the float will balance with the downward force of gravity. The position of the float along the length of the tube correlates with a certain flow rate when certain properties of the fluid are known. Flow rate scale graduations on the tube can be read by the operator.

Rotameters are very specific to each flow measurement application. It’s important that you know your fluid properties, ambient conditions, connection and readability specifications.

Start with these selection parameters

Desired flow rate range
Fluid specific gravity
Ambient temperature
Operating and maximum pressure
Line size
Connection type
Connection orientation
With or without a valve
Material requirements to accommodate fluid
Scale units of measure. Smallest scale divisions needed.

For each application, it’s advisable to work closely with a sales engineer to gather all the needed information and coordinate the product selection process.

Here are some things to consider for potential rotameter applications:

Simple design and operation provide a modest cost solution.
No external power is required for operation. Inherent fluid properties and gravity are used to measure flow rate.
Clear glass used for the measuring tube is highly resistant to thermal shock and corrosion.

Instrument orientation must be vertical, with fluid flowing upward.
Scale graduations are accurate for a given substance at a given temperature, making the devices application specific.
Operation of the rotameter may be impacted by changes in the viscosity of the fluid. Consult with a product and application specialist to explore your application.
Direct flow indication provides resolution that may not be as good as some other flow measurement methods.
Visual reading of the scale is subject to uncertainty due to float oscillation, parallax, and location on the scale.
Make sure the fluid turbidity, or another fluid characteristic will not obscure the visibility of the float.

Consult with a product specialist about your flow measurement application. A combination of your process knowledge and their product expertise will produce the best solution.

Basics of Control Valves

Control Valve Basics – Types

Valves are used for thousands of purposes, from simple and mundane tasks, such as turning on the water in a kitchen sink, to tasks as important and difficult as controlling water flow through a nuclear reactor. Regardless of the application, valves are crucial in controlling the flow of liquids and gases in everyday life. Certain valves are used to isolate systems, bleed off system pressure, and/or vacuum for maintenance and repair. Others are used to prevent flow reversal or throttle flow within a system. The type of valve to be used must align with the parameters of the intended service; otherwise, valves could perform poorly or even catastrophically fail. Let’s take a look at some common types of valves and their applications.

Globe Valves

The globe valve is the most commonly used valve and is applied in applications that require frequent operation and/or throttling of flow. A globe valve normally consists of a spherical body and a bridge wall that separates the inlet and outlet sections of the valve. Flow is regulated by a disc-type element or plug that forms a seal with the seat in the valve’s bridge wall and can be opened or closed by adjusting the stem.

Gate Valves

The gate valve is also a commonly used valve. It is used strictly for on/off service, as it is designed to operate either fully closed or fully open. The gate valve controls fluid flow by lifting and lowering a gate or wedge, which is sealed against a seating surface. Gate valves have a straight-through design and are beneficial when installed in straight-line piping, where a minimum amount of flow restriction is desired. Due to excessive vibration in partially open conditions, gate valves typically are not used to throttle fluid flow, but rather to start or stop it.

Butterfly Valves

The butterfly valve is a simply designed valve that is lightweight, compact, and inexpensive, particularly in larger valve sizes. It is essentially a flat, circular disc that is hinged in its center and fully closes or opens with a quarter turn of the stem. It is often used in place of a gate valve, but has the added ability to regulate flow.

Ball Valve

The ball valve uses a ball-shaped plug with a circular hole through its center, within its valve body. It also can fully open or close with a quarter turn of the stem.

Needle Valve

The needle valve is similar in construction to a globe valve and is used for precise throttling in high-pressure and/or high-temperature systems. They are designed for small diameter lines and piping that need exact control over the flow of gases, steam, oil, water, or any other light liquid. The valve consists of a sharp pointed stem that controls flow through the seat.

Plug Valves

The plug valve controls fluid flow through an internal plug, in either a cylindrically or conically tapered shape, which incorporates a straight-through opening. The valve is operated by rotating the plug and stem a quarter turn to either allow a straight-through passage of fluid, block the fluid, or any angle in between. It is popular due to its simple design and inexpensiveness.

Check Valves

The check valve is used to prevent flow reversal in a system. The two most common designs are swing check and lift check. These operate by allowing flow in one predetermined direction through their body. A swing check valve consists of a hinged disc that swings open when flow starts and closes due to either gravity or flow reversal. When fully open, the swing check valve offers less resistance than the lift check valve. The lift check valve is used when pressure drops are not as critical. Its flow path is very similar to that of a globe valve, and is also opened when flow starts and closes due to flow reversal. Most check valves are labeled with an arrow on the body’s exterior, which indicates the direction of flow and assists with proper installation.

What is a Limit Switch ?

Limit Switch is a switch operated by the motion of a machine part or presence of an object. They are used for control of a machine, as safety interlocks, or to count objects passing a point.

Standardized limit switches are industrial control components manufactured with a variety of operator types, including lever, roller plunger, and whisker type.

Limit switches may be directly mechanically operated by the motion of the operating lever. A reed switch may be used to indicate proximity of a magnet mounted on some moving part.

The class of Proximity Switches operates by the disturbance of an electromagnetic field, by capacitance, or by sensing a magnetic field. Rarely, a final operating device will be directly controlled by the contacts of an industrial limit switch, but more typically the limit switch will be wired through a control relay, a motor contactor control circuit, or as an input to a programmable logic controller.

Miniature snap-action switch may be used for example as components of such devices as photocopiers or computer printers, to ensure internal components are in the correct position for operation and to prevent operation when access doors are opened.

A set of adjustable limit switches are installed on a garage door opener to shut off the motor when the door has reached the fully raised or fully lowered position.

A numerical control machine such as a lathe will have limit switches to identify maximum limits for machine parts or to provide a known reference point for incremental motions.

A limit switch is usually mechanical, that is actuated by a moving part of some machine. Its operation is much like any other switch in that there are contacts that move when a plunger or lever on the outside of the switch is pushed.

Internally there is an over center spring mechanism that snaps the switch open or shut in response to a gradual motion of the plunger or lever.

Function of Limit Switch

Limit switches provide the function of making and breaking electrical contacts and consequently electrical circuits.

A limit switch is configured to detect when a system’s element has moved to a certain position. A system operation is triggered when a limit switch is tripped.

Disadvantages of Limit Switches

Generally restricted to equipment operating at relatively low speeds.

Must make direct contact with target.

Moving mechanical parts will wear out.

Application of Limit Switch

Limit switches are widely used in various industrial applications, and they can detect a limit of movement of an article and passage of an article by displacement of an actuating part such as a pivotally supported arm or a linear plunger.

The limit switches are designed to control the movement of a mechanical part. Limit switches are typically utilized in industrial control applications to automatically monitor and indicate whether the travel limits of a particular device have been exceeded.

Limit switches are used in a variety of applications and environments because of their ruggedness, simple visible operation, ease of installation and reliability of operation.

Ultrasonic Transmitters vs Guided Wave Radar for Level Measurement

Ultrasonic is a non-contact level measurement method that uses sound waves to determine the process material being measured.

Ultrasonic transmitters operate by sending a sound wave, generated from a piezo electric transducer, to the media being measured. The device measures the length of time it takes for the reflected sound wave to return to the transducer. A successful measurement depends on reflection from the process material in a straight line back to the transducer. However, there are various influences that affect the return signal. Factors such as dust, heavy vapors, tank obstructions, surface turbulence, foam and even surface angles can affect the returning signal. That is why the conditions that determine the characteristics of sound must be considered when using Ultrasonic measurement.

Other problematic aspects of Ultrasonic transmitters to consider include:

Vacuum Applications

– Sound must travel through a medium (usually air)

– The absence of air molecules prevents the propagation of sound waves

Surface Condition

Angles

– Sound waves must be sent and received in a straight line

– Reflective surfaces must be flat (i.e. Non-agitated/Non-turbulent condition)

Irregularities

– Foam and other debris collected on the surface of the liquid which absorbs the sound waves and impedes their return sound travel to the sensor

Temperature Limits

– Ultrasonic units are typically plastic with a maximum temperature of 140˚F (60˚C)

– Varying process temperatures may generate inaccurate readings

Pressure Limits

– Ultrasonic devices are not intended for extreme pressure limits

– Maximum working pressures should not exceed of 30 PSIG (2 Bar)

Environmental Conditions

– Ultrasonic devices should be mounted in a predictable environment

– Vapor, condensing humidity, and other contaminates that change the speed of sound through air greatly effect the accuracy of the return signal

The most popular benefit of through-air measurement principles like Ultrasonic, Radar, or Laser measurement is the fact that the measuring signal never comes in contact with the product being measured. But if you think about it, this ‘fact’ is not entirely accurate. Take Ultrasonics for example: When sound energy leaves the transducer, it travels through air at 1,125 feet per second until it reaches its target (i.e. liquid surface).

Similar to all other “non-contacting” type of level measurement, at some point the measuring signal must come in contact with the liquid surface before it begins its return trip back to the sensor. This not only explains why the air quality between the sensor and liquid surface can be problematic, but also why the quality of the liquid surface needs to be accounted for. Every disturbance it picks up on its way down and back will disturb the actual level measurement information in the signal

It is important to understand that Ultrasonic transmitters will provide a sensible solution, when properly applied. Remember, the Ultrasonic transmitter is just as good as the echo it receives.

GUIDED WAVE RADAR (GWR) TECHNOLOGY

Guided Wave Radar (GWR) is a contacting level measurement method that uses a probe to guide high frequency, electromagnetic waves as they travel down from a transmitter to the media being measured.

GWR is based upon the principle of Time Domain Reflectometry (TDR), which is an electrical measurement technique that has been used for several decades in various industrial measurement applications; among its first fields of application was the location of cable damage. In level measurement, however, TDR has only been used for a little over a decade.

With TDR, a low-energy electromagnetic pulse is guided along a probe. When the pulse reaches the surface of the medium being measured, the pulse energy is reflected up the probe to the circuitry which then calculates the fluid level from the time difference between the pulse sent and the pulse reflected. The sensor can output the analyzed level as a continuous measurement reading through its analog output, or it can convert the values into freely positionable switching output signals.

GWR is suitable for a variety of level measurement applications including:

Unstable Process Conditions

– Changes in viscosity, density, or acidity do not effect accuracy

Agitated Surfaces

– Boiling surfaces, dust, foam, vapor do not effect device performance

– Recirculating fluids, propeller mixers, aeration tanks

Extreme Operating limits

– GWR performs well under extreme temperatures up to 600ºF (315ºC)

– Capable of withstanding pressures up to 580 PSIG (40 Bar)

Fine Powders & Sticky Fluids

– Vacuum tanks with used cooking oil

– Paint, latex, animal fat and soy bean oil

– Saw dust, carbon black, titanium tetrachloride, salt, grain

One of the most common misconceptions of GWR is the effects of product build-up on the probe. One would think that if you have a mass of product stuck to the probe, or a coating of product throughout the entire probe length, that the signal would misidentify the true liquid surface.

This in fact is not the case with advanced GWR technology. The radar signal of GWR has a very large detection area around the probe covering 360˚ of area over several feet of coverage. When this pulse energy comes in contact with a mass of product on the probe, the signal is returned and analyzed to see if it is the true liquid level. Since the liquid level always has a larger signal return than the smaller mass that is sticking on the probe, the liquid surface is easily identifiable. The advanced algorithms developed over the last decade have made this contacting form of level measurement the ideal solution for even the stickiest of fluid applications.

Advantages of GWR in the level industry are endless. Unlike older technologies, GWR offers measurement readings that are independent of chemical or physical properties found in the contact media. Additionally, GWR performs equally well in liquids and solids.

Vibration Switch Working Principle

What is a vibration switch?

Why use a vibration switch?

Working Principle

Vibration Switch is working according to the pendulum switching principle.

Applications include all types of rotating or reciprocating machinery such as cooling tower fans, pumps, compressors etc.

Differential Pressure Switch Working Principle

A Differential Pressure Switch, just like a regular pressure switch, is a simple electro-mechanical device that operates on the basic principles of levers and opposite forces. Mainly, they are used for sensing a difference between two points in a process. Three key elements are used in various combinations to manufacture different kinds of differential and standard pressure switches to suit unique industrial needs.

These elements are:

* A sensing element made either of bellows or diaphragm,
metallic or elastomeric

* A hardened spring to determine the range set point

* A snap-acting micro switch available in a wide variety,
SPDT, DPDT, etc.

Principle

The purpose of the Differential Pressure Switch is to sense a difference in pressure between two pressure sources in a control process. When the

pressure from two different sources is connected across a sensing diaphragm, the pressure difference creates a force which then acts upon the pre-tensioned spring. This action moves a balancing arm or mechanism to effect the minimal movement required to activate the micro switch.

High and low pressures are applied on either side of the specially contoured sensing diaphragm. This feature helps to eliminate errors due to a difference in area which is commonly a problem present in twin element Differential Pressure Switches.

Pressure ports for high-process pressure, as well as low-pressure are separated by an elastic diaphragm. The difference in pressure between the two ports causes axial movement, otherwise known as measuring travel, of the diaphragm against a measure range spring. The differential pressure, which is proportional to the measuring level, is transmitted through a connecting rod with little friction to the plungers of the micro switch.

The micro switch contains the electrical contacts of the switch, and electrical contacts will actuate based on the switch points and set points. Overpressure is protected by contoured metal bolsters for the elastic diaphragm.

Adjustments for Setpoints

The adjustment of the switch point or setpoint can be accomplished by setpoint screws accessible from the front of a Differential Pressure Switch. The graduated scales allow a relatively accurate adjustment of the switch points, and indicate the setpoint has been changed.

In short, Differential Pressure Switches work off the basis of a difference in pressure between two low and high points. The difference is converted to axial movement that is used to actuate the contacts of a micro switch depending on setpoints.

Working Principle

Process pressure is sensed by a diaphragm-piston combination. Hi-side system pressure acts on the piston to product force Fh. It is counteracted by the adjustable range spring force Fs and Lo-side system pressure acting on the backside of the piston to produce force Fl . The resultant force Fd acts on the piston and overcomes the force of the adjustable range spring [Fd = Fh – (Fl + Fs)] and moves a shaft that actuates (deactuates) an electrical switching element to generate a NO or NC contact.

Types of Sensors used in Vibration Measurement

BRIEF EXPLANATION OF VIBRATION SENSOR PRINCIPLES:

1. VELOCITY SENSORS

2. ACCELERATION SENSORS

3. PROXIMITY SENSORS

Valve Actuators

What is a Valve Actuator?

A valve actuator is the device that is joined to the valve that converts motive power e.g. pneumatic power, into movement of the valve stem. This movement opens, closes or modulates the valve.

Types of Actuators

Valve actuators are generally split into one of four types, dependant on the motive force they receive, namely:

Manual Actuators

These rely on a person supplying the motive force, either through a hand wheel, lever or chain block. For this reason they are rarely, if ever, considered by the instrument engineer. The valve and actuator are most often specified by the piping engineer, and the valves are referred to as "piping valves".

Pneumatic Actuators

These are the most commonly used in the process and oil industries. Compressed air is used to move either a diaphragm, or piston, which in turn moves the valve stem. Pneumatic actuators are usually equipped with a spring, and the air pressure overcomes the spring to provide movement. The actuator is either configured to be spring-close or spring-open. For spring-close valves, the valve will "fail" to the closed position and air is required to open it. The opposite applies to spring-open valves. Some pneumatic actuators are "double acting" which means that they don't rely on a spring for the return movement but instead air is required to both open and close it.

Hydraulic Actuators

These rely on a virtually non-compressible fluid, e.g. hydraulic oil to provide the motive force. Hydraulic actuators can provide greater force than pneumatic actuators and this leads to them often being used in high pressure piping systems.

Electric Actuators

These uses an electric motor to provide torque to operate a valve. Electric actuators are not equipped with springs, therefore on a loss of power the valve will fail in its current position unless there is a back up power supply to move it to the fully open or fully closed position.

Things to Consider when Specifying Actuators

Compatibility with valve. An oversized actuator can damage the valve stem therefore it is important that the strength of the valve stem is considered in relation to the actuator selected.

Motive power available.

- For pneumatic actuators what pressure of air supply is available? How much air will be consumed by this actuator, and does this have a detrimental effect on the air supply system? Do you need a pressure regulator? Air Pressure Regulators maintain constant output pressure despite variances in input pressure. These are invariably used in conjunction with pneumatic actuators. It is common for them to be fitted with a filter so to ensure that no contaminants pass into the actuator, and in this case they are referred to as air filter regulators.,br> - For hydraulic actuators what pressure of hydraulic fluid is available? What volume of fluid will be required to be added to the system for this actuator?

- For electric actuators what voltage is available locally? If the valve is required to operate in shutdown conditions will the electric power supply be fed from a switchboard that will still be live in these conditions?

Hazardous Area. Will the actuator be located in a potentially hazardous area? If so all electric and electronic assemblies will need appropriate certification. See our page on Hazardous Area Certification for more information on hazardous areas.

Enclosure Ingress Protection. Location of the valve, e.g. in a splash zone, may require a higher IP rating than normally specified for other actuators on the plant. See our page on IP ratings for more information on Ingress Protection.

Ambient conditions. As always, thought should be given to ambient temperature, humidity etc. Also will the actuator be located in saliniferous atmosphere? If so then consider what type of coating it should have e.g. perhaps a two part epoxy resin.

Electric Connections. What size of electrical entry connections are required. Signal cables usually use M20x1.5 ISO. See our page on cable glands for further discussion on cable entries.

Limit Switches are often fitted to valves to provide positive indication to the control system that the valve is either fully open, partially open, or fully closed.

Solenoid valve. Required for on/off valves, and may also be required for control valves that are required to fully close or fully open in emergency situations.

What is Instrumentation Control System ?

An instrumentation control system is an electrical, electronic, or programmable electronic system (E/E/PES) which may perform some or all of the following functions:

Monitoring, recording and logging of plant status and process parameters;

Provision of operator information regarding the plant status and process parameters;

Provision of operator controls to affect changes to the plant status;

Automatic process control and batch/sequence control during start-up, normal operation, shutdown, and disturbance. i.e. control within normal operating limits;

Detection of onset of hazard and automatic hazard termination (i.e. control within safe operating limits), or mitigation;

Prevention of automatic or manual control actions which might initiate a hazard.

Instrumentation Control System

These functions are normally provided by, alarm, protection (trip, interlocks and emergency shutdown), and process control systems.

These engineered systems are individually and collectively described as control systems, and may be independent, or share elements such as the human interface, plant interface, logic, utilities, environment and management systems.

The human interface may comprise a number of input and output components, such as controls, keyboard, mouse, indicators, annunciators, graphic terminals, mimics, audible alarms, and charts.

The plant interface comprises inputs (sensors), outputs (actuators), and communications (wiring, fibre optic, analogue/digital signals, pneumatics, fieldbus, signal conditioning, barriers, and trip amplifiers).

The logic elements may be distributed, and linked by communications, or marshalled together and may be in the form of relays, discrete controllers or logic (electronic, programmable or pneumatic), distributed control systems (DCS), supervisory control and data acquisition (SCADA), computers (including PCs), or programmable logic controllers (PLC). The logic elements may perform continuous control functions, or batch or change of state (e.g. start-up/shut-down) sequences. It should also be noted that logic functions may be distributed to be undertaken within smart sensors or actuators.

Utilities are the power supplies and physical elements required for the systems, such as electricity and instrument air.

Environment is the physical accommodation and surroundings in which the control systems (including the operator) are required to work, including physical accommodation or routings, environmental conditions (humidity, temperature, flammable atmospheres), and external influences such as electromagnetic radiation and hazards which might affect the operation of the control system during normal or abnormal conditions such as fire, explosion, chemical attack etc.

Modern instrumented control systems are generally electrical, electronic or programmable electronic systems (E/E/PES), but some purely pneumatic systems may still be in operation.

What is Safety Control System ?

A safety control system or device is deemed to be safety related if it provides functions which significantly reduce the risk of a hazard, and in combination with other risk reduction measures, reduces the overall risk to a tolerable level, or if it is required to function to maintain or achieve a safe state for the equipment under control (EUC).

These functions are known as the safety functions of the system or device and are the ability to prevent initiation of a hazard or detect the onset of a hazard, and to take the necessary actions to terminate the hazardous event, achieve a safe state, or mitigate the consequences of a hazard.

Safety Control System

All elements of the system which are required to perform the safety function, including utilities, are safety related, and should be considered part of the safety related system.

Safety related control systems may operate in low demand mode, where they are required to carry out their safety function occasionally (not more than once/year) or in high demand (more than once/year) or continuous mode where failure to perform the required safety function will result in an unsafe state or place a demand on another protective system. The likelihood of failure of a low demand system is expressed as probability of failure on demand, and as failure rate per hour for high/continuous demand systems.

Safety related control systems operating in continuous or high demand mode where the E/E/PES is the primary risk reduction measure have been known as HIPS (high integrity protective systems).

However, use of such systems does not circumvent the need for a hierarchical approach to risk reduction measures such as inherent safety, and careful consideration of prevention of common mode failures by use of diverse technology and functionality (such as relief valves), independent utilities and maintenance and test procedures, physical separation, and external risk reduction (such as bunds).

Measures should favour simple technological solutions rather than complex ones. The lowest failure rate which can be claimed for high integrity systems operating in continuous or high demand mode is 10-9 dangerous failures per hour.

It should be noted that control systems for equipment under control which are not safety related as defined above may also contribute to safety and should be properly designed, operated and maintained. Where their failure can raise the demand rate on the safety related system, and hence increase the overall probability of failure of the safety related system to perform its safety function, then the failure rates and failure modes of the non-safety systems should have been considered in the design, and they should be independent and separate from the safety related system.

A control system operating in continuous or high demand mode, for which a failure rate of less than 10-5/hr is claimed in order to demonstrate a tolerable risk, provides safety functions, and is safety related.

In some circumstances, the safety function may require the operator to take action, in which case, he/she is part of the safety related system and will contribute significantly to the probability of failure on demand (PFD).

Typically, in a well designed system, a figure of 10-1 is assumed for the probability of an operator failing to take correct action on demand. Where exceptional care has been taken in design of human factors such as alarm management, instructions and training, and where such arrangements are monitored and reviewed, then a probability of failure on demand of not better than 10-2 may be achievable. Any supporting hardware or software, such as alarm systems, would also need the requisite integrity level).

Non-safety related systemNot better than 10-5/hr

Operator action10-1/demand (typical)10-2/demand (best)

High integrity protective systemNot better than 10-9/hr

System integrity

The integrity required of a safety related system depends upon the level of risk reduction claimed for the safety function to be performed.

Safety integrity is the probability that safety related system will satisfactorily perform the required safety function under all stated conditions within a stated period of time when required to do so.

Safety integrity is therefore a function of performance and availability.

Performance is the ability of the system or device to perform the required safety function in a timely manner under all relevant conditions so as to achieve the required state.

Availability is the measure of readiness of the system to perform the required safety function on demand, and is usually expressed in terms of probability of failure on demand.

Performance and availability depend on:

Proper design or selection, installation and maintenance and testing of the plant interfaces, including sensors actuators and logic, for the required duty and full range of process and environmental conditions under which they will be required to operate, including, where necessary, any excursions beyond the safe operating limits of the plant;

Accuracy and repeatability of the instrumentation;

Speed of response of the system;

Adequate margins between normal and safe operating limits and the system settings;

Reliability;

Survivability from the effects of the hazardous event or other external influences such as power system failure or characteristics, lightning, electromagnetic radiation (EMR), flammable, corrosive or humid atmospheres, temperature, rodent attack, vibration physical impact, and other plant hazards;

Independence (the ability of the system to act alone, without dependence on other protective measures, control systems or common utilities or to be influenced by them.

The following measures are required to ensure adequate performance and availability of the safety related system:

Protection against random failures by hardware reliability, fault tolerance (e.g. by redundancy) and fault detection (diagnostic coverage, and proof testing);

Protection against systematic and common mode failures by a properly managed safety lifecycle, independence from common utilities, common management systems and other protective systems, and by diversity. The lifecycle includes hazard and risk evaluation, specification, design, validation, installation, commissioning, operation, maintenance, and modification.

Integrity levels

Historically, little industry guidance has been available for qualifying or quantifying safety integrity levels to achieve to achieve a requisite risk reduction.

Most major companies will have developed internal standards which relate safety related system integrity to required risk reduction. These standards are likely to address the design process, system configuration, and demonstration that the required risk reduction has been achieved by qualitative or quantitative analysis of the failure rate of the design. They will also have procedures to ensure that the integrity is maintained during commissioning, operation, maintenance, and modification.

Underlying philosophy

Integrity levels for safety related systems may be determined from the hazard and risk analysis of the equipment under control. A number of different methodologies are available, but the process includes identification of hazards and the mechanisms which can initiate them, risk estimation (likelihood of occurrence), and risk evaluation (overall risk based on likelihood and consequences). The risk estimation provides a measure of the risk reduction required to reduce the risk to a tolerable level.

Hazard identification results in the identification of safety functions which are required to control the risk.

The safety functions may then be allocated to a number of different systems including E/E/PES, other technology and external measures.

For each system providing a safety function, a failure rate measure can be assigned which in turn determines the integrity required of the system. alternatively, a qualitative approach (based on the likelihood and consequence of the hazard, and the frequency and level of exposure and avoidability) may be used to define the required integrity.

Safety Integrity Levels

IEC 61508 assigns four software and hardware safety integrity levels (SILs) to required measures of risk reduction. Guidance is then provided on the system configuration, level of subsystem fault tolerance and diagnostic coverage, and safety life-cycle measures required to achieve the designated hardware SIL, and the software methods and life-cycle measures required to achieve the designated software SIL.

It also provides guidance on qualitative methods for establishing the SIL level required. Part 2 of the standard places architectural constraints on the hardware configuration by setting minimum fault tolerance and diagnostic coverage requirements for each element or subsystem. It should be noted that IEC 61508 limits the risk reductions which can be claimed for a safety related E/E/PES which operated in low demand mode or continuous mode to no better than 10-6 and 10-9 respectively for SIL4.

The requirement is more demanding for subsystems which do not have well defined behaviour modes or behaviour (e.g. programmable systems). The standard requires that a reliability model of the system architecture be created and the reliability predicted and compared with the target safety integrity level to confirm that the required risk reduction has been achieved.

It is necessary to demonstrate that the required level of integrity has been achieved in the design, installation, operation and maintenance of the system.

It should be noted that the integrity of a safety related system is critically dependant upon the detection and correction of dangerous failures. Where there is a low level of diagnostic coverage, as is usually the case with lower integrity systems, then the integrity is critically dependent upon the proof test interval. Where there is a high level of diagnostic coverage to automatically reveal failures on-line, for example for high demand high integrity systems, then the integrity is also heavily dependant upon the frequency of diagnostic checks, and the mean time to repair the equipment, which includes the diagnostic test interval.

SIL levels are now being quoted for proprietary subsystems (and certified by test bodies). Quoted SILs should be associated with proof test intervals, diagnostic coverage and fault tolerance criteria. They are useful for evaluation of architectural constraints, but do not eliminate the requirement to confirm that the requires safety integrity level for the safety function provided by the system has been achieved. Software includes high level user application programmes and parameter settings.

What is On/off valve ?

An on/off valve is the fluid equivalent of an electrical switch: a device that either allows unimpeded flow or acts to prevent flow altogether. These valves are often used for routing process fluid to different locations, starting and stopping batch processes, and engaging automated safety (shutdown) functions.

Valve styles commonly used for on/off service include ball, plug, butterfly (or disk), gate, and globe. Large on/off valves are generally of such a design that the full-open position provides a nearly unimpeded path for fluid to travel through. Ball, plug, and gate valves provide just this characteristic:

A plug valve is very much like a ball valve, the difference being the shape of the rotating element. Rather than a spherical ball, the plug valve uses a truncated cone as the rotary element, a slot cut through the cone serving as the passageway for fluid. The conical shape of a plug valve’s rotating element allows it to wedge tightly into the “closed” (shut) position for exceptional sealing.

A series of photographs showing a cut-away ball valve (hand-actuated) in three different positions reveals the inner workings common to all ball valve mechanisms:

The left-hand image shows the valve in the shut position, with the bore axis facing the viewer (preventing fluid flow). The right-hand image shows the valve in the open position, with the bore axis perpendicular to view and allowing flow. The middle image shows the valve in a partially-open condition.

Flow Switch : What is it ?

Flow Switch is a mechanical switch that is switched on or off in response to the flow or non-flow of a fluid such as air or water. The switch typically operates through the use of a paddle which gets displaced due to the force of fluid moving past it.

The flow switch consists of a paddle system. which has a permanent magnet located at its upper end. A reed contact is positioned outside the flow above this magnet. A second, magnet with opposite polarity is used to create a reset force.

The paddle system is moved once it comes into contact with the flow which is to be monitored. The magnet changes its position in relation to the reed switch contact. The contact opens/closes depending on the contact type.

As soon as the flow is interrupted, the paddle returns to its original position and the reed switch contact opens/closes depending on the contact type. This change in contact (NO to NC or NC to NO) will be used to indicate the required flow signal output.

Flow switch is a special electric device with a very simple design and of a small size. But despite of its simplicity, flow switch plays important role in the variety of different applications.

These devices are used with the purpose to protect a pump and when the flow of air, gas or liquid through the specific line is needed to be monitored.

Also the alarms can be triggered with the help of them when it is necessary. Switches may be specific to a type of application.

Why Flow switch Shows wrong indication ?

The below are the possible causes for the false activation of flow switch :

Entrapped air or gas.

Turbulence in tubing or unit

Mechanical sensor assembly damaged.

Liquid is too viscous.

Not using the fittings supplied by the manufacturer.

Applications

These switches find application in the detection of fluid flow and measurement of fan speeds.

A flow switch might be used to protect a central heating system electric heating element from being energized before the air flow from the blower is established.

Flow switches might also be used to alarm if a ventilation fan in a hazardous location fails and air flow has stopped.

Pump protection

Safety spray nozzle monitoring

Cooling water or heat exchangers

Oil well system testing

Drain line flow

Relief valve monitoring

Functions of Temperature Detectors

Detector Problems

Environmental Concerns

Detector Uses Summary

1.Temperature detectors are used for:

Indication

Alarm functions

Control functions

2.If a temperature detector became inoperative:

A spare detector may be used (if installed)

A contact pyrometer can be used

3.Environmental concerns:

Ambient temperature

Humidity

Thermocouple Calibration At Instronline

Thermocouples measure temperature and are used quite often in process controls.

How They Work

When wires of two different thermoelectrically homogeneous materials are joined at one end and placed in a temperature gradient, a thermoelectric voltage (EMF) is observed at the other end. The connection is called the measuring junction. On all thermocouples, the red lead is negative. The color of the other wire indicates the thermocouple type.

For example, on a J-type thermocouple, the positive wire is white. Tables for each type of thermocouple list the voltages produced at various temperatures. Thermocouples should be checked whenever there are indications that the output is not accurate. It may also be necessary to check a thermocouple that will be used for a measurement standard.

Input and Output Measurement Standards

A temperature bath provides controlled temperatures for testing a sensor. A well in the temperature bath is used to hold the sensor during the accuracy check. Another well is used to hold a measurement standard thermometer, it is used to confirm the actual bath temperature.

A second measurement standard thermometer is used to read the ambient temperature at the reference junction. The sensor output signal and ranges determine the thermocouple output measurement standard. Since the output is measured in millivolts, a millivolt meter is used to read the output.

Connections

Set up the temperature bath as a temperature input standard to the thermocouple. Select the output standard with the appropriate range for reading millivolts. Connect the red lead to the negative millivolt meter input and the white lead to the positive millivolt meter input.

Three Point Checks

Because no adjustments are possible, we can only check the calibration of a thermocouple sensor. This check is generally done at three test point input values: ambient temperature, mid-range temperature, and upper value of the application range.

Recall that in a thermocouple, it is the difference in the temperature between the reference and the measuring junction that produces a millvoltage output. Before inserting the thermocouple into the bath, determine the ambient temperature, which represents the temperature at the measuring junction of the thermocouple.

When using look-up tables that are referenced to 0 Deg., you must compensate for ambient temperature. The millivolt value in the tables for the ambient temperature is added to the value from the sensor. This compensated millivolt value is used to determine from the tables the correct temperature.

Thermocouple Transmitters

Calibration of temperature transmitters should be checked on a periodic basis.

Input and Output Measurement Standards

The temperature transmitter discussed here receives an input signal from a thermocouple. A millivolt input signal will be needed for calibration, so a millivolt source can be used for the input standard. A milliammeter can be used to measure the transmitter output. Use a standard thermometer to calculate the input signal compensation for the ambient temperature. Finally, a power supply for the transmitter is necessary.

To calibrate a temperature transmitter with a millivolt meter as an input standard, you must compensate for any reference temperature other than 0 Deg. C ( 32 Deg. F.).

Connections

To make the input connections, the location of the reference junction must first be determined. When thermocouple wires are used to connect the millivolt source to the transmitter, the reference junction is at the transmitter connection.

So, ambient temperature is measured in the transmitter housing. If copper wires are used, the reference junction is at the connection to the millvolt source, so measure ambient temperature at the millivolt source. Always observe the polarity of the leads. Connect the negative output from the millivolt source to the positive transmitter terminal. Connect the milliammeter in series with the transmitter and the power supply.

Setting the Equipment

Adjust the millivolt source and the milliammeter to the proper values as required, turn on equipment and begin calibration.

Five Point Check

Perform a five point check to determine if the transmitter is accurate according to specifications.

Accuracy of the Instrument

Adjust the zero shift first. It should be set with an input value of 10%. With the zero properly set, a 10% input results in a 10% output. Adjust the span using a 90% input. The zero and span may interact, check and readjust as required.

Functions of Pressure Detectors

Pressure Detector Functions

Although the pressures that are monitored vary slightly depending on the details of facility design, all pressure detectors are used to provide up to three basic functions: indication, alarm, and control. Since the fluid system may operate at both saturation and subcooled conditions, accurate pressure indication must be available to maintain proper cooling. Some pressure detectors have audible and visual alarms associated with them when specified preset limits are exceeded. Some pressure detector applications are used as inputs to protective features and control functions.

Detector Failure

If a pressure instrument fails, spare detector elements may be utilized if installed. If spare detectors are not installed, the pressure may be read at an independent local mechanical gauge, if available, or a precision pressure gauge may be installed in the system at a convenient point. If the detector is functional, it may be possible to obtain pressure readings by measuring voltage or current values across the detector leads and comparing this reading with calibration curves.

Environmental Concerns

Pressure instruments are sensitive to variations in the atmospheric pressure surrounding the detector. This is especially apparent when the detector is located within an enclosed space. Variations in the pressure surrounding the detector will cause the indicated pressure from the detector to change. This will greatly reduce the accuracy of the pressure instrument and should be considered when installing and maintaining these instruments.

Ambient temperature variations will affect the accuracy and reliability of pressure detection instrumentation. Variations in ambient temperature can directly affect the resistance of components in the instrumentation circuitry, and, therefore, affect the calibration of electric/electronic equipment. The effects of temperature variations are reduced by the design of the circuitry and by maintaining the pressure detection instrumentation in the proper environment.

Summary

The three functions of pressure monitoring instrumentation and alternate methods of monitoring pressure are summarized below.

Pressure detectors perform the following basic functions:

Indication

Alarm

Control

If a pressure detector becomes inoperative:

A spare detector element may be used (if installed).

A local mechanical pressure gauge can be used (if available).

A precision pressure gauge may be installed in the system.

Environmental concerns:

Atmospheric pressure

Ambient temperature

Humidity

Vacuum Gauges Working Principle

Vacuum Gauges where the Pressure Readings are Independent of the Type of Gas (Mechanical Vacuum Gauges)

Bourdon Vacuum Gauge

The inside of a tube which is bent into a circular arc (the so-called Bourdon tube) is connected to the vacuum system. Due to the effect of the external atmospheric pressure, the end of the tube bends more or less during the evacuation process. This actuates the pointer arrangement which is attached to this point. The corresponding pressure can be read off on a linear scale. With Bourdon gauges it is possible to roughly determine pressures between 10 mbar (7.5 Torr) and atmospheric pressure.

Capsule Vacuum Gauge

This vacuum gauge contains a hermetically sealed, evacuated, thin-walled diaphragm capsule which is located within the instrument. As the vacuum pressure reduces, the capsule bulges. This movement is transferred via a system of levers to a pointer and can then be read off as the pressure on a linear scale.

Diaphragm Vacuum Gauge

In the case of the diaphragm vacuum gauge which is capable of absolute pressure measurements, a sealed and evacuated vacuum chamber is separated by a diaphragm from the vacuum pressure to be measured. This serves as the reference quantity. With increasing evacuation, the difference between the pressure which is to be measured and the pressure within the reference chamber becomes less, causing the diaphragm flex. This flexure may be transferred by mechanical means like a lever, for example, to a pointer and scale, or electrically by means of a strain gauge or a bending bar for conversion into an electrical measurement signal. The measurement range of such diaphragm vacuum gauges extends from 1 mbar (0.75 Torr) to over 2000 mbar (1500 Torr).

Capacitance Vacuum Gauge

The pressure sensitive diaphragm of these capacitive absolute pressure sensors is made of Al2O3 ceramics. The term “capacitive measurement” means that a plate capacitor is created by the diaphragm with a fixed electrode behind the diaphragm. When the distance between the two plates of this capacitor changes, a change in capacitance will result. This change, which is proportional to the pressure, is then converted into a corresponding electrical measurement signal. Here too, an evacuated reference chamber serves as the reference for the pressure measurements. With capacitance gauges it is possible to accurately measure pressures from 10-5 mbar/Torr to well above atmospheric pressure, whereby different capacitance gauges having diaphragms of different thickness (and therefore sensitivity) will have to be used.

Vacuum Gauges where the Pressure Readings Depend of the Type of Gas

Thermal Conductivity Gauge (Pirani)

This measurement principle utilizes the thermal conductivity of gases for the purpose of pressure measurements in the range from 10-4 mbar/Torr to atmospheric pressure. The filament within the gauge head forms one arm of a Wheatstone bridge. The heating voltage which is applied to the bridge is controlled in such a way, that the filament resistance and thus the temperature of the filament remains constant regardless of the quantity of heat given off by the filament. Since the heat transfer from the filament to the gas increases with increasing pressures, the voltage across the bridge is a measure of the pressure. Improvements with regard to temperature compensation have resulted in stable pressure readings also in the face of large temperature changes, in particular when measuring low pressures.

Cold Cathode Ionization Vacuum Gauge (Penning)

Here the pressure is measured through a gas discharge within a gauge head whereby the gas discharge is ignited by applying a high tension. The resulting ion current is output as a signal which is proportional to the prevailing pressure. The gas discharge is maintained also at low pressures with the aid of a magnet. New concepts for the design of such sensors permit safe and reliable operation of these socalled Penning sensors in the pressure range from 10-2 to 1 x 10-9 mbar/Torr.

Hot Cathode Ionization Vacuum Gauge

These sensors commonly use three electrodes. A hot cathode emits electrons which impinge on an anode. The gas, the pressure of which is to be measured, is thus ionized. The resulting positive ion current is detected through the third electrode – the so-called ion detector – and this current is used as the signal which is proportional to the pressure. The hot cathode sensors which are mostly used today, are based on the Bayard-Alpert principle. With this electrode arrangement it is possible to make measurements in the pressure range from 10- 10 to 10-2 mbar/Torr. Other electrode arrangements permit access to a higher range of pressures from 10-1 mbar/Torr down to 10-10 mbar/Torr.

For the measurement of pressures below 10-10 mbar/Torr so-called extractor ionization sensors after Redhead are employed. In extractor ionization gauges the created ions are focused onto a very thin and short ion detector. Due to the geometrical arrangement of this system, interfering influences such as X-ray effects and ion desorption can be almost completely eliminated. The extractor ionization gauge permits pressure measurements in the range from 10-4 to 10-12 mbar/Torr.

How a Orifice Measures Flow ?

An Orifice Meter is basically a type of flow meter used to measure the rate of flow of Liquid or Gas, especially Steam, using the Differential Pressure Measurement principle. It is mainly used for robust applications as it is known for its durability and is very economical.

As the name implies, it consists of an Orifice Plate which is the basic element of the instrument. When this Orifice Plate is placed in a line, a differential pressure is developed across the Orifice Plate. This pressure drop is linear and is in direct proportion to the flow-rate of the liquid or gas.

Since there is a drop in pressure, just like Turbine Flow meter, hence it is used where a drop in pressure or head loss is permissible.

An orifice meter is a conduit and a restriction to create a pressure drop. A nozzle, venturi or thin sharp edged orifice can be used as the flow restriction. In order to use any of these devices for measurement it is necessary to empirically calibrate them. That is, pass a known volume through the meter and note the reading in order to provide a standard for measuring other quantities.

Due to the ease of duplicating and the simple construction, the thin sharp edged orifice has been adopted as a standard and extensive calibration work has been done so that it is widely accepted as a standard means of measuring fluids. Provided the standard mechanics of construction are followed no further calibration is required. An orifice in a pipeline is shown in below figure with a manometer for measuring the drop in pressure (differential) as the fluid passes thru the orifice. The minimum cross sectional area of the jet is known as the “vena contracta.”

How does it work?

When the velocity decreases as the fluid leaves the orifice the pressure increases and tends to return to its original level. All of the pressure loss is not recovered because of friction and turbulence losses in the stream. The pressure drop across the orifice ( ΔP in Fig.) increases when the rate of flow increases. When there is no flow there is no differential. The differential pressure is proportional to the square of the velocity, it therefore follows that if all other factors remain constant, then the differential is proportional to the square of the rate of flow.

Inlet Section

A linearly extending section of the same diameter as the inlet pipe for an end connection for an incoming flow connection. Here we measure the inlet pressure of the fluid / steam / gas.

Orifice Plate

An Orifice Plate is inserted in between the Inlet and Outlet Sections to create a pressure drop and thus measure the flow.

Outlet Section

A linearly extending section similar to the Inlet section. Here also the diameter is the same as that of the outlet pipe for an end connection for an outgoing flow. Here we measure the Pressure of the media at this discharge.

As shown in the adjacent diagram, a gasket is used to seal the space between the Orifice Plate and the Flange surface, prevent leakage.

Sections 1 & 2 of the Orifice meter, are provided with an opening for attaching a differential pressure sensor (u-tube manometer,differential pressure indicator).

Material of construction:

The Orifice plates in the Orifice meter, in general, are made up of stainless steel of varying grades.

Shape & Size of Orifice meter:

Orifice meters are built in different forms depending upon the application specific requirement, The shape, size and location of holes on the Orifice Plate describes the Orifice Meter Specifications as per the following:

-Concentric Orifice Plate

-Eccentric Orifice Plate

-Segment Orifice Plate

-Quadrant Edge Orifice Plate

Concentric Orifice Plate

It is made up of SS and its thickness varies from 3.175 to 12.70 mm. The plate thickness at the orifice edge should not be exceeded by any of following parameters:

1 – D/50 where, D = The pipe inside diameter

2 – d/8 where, d = orifice bore diameter

3 – (D-d)/8

*Beta Ratio(β): It is the ratio of orifice bore diameter (d) to the pipe inside diameter (D).

Eccentric Orifice Plate

It is similar to Concentric Orifice plate other than the offset hole which is bored tangential to a circle, concentric with the pipe and of a diameter equal to 98% of that of the pipe. It is generally employed for measuring fluids containing

-Media having Solid particles

-Oils containing water

-Wet steam

Segment Orifice Plate

It has a hole which is a semi circle or a segment of circle. The diameter is customarily 98% of the diameter of the pipe.

Quadrant Edge Orifice Plate

This type of orifice plate is used for flow such as crude oil, high viscosity syrups or slurries etc. It is conceivably used when the line Reynolds Numbers range from 100,000 or above or in between to 3,000 to 5,000 with a accuracy coefficient of roughly 0.5%.

Operation of Orifice meter:

-The fluid flows inside the Inlet section of the Venturi meter having a pressure P1.

-As the fluid proceeds further into the Converging section, its pressure reduces gradually and it finally reaches a value of P2 at the end of the Converging section and enter the Cylindrical section.

-The differential pressure sensor connected between the Inlet and the and the Cylindrical Throat section of the Venturi meter displays the difference in pressure (P1-P2). This difference in pressure is in direct proportion to the flow rate of the liquid flowing through the Venturi meter.

-Further the fluid passed through the Diverging recovery cone section and the velocity reduces thereby it regains its pressures. Designing a lesser angle of the Diverging recovery section, helps more in regaining the kinetic energy of the liquid.

Advantages of Orifice meter:

-The Orifice meter is very cheap as compared to other types of flow meters.

-Less space is required to Install and hence ideal for space constrained applications

-Operational response can be designed with perfection.

-Installation direction possibilities: Vertical / Horizontal / Inclined.

Limitations of Orifice meter:-

-Easily gets clogged due to impurities in gas or in unclear liquids

-The minimum pressure that can be achieved for reading the flow is sometimes difficult to achieve due to limitations in the vena-contracta length for an Orifice Plate.

-Unlike Venturi meter, downstream pressure cannot be recovered in Orifice Meters. Overall head loss is around 40% to 90% of the differential pressure .

-Flow straighteners are required at the inlet and the outlet to attain streamline flow thereby increasing the cost and space for installation.

-Orifice Plate can get easily corroded with time thereby entails an error.

-Discharge Co-efficient obtained is low.

Applications of Orifice meter:

-Natural Gas

-Water Treatment Plants

-Oil Filtration Plants

-Petrochemicals and Refineries

What is an Orifice Meter?

How does it work?

BETA RATIO is the ratio of orifice plate bore divided by pipe I.D. is referred to as the Beta Ratio or d/D where d is the plate bore and D is the pipe I.D.

THE ORIFICE PLATE

a. The Thin Plate, Concentric Orifice

b. Eccentric Orifice Plates

c. Segmental Orifice Plates

d. Quadrant Edge Plate

The quarter-circle or quadrant orifice is used for fluids of high viscosity. The orifice incorporates a rounded edge of definite radius which is a particular function of the orifice diameter.

e. Conic Edge Plate

The conic edge plate has a 45° bevel facing upstream into the flowing stream. It is useful for even lower Reynolds numbers than the quadrant edge.

METER TAP LOCATION

a. Flange Taps

These taps are located one inch from the upstream face of the orifice plate and one inch from the downstream face with a + 1/64 to +1/32 tolerance.

b. Pipe Taps

c. Vena – Contracta Taps

d. Corner Taps

General Installation Recommendations

1. Meter manifold piping should always be installed to enable calibration as well as to protect the differential element against over range.

2. The meter should be installed as close as possible to the orifice fitting.

3. Always slope the manifold lines gently from the orifice fitting to the meter to eliminate any high or low points in the manifold lines.

4. Use condensate chambers or air traps to remove either liquid from a gas system or gas from a liquid system if lows or highs in the manifold piping cannot be avoided.

Basics of Venturi Flow Meter At Instronline

A venturi tube contains a throat which is smaller in a diameter to the pipeline, into which it fits. The restriction diameter should not be less than 0.224 D, and not more than 0.742 D where D is the nominal bore diameter of the pipe. When the fluid flows through it, the pressure at the throat is lower than the upstream pressure

The venturi flow meter should always be used for turbulent flow. Its accuracy for a wide range of instruments is about 0.5%. ideal for use in Heat Ventilation Air Cond. (HVAC) applications, or air to furnaces and boilers and for liquids containing particles and slurries.

What is Venturi effect ?

The Venturi effect is the reduction in fluid pressure that results when a fluid flows through a constricted section (or choke) of a pipe. The Venturi effect is named after Giovanni Battista Venturi (1746–1822), an Italian physicist.

In fluid dynamics, a fluid’s velocity must increase as it passes through a constriction in accord with the principle of mass continuity, while its static pressuremust decrease in accord with the principle of conservation of mechanical energy. Thus any gain in kinetic energy a fluid may accrue due to its increased velocity through a constriction is balanced by a drop in pressure.

By measuring the change in pressure, the flow rate can be determined, as in various flow measurement devices such as venturi meters, venturi nozzles and orifice plates.

Main Features of Venturi meter:

- Pressure recovery for venturi tubes is a lot better as
compared to the orifice plates.

- Venturi tubes are appropriate for clean, dirty and viscous
liquid and few slurry services as well.

- Rangeability of a venturi tube varies from 4 to 1.

- In venturi tubes, pressure loss is low and viscosity effect is
high.

- Usually, accuracy of a venturi tube is 1% of its full range

- Essential upstream pipe length of a venturi tube is 5 to 20
diameters

- Venturi tubes exist in sizes up to 72″.

- A venturi tube can pass 25 to 50% extra flow than that of
an orifice plate keeping the same drop in pressure.

- Since, the early cost of a venturi tube is quite high, it is
mainly engaged on larger flows and in more complicated or
challenging flow applications.

- Unlike orifice plates, venturi tubes are almost insensitive to
velocity profile effects and consequently call for less
straight pipe run than an orifice.

- Venturi tubes are resistant to corrosion, erosion, and
internal scale build up, owing to their contoured nature,
pooled with the self- scouring action of the flow through
the tube.

- Use of venturi tubes involves a lot of savings in installation
and operating and maintenance costs.

- Venturi tube flowmeters are frequently used in applications
involving higher TurnDown Rates or lower pressure drops,
particularly in areas where orifice plates fails to perform.

- By means of right instrumentation and flow calibration, the
flowrate of a venturi tube can be brought down to about
10% of its full scale range with correct accuracy which in
turn results in a TurnDown Rate of 10:1.

Advantages of Venturi meter:

- They can handle large flow volumes at low pressure drops.

- Venturi tube flowmeters involve no moving parts.

- They can be mounted in large diameter pipes via flanged,
welded or threaded-end fittings.

- They can be used with nearly all liquids, as well as those
containing extreme solids content.

- Venturi tubes involve no projections into the fluid and no
sharp corners. Also there are no rapid changes in contour.

Disadvantages of Venturi meter:

- Highly expensive

- Occupies considerable space

- Cannot be altered for measuring pressure beyond a
maximum velocity.

Types of Flow Meters At Instronline

Fluid flow meters are divided into two functional groups – One measures quantity (Positive Displacement); the other measures rate of flow (Inferential.) All fluid meters, however, consist of two distinct parts, each of which has different functions to perform.

The first is the primary element, which is in contact with the fluid, resulting in some form of interaction. This interaction may be that of imparting motion to the primary element; the fluid may be accelerated etc.

The second or secondary element translates the interaction between fluid and primary element into a signal that can be converted into volume, weights or rates of flow and indicates or records the results.

For example, a weigher uses weighing tanks as its primary element and a counter for recording the number of fillings and dumpings as its secondary element.

n an orifice meter, the orifice together with the adjacent part of the pipe and the pressure connections, constitute the primary element, while the secondary element consists of a differential pressure device together with some sort of mechanism for translating a pressure difference into a rate of flow and indicating the result, in some cases also recording it graphically and integrating with respect to the time. This same combination of primary and secondary elements will be observed in almost all other types of meters.

Positive Displacement (Quantity Meters) –

Some of the more common positive displacement meters are: Weighers, Reciprocating Piston, Rotating Piston, Nutating Disk, Sliding and Rotating Vanes, Gear and Lobed Impeller, and the meter most commonly used to sell small quantities of gas at relatively low flow rates, the Bellows meter.

Inferential (Rate Meters) –

(a) Orifice Plates –

The most commonly used rate or inferential meter is the thin-plate, concentric orifice.

(b) Flow Nozzles & Venturi Tubes –

Flow Nozzles and Venturi Tubes are primary rate devices which will handle about 60% more flow than an orifice plate for the same bore under the same conditions, and can therefore handle higher velocity flows. If a differential limit is chosen, then a smaller bore nozzle or Venturi may be used to measure the same flow. They are more expensive to install and do not lend themselves to as easy size change or inspection as orifice plates.

A Pitot or impact tube makes use of the difference between the static and kinetic pressures at a single point. A similar device which is in effect a multiple pitot tube, averages the flow profile.

(d) Turbine Meters –

A Turbine meter is one in which the primary element is kept in rotation by the linear velocity of the stream in which it is immersed. The number of revolutions the device makes is proportional to the rate of flow.

(e) Swirlmeters, Vortex Shedding Meters, Rotometers, Mass Flow Meters, etc. –

These are devices that have similar applications in flow measurement.

Paddle Switch Working Principle

Paddle Type Level Switch is used for level detection for powder or bunk material in silo,hoppar,etc. The rotating paddle is continuously rotates by a motor. When this paddle contacts with the material, the force more than the rotating torque will be applied to the paddle and the rotation will stop. The Level Switch detects rotation ⇔ stop and outputs the contact.

Principle

The principle is based on the moment of resistance change of a rotating paddle in air or a medium. The electrically driven, slowly rotating paddle (frequency = 1Hz) is on the level of the selected limit. The rising product brakes the rotation, the hinge-mounted drive system changes its position and triggers a microswitch. As the level moves down, the drive returns to its original position by spring force and the microswitch restarts the motor.

Applications

Point level detection in bulk solids

The universally usable paddle point level switch is employed as a full, empty and requirement alarm in silos with bulk solids.

Advantages

Automatic rotation monitoring (optional)

Recognition of failures without dismantling the instrument

Easy installation

Robust plastic housing with transparent cover

Cover securing device

Density setting without any tools

Turbine Flow Meter Calibration At Instronine

Turbine Meters

A turbine meter consists of a practically friction-free rotor pivoted along the axis of the meter tube and designed in such a way that the rate of rotation of the rotor is proportional to the rate of flow of fluid through the meter. This rotational speed is sensed by means of an electric pick-off coil fitted to the outside of the meter housing.

The only moving component in the meter is the rotor, and the only component subject to wear is the rotor bearing assembly. However, with careful choice of materials (e.g., tungsten carbide for bearings) the meter should be capable of operating for up to five years without failure.

There are several characteristics of turbine flow meters that make them an excellent choice for some applications. The flow sensing element is very compact and light weight compared to various other technologies. This can be advantageous in applications where space is a premium

Primary Vs. Secondary Standards

A primary standard calibration is one that is based on measurements of natural physical parameters (i.e., mass, distance, and time). This calibration procedure assures the best possible precision error, and through traceability, minimizes bias or systematic error.

A secondary standard calibration is not based on natural, physical measurements. It often involves calibrating the user’s flow meter against another flow meter, known as a “master meter,” that has been calibrated itself on a primary standard.

Calibration

“To calibrate” means “to standardize (as a measuring instrument) by determining the deviation from a standard so as to determine the proper correction factors.” There are two key elements to this definition: determining the deviation from a standard, and ascertaining the proper correction factors.

Flow meters need periodic calibration. This can be done by using another calibrated meter as a reference or by using a known flow rate. Accuracy can vary over the range of the instrument and with temperature and specific weight changes in the fluid, which may all have to be taken into account. Thus, the meter should be calibrated over temperature as well as range, so that the appropriate corrections can be made to the readings. A turbine meter should be calibrated at the same kinematic viscosity at which it will be operated in service. This is true for fluid states, liquid and gas.

Master Meter

A master meter is a flowmeter that has been calibrated to a very high degree of accuracy. Types of flowmeters used as master meters include turbine meters, positive displacement meters, venturi meters, and Coriolis meters. The meter to be calibrated and the master meter are connected in series and are therefore subject to the same flow regime. To ensure consistent accurate calibration, the master meter itself must be subject to periodic recalibration

Gravimetric Method

This is the weight method, where the flow of liquid through the meter being calibrated is diverted into a vessel that can be weighed either continuously or after a predetermined time. The weight is usually measured with the help of load cells. The weight of the liquid is then compared with the registered reading of the flow meter being calibrated

Volumetric Method

In this technique, flow of liquid through the meter being calibrated is diverted into a tank of known volume. The time to displace the known volume is recorded to get the volumetric flow rate eg gallons per minute. This flow rate can then be compared to the turbine flow meter readings

K-Factor.

“K” is a letter used to denote the pulses per gallon factor of a flowmeter.

Repeatability.

The maximum deviation from the corresponding data points taken from repeated tests under identical conditions.

Flow Transfer Standards:

Unlike primary flow standards, whose most important characteristics are their traceability to primary physical measurements (resulting in the minimization of absolute uncertainties, with less concern for usability or cost issues), the key criteria for secondary Flow Transfer Standards are portability, low cost and the ability to calibrate the flowmeter in the physical piping configuration it lives in.

Instead of removing flowmeters from service for recalibration, FTS devices allow users to “bring the calibrator to the flowmeter.” These portable, documenting fieldflow calibrators are intended for in-line calibration and validation of meters using the actual process conditions for gas or liquid. Advanced FTS systems in corporate hand-held electronics with built-in signal conditioners, thus eliminating bulky interface boxes and the need to carry a laptop computer into the field. High-quality Flow Transfer Standards also have the capability of measuring and correcting the influences of line pressure and temperature effects on flow.

Operation of a portable Flow Transfer Standard requires that a master meter beinstalled in series with the flowmeter under test. The readings from theseinstruments are compared at various flow rates or flow totals. A technician caninstall the master meter in the same system as the test meter, perform thecalibration, and note any changes in performance. New calibration data might causerescaling or new data points to be programmed into a flowmeter’s computer to align the measurement with the current flow calibration data.

Typical Calibration Techniques

Most flowmeter calibration service suppliers provide a choice of calibration techniques to accommodate different applications and flow measurement requirements. One of the most common techniques is the single-viscosity calibration, which consists of running 10 evenly spaced calibration points at a specified liquid viscosity. Single-viscosity calibrations are recommended when the viscosity of the liquid being measured is constant. If a higher degree of accuracy is needed, again, the more data points taken the better defined the meter calibration curve will be.

Strouhal Number/Roshko Number

The best, and only completely correct way to present the data for a Turbine Meter is Strouhal Number as a function of Roshko Number, i.e., through the use of two dimensionless parameters. The St vs. Ro presentation takes into account all of the secondary effects to which the meter is sensitive. This presentation or correlation is correct for both liquids and gases. It is almost a must for gas calibrations since the density and kinematic viscosity are a function of both temperature and pressure

Your Calibrated Flowmeter

Once your flowmeter is calibrated, it may still read exactly the same under the same flow conditions as it did before it was calibrated. The difference is that you will know exactly how close those values are to the true values, and you will have a formula to use to calculate the true values from the actual values read by your flowmeter. You can have a correction factor obtained from calibratiob which you can apply to the flow meter readings to obtain the correct or true flowmeter readings. K-factor ignores the effects of changing temperature on the meter body since the meter will change diameter when the temperature changes. The use of Strouhal Number instead of simple K-Factor will account for this temperature effect.

Different Types of Relays and their Working Principles

Relays are the primary protection as well as switching devices in most of the control processes or equipments. All the relays respond to one or more electrical quantities like voltage or current such that they open or close the contacts or circuits. A relay is a switching device as it works to isolate or change the state of an electric circuit from one state to another.

Classification or the types of relays depend on the function for which they are used. Some of the categories include protective, reclosing, regulating, auxiliary and monitoring relays.

Protective relays continuously monitor these parameters: voltage, current, and power; and if these parameters violate from set limits they generate alarm or isolate that particular circuit. These types of relays are used to protect equipments like motors, generators, and transformers, and so on.

Reclosing relays are used to connect various components and devices within the system network, such as synchronizing process, and to restore the various devices soon after any electrical fault vanishes, and then to connect transformers and feeders to line network. Regulating relays are the switches that contacts such that voltage boosts up as in the case of tap changing transformers.

Auxiliary contacts are used in circuit breakers and other protective equipments for contact multiplication. Monitoring relays monitors the system conditions such as direction of power and accordingly generates the alarm. These are also called directional relays.

This article’s main aim is to give a brief idea about various relays that are employed for a wide variety of control applications. Some of these relays are described below.

Different Types of Relays

Depending on the operating principle and structural features relays are of different types such as electromagnetic relays, thermal relays, power varied relays, multi-dimensional relays, and so on, with varied ratings, sizes and applications.

1. Electromagnetic Relays

These relays are constructed with electrical, mechanical and magnetic components, and have operating coil and mechanical contacts. Therefore, when the coil gets activated by a supply system, these mechanical contacts gets opened or closed. The type of supply can be AC or DC.

DC vs AC Relays

Both AC and DC relays work on the same principle as electromagnetic induction, but the construction is somewhat differentiated and also depends on the application for which these relays are selected. DC relays are employed with a freewheeling diode to de-energize the coil, and the AC relays uses laminated cores to prevent eddy current losses.

The very interesting aspect of an AC is that for every half cycle, the direction of the current supply changes; therefore, for every cycle the coil loses its magnetism since the zero current in every half cycle makes the relay continuously make and break the circuit. So, to prevent this – additionally one shaded coil or another electronic circuit is placed in the AC relay to provide magnetism in the zero current position.

Attraction Type Electromagnetic Relays

These relays can work with both AC and DC supply and attract a metal bar or a piece of metal when power is supplied to the coil. This can be a plunger being drawn towards the solenoid or an armature being attracted towards the poles of an electromagnet as shown in the figure. These relays don’t have any time delays so these are used for instantaneous operation.

delays so these are used for instantaneous operation.

Induction Type Relays

These are used as protective relays in AC systems alone and are usable with DC systems. The actuating force for contacts movement is developed by a moving conductor that may be a disc or a cup, through the interaction of electromagnetic fluxes due to fault currents.

These are of several types like shaded pole, watt-hour and induction cup structures and are mostly used as directional relays in power-system protection and also for high-speed switching operation applications.

Magnetic Latching Relays

These relays use permanent magnet or parts with a high remittance to remain the armature at the same point as the coil is electrified when the coil power source is taken away.

2. Solid State Relays

Solid State uses solid state components to perform the switching operation without moving any parts. Since the control energy required is much lower compared with the output power to be controlled by this relay that results the power gain higher when compared to the electromagnetic relays. These are of different types: reed relay coupled SSR, transformer coupled SSR, photo-coupled SSR, and so on.

The above figure shows a photo coupled SSR where the control signal is applied by LED and it is detected by a photo-sensitive semiconductor device. The output form this photo detector is used to trigger the gate of TRIAC or SCR that switches the load.

3. Hybrid Relay

These relays are composed of electromagnetic relays and electronic components. Usually, the input part contains the electronic circuitry that performs rectification and the other control functions, and the output part include electromagnetic relay.

4. Thermal Relay

These relays are based on the effects of heat, which means – the rise in the ambient temperature from the limit, directs the contacts to switch from one position to other. These are mainly used in motor protection and consist of bimetallic elements like temperature sensors as well as control elements. Thermal overload relays are the best examples of these relays.

5. Reed Relay

Reed Relays consist of a pair of magnetic strips (also called as reed) that is sealed within a glass tube. This reed acts as both an armature and a contact blade. The magnetic field applied to the coil is wrapped around this tube that makes these reeds move so that switching operation is performed.

Based on dimensions, relays are differentiated as micro miniature, subminiature and miniature relays. Also, based on the construction, these relays are classified as hermetic, sealed and open type relays. Furthermore, depending on the load operating range, relays are of micro, low, intermediate and high power types.

Relays are also available with different pin configurations like 3 pin, 4 pin and 5 pin relays. The ways in which these relays are operated is shown in the below figure. Switching contacts can be SPST, SPDT, DPST and DPDT types. Some of the relays are normally open (NO) type and the other are normally closed (NC) types.

These are some of the different types of relays that are employed in most of the electronic as well as electrical circuits. The information about the different types of relays serves readers’ purpose and we hope that they will find this basic information very useful. Considering the huge significance of relays with zvs in circuits, this particular article on them deserves its readers’ feedback, queries, suggestions and comments. Therefore, readers can post their comments here.

Factors to Consider When Selecting a Gear Motor

There is a variety of options when it comes to Bauer’s gear motor line, but by choosing the right gearbox the motor can be optimized while meeting the required output speed and torque.

Basic Parts of Control Valves

Introduction

A valve is a mechanical device that controls the flow of fluid and pressure within a system or process. A valve controls system or process fluid flow and pressure by performing any of the Following functions.

a) Stopping and starting fluid flow

b) Varying (throttling) the amount of fluid flow

c) Controlling the direction of fluid flow

d) Regulating downstream system or process pressure

e) Relieving component or piping over pressure

There are many valve designs and types that satisfy one or more of the functions identified above. A multitude of valve types and designs safely accommodate a wide variety of industrial applications.

Regardless of type, all valves have the following basic parts: the body, bonnet, trim (internal elements), actuator, and packing. The basic parts of a valve are illustrated in Figure 1.

Control Valves mainly have Two parts:

1) Actuator Part

2) Body Part for easy understanding.

1. Actuator Part

For valve control, it will be classified as either a Phenumatic, Motorized and Hydrolics but is commonly used in our industry, it is Phenumatic Actuator Actuator or controlled by the wind itself. For easy maintenance Actuator simple structure which will include the Yoke, too.

Various components of the Actuator

Rain Cap I pray for them not to let water flow into the Actuator for Action of the Air to Open Actuator is that the wind will be from the bottom of the Actuator so the holes are left blank. Find something else to disabled To keep water when it rains. And must be taken off the air valve at the back.

Eye Bolt for use on the hook. Moving the valve

Diaphragm is flexible. To change the incoming wind power and power passed to Diaphragm plate to make Actuator Stem Cell.

Spring is in the Yoke Actuator Case or, depending on the design of the manufacturer. It will act as a force for Actuator Stem Cell and a strong wind from the opposite direction to the plate Diaphragm.

Actuator Stem is interconnected with Actuator Valve Stem.

Diaphragm Case are the parts that are used for packing Diaphragm plate consists of two parts: the upper and lower sections.

Scale Plate is based on the position of the valve between 0-100%.

Stem Connector is the link between them for Actuator Stem and Plug Stem.

Yoke is a component that is used for connecting sections of the Actuator and Valve Body.

2. Body Part

Part of Body Valve is included in the Bonnet valve with which this segment is exposed to the fluid (fluid) directly, so choosing the required qualifications material (material) as well as Fluid type, Temp, Pressure and. etc

Packing Flange is used for compression of the stud bolt to make the most of all the Gland Packing tight and fluid can not leak out of the neck Bonnet.

Packing Follwer is the strength of Packing Flange Gland Pakcing tightly compressed to tighten over time.

Yoke Claim Nut

Gland Packing is important that we prevent the leakage of fluid up to the neck and is in direct contact with Bonnet Plug Stem The choice of material and type to fit so there is a huge need.Most of the material used is PTFE or Graphite and maintenance each time. The need to change the Gland Packing all times.

Valve Stem is the strength of the Actuator and connected to Plug.

Bonnet was primarily used for supporting the position of the Plug-time scroll up, scroll down to find it. No left and right But some manufacturers cut output to reduce the Bonnet Cost for the production and sale of the valve. The maintenance is also difficult. It is not to come and support the position of the Plug and Seat to meet constantly Lapping.

Stud Bolt and Nut

Gasket is a device used to prevent leaks during the assembly of iron and steel as well as between the Body and Bonnet.

Guide Ring is located in Bonnet order to align Plug straight up. Another reason for having Guide Ring Bonnet, instead of doing all the reason to reduce maintenance time Cost. Because this section is always exposed to Stem Plug sometimes wear if not Guide Ring may be a whole instead of only replacing Bonnet Guide Ring.

Guide Bushing is used for supporting Guid Ring again.

Valve Plug is essential to use the force of fluid flow. And determine the flow properties as Linear, Equal Percentage or Quick Openning.

Seat Ring is a component that is part of Valve Body and given the size of the Rated Cv of the valve and which supports Plug and Plug and Seat Ring must be close together. To be able to follow the Class Leakage as needed.

Valve Body , a major component of the round and get direct contact with the fluid. The connection to the pipeline Therefore, the size and material must be chosen accordingly. Read more at PT Rating by Valve Body structure is a frequently encountered 1. Single-Ported is a 1 plug with 1 seat 2. Double-Ported is a 2 plug with 2 Port 3. Two-Way Valve is. There will be two connections (one inbound and one outbound) 4. Three-Way Valve is to have three connections (one or two inbound and two outbound, inbound and one outbound).

Trim Set the control valve (Trim Control Valve) is the word of Plug Stem Seat Ring, which collectively set trim (trim set) itself.

Positioner or position will be the key to control of the control valve. The industry standard device that converts the signal (signal standard), such as 4-20 mA, 3-15 psi as wind power to propel Actuator head movements.

Explain in detail about main valve parts ?

Valve Body

The body, sometimes called the shell, is the primary pressure boundary of a valve. It serves as the principal element of a valve assembly because it is the framework that holds everything together.

The body, the first pressure boundary of a valve, resists fluid pressure loads from connecting piping. It receives inlet and outlet piping through threaded, bolted, or welded joints.

Valve bodies are cast or forged into a variety of shapes. Although a sphere or a cylinder would theoretically be the most economical shape to resist fluid pressure when a valve is open, there are many other onsiderations.For example, many valves require a partition across the valve body to support the seat opening, which is the throttling orifice. With the valve closed, loading on the body is difficult to determine. The valve end connections also distort loads on a simple sphere and more complicated shapes. Ease of manufacture, assembly, and costs are additional important considerations. Hence, the basic form of a valve body typically is not spherical, but ranges from simple block shapes to highly complex shapes in which the bonnet, a removable piece to make assembly possible, forms part of the pressure-resisting body.

Narrowing of the fluid passage (venturi effect) is also a common method for reducing the overall size and cost of a valve. In other instances, large ends are added to the valve for connection into a larger line.

Valve Bonnet

The cover for the opening in the valve body is the bonnet. In some designs, the body itself is split into two sections that bolt together. Like valve bodies, bonnets vary in design. Some bonnets function simply as valve covers, while others support valve internals and accessories such as the stem, disk, and actuator.

The bonnet is the second principal pressure boundary of a valve. It is cast or forged of the same material as the body and is connected to the body by a threaded, bolted, or welded joint. In all cases, the attachment of the bonnet to the body is considered a pressure boundary. This means that the weld joint or bolts that connect the bonnet to the body are pressure-retaining parts.

Valve bonnets, although a necessity for most valves, represent a cause for concern. Bonnets can Complicate the manufacture of valves, increase valve size, and represent a significant cost portion of valve cost, and are a source for potential leakage.

Valve Trim

The internal elements of a valve are collectively referred to as a valve’strim. The trim typically includes a disk, seat, stem, and sleeves needed to guide the stem. A valve’s performance is determined by the disk and seat interface and the relation of the disk position to the seat.

Because of the trim, basic motions and flow control are possible. In rotational motion trim designs, the disk slides closely past the seat to produce a change in flow opening. In linear motion trim designs, the disk lifts perpendicularly away from the seat so that an annular orifice appears.

Disk and Seat

For a valve having a bonnet, the disk is the third primary principal pressure boundary. The disk provides the capability for permitting and prohibiting fluid flow. With the disk closed, full system pressure is applied across the disk if the outlet side is depressurized. For this reason, the disk is a pressure-retaining part. Disks are typically forged and, in some designs, hard-surfaced to provide good wear characteristics. A fine surface finish of the seating area of a disk is necessary for good sealing when the valve is closed. Most valves are named, in part, according to the design of their disks.

The seat or seal rings provide the seating surface for the disk. In some designs, the body is machined to serve as the seating surface and seal rings are not used. In other designs, forged seal rings are threaded or welded to the body to provide the seating surface. To improve the wear-resistance of the seal rings, the surface is often hard-faced by welding and then machining the contact surface of the seal ring. A fine surface finish of the Seating area is necessary for good sealing when the valve is closed. Seal rings are not usually considered pressure boundary parts because the body has sufficient wall thickness to withstand design pressure without relying upon the thickness of the seal rings.

Stem

The stem, which connects the actuator and disk, is responsible for positioning the disk. Stems are typically forged and connected to the disk by threaded or welded joints. For valve designs requiring stem packing or sealing to prevent leakage, a fine surface finish of the stem in the area of the seal is necessary. Typically, a stem is not considered a pressure boundary part.

Connection of the disk to the stem can allow some rocking or rotation to ease the positioning of the disk on the seat. Alternately, the stem may be flexible enough to let the disk position itself against the seat. However, constant fluttering or rotation of a flexible or loosely connected disk can destroy the disk or its connection to the stem.

Two types of valve stems are rising stems and nonrising stems. Illustrated in Figures 2 and 3, these two types of stems are easily distinguished by observation. For a rising stem valve, the stem will rise above the actuator as the valve is opened. This occurs because the stem is threaded and mated with the bushing threads of a yoke that is an integral part of, or is mounted to, the bonnet.

There is no upward stem movement from outside the valve for a non rising stem design. For the non rising stem design, the valve disk is threaded internally and mates with the stem threads.

Valve Actuator

The actuator operates the stem and disk assembly. An actuator may be a manually operated hand wheel, manual lever, motor operator, solenoid operator, pneumatic operator, or hydraulic ram. In some designs, the actuator is supported by the bonnet. In other designs, a yoke mounted to the bonnet supports the actuator.

Except for certain hydraulically controlled valves, actuators are outside of the pressure boundary.Yokes, when used, are always outside of the pressure boundary.

Valve Packing

Most valves use some form of packing to prevent leakage from the space between the stem and the bonnet. Packing is commonly a fibrous material (such as flax) or another compound (such as teflon) that forms a seal between the internal parts of a valve and the outside where the stem extends through the body.

Valve packing must be properly compressed to prevent fluid loss and damage to the valve’s stem. If a valve’s packing is too loose, the valve will leak, which is a safety hazard. If the packing is too tight, it will impair the movement and possibly damage the stem.

Introduction to the Types of Valves

Because of the diversity of the types of systems, fluids, and environments in which valves must operate, a vast array of valve types have been developed. Examples of the common types are the globe valve, gate valve, ball valve, plug valve, butterfly valve, diaphragm valve, check valve, pinch valve, and safety valve. Each type of valve has been designed to meet specific needs.

Some valves are capable of throttling flow, other valve types can only stop flow, others work well in corrosive systems, and others handle high pressure fluids. Each valve type has certain inherent advantages and disadvantages. Understanding these differences and how they effect the Valve’s application or operation is necessary for the successful operation of a facility.

1) Move a disc, or plug into or against an orifice (for example, globe or needle type valve).

2) Slide a flat, cylindrical, or spherical surface across an orifice (for example, gate and plug valves).

3) Rotate a disc or ellipse about a shaft extending across the diameter of an orifice (for example, a butterfly or ball valve).

4) Move a flexible material into the flow passage (for example, diaphragm and pinch valves).

Each method of controlling flow has a characteristic that makes it the best choice for a given application of function.

Types of valves

Gate valves are generally used in systems where low flow resistance for a fully open valve is desired and there is no need to throttle the flow.

Globe valves are used in systems where good throttling characteristics and low seat leakage are desired and a relatively high head loss in an open valve is acceptable.

Ball valves allow quick, quarter turn on-off operation and have poor throttling characteristics.

Plug valves are often used to direct flow between several different ports through use of a single valve.

Diaphragm valves and pinch valves are used in systems where it is desirable for the entire operating mechanism to be completely isolated from the fluid.

Butterfly valves provide significant advantages over other valve designs in weight,space, and cost for large valve applications.

Check valves automatically open to allow flow in one direction and seat to prevent flow in the reverse direction.

A stop check valve is a combination of a lift check valve and a globe valve and incorporates the characteristics of both

Safety/relief valves are used to provide automatic over pressurization protection for a system.

What is a Shutdown Valve ?

A shutdown valve (also referred to as SDV or Emergency Shutdown Valve, ESV, ESD, or ESDV) is an actuated valve designed to stop the flow of a hazardous fluid upon the detection of a dangerous event.

Types of valve

For air intake shut down, two distinct types are commonly utilized, i.e. butterfly valves and swing gate or guillotine valves. Because diesel engines ignite fuel using compression instead of an electronic ignition, shutting off the fuel source to a diesel engine will not necessarily stop the engine from running. When an external hydrocarbon, such as methane gas, is present in the atmosphere, it can be sucked into a diesel engine causing overspeed or over revving, potentially leading to a catastrophic failure and explosion. When actuated, ESD valves stop the flow of air and prevent these failures.

Types of Actuation

As shutdown valves form part of a SIS. It is necessary to operate the valve by means of an actuator.

These actuators are normally fail safe fluid power type.

Typical examples of these are:

Pneumatic cylinder

Hydraulic cylinder

Electro-hydraulic actuator

In addition to the fluid type, actuators also vary in the manner in which the energy is stored to operate the valve on demand as follows:

Single acting cylinder – Or spring return where the energy is stored by means of a compressed spring

Double acting cylinder – Energy is stored using a volume of compressed fluid

Measuring Performance

For shutdown valves used in safety instrumented systems it is essential to know that the valve is capable of providing the required level of safety performance and that the valve will operate on demand. The required level of performance is dictated by the Safety Integrity Level (SIL). In order to adhere to this level of performance it is necessary to test the valve. There are 2 types of testing methods available being

Proof test – A manual test that allows the operator to determine whether the valve is in the “as good as new” condition by testing for all possible failure modes and requires a plant shutdown

Basics of Flow measurement

Flow measurement has a history of about 3000 years. It has been studied only in the last 200 years and in the last 30 years all the new techniques have evolved. There is now a wide variety of methods available to measure the flow of liquids, solids, gases and vapours.

There are three different flow quantities to be measured :-

The actual velocity of the fluid at a given point (measured in metres per second).

The volume rate of flow (measured in metres cubed per minute).

The mass flow rate (measured in kilograms per second).

It is also possible to measure total flow which is the total volume or mass which has flowed in a set time period.

Fluid flow metering systems provide vital information for the following purpose :-

Production Planning ;- the quantities of product supplied to customers generally vary according to seasonal demand. Usually an average rate of production is planned on a calendar day which takes into account any periods of shutdown necessary for maintenance and inspection.

Product Quality ;- flow controllers are necessary in the proportional blending of intermediate products to produce on-specification finished products of consistent quality.

Control of Process ;- sometimes flow meters are used for control of some other main process variables. Examples in Separator column, liquid levels are kept constant by varying the flow rate of the process in columns are also kept constant by varying the flow rate of the process fluid passing through them. Pressure in column are also kept constant by varying the flow rate of the cooling medium .

What is Flow?

Flow is defined as fluid (liquids or/and gases) in motion.

Factors Affecting Flow Rates in pipes :

The major factors affecting the flow of fluids through pipes are:

the velocity of the fluid.

the friction of the fluid in contact with the pipe.

the viscosity of the fluid.

the density of the fluid.

Fluid velocity depends on the head pressure which is forcing the fluid through the pipe. The greater the head pressure, the faster the fluid flow rate (all other factors remaining constant), and consequently, the greater the volume of flow. Pipe size also affects the flow rate. For example, doubling the diameter of a pipe increases the potential flow rate by a factor of four times.

Pipe friction reduces the flow rate of fluids through pipes and is, therefore, considered a negative factor. Because of the friction of a fluid in contact with a pipe, the flow rate of the fluid is slower near the walls of the pipe than at the center. The smoother, cleaner, and larger a pipe is, the less effect pipe friction has on the overall fluid flow rate.

Viscosity (η), or the molecular friction within a fluid, negatively affects the flow rate of fluids. Viscosity and pipe friction decrease the flow rate of a fluid near the walls of a pipe. Viscosity increases or decreases with changing temperature, but not always as might be expected. In liquids, viscosity typically decreases with increasing temperature. However, in some fluids viscosity can begin to increase above certain temperatures. Generally, the higher a fluid’s viscosity, the lower the fluid flow rate (other factors remaining constant). Viscosity is measured in units of centipoise. Another type of viscosity, called kinematic viscosity, is measured in units of centistokes. It is obtained by dividing centipoise by the fluid’s specific gravity.

Density (ρ) of a fluid affects flow rates in that a more dense fluid requires more head pressure to maintain a desired flow rate. Also, the fact that gases are compressible, whereas liquids essentially are not, often requires that different methods be used for measuring the flow rates of liquids, gases, or liquids with gases in them. It has been found that the most important flow factors can be correlated together into a dimensionless parameter called the Reynolds Number.

Brief Introduction to Types of valves

Ball Valve

Ball valve is a quarter turn operated valve. The closure member is a spherical plug with a through hole. When the valve is in open state, the through hole is in-line with the fluid flow and hence, the fluid passes through it. The valve is closed by rotating the globe by 90 Deg. such that the hole now becomes perpendicular to the flow and hence, stops the flow

The seat is usually circumferential, made up of soft materials to offer a tight shutoff. The seat can be made either out of plastic or metals. Ball valves are not recommended to be used in a partially open condition. Due to misalignment between the flow direction and opening of the plug, large pressure drop takes place in partially open condition.

Due to above specified challenges, ball valves are mostly used in shutoff applications. Ball valves are commonly used in steam, water, oil, gas, air, corrosive fluids. They can handle slurries and dusty dry fluids. Ball valves are not used with abrasive and fibrous materials as it poses risk of damage to the seat and plug surface.

Gate Valve

Gate valve is a sliding type of valve. In gate valves, the closing member is a metal gate. The gate slides down to close the valve. In fully open conditions, the flow area is equal to the area of the pipe and hence, there is negligible pressure drop across the valve.

Gate valve should ideally be used as on-off valve. It is not advisable to use them as throttling valves because in partly open conditions, erosion of gate might take place. In partially open consitions, due to vibrations, valve is exposed to quick wear and tear. Also, during closing and opennig, there is considerable amount of friction and hence, opening and closing these vales quickly and frequently is not possible.

These valves find their use in petrochemical industry due to the fact that they can work with metal-metal sealing.

Plug Valve

Similar to ball valves, plug valves are also quarter turn type of valves. This valve consists of a plug which can be either cylindrical or conical in shape. The plug has a through slit which remains in-line with the flow in the open condition. When the plug is turned by 90 Deg., this slit becomes perpendicular to flow and the valve gets closed.

Plug valves are well suited to handle fluids with suspended solids, slurries etc.

Plug valves are primarily used for on-off applications. When used for throttling purpose, the pressure drop through the valve is higher because of misalignment between flow direction and the direction of the opening (slit).

Butterfly Valve

Butterfly valves are most simple yet versatile valves. They are quarter turn operated valves which are commonly used in multiple industries for varied applications. Quarter turn operation ensures quick operating of the valve. In the open condition there is minimum obstruction to the fluid flow through the valve as the flow passes around the disc aerodynamically. This results in very less pressure drop through the valve.

Due to its unique mode of operation, the valve can be actuated easily without requiring high torques and wear and tear. Due to lack of friction, use of bulky actuators can be avoided. Another advantage offered by butterfly valve is their compact size. The valve is quite compact, resembling a metal disc. This makes their installation very easy. They can be used to handle slurries and fluids with suspended solids as there are no cavities for deposition of solid particles inside the valve body.

Globe Valve

Globe valve is a linear motion type of valves and is typically used in both on-off and throttling applications. In globe valves, the flow of the fluid through valve follows an S-path. Due to this, the flow direction changes twice which results in higher pressure drops. Due to other advantages offered by them, they are widely used in applications where pressure drop through the valve is not a controlling factor.

These valves are generally not used beyond sizes larger than NPS 12 (DN 300) as enormous forces are exerted on the stem to open or close the valve under fluid pressures. Globe valves require high pressures on the seat to keep it closed when the fluid exerts pressure from the bottom of the disc.

They are used for both on-off and throttling applications but special types of trims are required for throttling applications where large pressure drops are involved. These valves can be used in three configurations, depending upon the applications-

a. Tee pattern

b. Angle Pattern

c. Wye Pattern

When the disc is removed from the stem and allowed to rest on its own weight, globe valves can be used as non-return valves. Machining of seats is easier and cheaper compared to other types of valves.

Pinch Valve

Pinch valves consist of a plastic tube/sleeve which is made up of reinforced elastomers. The sealing/ closing action is achieved by throttling or pinching this sleeve/tube. Pinch valves are best suited for handling slurries and fluids having suspended solids.

Pinch valves offer many benefits over the other types of valves. They can be used for handling corrosive fluids as there is no contact between the fluid carried and the actual valve mechanism. Once suitable sleeve material is selected, this valve can work with a variety of fluids. As fluid being carried does not come in contact with the metal parts, these valves can be used for food grade applications also.

Generally, pinch valves are suitable for low pressure applications. When used with abrasive slurries, they should be used as on-off valves; if used for throttling purposes, the sleeve will get worn out.

Disc Check Valves

Disc check valves, also called as non-return valves allow the flow to pass through them in only one direction and stop the flow in reverse direction. Because of this unique directional property, disc check valves are essentially used for some critical applications in the steam systems.

There are four major types of disc check valves as follows-

1. Lift Check Valve- Lift check valves work simply on the principle of gravity. When the fluid comes in the forward direction, the disc gets lifted from the seat against the gravitational force by the force of incoming fluid. The valve thus allows fluid to pass in this direction. When the fluid comes in opposite direction, it supports the force of gravity and the disc remains on the seat, keeping the valve closed.

Tight shutoff can be difficult to achieve in case back pressures are low. The valve will leak the fluid in such situations.

2. Swing Check Valve- In this kind of check valve, the disc or the closing element swings around a point to which it is hinged. When the fluid comes in the forward direction, the disc swings in an open position allowing the fluid to pass. When the fluid flow comes in the opposite direction, the disc swings and rests on the seat to lose it.

3. Spring loaded Check Valves- In this kind of check valves, tight shut-off it provided using a spring. The spring holds back the disc on the seat. Even in the forward flow condition, the fluid should exert some pressure, called cracking pressure in order to open the disc against the spring pressure.

4. Diaphragm Type Check Valve- This kind of check valves uses diaphragms arranged in such a way that that open to allow the flow only in forward direction. When flow comes from the reverse direction, the diaphragms remain closed.

Typical applications in a steam system-

1. After a float trap- Steam traps are passive device and work on the principle of the pressure difference. During operation, process pressure might go under the back pressure after trap. In such situations, because of the negative pressure across trap, condensate might go back into the process equipment through the trap. Hence, it is always advisable to fix a disc check or non-return valve after the float trap. This check valve will allow the condensate to flow from the trap outlet to the condensate recovery system but will ensure that it does not flow in reverse direction.

2. Mixing applications- Applications where two or more fluid are mixed, check valves should be installed at the end of each individual line. This avoids the contamination of one fluid by the other.

3. Disc check valves as vacuum breakers- Disc check valves, when fitted in a reverse way, can act as vacuum breakers. While being used as vacuum breakers.

Under normal operating conditions, the valve will remain closed not allowing the steam to pass through it. When the vacuum formation takes place (during shutoff) the disc will open and will allow the air to come in thus avoiding the formation of vacuum.

Temperature Sensor calibration procedure at Instronline Instrumentation

Most instrument manuals state there is no calibration of the temperature sensor, but the temperature sensor must be checked to determine its accuracy. This accuracy check is performed at least once per year and the accuracy check date/information is kept with the instrument.

If the accuracy check date/information is not included with the instrument or the last check was over a year, the temperature sensor accuracy needs to be checked at the beginning of the sampling event. If the instrument contains multiple temperature sensors, each sensor must be checked.

This procedure is not normally perform in the field. If the instrument is obtained from a rental company, the rental company should performed the calibration check and include with the instrument documentation that it was performed.

Calibration Procedure:

1. Fill a container with water and adjust the water temperature to below the water body’s temperature to be measured. Use ice or warm water to adjust the temperature.

2. Place a thermometer that is traceable to the National Institute of Standards and Technology (NIST) and the instrument’s temperature sensor into the water. Wait for both temperature readings to stabilize.

3. Compare the two measurements. The instrument’s temperature sensor must agree with the reference thermometer measurement within the accuracy of the sensor (e.g.,±O.2°C). If the measurements do not agree, the instrument may not be working properly and the manufacturer needs to be consulted.

4. Adjust the water temperature to a temperature higher than the water body to be measured.

5. Compare the two measurements. The instrument’s temperature sensor must agree with the reference thermometer measurement within the accuracy of the sensor (e.g.,± 0.20 C). If the measurements do not agree, the instrument may not be working properly and the manufacturer needs to be consulted.

Turbidity Sensor Calibration Procedure at Instronline

The turbidity method is based upon a comparison of intensity of light scattered by a sample under defined conditions with the intensity of light scattered by a standard reference suspension. A turbidimeter is a nephelometer with a visible light source for illuminating the sample and one or more photo-electric detectors placed ninety degrees to the path of the light source. Note: the below calibration procedure is for a turbidimeter which the sample is placed into a cuvette.

Some instruments will only accept one standard. For those instruments, the second, third, etc., standards will serve as check points.

Calibration Procedure:

1. Allow the calibration standards to equilibrate at the ambient temperature. The use of commercially available polymer primary standards (AMCO-AEPA-l) is preferred; however, the standards can be prepared using Formazin (read the warning on the label before use) according to the EPA analytical Method 180.1. Other standards may be used if they can be shown that they are equivalent to the previously mentioned standards.

2. If the standard cuvette is not sealed, rinse a cuvette with deionized water. Shake the cuvette to remove as much water as possible. Do not wipe dry the inside of the cuvette because lint from the wipe may remain in the cuvette. Add the standard to the cuvette.

3. Before performing the calibration procedure, make sure the cuvettes are not scratched and the outside surfaces are dry and free from fingerprints and dust. If the cuvette is scratched or dirty, discard or clean the cuvette respectively. Note: some . manufacturers require the cuvette to be orientated in the instrument in a particular direction for accurate reading.

4. Select a low value standard such as a zero or 0.02 NTU and calibrate according to manufacturer’s instructions. Note: a zero standard (approximately 0 NTU) can be prepared by passing distilled water through a 0.45 micron pore size membrane filter.

5. Select a high standard and calibrate according to manufacturer’s instructions or verify the calibration if instrument will not accept a second standard. In verifying, the instrument should read the standard value to within the specifications of the instrument. If the instrument has range of scales, check each range that will be used during the sampling event with a standard that falls within that range.

6. Record the calibration information on calibration log sheet.

Basics of Pressure Measurement At Instronline Instrumentation

A major portion of all industrial measurement relates in some way to pressure in its several forms. Flow, for example, is often measured by determining the pressure that exists at two different points in a system. In a Bourdon system, pressure changes are used to produce the mechanical motion of a recording stylus.

Pressure can also be used to measure temperature in a filled system through changes produces by an expansion of the liquid or fluid in the filled system.

Pressure measurement is made more than any measurement in the process industries. It is the best quick indication of the work done by pumps and compressors. It is also the most important measure of the status of operating pressure vessels.

What is Pressure ?

For the pressure in a container, it is a measure of force exerted by a fluid due to its molecular activities. This is a derivation from the concept above combined with the Kinetic Theory of Matters.

Types of Pressure Exerted by Fluids

Pressure Produced by Liquids

All fluids (liquids and gases) have weight, thus they exert a pressure against the wall of their containers. The pressure exerted by a liquid at any given point or location in the vessel depends upon the height of liquid above it. This pressure is independent of the shape of the vessel.

Pressure Produced by Density

Density is the weight of one cubic meter of material. Different liquids weight different amounts for the same volume and therefore would create different pressures. Since we know that, pressure is equal to force (or weight) over a unit area, and in any fixed volume of column, the weight of liquid contained varies with density; therefore density change will change the pressure of the container.

Pressure Produced by Gases

To study some of the principles governing the behaviour of gases, we will use air as common gas known. Since air does have weight, it builds up static pressure, much the same as liquids do. One cubic foot of air weighs about 0.08 lbs. A room 10 feet wide, 20 feel long and 8 feet high has 1600 cubic feet of air in it weighing about 128 lbs. The deep layer of air which blankets the earth exerts a pressure much like the water pressure at the bottom of the ocean. This pressure is known as atmospheric pressure and is about 14.7 psi at sea level.

Pressure Resulting From External Load

The final or total pressure exerted at any given point in a vessel, pump, line, etc. will depend upon the head, or weight of liquid being handled plus any external pressure being exerted on the liquid being handled. Figure below shows the effect of the external pressure.

Vessel filled with water to a height 20 feet and is open to atmosphere. Pressure at the bottom would be 20 × 0.433, or 8.66 psi. If we close the vessel and add compressed gas of 200 psi on the top of the vessel, we would find that pressure of the bottom would be (200 + 8.66) psi, or 208.66 psi.

Glossary of Pressure

Two reference points for pressure measurement exists. The most logical one is absolute zero – a condition existing only in a perfect vacuum. Pressures measured from this reference point are called absolute pressure.

The other reference point used is atmospheric pressure. The difficulty with this reference point is that it changes with altitude (reference with sea level) and to some extent with weather conditions. At or near sea level, this pressure is about 14.7 psia or 29.9 inches or 760 mmHga.

Absolute Pressure, Pabs

Absolute pressure is the pressure measured with respect to zero pressure (vacuum).

Gauge Pressure, Pgauge

Gauge pressure (or sometimes called Internal pressure) is the pressure measured by a gauge in access of the pressure of the atmosphere. A pressure gauge indicates the difference between pressure on a system or vessel and the local atmospheric pressure. However, be careful ! when reading a pressure gauge; determine whether it is reading absolute pressure or gauge pressure, normally indicated by “a” or “g”, e.g. psia or barg.

Atmospheric Pressure, Patm

Atmospheric pressure is the pressure measure on the surface in the atmosphere. However, the difficulty is that it changes with altitude and humidity. Thus, atmospheric pressure may differ from one area or place to another.

Differential Pressure (DP)

Differential pressure is the pressure difference, measured between two different pressure points, within the same pressure reference point., e.g. between unknown pressure and a local atmospheric pressure.

Head Pressure

Head pressure is the pressure exerted by a liquid that indicated by height of the liquid in a liquid column.

It depends on;

1. the height of the liquid column.

2. the relative density of the liquid.

Pressure head = R.D x h x 9.8 kPa

where, R.D = relative density of the liquid, h = the height of the liquid g = gravitational force

Note: Relative density is the density of a liquid relative to the referral standard density (water = 1000 kgm-3)

Vacuum

Pressure less than atmospheric pressure is called vacuum. A vacuum is a lack of air fluid. The vacuum scale extend between the absolute zero reference point and atmospheric pressure, thus it is not a positive pressure. It is treated as a sucking force or negative pressure.

Pressure Conversions between Units

Methods of Pressure Measurement

There are 3 basic methods for pressure measurement;

I. The first method involves balancing the unknown pressure against the pressure produced by a column of liquid of known density.

II. The second method involves allowing the unknown pressure to act on a known area and measuring the resultant force either directly or indirectly.

III. The third method involves allowing the unknown pressure to act on an elastic material and measuring the resultant stress or strain.

What is a Thermal flow meter ?

Wind chill is a phenomenon common to anyone who has ever lived in a cold environment. When the ambient air temperature is substantially colder than the temperature of your body, heat will transfer from your body to the surrounding air. If there is no breeze to move air past your body, the air molecules immediately surrounding your body will begin to warm up as they absorb heat from your body, which will then decrease the rate of heat loss. However, if there is even a slight breeze of air moving past your body, your body will come into contact with more cool (unheated) air molecules than it would otherwise, causing a greater rate of heat loss. Thus, your perception of the surrounding temperature will be cooler than if there were no breeze.

The simplest form of thermal mass flowmeter is the hot-wire anemometer, used to measure air speed. This flowmeter consists of a metal wire through which an electric current passes to heat it up. An electric circuit monitors the resistance of this wire (which is directly proportional to wire temperature because most metals have a definite temperature coefficient of resistance). If air speed past the wire increases, more heat will be drawn away from the wire and cause its temperature to drop. The circuit senses this temperature change and compensates by increasing current through the wire to bring its temperature back up to setpoint. The amount of electrical power required to maintain the hot wire at a constant elevated temperature is a direct function of mass air flow rate past the wire.

Most mass air flow sensors used in automotive engine control applications employ this principle. It is important for engine control computers to measure mass air flow and not just volumetric air flow because it is important to maintain proper air/fuel ratio even if the air density changes due to changes in altitude. In other words, the computer needs to know how many air molecules are entering the engine per second in order to properly meter the correct amount of fuel into the engine for complete and efficient combustion. The “hot wire” mass air flow sensor is simple and inexpensive to produce in quantity, which is why it finds common use in automotive applications.

Thermal mass flowmeters lend themselves well to “insertion” style probes, sensing the passage of fluid molecules at one point within the flowstream. An example is shown in the next two photographs, where a thermal mass flowmeter (manufactured by Sage) senses the amount of gas sent to a flare. The insertion probe appears in the left-hand photo (mounted in the vertical flare pipe) while the transmitter head appears in the right-hand photo (located inside of a weather-sheltered building):

The simple construction of thermal mass flowmeters allows them to be manufactured in very small sizes. The following photograph shows a small device that is not only a mass flow meter, but also a mass flow controller with its own built-in throttling valve mechanism and control electronics. To give you a sense of scale, the tube fittings seen on the left- and right-hand sides of this device are 1/4 inch, making this photograph nearly full-size:

An important factor in the calibration of a thermal mass flowmeter is the specific heat of the process fluid. “Specific heat” is a measure of the amount of heat energy needed to change the temperature of a standard quantity of substance by some specified amount. Some substances have much greater specific heat values than others, meaning those substances have the ability to absorb (or release) a lot of heat energy without experiencing a great temperature change.

Fluids with high specific heat values make good coolants, because they are able to remove much heat energy from hot objects without experiencing great increases in temperature themselves. Since thermal mass flowmeters work on the principle of convective cooling, this means a fluid having a high specific heat value will elicit a greater response from a thermal mass flowmeter than the exact same mass flow rate of a fluid having a lesser specific heat value (i.e. a fluid that is not as good of a coolant).

This means we must know the specific heat value of whatever fluid we plan to measure with a thermal mass flowmeter, and we must be assured its specific heat value will remain constant. For this reason, thermal mass flowmeters are not suitable for measuring the flow rates of fluid streams whose chemical composition is likely to change over time. This limitation is analogous to that of a pressure sensor used to hydrostatically measure the level of liquid in a vessel: in order for this level-measurement technique to be accurate, we must know the density of the liquid and also be assured that density will be constant over time.

Thermal mass flowmeters are simple and reliable instruments. While not as accurate or tolerant of piping disturbances as Coriolis mass flowmeters, they are far less expensive.

Perhaps the greatest disadvantage of thermal mass flowmeters is their sensitivity to changes in the specific heat of the process fluid. This makes the calibration of any thermal mass flowmeter specific for one composition of fluid only. In some applications such as automotive engine intake air flow, where the fluid composition is constant, this limitation is not a factor. In many industrial applications, however, this limitation is severe enough to prohibit the use of thermal mass flowmeters. Industrial applications for thermal mass flowmeters include natural gas flow measurement (non-custody transfer), and the measurement of purified gas flows (oxygen, hydrogen, nitrogen) where the composition is known to be very stable.

Another (potential) limitation of thermal mass flowmeters is the sensitivity of some designs to changes in flow regime. Since the measurement principle is based on heat transfer by fluid convection, any factor influencing the convective heat-transfer efficiency will translate into a perceived difference in mass flow rate. It is a well-known fact in fluid mechanics that turbulent flows are more efficient at convecting heat than laminar flows, because the “stratified” nature of a laminar flowstream impedes heat transfer across the fluid width.

In some thermal flowmeter designs, the walls of a heated metal tube serve as the “hot” element cooled by the fluid, and the difference between the rate of heat transferred by a laminar flowstream from the walls of a heated tube versus a turbulent flowstream can be great. Therefore, a change in flow regime (from turbulent to laminar, and vice-versa) will cause a calibration shift for this design of thermal mass flowmeter.

Differential Pressure Sensors Calibration Procedure

Differential pressure sensors are common in the process industry and cover a variety of applications. To understand what a differential pressure sensor is, it becomes important to put it in contrast to other pressure measurement types. The most common types of pressure measurement are absolute, gauge and differential.

Gauge Pressure: Gauge pressure is the pressure difference in reference to barometric (or atmospheric) pressure as showing in figure 1. This is the most common pressure measurement type in industry today.

Absolute Pressure: Absolute pressure is when zero pressure is referenced to absolute vacuum as shown in figure 1. This is done by pulling a very hard vacuum, achieving as close to absolute zero as possible, and then referencing the zero of the sensor to that vacuum point. Often absolute sensors utilize a gauge sensor and a barometric sensor and calculate the absolute pressure by subtracting the barometric pressure from the gauge pressure.

Differential Pressure: Differential pressure (DP) can be independent of the atmospheric and absolute pressures. It is the pressure difference between two applied pressures and as shown in figure 1. These sensors are very useful in determining the pressure difference between two places or systems and are often used in flow calculation, filtering, fluid level, density, and viscosity.

So now that we’ve reviewed the different pressure types and we know what differential pressure is and how it compares to other pressure measurement types. Now, we can consider how we calibrate a DP sensor and some of the challenges associated with calibration of DP sensors. First, let’s start with the challenges.

Common Challenges in Calibrating DP Sensors

Producing a stable, controlled pressure – to have a meaningful measurement for calibration we must be able to have stable pressure generation from a pressure source, such as a pump or a controller. DP sensors can be very sensitive, so a solution that will produce and hold a stable pressure is very important. Also, the pump or controller needs to have sufficient resolution to be able to exactly generate the desired pressure points. Producing a stable, controlled pressure with high resolution is often a challenge because many pump solutions rely on check valves, or non-returning valves, within the pump as shown in Figure 2 : DP gauge and pump stability. These check valves are prone to leaks over time and use and are often the source of frustration when trying to hold highly stable pressures for a DP sensors calibration.

Temperature effects – Possibly the largest challenge to calibrating DP sensors has to do with the impact of the environmental temperature on the DP sensor and the calibration standards. Because many DP sensors are measuring very low full scale (FS) pressures, a small change in temperature can amount to a very noticeable change in pressure. This change in temperature often equates to constant instability in both the sensor being tested and the calibration standard (both reference gauge and pump).

Changing atmospheric pressure – Several DP sensor manufacturers recommend the calibration be performed with the reference port (or low port) be open to atmosphere. The challenge with this requirement is that throughout a calibration, the atmospheric pressure is constantly changing which influences the stability and repeatability of the calibration results.

Methods of Calibration

Example 1 – Using an pressure pump, DP reference gauge with the DUT’s reference port open to atmosphere

Required Equipment:

 Low pressure calibration pump

 Device under test

 Reference DP Gauge

 Lines and fittings to connect from the gauges to the pump

Connection

 Both the high ports of each gauge are connected into the calibration pump

 The reference or low ports of each gauge are left open to atmosphere

 Ensure the DUT is in the proper orientation (typically vertical or horizontal)

Procedure

 Depending on the DUT, you may need to exercise the gauge multiple times to its full scale.

 Ensure the vent valve is open and zero both the reference gauge and the DUT (assuming the DUT is a digital gauge that requires regular zeroing).

 Close the vent valve and proceed to the next calibration points and record the data when the measurement is stable.

 Increase the Pressure by using pump and note down the readings in DUT & Reference gauge.

 Typically, 3-5 calibration points are taken both upward then downward so as to determine hysteresis.

Pros: This method is inexpensive and the set up is easy.

Cons: You’ll need to account for barometric pressure and temperature changes throughout the test. Depending on the environmental conditions this can produce very unstable measurements. This is the least accurate method for calibration of DP sensors.

Example 2 – Using an Low pressure calibration pump, DP reference gauge with the DUT’s reference ports connected together

Required Equipment:

 Low pressure calibration pump

 Device under test

 Reference DP Gauge

 Lines and fittings to connect from the gauges to the pump and the gauges together

Connection

 Both high ports of each gauge are connected into the calibration pump.

 The reference or low ports of each gauge are connected together.

 Ensure the DUT is in the proper orientation (typically vertical or horizontal).

Note: In this method pressure is generated on both the high and low pressure lines and the DP is measured by the reference gauge. Depending on the DP range required the best solution to reach the full scale of the DUT.

Differential Pressure Sensor Calibration

Procedure

 Depending on the DUT, you may need to exercise the gauge multiple times to its full scale

 Recording the zero point may vary depending on the type of DUT. If the DUT is a digital gauge, then keep the reference gauge and the DUT reference ports connected together and zero both gauges. If the DUT is an analog gauge that doesn’t require a regular zero, then disconnect both reference ports and leave them open to atmosphere to zero the gauges. After recording the zero point connect both the reference ports together and proceed through the calibration.

 Close the vent valve and proceed to the next calibration points and record the data when the measurement is stable.

 Increase the Pressure by using pump and note down the readings in DUT & Reference gauge.

 Typically, 3-5 calibration points are taken both upward then downward so as to determine hysteresis

Pros: This method is inexpensive and better accounts for atmospheric pressure changes throughout the test. The stability at each point is improved from the first example.

Cons: The set up is more complicated than the first example and temperature effects can potentially have a larger impact than the first example because we have a sealed system with the low (reference) lines being connected.

Example 3 – Using the automated calibration Equipment

Required Equipment:

 Automatic Calibrator

 Device under test

 Lines and fittings to connect the DP gauge to the Calibrator

Connection

 Connect the high port of the DP gauge to the OUTLET port of the Automatic Calibrator Equipment

 Connect the low port of the DP gauge to the REF port of the Automatic Calibrator Equipment.

 Ensure the DUT is in the proper orientation (typically vertical or horizontal).

Calibrator with DUT

Procedure

 Depending on the DUT, you may need to exercise the gauge multiple times to its full scale.

 Program in a task and run an automated test which will automatically generate the pressure, stabilize the measurement, and allow for the DP gauge reading to be recorded.

 Typically, 3-5 calibration points are taken both upward then downward and the Calibrator will automatically calculate the hysteresis and display the test results with pass/fail criteria.

Pros: This method is fully- or semi-automated depending on the DUT. Measurements are controlled and stability is ensured by the Calibrator controller. The Calibrator is much less influenced by changes in temperature and barometric pressure than the previous examples. Results are automatically displayed and calculated. The Calibrator can calibrate pressure gauges and transmitters.

Ultrasonic Level Transmitter Principle, Limitations, Calibration and configuration At Instronline Instrumentation

Measurement principle

Continuous non‐contacting ultrasonic level measurement is based on the time of flight principle.

An ultrasonic level instrument measures the time between sound energy transmitter from the sensor, to the surface of the measured material and the echo returning to the sensor.

As the speed of sound is known through the travel medium at a measured temperature, the distance to the surface is calculated. Level can be calculated from this distance measurement.

Echo Processing built in to the instrument can allow the instrument to determine the material level of liquids, solids or slurries even in narrow, obstructed or agitated vessels.

Limitations

Maximum measurement distance should be checked against the technology (above 30 m the reflectivity may be reduced and might cause a measurement error/problem).

Ultrasonic sensors have, as physical limitation, a blocking distance (close to the sensor) where they cannot measure reliably, e.g. 0.25 metres.

Vessel pressure limitation should approximately be, e.g. 0.5 bar or less. Higher pressure may introduce uncertainty in the level measurement.

Vapour, vacuum or temperature gradients can influence the speed of sound and consequently can cause incorrect measurements.

Presence of foam or heavy turbulence on the surface of the measured material can cause unreliable measurement.

Selection

Design

When possible, a flat target plate that is parallel to the sensor face and directly below the sensor mounting position should be added to the bottom of the vessel for best empty tank performance.

The maximum level (distance F/full span) should be configured. This distance F should take into account both BD ‘blocking distance’ and SD ‘safety distances’.

Where BD represents a dead zone in which the wave cannot make any measurement and SD corresponds to a warning or an alarm zone.

Working Principle Of Ultrasonic Level Switch

An ultrasonic switch is a device that uses inaudible high-frequency sound (ultrasound) to detect the presence or absence of a liquid at a designated point. The device consists of an electronic control unit and a sensor. Ultrasonic level switches use the properties of sound transmission in vapor and liquids to detect liquid level. When sound travels in air, it loses a great deal of signal strength. When traveling in liquid, sound retains almost all of its signal strength.

To detect liquid level, we must determine if there is a liquid or gas (air) in the gap. Since liquids have a higher density than gasses, it is easier to transmit sound through them. One side of the sensor gap transmits sound, the other side detects it. When liquid is present, a high amount of sound is received at the detection side. When gas (air) is present, a small amount of sound is received. The electronics detect this difference and switch a relay accordingly.

Ultrasonic switch sensors contain two piezoelectric crystals, one transmits sound and one receives sound. Each crystal is mounted on one side of a gap in the metal sensor. The transmit crystal generates high frequency sound (1MHz to 3 MHz) that is directed across the gap to the receiver crystal. The receiver crystal converts the sound energy received into an electric signal, which is processed by the electronics to determine if the gap has liquid or air in it.

Ultrasonic Gap Switch/Level Switch Working Principle

Ultrasonic Switches employ a pair of piezoelectric crystals that are encapsulated within epoxy at the tip of the transducer.

The crystals are comprisedUltrasonic Gap Switch Working Principle of a ceramic material that vibrates at a given frequency when subjected to an applied voltage. When the voltage is sent from the electronics, one of the two crystals, the “transmitting crystal” converts the voltage to an ultrasonic signal.

The presence of liquid within the transducer gap allows the second crystal, the “receiving crystal” to sense the ultrasonic signal and converts it back into an electronic signal. The signal informs the electronics that liquid is present within the transducer gap. If no liquid is present, the ultrasonic signal is attenuated and cannot be detected by the receiving crystal.

The ultrasonic transducer continuously monitors the gap to determine the presence of liquid. When used as a high-level switch, the electronics will immediately actuate a relay if it detects a wet gap.Similarly when used as a low-level switch, it continuously monitors the gap for a dry condition.

Applications:

Ultrasonic level switches can be used in a wide variety of applications without any calibration or setup. However, there are limitations to the types of process they will work in.

The factors below must be taken into consideration before selecting an ultrasonic level switch for your application.

 Liquids only – the process media must be a liquid. The ultrasonic level switch cannot detect the difference between two gases or a gas and a solid. The even density of a liquid is required for proper detection.

 Clean liquids only – a liquid that has too high a percentage of solids will not transmit sound well enough to allow detection. Typically 5% suspended solids are the maximum amount allowed.

 The liquid must flow – an application where the liquid cannot drain out of the sensor gap will cause false alarms. If a liquid is too viscous to flow out of a 3/4” gap then the unit will not operate properly. Sometimes this can be solved by different mounting, but some liquids are just too viscous.

 No (or few) bubbles – especially in fluids with a higher viscosity. Large bubbles in thick fluids will block the sound signal from crossing the gap. Low viscosity fluids can have a fairly large amounts of bubbles as they tend to be very small (Alka-Seltzer in water). If these guidelines are properly observed, the ultrasonic level switches will provide trouble-free operation without any calibration or periodic adjustment.

Some Information About Hydraulic Actuator....At Instronline Instrumentation

Pneumatic actuators are normally used to control processes requiring quick and accurate response, as they do not require a large amount of motive force. However, when a large amount of force is required to operate a valve (for example, the main steam system valves), hydraulic actuators are normally used. Although hydraulic actuators come in many designs, piston types are most common.

Also Read : What is a Pneumatic Actuator ?

A typical piston-type hydraulic actuator is shown in Below Figure. It consists of a cylinder, piston, spring, hydraulic supply and return line, and stem. The piston slides vertically inside the cylinder and separates the cylinder into two chambers. The upper chamber contains the spring and the lower chamber contains hydraulic oil.

The hydraulic supply and return line is connected to the lower chamber and allows hydraulic fluid to flow to and from the lower chamber of the actuator. The stem transmits the motion of the piston to a valve.

Initially, with no hydraulic fluid pressure, the spring force holds the valve in the closed position. As fluid enters the lower chamber, pressure in the chamber increases. This pressure results in a force on the bottom of the piston opposite to the force caused by the spring. When the hydraulic force is greater than the spring force, the piston begins to move upward, the spring compresses, and the valve begins to open. As the hydraulic pressure increases, the valve continues to open. Conversely, as hydraulic oil is drained from the cylinder, the hydraulic force becomes less than the spring force, the piston moves downward, and the valve closes. By regulating amount of oil supplied or drained from the actuator, the valve can be positioned between fully open and fully closed.

The principles of operation of a hydraulic actuator are like those of the pneumatic actuator. Each uses some motive force to overcome spring force to move the valve. Also, hydraulic actuators can be designed to fail-open or fail-closed to provide a fail-safe feature.

Advantages of Hydraulic Actuators

1). Hydraulic actuators are rugged and suited for high force
applications. They can produce forces 25 times greater
than pneumatic cylinders of equal size. They also operate
in pressures of up to 4,000 psi.

2). A hydraulic actuator can hold force and torque constant
without the pump supplying more fluid or pressure due to
the incompressibility of fluids.

3). Hydraulic actuators can have their pumps and motors
located a considerable distance away with minimal loss of
power.

Disadvantages of Hydraulic Actuators

Hydraulics will leak fluid. Like pneumatic actuators, loss of fluid leads to less efficiency and cleanliness problems resulting in potential damage to surrounding components and areas.

Hydraulic actuators require many complementary parts, including a fluid reservoir, motor, pump, release valves, and heat exchangers, along with noise reduction equipment.

Bourdon Tube Pressure Gauge at Instronline Instrumentation

when an elastic transducer ( bourdon tube in this case ) is subjected to a pressure, it defects. This deflection is proportional to the applied pressure when calibrated.

Description of Bourdon tube Pressure Gauge

The main parts of this instruments are as follows:

An elastic transducer, that is bourdon tube which is fixed and open at one end to receive the pressure which is to be measured. The other end of the bourdon tube is free and closed.

The cross-section of the bourdon tube is eliptical. The bourdon tube is in a bent form to look like a circular arc. To the free end of the bourdon tube is attached an adjustable link, which is in-turn connected to a sector and pinion as shown in diagram. To the shaft of the pinion is connected a pointer which sweeps over a pressure calibrated scale.

Operation of Bourdon tube

Tthe pressure to be measured is connected to the fixed open end of the bourdon tube. The applied pressure acts on the inner walls of the bourdon tube. Due to the applied pressure, the bourdon tube tends to change in cross – section from elliptical to circular. This tends to straighten the bourdon tube causing a displacement of the free end of the bourdon tube.

This displacement of the free closed end of the bourdon tube is proportional to the applied pressure. As the free end of the bourdon tube is connected to a link – section – pinion arrangement, the displacement is amplified and converted to a rotary motion of the pinion.

As the pinion rotates, it makes the pointer to assume a new position on a pressure calibrated scale to indicate the applied pressure directly. As the pressure in the case containing the bourdon tube is usually atmospheric, the pointer indicates gauge pressure.

Applications of Bourdon Tube pressure gauge

They are used to measure medium to very high pressures.

Advantages of Bourdon tube pressure gauge

These Bourdon tube pressure gauges give accurate results.
Bourdon tube cost low.
Bourdon tube are simple in construction.
They can be modified to give electrical outputs.
They are safe even for high pressure measurement.
Accuracy is high especially at high pressures.

Limitations of bourdon tube pressure gauge

They respond slowly to changes in pressure
They are subjected to hysteresis.
They are sensitive to shocks and vibrations.
Amplification is a must as the displacement of the free end of the bourdon tube is low.
It cannot be used for precision measurement.

Fiber Optic Cable Connectors, Routing, and Safety at Instronline Instrumentation

One of the most popular styles of single-fiber connector is the so-called “ST” style, which uses a quarter-turn locking barrel to secure the connector into its matching socket:

Communication patch cables such as the one shown above come in pairs of fibers, one for receiving and one for transmitting. Note how the plastic strain-relief grips between the metal barrel of each connector and each orange-jacketed cable are color-coded (one white, one black) for easy identification at each end of the cable.

An older style of connector based on the type used to connect small coaxial cables together is the “SMA” style, which used a threaded barrel to lock each fiber in place. The SMA-style connectors were very secure, but laborious to engage and disengage due to the fine pitch of the barrel’s threads and the subsequent need to turn the barrel multiple rotations (versus one-quarter turn of the barrel for an ST connector).

Given that communication patch cables typically have two fibers (one for each direction of data flow), connector styles have emerged to accommodate fiber pairs. One such style is the so-called “SC” connector, with a pair of side-by-side plugs accommodating twin optical fibers.

Terminating a bare cable of fibers with individual connectors is a time-consuming process, requiring the technician to unbundle the individual fibers, strip the jacketing off of each one to reveal the core and cladding, cleave each glass fiber to give it a flat end, and finally insert and secure each fiber into its respective connector. Typical fiber connectors use either a “hot-melt” or a chemical epoxy system of attachment, where the glue adheres to the strain-relief fibers of the cable for tensile strength, while the central glass fiber protrudes through a small hole in the center of the connector tip. This protruding glass fiber must be carefully cut and polished to produce a flat end suitable for engagement with another optical fiber aligned to its center.

Optical fibers may be spliced mid-way in a cable run, although this practice should be avoided whenever possible. If the fibers are multi-mode, the splicing may be done using “butt” connectors but the power losses may be unacceptable. Alternatively, stripped fibers may be inserted into both ends of a small-diameter tube filled with gel having the same index of refraction as the core glass, to “conduct” light with as little loss as possible from one fiber core to the other.

A very good technique often applied to single-mode fiber is that of fusion splicing, where two single-mode fiber ends are literally melted together using an electric arc so that they form one seamless glass fiber. The alignment of fibers prior to fusion is done under the view of a microscope, and often with the aid of a light source on one end and an optical power meter on the other end to give a quantitative measurement of alignment accuracy. When the two fibers are aligned as close as possible, the electric arc is fired to melt the two fibers together, creating a single fiber. Fusion splicing is the method of choice for long-distance runs of single-mode fiber, where low power loss and high integrity of the splice are paramount factors.

When laying optical fiber in wire trays, pulling through rigid conduit, or arranging it in connection panels, an important physical consideration is to maintain a minimum bend radius at all points along the fiber’s length. This is important because sharp bends will cause light to “leak” out of the fiber core and into the cladding where it may then escape the cable altogether. A sharp bend in an optical fiber will cause the angle between the light ray and the core/cladding interface to reach the critical point where total internal reflection no longer occurs:

The light leakage from an optical fiber may be dramatic if the bend is sharp enough. On an indoor cable, using visible laser light, you can actually see the light “leak” through to the PVC outer coating on the outside of the cable!

Junction boxes and connection panels where excess lengths of fiber optic cabling may be coiled will typically provide plastic forms over which those loops of cable may be bent, the radius of that plastic form exceeding the manufacturer’s specification for minimum bend radius.

A common way in which the minimum bend radius requirement is violated is when a cable tie is used to anchor a fiber optic cable to some sturdy surface such as a wire tray or a cabinet post. The sharp bend created by the tension of a tightened cable tie on the fiber optic cable will easily exceed the minimum bend radius for that cable, creating light leakage and subsequent performance problems. Therefore, a good installation practice for fiber optic cables is to always leave cable ties loose enough that they do not tightly grip the cable.

There are multiple safety concerns when working with optical fibers, both when installing them and when doing maintenance-type work.

Installation hazards center around dangers of the glass fiber itself, while maintenance hazards center around the light sources used to “power” the optical fibers. Installation of fiber optic cable requires that individual glass fibers be separated from each other in a multi-fiber cable and each one terminated with a connector, and this requires at some point that the technician strip each fiber down to its glass core and cladding. Both the core and the cladding are extremely small in diameter, and are made of ultra-pure glass. If a piece of core/cladding breaks off the fiber and penetrates the skin, the resulting “sliver” will be nearly invisible due to its exceptional transparency. Its outer surface is also very smooth, making extraction difficult. Unextracted pieces of an optical fiber, if left in the body, can actually migrate through the victim’s flesh and become buried even deeper to the point where they can cause serious health problems. Technicians working with optical fiber typically lay a length of adhesive tape, sticky-side up, on whatever workbench or table they are using to prepare the cable, as a tool to catch any loose fiber ends they cut off. At the conclusion of the job, this length of tape is carefully rolled up and then disposed of in the same manner that “sharps” may be disposed of in a medical environment.

Maintenance technicians working with functioning fiber optic systems need to be careful when disconnecting “hot” fibers, due to the intensity of the light used in some systems. This is especially true of long-distance telecommunication fibers using laser sources rather than regular LEDs, which may have power levels reaching a half watt or so. One-half of a watt doesn’t sound like very much power, but when you consider this power level is concentrated over a circular area with a diameter less than 10 microns (for single-mode fiber), the watt-per-square-meter value is actually large enough to cause significant temperature increases wherever the light beam happens to fall. In fact, you can actually damage a fiber-optic connector on such a system by disconnecting the fiber with the fiber “powered”, the laser light being intense enough to burn and pit the aluminum ferrule of the connector!

Even standard LED light sources may pose a hazard if a technician directly views the end of the cable with his or her eyes, due to the focused nature of the light beam. The retina of your eye is extremely sensitive to light, and may easily be damaged by viewing such an intensely focused beam coming out of an optical fiber, where the entire LED’s light output is channeled into a core just a fraction of a millimeter in diameter. The optical hazard is even greater when infra-red light sources are used, because there is no visible indication of the light’s presence. A technician won’t even be able to see the light coming out, yet it could still be intense enough to damage their retina(s).

Laser-sourced fibers should never be unplugged from the equipment. One should treat a lasersourced fiber with the same respect as a “live” electrical circuit, and use the same lockout/tagout procedures to ensure personnel safety. In systems using visible light wavelengths, a safe way to view the light coming out the end of an optical fiber is to point the fiber end at a piece of paper and look for the colored dot falling on the paper. The paper’s rough surface scatters the light so that it is no longer a focused beam.

The only time it is truly safe to view the end of an optical fiber to check for light is when the light source is something diffuse such as natural sunlight or a flashlight. It is common for technicians to use a flashlight to identify fibers from one end of a multi-fiber cable to the other, one technician shining the flashlight at the end of one fiber while another technician views all the fibers at the other end of the cable to see which one is lit.

Some optical communications equipment come equipped with a feature called an Open Fiber Control (OFC) safety system, which turns off all light sources on a channel whenever an interruption of light is detected at the receiver port. Since most duplex (two-way) optical fiber channels consist of two fibers (one for each direction of light), a break in any one fiber will darken one receiver, which then commands the transmitter port on that equipment to darken as well to prevent anyone getting injured from the light. It also completely disrupts communication in that channel, requiring a re-initialization of the channel after the fiber is plugged back in.

Why RTD installed after the Orifice Plate ?

The location of the RTD (thermowell), positioned downstream of the orifice plate so the turbulence it generates will not create additional turbulence at the orifice plate. The American Gas Association (AGA) allows for upstream placement of the thermowell, but only if located at least three feet upstream of a flow conditioner.

A major reason for this is von K´arm´an vortex shedding caused by the gas having to flow around the width of the thermowell. The “street” of vortices shed by the thermowell will cause serious pressure fluctuations at the orifice plate unless mitigated by a flow conditioner, or by locating the thermowell downstream so that the vortices do not reach the orifice.

How can we use a DP Flow Transmitter for Level Measurement

Firstly, I need to clarify, that a DP transmitter is not only used for measuring flow, as the user referred to in his question, to a DP flow transmitter.

A differential pressure transmitter (or DP cell) literally measures any differential pressure across its High and Low pressure measuring ports, and provides an output proportional to the difference in pressure between the High and Low pressure ports.

If you look at the mechanical hydraulic properties of a liquid inside a vessel, you will remember that the liquid exerts a specific pressure on the bottom of the vessel, based on the liquid level height (h=meters), the specific gravity (g=9.8 m/s), and the density (rho kg/m3) of the liquid.

The formula for calculating this pressure is P = rho x g x h.

A DP cell can thus be used to measure the pressure of the liquid at the bottom of the vessel, and scaled to give a percentage level value proportional to the pressure measured.

In an open vessel scenario, a standard pressure transmitter can also be used.

However, in a closed vessel, a DP cell must be used. The High pressure port measuring the bottom pressure of the liquid inside the vessel, and the Low pressure port, measuring the top pressure of the vessel to compensate for non-atmospheric pressures inside the sealed vessel.

Working Principle of a Pressure Sensor

What is the working principle of a pressure sensor? A pressure sensor works by converting pressure into an analogue electrical signal.

The demand for pressure measuring instruments increased during the steam age. When pressure sensing technologies were first manufactured they were mechanical and used Bourdon tube gauges to move a needle and give a visual indication of pressure. Nowadays we measure pressure electronically using pressure transducers and pressure switches.

Static Pressure

Pressure can be defined as force per unit area that a fluid exerts on its surroundings. The basic physics of static Pressure (P), is calculated as force (F) divided by area (A).

P=F/A

The Force can be generated by liquids, gases, vapours or solid bodies.

The most commonly used pressure units are;

Pa - [Pascal] in 1 Pa = 1(N/m²)

Bar - [Bar] in 1 bar = 105 𝑃𝑎

psi: (pound(-force) per square inch)

Working Principle of a Pressure Transducer

Pressure transducers have a sensing element of constant area and respond to force applied to this area by fluid pressure. The force applied will deflect the diaphragm inside the pressure transducer. The deflection of the internal diaphragm is measured and converted into an electrical output. This allows the pressure to be monitored by microprocessors, programmable controllers and computers along with similar electronic instruments.

Most Pressure transducers are designed to produce linear output with applied pressure.

What are pressure sensors used for?

Pressure sensors are used in a range of industries, including the automotive industry, Bio medical Instrumentation, aviation and the marine industry, to name a few.

Pressure Sensors from Instronline

We can offer Pressure Sensors in the form of pressure transducers, pressure switches, combined pressure and temperature transducers, PCB mountable pressure sensors and hazardous area pressure sensors. Our Combined Pressure and Temperature Transducers are particularly well suited for applications where space is at a premium.

Our pressure transducers have a robust and modular design, stainless steel housing and a welded housing into the pressure port. They are available in miniature format starting from 12mm diameter.

What is a solenoid valve?

A Solenoid valve is used wherever fluid flow has to be controlled automatically. They are being used to an increasing degree in the most varied types of plants and equipment. The variety of different designs which are available enables a valve to be selected to specifically suit the application in question.

How is a solenoid operated valve being made?

Solenoid valve is a control units which, when electrically energized or de-energized, either shut off or allow fluid flow. The actuator takes the form of an electromagnet. When energized, a magnetic field builds up which pulls a plunger or pivoted armature against the action of a spring. When de-energized, the plunger or pivoted armature is returned to its original position by the spring action.

How does a solenoid valve operate?

To the mode of actuation, a distinction is made between direct- valves, internally piloted valves, and externally piloted valves. A further distinguishing feature is the number of port connections or the number of flow paths ("ways").

Direct-acting solenoid valve

With a direct-acting solenoid valve, the seat seal is attached to the solenoid core. In the de-energized condition, a seat orifice is closed, which opens when the valve is energized.

Direct-acting 2-way solenoid valve

Two-way solenoid operated valves are shut-off valves with one inlet port and one outlet port (Fig. 1). In the de-energized condition, the core spring, assisted by the fluid pressure, holds the valve seal on the valve seat to shut off the flow. When energized, the core and seal are pulled into the solenoid coil and the valve opens. The electro-magnetic force is greater than the combined spring force and the static and dynamic pressure forces of the medium.

Direct-acting 3-way solenoid valve operation

3-way solenoid valve Three-way solenoid operated valves have three port connections and two valve seats. One valve seal always remains open and the other closed in the de-energized mode. When the coil is energized, the mode reverses. The 3-way solenoid valve shown in Fig. 2 is designed with a plunger type core. Various valve operations can be obtained according to how the fluid medium is connected to the working ports in Fig. 2. The fluid pressure builds up under the valve seat. With the solenoid coil de-energized, a conical spring holds the lower core seal tightly against the valve seat and shuts off the fluid flow. Port A is exhausted through R. When the coil is energized the core is pulled in, the valve seat at Port R is sealed off by the spring-loaded upper core seal. The fluid medium now flows from P to A. Pivoted-armature solenoid valve Unlike the versions with plunger-type cores, pivoted-armature valves have all port connections in the valve body. An isolating diaphragm ensures that the fluid medium does not come into contact with the solenoid coil chamber. Pivoted-armature valves can be used to obtain any 3-way valve operation. The basic design principle is shown in Fig. 3. Pivoted-armature valves are provided with manual override as a standard feature.

Internally piloted solenoid valve

With direct-acting valves, the static pressure forces increase with increasing orifice diameter which means that the magnetic forces, required to overcome the pressure forces, become correspondingly larger. Internally piloted solenoid valves are therefore employed for switching higher pressures in conjunction with larger orifice sizes; in this case, the differential fluid pressure performs the main work in opening and closing the valve.

Internally piloted 2-way solenoid valve

Internally piloted solenoid valves are fitted with either a 2- or 3-way solenoid valve. A diaphragm or a piston provides the seal for the main valve seat. The operation of such a valve is indicated in Fig. 4. When the pilot valve is closed, the fluid pressure builds up on both sides of the diaphragm via a bleed orifice. As long as there is a pressure differential between the inlet and outlet ports, a shut-off force is available by virtue of the larger effective area on the top of the diaphragm. When the pilot valve is opened, the pressure is relieved from the upper side of the diaphragm. The greater effective net pressure force from below now raises the diaphragm and opens the valve. In general, internally piloted valves require a minimum pressure differential to ensure satisfactory opening and closing. Omega also offers internally piloted valves, designed with a coupled core and diaphragm that operate at zero pressure differential (Fig. 5).

Internally piloted multi-way solenoid valve

Internally piloted 4-way solenoid valves are used mainly in hydraulic and pneumatic applications to actuate double-acting cylinders. These valves have four port connections: a pressure inlet P, two cylinder port connections A and B, and one exhaust port connection R. An internally piloted 4/2-way poppet valve is shown in Fig. 6. When de-energized, the pilot valve opens at the connection from the pressure inlet to the pilot channel. Both poppets in the main valve are now pressurized and switch over. Now port connection P is connected to A, and B can exhaust via a second restrictor through R.

Externally piloted solenoid valve

With these types an independent pilot medium is used to actuate the valve. Fig. 7 shows a piston-operated angle-seat valve with closure spring. In the unpressurized condition, the valve seat is closed. A 3-way solenoid valve, which can be mounted on the actuator, controls the independent pilot medium. When the solenoid operated valve is energized, the piston is raised against the action of the spring and the valve opens. A normally-open valve version can be obtained if the spring is placed on the opposite side of the actuator piston. In these cases, the independent pilot medium is connected to the top of the actuator. Double-acting versions controlled by 4/2-way valves do not contain any spring.

How to Integrate Valve Actuators with an Automation System

There are two key issues currently affecting the actuation industry: host system integration and functional safety.

Host system integration

In any plant installation, a key requirement is being able to smoothly integrate the actuators used for opening or closing valves with the plant’s automation system. While the mechanical interface between actuator and valve is standardized, interfaces to the control system undergo permanent development. There are a number of challenging decisions: should companies adopt parallel control, fieldbus, or both for redundancy? And, when opting for fieldbus, which protocol should be used? System integration of communication protocols has become a central topic for the supply of actuators for modern plant installations. Today, it is considerably more than mechanical design that is important—system integration is required, centered on effective communication between the actuator and the host system.

Automated opening and closing of valves is the primary functionality, and is usually the straightforward aspect of system integration. In simple applications, operation commands open and close, position feedback signals, and a fault signal often suffice.

However, if fieldbus protocols are used, the bandwidth for information transmission is considerably increased. Further transmission of commands and feedback signals required for operation, access to all device parameters, and operating data via fieldbus from the distributed control system (DCS) are made available. This “secondary” information for diagnostic and maintenance purposes is not a prerequisite for operation, but it aids commissioning, maintenance, and asset management, because it helps give a better overall picture of an actuator.

Cost reduction is one of the main benefits of fieldbus technology. In addition, the introduction of serial communication in process automation has become an innovation driver for field devices and, consequently, for actuators. Concepts for efficiency gains, such as remote parameterization or central-plant asset management, would not be feasible without fieldbus technology. Many different fieldbus systems are available on the market. Established communication systems frequently used with actuators include Profibus DP, Modbus RTU, Modbus TCP/IP, FOUNDATION Fieldbus, and HART.

A large variety of different data and information packages need to be exchanged between the host system and actuators. Communication protocols and data interfaces therefore need to function accurately to facilitate smooth system integration.

As a result, an important requirement for an actuator supplier is to provide evidence of an established track record in the field of system integration and to demonstrate relevant certification for the different fieldbus protocols. Conformity of protocol implementation with fieldbus specifications has to be certified by the international fieldbus organizations: these authorities, or test laboratories accredited by them, carry out extensive tests to verify that products function according to the specifications.

In addition to device registrations, DCS manufacturers carry out dedicated integration tests with field devices. Generally, actuator manufacturers cooperate closely with DCS manufacturers, providing sample actuators for their test laboratories and support regarding actuator interfaces. Typically, product references are then made available on their websites.

Redundancy is another key issue regarding system integration. There are a multitude of different approaches to achieve it. It is critical that, at a very early design stage, the different variants of redundancy supported by the DCS components are effectively assessed, coordinated, and extensively tested using the selected network equipment and field devices.

It is suggested that system integration should always be tailored to the specific requirements of an installation. For example, it may be necessary to configure the data interface in such a way that communication cycle times or bandwidth slots are optimized, and only the data needed for an application is transmitted, thus speeding up communication efficiency. It is strongly recommended that the actuator manufacturer is consulted at the earliest possible stage of design considerations.

Functional safety

The second important topic is functional safety. This issue is critical for the process industry in general and particularly for chemical or oil and gas applications, where protection of people and the environment is essential and, in the event of accidents, financial losses can be extremely high.

Compliance with IEC 61508 and 61511 standards is increasingly demanded by authorities and insurance companies. According to IEC 61508, functional safety relates to systems that automatically intervene in the event of plant emergency alerts, and ensure that the plant is maintained at, or brought into, a safe state.

A hazard or risk assessment should be conducted whenever designing a production plant that is potentially dangerous to people or that may cause severe environmental damage. Frequently, one measure is implementing a functional safety system safety instrumented system (SIS); this is viewed as a state-of-the-art method for risk reduction.

Hazard and risk analyses also determine the safety integrity level (SIL) that the SIS must fulfill. Put simply, SILs are “measuring units” for risk reduction with functional safety systems; the level depends on the severity of the potential dangers.

The required SIS typically consists of a sensor, a safety programmable logic controller (PLC), and an “actor.” In the valve sector, the actor consists of an actuator and a valve. To achieve the required risk reduction, these components need to be capable of the SIL required for the SIS as a whole.

Taking one example to illustrate the complexities of functional safety, it is essential to recognize that, even if exclusively SIL 2–capable components are used, it is not guaranteed that the safety instrumented function (SIF) as a whole will also meet SIL 2 requirements. This level is only achieved if the integral failure probability for all the components of the SIF combined is within the SIL 2 limits and certain additional requirements are met.

As a result, during a plant’s design phase, when deciding on the components for a SIS, it is advisable to closely examine declared safety figures. As an illustration, it is a best practice that the probability of failure on demand (PFD) value for an actuator should not account for more than approximately 25 percent of the allowed PFD value for the required SIL. If, for example, the actuator alone would take 80–90 percent of the permitted PFD value for the SIF, it is very unlikely to meet the requirements for the SIF as a whole. The other components also have a certain failure probability. Use a considered and conservative approach to calculations to ensure that estimations are on the safe side.

One of the most complex tasks within a SIS is to make sure that the interfaces between sensor, safety PLC, and actuator harmonize and function together. This is more complicated than in a standard process control system, because, for safety reasons, there are often restrictions regarding permissible configurations of components. Modular actuator design helps to achieve this, because individual components can be exchanged, as long as all safety requirements are observed.

It is also extremely important that plant designers have access to all the component-specific documentation required to correctly configure and document their SIS in full to achieve certification from a notifying body. To offer maximum support, an actuator manufacturer needs to supply safety figures, test reports, certificates, and comprehensive safety manuals. Support can also include checklists for commissioning and proof testing. Again, close cooperation with the actuator manufacturer is recommended to ensure that the functional safety system achieves the intended risk reduction.

Host system integration and functional safety are two highly significant topics that are currently affecting a wide range of valve control applications. This article has given insight into the importance, challenges, and impact of these issues. However, every installation is different, and adopters of actuation technology should work in partnership with their suppliers to obtain expert advice to achieve the most practical solution

How a Gear Motor Works

A gear motor is a specific type of electrical motor that is designed to produce high torque while maintaining a low horsepower, or low speed, motor output. Gear motors can be found in many different applications, and are probably used in many devices in your home.

Gear motors are commonly used in devices such as can openers, garage door openers, washing machine time control knobs and even electric alarm clocks. Common commercial applications of a gear motor include hospital beds, commercial jacks, cranes and many other applications that are too many to list.

Basic Principles of Operation

A gear motor can be either an AC (alternating current) or a DC (direct current) electric motor. Most gear motors have an output of between about 1,200 to 3,600 revolutions per minute (RPMs). These types of motors also have two different speed specifications: normal speed and the stall-speed torque specifications.

Gear motors are primarily used to reduce speed in a series of gears, which in turn creates more torque. This is accomplished by an integrated series of gears or a gear box being attached to the main motor rotor and shaft via a second reduction shaft. The second shaft is then connected to the series of gears or gearbox to create what is known as a series of reduction gears. Generally speaking, the longer the train of reduction gears, the lower the output of the end, or final, gear will be.

An excellent example of this principle would be an electric time clock (the type that uses hour, minute and second hands). The synchronous AC motor that is used to power the time clock will usually spin the rotor at around 1500 revolutions per minute. However, a series of reduction gears is used to slow the movement of the hands on the clock.

For example, while the rotor spins at about 1500 revolutions per minute, the reduction gears allow the final secondhand gear to spin at only one revolution per minute. This is what allows the secondhand to make one complete revolution per minute on the face of the clock.

Gear Motors and Increased Force

Gear motors are commonly used in commercial applications where a piece of equipment needs to be able to exert a high amount of force in order to move a very heavy object. Examples of these types of equipment would include a crane or lift Jack.

If you've ever seen a crane in action, you've seen a great example of how a gear motor works. As you have probably noticed, a crane can be used to lift and move very heavy objects. The electric motor used in most cranes is a type of gear motor that uses the basic principles of speed reduction to increase torque or force.

Gear motors used in cranes are usually specialty types that use a very low rotational output speed to create incredible amounts of torque. However, the principles of the gear motor used in a crane are exactly the same as those used in the example electric time clock. The output speed of the rotor is reduced through a series of large gears until the rotating, RPM speed, of the final gear is very low. The low RPM speed helps to create a high amount of force which can be used to lift and move the heavy objects.

5 Different Types of Solenoid Valves at Instronline

Solenoid valves are used to control the rate of flow in fluid and air powered tools, systems, and motors. Washing machines and gas boilers use these valves, as well as hydraulic pumps and air hammers because they are diverse enough to perform both simple and complex tasks with ease. Solenoid valves can be customized to suit specific needs and can be utilized to control a variety of mediums such as air, electricity, gas, steam, and oil.

The most common solenoid valve is the two-way valve. A two-way valve only has two ports, whereas more advanced designs may have three or more, depending on what it will be used for. All solenoid valves, no matter the design, are specified to be one of two general types: either a direct acting valve or a pilot operated valve.

1. Direct Acting Valves

In a direct acting solenoid valve, a coil magnetically opens the valve in a direct action, lifting the shaft and the seat of the valve without depending on outside pressure.

2. Pilot-Operated Valves

In pilot operated valves, the plunger opens up the pilot opening while built-up pressure causes the valve to open and close.

Although piloted valves require less electrical energy to operate, they usually need to maintain full power in order to remain in an open state, and they perform at a slower rate than direct acting solenoids. Direct acting solenoid valves only need full power when opening the valve, as they can hold their open position even when operating on low power.

3. Two-Way Valves

Each of the two ports on a two-way valve is alternately used to permit flow as well as close it off. A two-way valve can be specified to be either “normally open" or “normally closed” in its operation. With a normally open valve, the valve remains open until some type of current is applied to close the valve. Suspension of the electrical power causes the valve to automatically reopen to its normal state. A normally closed solenoid valve is the most common, working in the opposite fashion, remaining closed until a power source causes it to open.

4. Three-Way Valves

Three-way valves come with three ports. These are commonly used when alternate and exhaustive pressure are required for operation, as with a coffee machine or dishwasher.

5. Four-Way Valves

These valves can have four or more port connections. Four-way valves are commonly used with a dual acting cylinder or actuator. In this version, half of the port connections supply pressure, and the remaining connections provide exhaust pressure. You can specify these valves to be either normally closed, normally open or universal.

Before purchasing a solenoid valve, be sure to do enough research to select the proper valve for your needs. Take note of what specifications will be required for the system, and consider what type of fluid will be used in operation. Also, take into consideration what type of material should be selected for the seals. Whether your equipment uses steam, gas, or air, selecting the right solenoid valve is crucial to its proper operation.

About Single Function / Loop Calibrators

Loop calibrators are a type of electrical calibrator specifically designed to troubleshoot 4-20 mA current loops. These versatile instruments are capable of measuring current, sourcing current to unpowered devices in a loop, as well as simulating the operation of loop-powered 4-20 mA transmitters.

An analog current loop is an electrical signaling scheme that uses a current source and a current receiver. Current loops are extremely common in industrial measurement and control applications due to their ease in setting up, wide power supply requirements, low noise output, and ability to be transmitted over great distance without loss—even if there is significant electrical resistance in the line.

With current loops, the sensor draws current from its power source in direct proportion to the mechanical property it measures. For example, a 0 to 100 psi pressure sensor with a 4-20 mA current loop draws 4 milliamps from its power supply at 0 psi and 20 milliamps at 100 psi. The relationship between current value and the corresponding process measurement value is determined by calibration by which measurement values are assigned ranges within the span of 4-20 mA.

A primary benefit of the current loop is its simple wiring. Generally, a current loop consists of a power supply, a transducer and one or more pieces of instrumentation all connected together in a ring with the supply voltage and measuring current supplied over the same two wires. Current loops are used to measure pressure, temperature, flow, pH, or other process variable. A current loop can also be used to control a valve positioner or other output actuator.

Depending on the source of current for the loop, devices may be classified as active or passive. Some instruments have an active output which includes both the control of the current in the loop as well as provide the supply voltage. Passive loops, on the other hand, require an external power supply.

Calibration

Calibration is a comparison between two devices. The first device is the unit to be calibrated, often called the unit under test. The second device is the calibrator, which has been fixed to a standard of a known accuracy.

The exact calibration procedure depends on the type of instrument being calibrated. For displays and controllers, the calibrator generally sources or simulates a signal which is read by the unit under test. As the signal sent by the calibrator is of a known accuracy, any discrepancy is the error of the unit under test. The unit under test can then be adjusted until it displays the correct value.

For sensors and transmitters, the calibrator generally reads the signal sent from them while they are under test conditions, such as a pH sensor being immersed in a calibration solution of a known value. With the test conditions being exactly known, any discrepancy between those conditions and the measured value is the error of the unit under test. Adjustments can then be made to account for that error.

Typically, calibration of an instrument is checked at several points throughout the calibration range of the instrument.

Not all standards are created equally. While all standards have a known accuracy, there are some—known as primary standards— that are the highest level of accuracy for a specific parameter. Primary standards achieve their high accuracy by relying upon measurement technologies using fundamental physical constants that do not drift. For example, the value of the volt is defined by the Josephson Effect which has an accuracy of 1 part per billion. These fixed values minimize uncertainty, making primary standards the most accurate calibration tools.

Though the accuracy of calibrators varies pretty widely depending upon the model and the measurement parameters, they can be roughly categorized into three groups :

Industrial standards, also known as field standards ideally have an accuracy 4 times greater than the instrument being calibrated. These are useful for spot checking sensors at the point of use rather than a laboratory environment.
Secondary standards, also known as laboratory standards provide greater accuracy than field standards and are used to calibrate field standards.
Primary standards, provide the highest calibration accuracy. Primary standards are used to calibrate secondary standards.

Traceability

To improve the quality of a calibration to levels acceptable to outside organizations, it is generally desirable for the calibration and subsequent measurements to be traceable to internationally recognized standards. Establishing traceability is accomplished by a formal comparison to a standard which is directly or indirectly related to national standards (such as NIST in the USA), international standards, or certified reference materials.

Things to Consider When Selecting an Electrical Calibrator:

What type of signal is used by the equipment to calibrate?
What measurement parameters do the units to be calibrated have?
Where will calibrations take place? The lab? The field?
What level of accuracy is needed?
Are any communication protocols needed?
What types of adapters are needed to attach the unit to be calibrated to the calibrator?
Is a calibration certificate is needed? Which one?

If you have any questions regarding electrical calibrators please don't hesitate to speak us by e-mailing at info@instronline.com

ABSOLUTE VS INCREMENTAL ROTARY ENCODERS

Incremental or Absolute?

Positioning tasks require precise position values to monitor or control motion activity. In many applications position sensing is done using rotary encoders, also called shaft encoders or simply encoders. These sensors transform a mechanical angular position of a shaft or axle into an electronic signal that can be processed by a control system.

Absolute Rotary Encoders

Absolute rotary encoders are capable of providing unique position values from the moment they are switched on. This is accomplished by scanning the position of a coded element. All positions in these systems correspond to a unique code. Even movements that occur while the system is without power are translated into accurate position values once the encoder is powered up again.

Multiple Interface Options: Analog, Ethernet, Fieldbus, Parallel, Serial
Singleturn and Multiturn Revolution
Resolution up to 16 bit
Optical an Magnetic Measuring Principle

Incremental Rotary Encoders

Incremental encoders generate an output signal each time the shaft rotates a certain amount. (The number of signals per turn defines the resolution of the device.) Each time the encoder is powered on it begins counting from zero, regardless of where the shaft is. Initial homing to a reference point is therefore inevitable in all positioning tasks, both upon start up of the control system and whenever power to the encoder has been interrupted.

A, B, Z, and Inverted Signals as HTL (Push-Pull) or TTL (RS422).
Any Pulse Count up to 16384 Pulses per Revolution Available
Flexible Scaling Functionality
Magnetic Measuring Principle

What Is a Slice Valve?

Slice valves operate with a sliding gate that slices through the water flow. The operator pushes a plunger-type handle that pushes the gate through the opening. This gate fits into the flanges within the frame of the valve that form seals preventing the flow of liquid through the valve. The device is sometimes called a gate valve for its design features.

Common Uses

Plumbers use slice valves in sewer drains systems in some homes. The valve is installed before the floor drain in a basement. Closing the valve prevents sewage backup through the floor drain and is accessed through an access panel in the basement floor. Hot tubs and pools also use slice valves as part of the drain system.

Materials

Makers build slice valves out of PVC, ABS and metal. Choose the proper material based on the pipe materials. PVC and ABS are less likely to corrode than the metal slice valves. The valves commonly can be opened for cleaning and service if corrosion or mineral buildup occurs.

Advantages

Slice valves work by pushing or pulling the control handle. The position of the valve has to have enough clearance to accommodate this action. Clean slice valves operate easily and can be opened or closed with little effort. The valves also operate at a wide range of water pressures.

Disadvantages

Corrosion or mineral buildup in the flanges of the valve house can prevent the gate of the valve from fitting completely. This prevents the valve from sealing completely and allows water to trickle through the slice valve. The valve is also larger than most. The housing of the valve is as large as the diameter of the pipe to allow for the housing of the gate. Not all installations have enough open room for a slice valve.

Why Use A Digital Tachometer?

It’s all about revolution. Digital tachometers, and all tachometers, measure the revolutions of a spinning object to determine the rate at which it is spinning. Nearly all types of transportation vehicles, from planes to trucks to buses to trains to cars have tachometers. The instrument is also vital in troubleshooting machinery performance and conducting preventive maintenance inspections. You’ll even find tachometers used for production line checks, monitoring turbines, measuring sewing machine speeds, and maintaining quality control.

What sets digital tachometers apart is the display that shows a digital reading, which may be gathered by an optical sensor. Optical digital tachometers are non-contact and can be used to assess RPMs by measuring the number of rotations a reflective surface makes in a minute. Photo tachometers, using laser beam technology, are Class II rated and enable users to measure objects up to 14 feet away. A laser tachometer can operate in hard-to-reach or remote locations for added versatility.

Conversely, contact tachometers physically touch a rotating or moving object to measure its linear speed or RPMs. Dual-type technology (or combination) styles are also available.

Two Options: Portable or Panel Mount

Portable tachometers can be used in the field or in a facility and are handy when measuring RPMs in many locations. Panel-mount tachometers are typically dedicated units near a specific machine or in a control room in an industrial environment. Both are ruggedly designed for industrial applications.

Features to Consider

Easy-to-read display

Accuracy

Units of measure

TTL pulse output

Auto ranging function

Expanded memory capacity

Recall for minimum, maximum, and last values

Lengthy battery life

HOW DOES A VALVE WORK WITH ACTUATORS

Valves are one of those critical inventions that go unnoticed by many. They play an important role in our world by controlling, regulating, guiding and directing the flow of assorted types of liquids, gases, steam or flowing materials such as mill, grain, etc.

Valves are made of steel, iron, steel, bronze or PVC and can handle high temperatures and pressure points. In certain applications, the velocity, which is controlled by the valve, is vital in the success of the system in which it is applied and can be manually controlled or automated. In every industry, there are various types of valves including ball, butterfly, v-port, solenoid, sanitary, knife gate, plug and many more. The following is just a few examples of where valves are critical in a particular application: sewage/waste water plant, dams that controls a body of water, valves in your vehicle that control gas flow or oil flow to your engine and oil and gas refinery companies.

Oftentimes, an actuator is attached to the valve to administer pressure control and flow control in applications where it is crucial that the actual value be the same as the set point value. This motor box is operated by pneumatic pressure or an electric current. It then changes this energy into motion which changes or moves the valve positioning in order to keep to the set point that was entered into the actuator by the operator.

Difference Between Pneumatic,Hydraulic and Electrical Actuators

A linear actuator moves a load, which can be an assembly, components, or a finished product, in a straight line. It converts energy into a motion or force and can be powered by pressurized fluid or air, as well as electricity.

Here is a breakdown of common linear actuators, their advantages and their disadvantages.

How They Work

• Pneumatic linear actuators consist of a piston inside a hollow cylinder. Pressure from an external compressor or manual pump moves the piston inside the cylinder. As pressure increases, the cylinder moves along the axis of the piston, creating a linear force. The piston returns to its original position by either a spring-back force or fluid being supplied to the other side of the piston.

• Hydraulic linear actuators operate similarly to pneumatic actuators, but an incompressible liquid from a pump rather than pressurized air moves the cylinder.

• An electric linear actuator converts electrical energy into torque. An electric motor mechanically connected turns a lead screw. A threaded lead or ball nut with corresponding threads that match those of the screw is prevented from rotating with the screw. When the screw rotates, the nut gets driven along the threads. The direction the nut moves depends on which direction the screw rotates and also returns the actuator to its original position.

Pneumatic Actuators

Advantages

• The benefits of pneumatic actuators come from their simplicity. Most pneumatic aluminum actuators have a maximum pressure rating of 150 psi with bore sizes ranging from ½ to 8 in., which translate into approximately 30 to 7,500 lb. of force. Steel actuators have a maximum pressure rating of 250 psi with bore sizes ranging from ½ to 14 in., and they generate forces ranging from 50 to 38,465 lbf.

• Pneumatic actuators generate precise linear motion by providing accuracy, for example, within 0.1 inches and repeatability within .001 inches.

• Pneumatic actuators typical applications involve areas of extreme temperatures. A typical temperature range is -40°F to 250°F. In terms of safety and inspection, by using air, pneumatic actuators avoid using hazardous materials. They meet explosion protection and machine safety requirements because they create no magnetic interference due to their lack of motors.

• In recent years, pneumatics has seen many advances in miniaturization, materials, and integration with electronics and condition monitoring. The cost of pneumatic actuators is low compared to other actuators. According to Bimba Manufacturing, for example, the average pneumatic actuator costs $50 to $150. Pneumatic actuators are also lightweight, require minimal maintenance, and have durable components that make pneumatics a cost-effective method of linear motion.

Disadvantages

• Pressure losses and air’s compressibility make pneumatics less efficient than other linear-motion methods. Compressor and air delivery limitations mean that operations at lower pressures will have lower forces and slower speeds. A compressor must run continually operating pressure even if nothing is moving.

• To be truly efficient, pneumatic actuators must be sized for a specific job. Hence, they cannot be used for other applications. Accurate control and efficiency requires proportional regulators and valves, but this raises the costs and complexity.

• Even though the air is easily available, it can be contaminated by oil or lubrication, leading to downtime and maintenance. Companies still have to pay for compressed air, making it a consumable, and the compressor and lines are another maintenance issue.

Hydraulic Actuators

Advantages

• Hydraulic actuators are rugged and suited for high-force applications. They can produce forces 25 times greater than pneumatic cylinders of equal size. They also operate in pressures of up to 4,000 psi.

• Hydraulic motors have high horsepower-to-weight ratio by 1 to 2 hp/lb greater than a pneumatic motor.

• A hydraulic actuator can hold force and torque constant without the pump supplying more fluid or pressure due to the incompressibility of fluids

• Hydraulic actuators can have their pumps and motors located a considerable distance away with minimal loss of power.

Disadvantages

• Hydraulics will leak fluid. Like pneumatic actuators, loss of fluid leads to less efficiency. However, hydraulic fluid leaks lead to cleanliness problems and potential damage to surrounding components and areas.

• Hydraulic actuators require many companion parts, including a fluid reservoir, motors, pumps, release valves, and heat exchangers, along with noise-reduction equipment. This makes for linear motions systems that are large and difficult to accommodate.

Electrical Actuators

Advantages

• Electrical actuators offer the highest precision-control positioning. An example of the range of accuracy is +/- 0.000315 in. and a repeatability of less than 0.0000394 in. Their setups are scalable for any purpose or force requirement, and are quiet, smooth, and repeatable.

• Electric actuators can be networked and reprogrammed quickly. They offer immediate feedback for diagnostics and maintenance.

• They provide complete control of motion profiles and can include encoders to control velocity, position, torque, and applied force.

• In terms of noise, they are quieter than pneumatic and hydraulic actuators

• Because there are no fluids leaks, environmental hazards are eliminated.

Disadvantages

• The initial unit cost of an electrical actuator is higher than that of pneumatic and hydraulic actuators. According to the example from Bimba Manufacturing, an electrical actuator can range from $150 to greater than $2,000 depending on its design and electronics.

• Electrical actuators are not suited for all environments, unlike pneumatic actuators, which are safe in hazardous and flammable areas

• A continuously running motor will overheat, increasing wear and tear on the reduction gear. The motor can also be large and create installation problems.

• The motor chosen locks in the actuator’s force, thrust, and speed limits to a fixed setting. If a different set of values for force, thrust, and speed are desired, the motor must be changed.

Why Should You Use a Diaphragm Seal

In applications where the process fluid is corrosive

In applications where the process fluid has a high viscosity, is comprised of slurries, sludge or other material that can actually coat or damage a traditional pressure measuring device

In applications where the process fluid can freeze or polymerize, thus causing a condition that might lead to the instrument becoming immobilized or incapable of transmitting an accurate pressure measurement or signal

Operational Theory:

Mansfield & Green brand diaphragm seals typically comprise a metal, TEFLON or elastomer diaphragm mounted between two housings and sealed to prevent leakage of process gases or fluids. The space on the instrument side of the diaphragm, the connections and the instrument- sensing element, are all completely filled with instrument oil, silicon or other suitable fluid.

Pressure:

In-Line Flow Thru seal Types R, S, and T are rated at 1500 psi at 100°F (105 bar at 38°C). Type L seals are rated at 1250 psi at 100°F (88 bar at 38°C).

INSTRONLINE offers special diaphragm seal designs with a maximum working pressure rating of up to 5000 psig (690 bar). Please consult your INSTRONLINE representative for more information.

Vacuum:

L Series elastomer diaphragm seals (except for Types LB and LG) are ideal for most vacuum instrument applications in ranges from 0 to 29" Hg (0 to 736mm Hg at 0°C).

Type ST Series seals are suitable for vacuum applications from 0 to 29" Hg (0 to 736mm Hg at 0°C).

Working of Relays

What is a relay?

We know that most of the high end industrial application devices have relays for their effective working. Relays are simple switches which are operated both electrically and mechanically. Relays consist of a n electromagnet and also a set of contacts. The switching mechanism is carried out with the help of the electromagnet. There are also other operating principles for its working. But they differ according to their applications. Most of the devices have the application of relays.

Why is a relay used?

The main operation of a relay comes in places where only a low-power signal can be used to control a circuit. It is also used in places where only one signal can be used to control a lot of circuits. The application of relays started during the invention of telephones. They played an important role in switching calls in telephone exchanges. They were also used in long distance telegraphy. They were used to switch the signal coming from one source to another destination. After the invention of computers they were also used to perform Boolean and other logical operations. The high end applications of relays require high power to be driven by electric motors and so on. Such relays are called contactors.

Relay Design

There are only four main parts in a relay. They are

Electromagnet

Movable Armature

Switch point contacts

Spring

It is an electro-magnetic relay with a wire coil, surrounded by an iron core. A path of very low reluctance for the magnetic flux is provided for the movable armature and also the switch point contacts. The movable armature is connected to the yoke which is mechanically connected to the switch point contacts. These parts are safely held with the help of a spring. The spring is used so as to produce an air gap in the circuit when the relay becomes de-energized.

How relay works?

The diagram shows an inner section diagram of a relay. An iron core is surrounded by a control coil. As shown, the power source is given to the electromagnet through a control switch and through contacts to the load. When current starts flowing through the control coil, the electromagnet starts energizing and thus intensifies the magnetic field. Thus the upper contact arm starts to be attracted to the lower fixed arm and thus closes the contacts causing a short circuit for the power to the load. On the other hand, if the relay was already de-energized when the contacts were closed, then the contact move oppositely and make an open circuit.

As soon as the coil current is off, the movable armature will be returned by a force back to its initial position. This force will be almost equal to half the strength of the magnetic force. This force is mainly provided by two factors. They are the spring and also gravity.

Relays are mainly made for two basic operations. One is low voltage application and the other is high voltage. For low voltage applications, more preference will be given to reduce the noise of the whole circuit. For high voltage applications, they are mainly designed to reduce a phenomenon called arcing.

Relay Basics

The basics for all the relays are the same. Take a look at a 4 – pin relay shown below. There are two colours shown. The green colour represents the control circuit and the red colour represents the load circuit. A small control coil is connected onto the control circuit. A switch is connected to the load. This switch is controlled by the coil in the control circuit. Now let us take the different steps that occour in a relay.

Energized Relay (ON)

As shown in the circuit, the current flowing through the coils represented by pins 1 and 3 causes a magnetic field to be aroused. This magnetic field causes the closing of the pins 2 and 4. Thus the switch plays an important role in the relay working. As it is a part of the load circuit, it is used to control an electrical circuit that is connected to it. Thus, when the relay in energized the current flow will be through the pins 2 and 4.

De – Energized Relay (OFF)

As soon as the current flow stops through pins 1 and 3, the switch opens and thus the open circuit prevents the current flow through pins 2 and 4. Thus the relay becomes de-energized and thus in off position.

Pole and Throw

Relays have the exact working of a switch. So, the same concept is also applied. A relay is said to switch one or more poles. Each pole has contacts that can be thrown in mainly three ways. They are

Normally Open Contact (NO) – NO contact is also called a make contact. It closes the circuit when the relay is activated. It disconnects the circuit when the relay is inactive.

Normally Closed Contact (NC) – NC contact is also known as break contact. This is opposite to the NO contact. When the relay is activated, the circuit disconnects. When the relay is deactivated, the circuit connects.

Change-over (CO) / Double-throw (DT) Contacts – This type of contacts are used to control two types of circuits. They are used to control a NO contact and also a NC contact with a common terminal. According to their type they are called by the names break before make and make before break contacts.

Relays are also named with designations like

Single Pole Single Throw (SPST) – This type of relay has a total of four terminals. Out of these two terminals can be connected or disconnected. The other two terminals are needed for the coil.

Single Pole Double Throw (SPDT) – This type of a relay has a total of five terminals. Out f these two are the coil terminals. A common terminal is also included which connects to either of two others.

Double Pole Single Throw (DPST) – This relay has a total of six terminals. These terminals are further divided into two pairs. Thus they can act as two SPST’s which are actuated by a single coil. Out of the six terminals two of them are coil terminals.

Double Pole Double Throw (DPDT) – This is the biggest of all. It has mainly eight relay terminals. Out of these two rows are designed to be change over terminals. They are designed to act as two SPDT relays which are actuated by a single coil.

Relay Applications

Relays are used to realize logic functions. They play a very important role in providing safety critical logic.

Relays are used to provide time delay functions. They are used to time the delay open and delay close of contacts.

Relays are used to control high voltage circuits with the help of low voltage signals. Similarly they are used to control high current circuits with the help of low current signals.

They are also used as protective relays. By this function all the faults during transmission and reception can be detected and isolated.

Relay Selection

You must note some factors while selecting a particular relay. They are

Protection – Different protections like contact protection and coil protection must be noted. Contact protection helps in reducing arcing in circuits using inductors. Coil protection helps in reducing surge voltage produced during switching.

Look for a standard relay with all regulatory approvals.

Switching time – Ask for high speed switching relays if you want one.

Ratings – There are current as well as voltage ratings. The current ratings vary from a few amperes to about 3000 amperes. In case of voltage ratings, they vary from 300 Volt AC to 600 Volt AC. There are also high voltage relays of about 15,000 Volts.

Type of contact used – Whether it is a NC or NO or closed contact.

Select Make before Break or Break before Make contacts wisely.

Isolation between coil circuit and contacts

Volume Booster Working Principle

A pneumatic air volume booster reproduce a low flow control signal with a higher regulated flow output pressure. It uses an unregulated input pressure to maintain a regulated output pressure under flowing and non-flowing conditions.

The volume booster is connected to the supply line and the output plumbing. It receives a pneumatic control signal, however, from another device, such as a transducer, valve positioner or other control means.

This pneumatic signal controls the pressure into and out of the booster, while allowing the booster to flow the maximum volume of the supply line. Boosters may also be referred to as pilot-operated regulators, as your control or pilot signal maintains the pressure control.

The regulated output of a pneumatic air volume booster can be any of the following:

A direct reproduction of the pneumatic control signal

A multiple of the pneumatic control signal

A fraction of the pneumatic control signal

The volume booster ratio is the multiplier or divider of signal pressure to output pressure. For example, a 2:1 ratio means output pressure is 1/2 the signal pressure. Similarly, a 2:1 ratio would provide output pressure twice the signal pressure. Note, however, the output pressure can never exceed the supply pressure to the booster.

Often the signal pressure is lower than the supply pressure because a control device (valve positioner, I/P, etc.) will only handle a lower supply pressure.

Self Actuated Pressure Control Valves

Self actuated pressure control valves do not depend on any external signal for pressure control. As the name suggests, pressure in the process line itself is used as an actuating signal to open or close the pressure control valve.

A self actuated pressure control valve can be used to control the pressure at either upstream or downstream of the control valve. If the pressure upstream to the valves is used to throttle the control valve, then the upstream pressure is maintained at a specified set point and such a valve is known as a backpressure control valve, as it maintains the backpressure imposed by the control valve. If pressure at immediate downstream point of the valve is used as a signal to throttle the control valve, then the downstream pressure is maintained at a specified set point and such valves are known as self actuated pressure control valves.

For a pressure regulator valve, pitot tube connects the diaphragm casing to a point downstream of control valve. When the pressure downstream to control valve increases beyond setpoint, process fluid exerts increased pressure on the diaphragm thus closing the valve. Closing of the valve stops process flow thus reducing the valve downstream pressure back to setpoint level. When the pressure downstream of control valve drops below the setpoint level, process fluid from diaphragm casing recedes back to process line. This relieves pressure on diaphragm and opens the valve to allow increased process flow. Increased process flow leads to increase in pressure back to its setpoint.

For a back-pressure regulator valve, the pitot tube connects diaphragm casing to a point upstream of the pressure control valve and the process fluid from upstream point acts on the valve diaphragm to open or close the valve in case of high or low pressure respectively.

Soft Starter – Principle and Working

A soft starter is any device which controls the acceleration of an electric motor by means of controlling the applied voltage.

Now let us have a brief recall of the need for having a starter for any motor.

An Induction motor has the ability to self start owing to the interaction between the rotating magnetic field flux and the rotor winding flux, causing a high rotor current as torque is increased. As a result the stator draws high current and by the time the motor reaches to full speed, a large amount of current (greater than the rated current) is drawn and this can cause heating up of the motor, eventually damaging it. To prevent this, motor starters are needed.

Motor starting can be in 3 ways

Applying full load voltage at intervals of time: Direct On Line Starting

Applying reduced voltage gradually : Star Delta Starter and Soft starter

Applying part winding starting: Autotransformer starter

Defining Soft Starting

Now let us shift our particular attention to soft starting.

In technical terms, a soft starter is any device which reduces the torque applied to the electric motor. It generally consists of solid state devices like thyristors to control the application of supply voltage to the motor. The starter works on the fact that the torque is proportional to the square of the starting current, which in turn is proportional to the applied voltage. Thus the torque and the current can be adjusted by reducing the voltage at the time of starting the motor.

There can be two types of control using soft starter:

Open Control: A start voltage is applied with time, irrespective of the current drawn or the speed of the motor. For each phase two SCRs are connected back to back and the SCRs are conducted initially at a delay of 180 degrees during the respective half wave cycles (for which each SCR conducts). This delay is reduced gradually with time until the applied voltage ramps up to the full supply voltage. This is also known as Time Voltage Ramp System. This method is not relevant as it doesn’t actually control the motor acceleration.

Closed Loop Control: Any of the motor output characteristics like the current drawn or the speed is monitored and the starting voltage is modified accordingly to get the required response. The current in each phase is monitored and if it exceeds a certain set point, the time voltage ramp is halted.

Thus basic principle of soft starter is by controlling the conduction angle of the SCRs the application of supply voltage can be controlled.

2 Components of a basic soft starter

Power switches like SCRs which need to be phase controlled such that they are applied for each part of the cycle. For a 3 phase motor, two SCRs are connected back to back for each phase. The switching devices need to be rated at least three times more than the line voltage.

Control Logic using PID controllers or Microcontrollers or any other logic to control the application of gate voltage to the SCR, i.e. to control the firing angle of SCRs in order to make the SCR conduct at the required part of the supply voltage cycle.

Working Example of Electronic Soft Start System for 3 phase induction motor

The system consists of the following components.

Two back to back SCRs for each phase, i.e. 6 SCRs in total.

Control Logic circuitry in form of two comparators- LM324 and LM339 to produce the level and the ramp voltage and an opto-isolator to control the application of gate voltage to the each SCR in each phase.

The level voltage is generated using the comparator LM324 whose inverting terminal is fed using a fixed voltage source and the non inverting terminal is fed through a capacitor connected to the collector of an NPN transistor. The charging and discharging of the capacitor causes the output of the comparator to change accordingly and the voltage level to change from high to low. This output level voltage is applied to the non inverting terminal of another comparator LM339 whose inverting terminal is fed using a ramp voltage. This ramp voltage is produced using another comparator LM339 which compares the pulsating DC voltage applied at its inverting terminal to the pure DC voltage at its non inverting terminal and generates a zero voltage reference signal which is converted to a ramp signal by the charging and discharging of a electrolyte capacitor.

The 3rd comparator LM339 produces a High pulse width signal for every high level voltage, which decreases gradually as the level voltage reduces. This signal is inverted and applied to the Opto isolator, which provides gate pulses to the SCRs. As voltage level falls, the pulse width of the Opto isolator increases and more the pulse width, lesser is the delay and gradually the SCR is triggered without any delay. Thus by controlling the duration between the pulses or delay between applications of pulses, the firing angle of SCR is controlled and the application of supply current is controlled, thus controlling the motor output torque.

The whole process is actually an open loop control system where the time of application of gate triggering pulses to each SCR is controlled based on the how earlier the ramp voltage decreases from the level voltage.

Advantages of Soft Start

Now that we have learnt about how an electronic soft start system works, let us recollect few reasons why it is preferred over other methods.

Improved Efficiency: The efficiency of soft starter system using solid state switches is more owing to the low on state voltage.

Controlled startup: The starting current can be controlled smoothly by easily altering the starting voltage and this ensures smooth starting of the motor without any jerks.

Controlled acceleration: Motor acceleration is controlled smoothly.

Low Cost and size: This is ensured with the use of solid state switches.

ABOUT SIEMENS TS-3 TEMPERATURE SENSOR

The TS-3 temperature sensor provides an input signal for temperature compensation of specific Siemens ultrasonic level controllers.

Temperature compensation is essential in applications where temperature variations of the sound medium are expected.

By installing the temperature sensor close to the sound path of the associated ultrasonic transducer, a signal representative of the sound medium’s ambient temperature is obtained. The temperature sensor should not be mounted in direct sunlight.

The TS-3 is used in conjunction with ultrasonic transducers that do not have an integral temperature sensor. It is also recommended in cases where the integral temperature sensor of the transducer cannot be used.

The following conditions are typical for use of the TS-3 sensor: where a fast reaction to temperature variations is required, where a flanged ultrasonic transducer is used, or where high temperatures are encountered.

The TS-3 is not compatible with devices using the TS-2 or LTS-1 temperature sensors. Refer to the associated transceiver manual for more details.

Key Applications: For use in applications where temperature sensor measurement from transducer does not accurately represent vessel temperature. Used for applications requiring quick temperature response (open channel monitoring).

Learn How to Calibrate a Pressure Transmitter

Transmitters are used in the process industry environments to measure pressure and other parameters. The plant operators rely upon these devices for accurate measurements and process optimization. The performance of these transmitters may weaken with time due to several factors. This is when they need calibration.

During calibration, a comparison is made between the current reading and the standard set reading. This helps plant operators determine the shift in readings and make necessary adjustments.

The calibration procedures may slightly vary across the types of branded pressure transmitters due to their designs. However, there are some general steps to follow before calibrating your transmitter. This post discusses them all.

Basic Setup for Calibrating a Pressure Transmitter

Following are the basic steps before starting the actual calibration.

Read Instruction Manual: The transmitter can be easily calibrated following the manufacturer’s specific instructions on calibration, provided with the equipment. Read the instruction manual carefully to understand different steps involved in the calibration. Additionally, you can refer various videos available online to understand the procedure.

Arrange All Instruments Needed for the Calibration: Using a proper instrument is a requisite of any calibration procedure. Arrange all instruments needed for calibration such as pressure gauge, digital multimeter, pressure source, and power supply module (24V). Ensure that the readout device and pressure source used are of great accuracy than the transmitter to be calibrated. Accurate measurements cannot be achieved, if low accuracy equipment are used for the calibration. The instruments used for the calibration procedure should be regularly tested to ensure they are working perfectly and serving their purpose.

Record Important Information: Before starting with the procedure, you need to record the following information:

Transmitter Model

Calibration Range

Transmitter Maximum Working Pressure

Transmitter Span

Follow the Diagram: Most instruction manuals provide the connection diagram, or you can download the one from the Internet. Connect all equipment appropriately as mentioned in the diagram. To avoid any mistake, you can take several printout of the diagram. You need to pay attention to power source as well as polarity of the transmitter.

Prepare the Instrument for Calibration: Mostly the calibration is done in either of the two ways:

Bench Top Calibration: This is a procedure, where the transmitter is calibrated at a bench using various calibration devices.

Field Calibration: This is a procedure, where the actual calibration is done as per the tips mentioned in this post.

In both of the above-mentioned types, the low port of the transmitter cell is vented to atmosphere, and the high port to a pressure source. Examples of high port include pneumatic calibrator, pressure regulator, or a hand pump.

After setting up the connection, switch on the power supply, and pressurize the high port. Record the reading of current (mA) and this will be the first reading. Continue pressurizing the transmitter, and record readings in five points – 0%, 25%, 50%, 75%, and 100%. Take down readings for increasing, as well as decreasing input values and corresponding output values.

After the initial setup, you can start with the actual calibration. In the next post, we will discuss steps for calibrating the pressure transmitter

Industrial Instrumentation and Control: An Introduction to the Basic Principles

In part one of this instrumentation and control (I & C) series, we'll go over the fundamental terminology and concepts used when working with industrial plants.

This is the first of a series of technical articles about instrumentation and control. In this series, we will discuss the basic concepts and principles that govern the operation of industrial plants. Concepts associated with measurements of flow, level, temperature and pressure, electronics and pneumatics instrumentation, control loops, PID control, and others will be addressed.

Article Scope

Someone once asked a colleague what his occupation was. He replied without hesitation, "I am an instrumentation and control engineer." "And what is that?" asked his interlocutor. "...Oh. Oh ... I'm in trouble," thought the engineer.

To explain what a mechanical, electrical, chemical, or electrical engineer does is relatively easy, but it is another story to concisely describe the work performed by an engineer who specializes in instrumentation and control.

Instrumentation and control are interdisciplinary fields. They require knowledge of chemistry, mechanics, electricity and magnetism, electronics, microcontrollers and microprocessors, software languages, process control, and even more such as the principles of pneumatics and hydraulics and communications.

This is what makes instrumentation and control so interesting and instructive.

In this article and the next, I will give a complete overview of the basic principles of instrumentation and control (I & C) used for the functioning and operation of industrial plants such as those involving oil and gas, pulp and paper, sugar, pharmaceutical products, food, and chemicals.

First, we'll need to cover how to measure, and to measure we need a measurement instrument.

What is a measurement instrument?

A measurement instrument is a device capable of detecting change, physical or otherwise, in a particular process. It then converts these physical changes into some form of information understandable by the user.

When the switch is closed, the resistor generates heat, increasing the temperature of the liquid in the tank. This increase is detected by the measurement instrument and shown on the scale of that instrument.

We can get the information on the physical changes in a process using direct indication or a recorder.

Indication

This is the simplest form of measurement; it allows us to know the current state of the variable.

Recorder

A device that can store data allows us to observe the current state of the variable and how it behaved in the past. A recorder provides us with the history of the variable.

Elements of a Measurement Instrument

Measurement instruments consist primarily of the following parts:

Sensor: This element is a device that experiences changes in its physical properties as a result of changes in the process it's measuring.

Amplifier / Conditioner: Changes detected by the sensor may be very small, so they must be amplified and then conditioned such that they can be properly displayed.

Display: The measured data should be presented in an understandable way. This can be done using a graduated instrument or an electronic display. Sometimes the display additionally acts as a recorder in order to convey the measurement's history or trends.

Usually, the measurement information generated by an instrument must be sent to a control center (or control room) that is physically distant from the instrument. In general, this information must conform to established specifications.

When an instrument has the ability to send information, we call it a transmitter (XMTR).

Classification of Instruments

There are different classifications for measurement instruments. We can classify them, for example, as in-field instruments or panel instruments. The in-field instrument is installed close to the process or measuring point. It must be physically robust if it will be exposed to harsh environmental conditions. Panel instruments are in a controlled-environment room (often a clean space with air conditioning and controlled humidity).

Another classification is pneumatic instruments vs. electrical/electronic instruments.

Pneumatic Instruments

As the name suggests, these are devices that are powered by air.

One of the advantages of these instruments is that they do not consume electricity, so they can be used in areas where it would be dangerous or inconvenient to use electrical power. They work with a single variable, are imprecise instruments, are affected by vibrations and temperature changes, and have high maintenance requirements. The output signal of the transmitters is between 3 and 15 psi, and the maximum transmission distance is approximately 200 meters.

Electrical / Electronic Instruments

Electronic instruments can be divided into three general categories: analog, smart analog, and digital.

Analog:

Output signal: 4 - 20 mA

Transmission distance: 1200 m (typical)

Data for one variable is transmitted

Good accuracy

Easy maintenance

Smart Analog:

Characterization of the sensor as measuring temperature, static pressure, etc.

Excellent accuracy

Self-diagnosis (i.e., the sensor can analyze problems in its own functionality)

One variable

Digital:

Multiple instruments can use a single cable

Transmission of multiple values for each instrument (process variables, calibration, diagnostics, range)

Distance: approximately 1900 m without a repeater

Data capacity is influenced by the mode of transmission (cable, fiber optic, wireless)

General Concepts

Range: The region between the limits within which a variable is measured. It indicates the minimum and maximum values that limit the region. The range is expressed with two numbers, e.g., 10 to 20 °C, 10 to 150 V, 0 to 100%

Span: Calculated as the maximum value of the range minus the minimum value of the range. Span is expressed with a single number in process units, e.g., 120 °C, 30 V, 150 liters per second.

Elevation: If the lower limit of the range is a positive value, this lower limit is the elevation. Example: If the range is 50 °C to 200 °C, we can say that the elevation is 50 °C or 33.3% of the span.

Depression (also referred to as suppression): If the lower limit of the range is negative, the absolute value of this lower limit is the depression. Example: If the range is -10 °C to 80 °C, we can say that the depression is 10 °C or 11.1% of the span.

Overrange: When a device is calibrated to operate within a certain range but may be subjected to values above or below that range, then it requires a protection mechanism to prevent damage to the instrument or to prevent the indicator from exceeding its upper or lower limit. When the measured values are above the maximum value, we have positive overrange. When the measured values are below the minimum value, we have negative overrange.

Error: The difference between the measured value and the actual (or expected, or desired) value of a physical variable. The error can be positive or negative. When the measured value is greater than the actual value, the error is positive. When the measured value is less than the actual value, the error is negative.

If measured > actual, error > 0

If measured < actual, error < 0

The error can be expressed

in engineering units (e.g., °C, psi)

as a percentage of the span (e.g., +/- 3% of the span)

as a percentage of the measurement (e.g., +/- 5% of the measurement)

Reference value: In a general sense, this refers to the actual, expected, or desired value of a variable. In the context of a feedback control system, the measured value is fed back and subracted from the reference value in order to generate the error signal.

Accuracy: A number that defines the limits of the error. When we say that an instrument has an accuracy of 0.1% of the span, this means that anywhere within the range, the readings do not differ from the actual value by more than 0.1% of the span.

An Example

For a better understanding of the concepts expressed above, consider the following example.

We have an oil tank where we are required to continuously measure the temperature. The operating conditions for this process are as follows:

Minimum temperature: -10 °C

Maximum temperature: 90 °C

The measurement accuracy must be 1% of the span or better

The temperature measurement must be displayed locally and remotely

First, we must select a measuring instrument that allows us to measure the temperature of the liquid in the tank. Since the information should be available locally and remotely, we will choose a temperature transmitter.

This transmitter must have the following characteristics:

Range: -10 °C to 90 °C

Span: 90 °C - (-10 °C) = 100 °C

Depression: 10 °C or 10% of the span

Accuracy: 1% of the span = 1% × 100 °C = 1 °C

This accuracy of 1% ensures that, in each measurement or temperature reading, variation or errors will not exceed +/- 1 °C

On an additional note, we must ensure a proper relationship between the range and the standardized transmitter output. To calibrate the instrument, we must associate the minimum value of the range (-10 °C) with the minimum value of the output (4 mA) and the maximum value of the range (90 °C) with the maximum value of the output (20 mA).

Conclusion

In this article we have discussed measurement devices and fundamental measurement concepts in the context of instrumentation and control systems. We also looked at a simple example system involving a heating element and an instrument that can collect and transmit temperature data. In the next article, we will cover the four basic variables used in industrial applications: flow, level, temperature, and pressure. Also, we will discuss various sensors such as orifice plates, thermocouples, and RTDs, and we will review instruments and transmitters used for measuring these four physical variables.

Level Measurement Showdown: Ultrasonic Vs. Radar

There is nothing like a good old-fashioned competition to keep things interesting. In the level measurement world, that rivalry is between the two most commonly used measurement instruments: ultrasonic, which uses sound-based measurement, and radar, which uses high-frequency electromagnetic waves to determine distance. Both ultrasonic and radar level measurement devices can also be used to measure flow rates in all types of open channel flow applications through the addition of a flume or weir.

Up until recently, ultrasonic was the unchallenged king of level and flow measurement in the water and wastewater sectors. But things are changing.

“The benefits of ultrasonic are that it is cheap, has low power consumption, is well developed and understood, and is basically the incumbent,” explained Oliver Grievson, a flow compliance and regulatory efficiency manager at Anglian Water Services. “But it is subject to interferences when it’s not monitored closely. This is where the potential for radar comes in.”

So which technology is best? Water Online examines how they compare in price, effectiveness and versatility, setup and use, and familiarity.

Price

Radar technology isn’t new — it has been on the market for nearly 20 years. But up until a few years ago, it was significantly more expensive than ultrasonic, causing most to stick with ultrasonic.

“Radar started dropping in price about three to four years back,” said Richard Lowrie of Krohne, an instrumentation manufacturer that sells both ultrasonic and radar instruments. “Radar has been streamlined; a lot of the things that were unnecessary have been trimmed for simpler application and to reduce the price.”

The average ultrasonic level measurement instrument costs $500 to $2,000. Radar level measurement instruments used to cost up to $4,000 but now have dropped down to $1,000 to1,200 on average, putting the two instruments at a nearly level playing field in terms of cost.

“People should still look at ultrasonic because it is still less expensive; a high-end ultrasonic will cost the same as a low-end radar,” Lowrie explained. “But I think the radar will keep dropping in price because people want the technology.”

Effectiveness And Versatility

One factor in determining which instrument is best is the intended application. Nicholas Paradiso, a consulting engineer with CDM Smith, recommends radar level measurement instruments to his clients that work in wastewater because oil, grease, and other coatings can sometimes interfere with the accuracy of ultrasonic measurement instruments.

“Any application where you aren’t dealing with 100% liquid, we would want to use radar over ultrasonic, because radar can see through solids better,” Paradiso explained. “But this is only really relevant in wastewater and not water treatment, unless you are dealing with a chemical tank.”

Dust, foam, and cobwebs can also present problems for ultrasonic level measuring instruments, and measurement accuracy can be affected by wind, temperature, and snow in outdoor tanks. Radar doesn't have these limitations, said Anglian’s Grievson.

“If the instrument isn't cleaned, which is a common problem, or there is foam, direct sunlight, or other difficult conditions, this is where radar has a benefit,” he said.

Operations that use silos, large wells, or oversized tanks may also benefit from radar, which has a longer range. Typically, an ultrasonic instrument can get an accurate return signal from a maximum of 60 feet away, while a radar instrument can get a return at up to 300 feet. However, this large range isn’t always necessary.

“In the water and wastewater industry, a lot of times ultrasonic’s range is suitable,” said Krohne’s Lowrie. “Normally you are dealing with 30- to 40-foot tanks at a wastewater facility. It could be considered overkill to use radar in some applications.”

Setup And Use

Complexity is also a consideration when it comes to selecting between ultrasonic and radar.

Ultrasonic meters have a shorter deadband — a minimum distance they have to be above the liquid surface — which can be limiting. But setting up a radar instrument isn’t as simple as setting up an ultrasonic instrument.

“With radar, when mounting the actual instrument, I’ve noticed that there are very specific distances you have to have it away from other equipment,” CDM Smith’s Paradiso pointed out. “You may also need to provide a metal plate above it, or the radar waves won’t reflect back properly.”

Lowrie feels ultrasonic level meters are also slightly easier to use.

“It is just simpler technology,” he says. “But I think radar has a wider range of applications.”

Familiarity

Despite the benefits of radar, Paradiso believes ultrasonic will stay in the lead for a while. This is because level measurement devices last 10 to 15 years, and aren’t likely to be replaced often. While Paradiso does believe radar devices are the future, he doesn’t recommend switching unnecessarily.

“If it isn’t broken and is still working, don’t mess with it,” Paradiso suggested. “There are other things that could be done to the plant aside from just going around and replacing all of your instruments.”

There is also some hesitation in the industry to try radar measurement devices because they are not as well known.

“Most of the industry is familiar with ultrasonic — it isn’t black magic as radar technology is thought of by some to be,” said Lowrie.

Grievson feels more education is necessary on radar use in both level and flow measurement before it can surpass ultrasonic. In the United Kingdom, where Grievson is located, few companies have promoted radar level measurement devices for flow measurement, as many ultrasonic level measurement companies have. This step will help the technology flourish.

Signal Isolators Information

Signal isolators provide electrical (galvanic) isolation between the input and output circuits. They couple the signal to the output through a transformer or optical isolator. Signal isolators also break the direct electrical galvanic path between two or more loop points. They protect against dangerous measured-variable voltages and increase protection from surges and spikes.

Signal isolators are closely related to signal converters and signal interfaces. These devices are often used to share, split, boost, protect, step-down, linearize, and digitize process signals.

The most important role of a signal isolator is to break the galvanic path between circuits that are "grounded" to different potentials. A galvanic path is defined as a path in which there is a direct electrical connection between two or more electrical circuits that allow current to flow.

For example, if a differential pressure transmitter is sending a 4-20mA measurement to a receiver, such as a recorder, and the two ground points are different, an additional and unpredictable amount of current can be introduced into the loop, distorting the true measurement. This current path is known as a ground loop and is a very common cause of signal inaccuracies, along with the current path having two grounds, the ground at different potentials, and a galvanic path between the grounds. In order to remove the ground loop, the galvanic path between the grounds must be removed.

Signal isolators are especially important since the other two causes for ground loops cannot always be removed safely. The ground may be there for safe operation of the electronic device.

Function

There are two prevalent methods for galvanic isolation.

Optical isolation uses light to transfer a signal between elements of a circuit. The isolator is usually in a small module mounted on a circuit board. The isolation circuit is composed of an LED and a photo-sensitive detector, such as a phototransistor. The insulating air gap between the LED and the photo transistor serves as the galvanic separation between the two circuits.

The advantages of optical isolation are: the device is small, can sometimes provide higher levels of isolation than transformer isolation, and the device has better common-mode noise rejection. Disadvantages of optical isolation are that each element needs its own power supply and the signals on both sides must be quite small.

Transformer isolation is also referred to as electromagnetic isolation. It uses a transformer to electromagnetically couple the desired signal across an air gap or non-conductive isolation gap.

Transformers are very efficient at transforming AC signals. This is a disadvantage since many process control signals are DC and must be changed into an AC signal so they can pass across the transformer. Once passed, they have to be rectified and amplified back into the desired DC signal output.

Advantages of a transformer circuit include: the device does not need a power supply and it works well with AC signals such as audio. A disadvantage is that a transformer does not work with DC signals since at some frequencies the device will begin to act as a filter for AC signals.

Specifications

Signal isolators are often specified by what the isolation levels are from input to output. Two-way (input-to-output) isolation is used to describe a 2-wire transmitter since it is powered from either its input or output terminals.

Three-way isolation is defined as input-to-output, power-to-input, and power-to-output isolation. It is important to note if the isolator is powered by a DC supply which could cause a problem with common mode noise, or failing to switch power supply, creating unwanted output signal errors.

If the signal isolation is a 4-wire device it may require 24Vdc, 110Vac, or 220Vac to operate its circuits. For these devices, it is important to ensure the isolator has full three-way isolation.

Each type of signal isolator should provide signal isolation between the input, output, and power source. A typical signal isolator is capable of withstanding 1000 V, or more common-mode signals at the input.

The level of isolation is also important when selecting a signal isolator. Level of isolation describes the level of voltage needed to create an arc from one side of the circuit to the other. Optical isolators have the advantage here as the electrical parts of the circuit can be designed to be further apart.

Environmental Factors

Due to the widespread application of signal isolation many devices are available with built-in safety features for use in various environments.

For example, intrinsically-safe, nonincendive, and explosion proof options are all available for hazardous areas within a plant. Hazardous conditions also include the amount of heat the electronics will be exposed to while installed in the plant.

Other devices may need protection from radio frequency interference (RFI) and electromagnetic interference (EMI) which can cause unpredictable and non-repeatable degradation in instrument performance.

Variable frequency drives (VFDs) are also known to cause noise that interferes with signal isolators and are common in plants. This interference can be avoided by installing a 4-wire isolator to filter the unwanted common mode noise.

Applications

Signal isolators are used in industrial, medical, and other environments in which electrical isolation is essential for safety. Signal isolators can also be used to amplify signals, enable instruments to be added to an overburdened loop, or to step down dangerous, high-voltage signals to safer levels.

Specific examples of applications include resistance input for use in RTD, slidewire, strain, and potentiometer transmitters, and current/voltage isolators for use as alarm tripping and deviation alarm notification.

About Pressure Gauges

Pressure is the second most common process measurement, after temperature, in industrial and commercial applications. Even around the house, when inflating a tire or checking the status of a boiler system, accurately and immediately knowing the pressure is of importance. Pressure gauges are the simplest, most direct way of measuring and displaying pressure. While other pressure measurement devices such as sensors, transmitters and transducers convert pressure into an electrical signal to be sent to a controller, recorder, or another type of data-acquisition device, pressure gauges are meant to be a local display showing, at a glance, the pressure inside your fire extinguisher, tires, boiler, pressure cooker, or an important process in an industrial setting.

Understanding Pressure

Pressure is defined as the amount of force applied over a unit area. Usually involving liquids and gases, pressure is a critical component of a diverse array of applications, both those that rely on accurate pressure control as well as those that derive other values (such as depth/level or flow) based upon pressure.

Pressure measurements can be made in a number of units. Most commonly, we see PSI ( pounds per square inch) or bar. Other units of measure include kg/cm2, inH2O, mmHg, Pa, and many others.

There are also different types of pressure to consider. The type of pressure refers to the zero reference point of a measurement. For example:

Gauge pressure: The pressure gauge is referenced against atmospheric pressure so it does not include the effects of that pressure making it equal to absolute pressure minus ambient air pressure. Sealed gauge sensors may use a fixed pressure different than ambient atmospheric temperature.

Absolute pressure: The pressure gauge is referenced against a perfect vacuum so it, therefore, includes the effects of atmospheric pressure. It is equal to gauge pressure plus atmospheric pressure.

Differential pressure: The pressure gauge contains two process connections to measure the difference between two pressures, such as each side of a filter to measure pressure drop.

Pressure Gauge Technology

Pressure gauges are fairly simple devices though there are many considerations that go into selecting the best instrument for your particular application. The most obvious difference, when looking at pressure gauges, is that some are digital while others are analog. While they fulfil the same basic role, analog and digital gauges use different technology and excel under different conditions.

Analog Gauges

Analog pressure gauges, often referred to as mechanical gauges, use a needle that points to a number on a scale corresponding to the pressure sensed by the measuring element. Analog pressure gauges are found everywhere as they provide an accurate, inexpensive option that requires no power and little, if any, maintenance.

Analog gauges can be tailored to fit nearly any application. They can be accurate enough to use as test gauges, reliable enough for use in complex process environments, rugged enough for industrial use, and inexpensive enough for commercial use.

Most analog gauges rely on either of two measurement principles:

Bourdon Tube: Gauges with bourdon tubes are the most common type of analog gauges in use. Bourdon tubes rely on the principle that a curved tube tends to straighten out when subjected to pressure. The tube is connected to a pointing device so that subtle movements due to pressure fluctuations are indicated on pressure calibrated scale on the dial.

Bourdon tube pressure gauges work very well for most applications, particularly those involving medium to very high pressures. They are simple in construction, which keeps them inexpensive and easy to use. Bourdon tubes also offer superior linearity and can be accurate up to ±0.1% making them suitable for precision measurements.

Bourdon tube pressure gauges also have limitations, though. They lack the sensitivity for highly accurate readings at low pressures and can be also be sensitive to shocks and vibration as well as subject to hysteresis. Bourdon tubes can also respond slowly, so applications involving rapid pressure fluctuations are not ideal. Also, like all analog gauges, Bourdon tubes cannot make absolute pressure measurements nor are they particularly adept at precision measurements.

Bellows: Bellows gauges are a great solution when measuring pressure ranges below what is ideal for Bourdon tube gauges. Bellows gauges contain an elastic element that radially expands and contracts to respond to pressure changes. The internal bellows is connected to a pointing device so that subtle movements due to pressure fluctuations are indicated on pressure calibrated scale on the dial.

Bellows gauges excel in low pressure applications and have the accuracy and sensitivity for precise measurement. Additionally, bellows gauges are rugged and reliable with low hysteresis and creep. Like Bourdon tubes, bellows gauges are sensitive to vibration and shock.

Analog gauges are widespread for a reason, they offer accuracy across wide range at a good price. Though they cannot match the features of digital gauges, analog gauges are often available with temperature compensation for greater accuracy, liquid fill to dampen movement of the pointer, multiple dial sizes to improve visibility and space requirements.

Digital Gauges

Digital pressure gauges use advanced sensors and microprocessors to display highly accurate pressure readings on a digital indicator. Though generally more expensive than analog gauges, digital gauges offer a number of features that make them attractive alternatives for a number of applications.

Digital gauges provide quick and easy to read results. Rather than having to count hashes to read the pressure, digital gauges provide resolutions of up to 0.01 or 0.001 making them ideal for very low pressures or small incremental pressure changes, such as those found when leak testing, that would be impossible to identify with an analog gauge.

Digital pressure gauges have fewer moving parts than analog gauges making them more reliable. Simple to operate, they nonetheless can be programmed for multiple pressure units and include outputs for sending results to a computer, data logger, or other instrument for storage or analysis.

Most digital pressure gauges rely on one of two measurement technologies:

Strain gauge: Strain gauge sensors rely on the piezoresistive effect which describes changes in the electrical resistivity of a semiconductor or metal—commonly silicon, polysilicon thin film, bonded metal foil, thick film, or sputtered thin film—when mechanical strain (pressure) is applied. Most commonly this technology consist of a diaphragm with patterned metallic strain gauge embedded into it. Increasing pressure causes the diaphragm, and subsequently, the gauge to deform which effects it’s resistivity. That change is measured and converted into an electrical signal proportional to the pressure. Generally, strain gauges are connected to form a Wheatstone bridge circuit to maximize the output of the sensor and to reduce sensitivity to errors.

Piezoelectric: Piezoelectric sensors rely on the piezoelectric effect in certain materials such as quartz to measure the strain upon the sensing mechanism due to pressure. As pressure is applied a charge develops across the sensor in proportion to the force.

Things to Consider When Selecting a Pressure Gauge:

What is the type and range of the pressure?

Is an output required? If so, which type?

What accuracy is required?

What units of measurement are preferred?

Which process connection is required?

Are there any issues with material compatibility or chemical resistance?

What is the temperature range? Is compensation needed?

What burst pressure is required?

Are any agency approvals needed?

What is the preferred dial size?

Characteristics of Pressure Transmitters, Pressure Sensors and Pressure Transducers

Pressure Transmitters

Pressure Transmitters, a sub-group of pressure transducers, feature additional reset and calibration options. With some sensor types it is possible, for example, to re-set the measuring span over large ranges. This calibration option is usually referred to by such terms as “scale down”, “span reset” or “turn down”. For instance, a transmitter with a measuring range of 0 to 400 psi and a range reset 1/10 can be calibrate to a measuring range of 0 - 40 psi while still giving a full output signal (4 - 20 mA, for example).

It is also possible to shift the zero point over a wide range and to calibrate the damping of the output signal between 0 and 32 seconds. Smart transmitters such as Hart®, which also have logging capabilities, can be calibrated, tested and reset via the control desk or hand terminals.

Transmitters are often used in process applications where they can be combined with various chemical seals.

Pressure Sensors

Today many measuring principles are used in electronic pressure measurement instruments. Most methods are based on the measurement of a displacement or force. In other words, the physical variable “pressure” has to be converted into an electrically quantifiable variable. Unlike mechanical pressure measuring methods, this conversion requires an external power source for the pressure sensor.

This pressure sensor is the basis of electronic pressure measurement systems. While mechanical gauge element displacements of between 0.004 and 0.012 inches are standard, the deformations in electronic pressure sensors amount to no more than a few microns.

Thanks to this minimal deformation, electronic pressure measurement instruments have excellent dynamic characteristics and low material strain resulting in high resistance to alternating loads and long-term durability.

Listed below are pressure sensor technologies used by WIKA in its transmitter, transducer and sensor instruments:

Ceramic Thick Film Sensor
LVDT (Linear Variable Differential Transformer) Sensor
Piezoresistive (Piezo) Sensor
Thin Film Sensor

Pressure Transducers

Pressure transducers are an advanced form of the pressure sensor element. The simplest form of an electronic pressure measurement system is the pressure sensor. It is the pressure sensor which changes the physical variable “pressure” into a quantity that can be processed electronically. A pressure transducer is the next level of sophistication. In a pressure transducer, the sensor element and housing are in electrical contact and have a pressure connection.

Typical output signals from pressure transducers [WJ2] are between 10 mV and around 100mV, depending on the sensor type. These signals are not standardized, however, nor are they compensated. With thin-film type pressure transducers it is customary for just the sensor element to be welded to the pressure connection and then bonded electrically. Piezoresistive pressure transducers, on the other hand, require far more production steps since the semiconductor sensor element has to be protected from the effects of various media by a chemical seal.

Why Calibration of Your Measuring Instruments is Important

What is calibration?

Calibration is a comparison between a known measurement (the standard) and the measurement using your instrument. Typically, the accuracy of the standard should be ten times the accuracy of the measuring device being tested. However, accuracy ratio of 3:1 is acceptable by most standards organizations.

Calibration of your measuring instruments has two objectives. It checks the accuracy of the instrument and it determines the traceability of the measurement. In practice, calibration also includes repair of the device if it is out of calibration. A report is provided by the calibration expert, which shows the error in measurements with the measuring device before and after the calibration.

To explain how calibration is performed we can use an external micrometer as an example. Here, accuracy of the scale is the main parameter for calibration. In addition, these instruments are also calibrated for zero error in the fully closed position and flatness and parallelism of the measuring surfaces. For the calibration of the scale, a calibrated slip gauge is used. A calibrated optical flat is used to check the flatness and parallelism.

Why calibration is important?

The accuracy of all measuring devices degrade over time. This is typically caused by normal wear and tear. However, changes in accuracy can also be caused by electric or mechanical shock or a hazardous manufacturing environment (e.x., oils, metal chips etc.). Depending on the type of the instrument and the environment in which it is being used, it may degrade very quickly or over a long period of time. The bottom line is that, calibration improves the accuracy of the measuring device. Accurate measuring devices improve product quality.

When should you calibrate your measuring device?

A measuring device should be calibrated:

According to recommendation of the manufacturer.

After any mechanical or electrical shock.

Periodically (annually, quarterly, monthly)

Hidden costs and risks associated with the un-calibrated measuring device could be much higher than the cost of calibration. Therefore, it is recommended that the measuring instruments are calibrated regularly by a reputable company to ensure that errors associated with the measurements are in the acceptable range.

Basics of the HART Communication Protocol -Working principle

The worldwide accepted measure for analog signals inwards the measure manufacture is the iv to 20mA signal. One key drawback of this signal measure is that it tin entirely transmit i parameter or measured value.

Influenza A virus subtype H5N1 two-way or bidirectional communication protocol, which addresses this drawback, has been developed amongst which additional information tin move transmitted using an alternating electrical current signal superimposed on the iv – 20mA analog signal. This organisation is called the HART communication protocol.

HART stands for: Highway Addressable Remote Transducer.

The HART communication protocol has leave of absence a widespread solution, allowing for convenient as well as efficient parameterization of smart (intelligent) measuring devices. Additionally, device-specific diagnostic information tin move read which provides information well-nigh the device’s physical wellness as well as allow for predictive maintenance. Monitoring diverse device parameters is also possibility amongst the HART protocol.

How the HART Protocol Works:

The FSK (Frequency Shift Keying) physical care for is the footing for the HART communication.

The HART digital signal is made upwardly of 2 frequencies — 1,200 Hz as well as 2,200 Hz representing bits 1 as well as 0,

Sine waves of these 2 frequencies (shown inwards the diagram above) are superimposed on the at i time electrical current (dc) analog signal to supply simultaneous analog as well as digital communications. Because the average value of the FSK signal is ever zero, the 4‐20mA analog signal is non affected. The HART protocol is oft called a hybrid protocol because it combines analog as well as digital communication. Influenza A virus subtype H5N1 typical HART setup inwards a iv -20mA organisation

In this setup, the HART devices (PC or handheld communicator) requests information from the plain device(HART compatible). The plain device supplies the information which tin as well as so move used for status monitoring, diagnostics, predictive maintenance as well as whatsoever other utilization that is required of the digital information supplied to the HART device. Meanwhile, the analog iv -20mA signal is active as well as undistorted as well as tin move used for command purposes land digital communication amongst HART is on-going.

Wireless HART

The HART measure has evolved over the years since its showtime introduction as well as is at nowadays offering a novel phase amongst completely novel possibilities for wireless transmission of HART information through a applied scientific discipline called WirelessHART.

WirelessHART is the showtime standardized wireless communication inwards the plain of physical care for automation. However, every bit this solution does non include the connector cable, entirely the digital parameter arrive at is available. The analog measuring signal is non provided. Digital wireless communication does away amongst cabling thus, allowing for slow as well as cost-saving installation of additional measuring points for diagnostic purposes.

Basically, at that spot are 2 dissimilar WirelessHART solutions:

(a) WirelessHART Adapter for enhancing existing HART devices

(b) Self-powered Wireless HART transmitter.

These wireless solutions utilization the primal chemical cistron of wirelessHART transmission – the WirelessHART gateway – for communication. Besides the protocol, the measure also defines diverse safety mechanisms which ensure availability as well as tap-proof wireless signal transmission.

Incremental encoder working principle and characteristics

Incremental encoder (encoder type selection) is the displacement into periodic electrical signal, then change the electrical signals into counting pulses, pulse number indicate the size of the displacement.

Incremental encoder works:

Uniform grating engraved on the shaft to rotate together with the pulse encoder on the code disk evenly distributed in a number of light transmission section and blackout zone. Incremental encoder is no fixed starting zero, the output is proportional to the pulse increment corner, the counter needs to count the number of pulses. Each turned a light transmission area, it sends a pulse signal, the current value of the counter is incremented, increment the counting result corresponds to the corner. The encoder is the angular displacement or linear displacement into electrical signals a device.

The former becomes encoder, which said the yardstick. Readout method according to the encoder can be divided into touch and non-touch two. Touch selection brush output, a brush touch conductive or insulating zone area to indicate the status of the code is "1" is still "0"; a non-touch-sensitive element is subjected to a photosensitive element or magnetic components, the selection of the photosensitive member In the photic zone and opaque regions to indicate the status of the code is "1" is still "0."

Incremental encoder features:

Incremental encoder (electronic handwheel) color is: a non-touch, non-conflict and wear, small size, light weight, compact organization, convenient device to protect the simple, drive torque, which has a high-precision, large range measurement , fast response, digitized output characteristics;

Very appropriate incremental encoder measurement speed, unlimited accumulation measure. But the existence of zero cumulative error, poor immunity, receiving equipment downtime required to power the memories, power should give change or see bits and other questions, such as the selection of these questions will certainly be able to handle encoder.

Built-in battery Skills: Some encoder built-in battery power is lost to prevent signal, there are some encoder (electronic handwheel) ring is certainly signal, the number of signals and multi-circle is built-in battery and circuitry incremental counting method to get, this is a pseudo-affirmative encoder, its battery life expectancy by, low battery failure, vibration factor affected by poor battery contacts, etc., and greatly reduced reliability.

General application speed incremental encoder measuring rotational direction, moving angle measured from the (relative). The encoder according to the measurement selection first asked to select the type of encoder, incremental encoder pulses per revolution is equal to the number of lines issued its grating. Speed measurement shall be based on the design or location requirement, and the encoder speed, to determine the number of lines of the encoder. The encoder mounted on the motor shaft or mounted on a shaft decelerated, encoder speed is quite different. It should also consider whether the maximum frequency of the pulses within it emits a high-speed counter in the PLC allows.

About the encoder number one topic of aftermarket products, our company has established a sound marketing network and service system operates in a number of cities and regions.

Different Types of Pressure Gauges

Pressure gauges measure the increase and reduction of pressure in a contained field. The earliest patent for a tube pressure gauge was issued to France's Eugene Bourdon in 1849. Still in use in the twenty-first century, the popular Bourdon pressure gauge measures different kinds of liquids and gases including steam, water and air. The coiled tube connects to gears measuring pressures up to 100,000 psi (pounds per square inch) of the container. Whether used for industry, medicine, transportation or in the mechanics of everyday life and recreation, the variety of pressure gauges available add to the safety and quality of life of our modern global community.

Air Pressure Gauges

Air pressure gauges measure the amount of air needed to maintain the optimum use of the object containing this gas. A common container of air is a tire. Using an air pressure gauge ensures the correct amount of air fills the tire for optimum performance. Too little air in a tire eventually makes it flatten while too much air makes it wear unevenly or even explode.

Oil Pressure Gauges

Machine engines use oil to lubricate the moving parts while in motion to prevent the natural friction from damaging the motor components. Oil pressure gauges indicate safe or unsafe levels of oil.

Differential Pressure Gauges

Differential pressure gauges, such as a liquid-column manometer (measuring vacuum pressures), show the variation in pressure between two points by observing the fluid used in a U-tube. Such instruments contain two entrance ports with each connected to one of the monitored pressure capacities. Using this type of pressure gauge allows operators to monitor pressure at one point rather than having to check two pressure gauges and calculate the difference.

Digital Pressure Gauges

Used in a variety of industries, digital pressure gauges convert applied pressure into signals that read out in numerical displays. These gauges have pharmaceutical, food processing and automotive applications as well as use for containment and monitoring of hazardous materials.

Diaphragm Pressure Gauges

Instead of using a liquid level to measure the difference between an unknown and a reference pressure as with the differential pressure gauge, the diaphragm pressure gauge uses the expandable deformation of a diaphragm or membrane. This pressure gauge contains a capsule divided by a diaphragm open to the external targeted (unknown) pressure while the other side of the diaphragm connects to the known pressure. Mechanically, the undesirable pressure difference exhibits with the deflection of the diaphragm from a leveled position.

Magnetic Flow Meters

A magnetic flow meter (mag flowmeter) is a volumetric flow meter which does not have any moving parts and is ideal for wastewater applications or any dirty liquid which is conductive or water based. Magnetic flowmeters will generally not work with hydrocarbons, distilled water and many non-aqueous solutions). Magnetic flowmeters are also ideal for applications where low pressure drop and low maintenance are required.

Principle of Operation

Faraday's Law The operation of a magnetic flowmeter or mag meter is based upon Faraday's Law, which states that the voltage induced across any conductor as it moves at right angles through a magnetic field is proportional to the velocity of that conductor.

Faraday's Formula

E is proportional to V x B x D where:

E = The voltage generated in a conductor

V = The velocity of the conductor

B = The magnetic field strength

D = The length of the conductor

To apply this principle to flow measurement with a magnetic flowmeter, it is necessary first to state that the fluid being measured must be electrically conductive for the Faraday principle to apply. As applied to the design of magnetic flowmeters, Faraday's Law indicates that signal voltage (E) is dependent on the average liquid velocity (V) the magnetic field strength (B) and the length of the conductor (D) (which in this instance is the distance between the electrodes).In the case of wafer-style magnetic flowmeters, a magnetic field is established throughout the entire cross-section of the flow tube (Figure 1). If this magnetic field is considered as the measuring element of the magnetic flowmeter, it can be seen that the measuring element is exposed to the hydraulic conditions throughout the entire cross-section of the flowmeter. With insertion-style flowmeters, the magnetic field radiates outward from the inserted probe

Magmeter Selection

The key questions which need to be answered before selecting a magnetic flowmeter are:

Is the fluid conductive or water based?

Is the fluid or slurry abrasive?

Do you require an integral display or remote display?

Do you require an analog output?

What is the minimum and maximum flow rate for the flow meter?

What is the minimum and maximum process pressure?

What is the minimum and maximum process temperature?

Is the fluid chemically compatible with the flow meter wetted parts?

What is the size of the pipe?

Is the pipe always full?

Insertion Magmeters

Insertion type meters offered by Omega Engineering have a standard 2" NPT or fit into a specific size fitting. The FMG-550 Series are designed for 2" to 48" in size with a flow rate of 0.05 to 10 m/sec (0.15 to 33 ft/sec). The FMG-550 Series offers an analog output with an integral display for flow rate and totalization. The FMG3000 series offers corrosion resistant materials for pipes from 0.5 to 8". These insertion type flowmeters are ideal for large pipe applications.

Minimum conductivity: 5 to 20 microSiemens/cm

Installation Considerations

Select a location for the sensor where the flow profile is fully developed and not affected by any disturbances. A minimum of 10 pipe diameters of straight run upstream and 5 diameters downstream is recommended. Some situations may require 20 pipe diameters or more upstream to insure a fully developed turbulent flow profile. The insertion magmeter is sensitive to air bubbles at the electrodes. If there is any question that the pipe is absolutely full, mount the sensor at a 45 to 135 angle.

Grounding requirements

Magnetic flow sensors are sensitive to electrical noise which is present in most piping systems. In plastic piping systems, the fluid carries significant levels of static electricity that must be grounded for best magmeter performance. Instructions are included with the installation manual on how to best ground the magnetic flow meter.

In Line Magmeters

The in line type magnetic flow meters offer a higher accuracy. They can be as accurate as 0.5% of the flow rate. The insertion styles offer a 0.5 to 1% accuracy. Omega's FMG-600 series in line flange and wafer style meters offer higher flow rates of 1 to 10 m/sec. These in line meters are offered in pipe sizes up to 12".

Minimum conductivity: 5 microSiemens/cm

Installation Considerations

In line flow meters do not require as much straight pipe as the insertion styles. A minimum of 5 to 10 pipe diameters of straight run upstream and 1 to 2 diameters downstream is recommended. In vertical pipe runs, flow should always run up and not down. These flowmeters are very sensitive to air bubbles. The magmeter cannot distinguish entrained air from the process fluid; therefore, air bubbles will cause the magmeter to read high.

Low Flow Magmeters

These low flow mag flow meters are also in line and offer 3/8" to ½" NPT connections. The FMG200 series offer flow rates down to 0.38 LPM (.1 GPM). A digital display with relay and analog outputs are standard.

For many years sensors used in high reliability applications, such as those used in aerospace and military applications, relied upon connectors such as the Mil-C-5015 or MIL-C-38999 connectors that provided high reliability and secure connections but at a high price. With the expanded use of industrial automation systems however, the number of sensors used have increased dramatically, driving the need for a reliable, cost effective connection system for these sensors.

Shop for Magnetic Flow Meters in India

The OMEGA Engineering Singapore office handles all inquiries and orders for India. We have Application Engineers and Sale Support Staff ready to assist you with your technical questions, quotations and orders. A one-stop source for process measurement and control, OMEGA provides support through web chat, e-mail and telephone. View our contact page to call or email us.

Choosing the Correct Temperature Transmitter for your Application

What is a Temperature Transmitter?

The thermocouple or RTD signal is converted to a 4 - 20 mA output signal using a temperature transmitter, which is considered to be the ideal solution for a number of remote temperature measurement applications. In comparison to conventional temperature measuring devices, temperature transmitters have definite advantages but must be selected with caution to avoid “ground loop” problems.

Why use Temperature Transmitters?

It is essential to monitor the temperature of a remote process in many cases. Extremely small signals are produced by common temperature sensing devices such as RTDs and thermocouples. It is possible to connect these sensors to a two-wire transmitter that will amplify and condition the small signal.

After being conditioned to a usable level, this signal can be transmitted through ordinary copper wire and used to drive other equipment such as controllers, computers, chart recorders, dataloggers or meters.

How to use a Temperature Transmitter?

Current is drawn using a temperature transmitter from a remote dc power supply in proportion to its sensor input. The actual signal is transmitted as a change in the power supply current.

Specifically, to measure the lowest temperature of a process, a thermocouple input transmitter will draw 4 mA of current from a dc power supply. With increasing temperature, the thermocouple transmitter will draw proportionally more current, until it reaches 20 mA.

This 20 mA signal corresponds to the highest sensed temperature of the thermocouple. The temperature range that the output current signal will represent is determined by the transmitter’s internal signal-conditioning circuitry (powered by a portion of the 4 - 20 mA current).

Physically, only two copper wires are needed to connect the temperature transmitter output signal in a series circuit with the process equipment and the remote power supply. This is made possible because the power supply line and the signal are combined (one circuit serves a dual function).

Choose the Right Temperature Transmitter

This unique probe is considered to be perfect for areas with space limitations, where traditional head connections are too large to fit. A secure industrial connection is provided by the M12 thread design.

Smart Temperature Transmitters

This smart head transmitter accepts thermocouple temperature sensors and transforms sensor output over a configured range to a standard industrial (4 to 20 mA) transmission signal.

Isolated 4 to 20 mA Transmitters

With no need for separate power input, two-wire operation power can be obtained directly from the 4 to 20 mA loop. This simplifies field wiring and prevents the possibility of noise pickup from power lines.

DIN Rail Temperature Transmitter

The TXDIN1600 Series has been custom designed to accept most common process and temperature sensor inputs. This new generation DIN rail mounted temperature transmitter provides the user with a standard two wire 4 to 20 mA output signal. Isolation is provided between output and input, and all temperature ranges are linear to temperature.

Advantages of Temperature Transmitters

Temperature transmitters provide many advantages over traditional temperature measuring methods:

AC power is not required at the remote location in order to operate a two-wire transmitter

The supply of additional power at the remote location is not needed, as transmitters are powered by a low level 4 - 20 mA output current signal. Additionally, the usual 24 Vdc signal necessary for operation is standard in plants that have increased amounts of instrumentation.

Electrical noise and signal degradation are not a problem for two-wire transmitter users

When it comes to ambient electrical noise, the transmitter's current output signal lends itself to a high immunity. Any noise that does appear in the output current is usually prevented by the common-mode rejection of the receiving device. In addition, the current output signal will not diminish (change) with distance as can be seen in most voltage signals.

Wire costs decrease significantly when using transmitters

A shielded cable is almost always required by low voltage signals produced by thermocouples when they are sent any significant distance. Ambient electrical noise from ac power lines, motors and arcing electrical relays can raise havoc with these signals that are transmitted in an unshielded cable. Additionally, expensive, heavy gage wire is often installed in applications requiring long cable runs as it decreases errors from signal voltage drops caused by line resistance.

Ordinary copper wire can be used to connect all of the pertinent equipment in a two-wire transmitter system. The 4 - 20 mA current output signal is relatively immune to ambient electrical noise and does not get degraded by long distance transmission, even over a small diameter wire. The addition of a temperature transmitter to a system prevents the problem of having to provide long runs of costly wire and an increasing amount of shielding.

Ground Loop Problems

If a grounding rod was driven into the earth at two different points with a voltmeter connected between them, a voltage difference would be detected between them. This potential difference exists between practically any two points along the surface of the earth.

This voltage difference will induce an error current along the line, which is referred to as a “ground loop” signal, when an attempt is made to measure a process that is at a remote location. Its result will be an error at the display.

An isolating temperature transmitter should be selected for a system in order to prevent “ground loop” errors of this type. The sensor signal will be optoelectronically isolated from the output current loop by this type of transmitter. This will allow the user to ground both the sensor and one side of the current loop.

Features of the Temperature Transmitter

A two-wire output with the same wiring used for output and power is provided by transmitters. The load resistance is connected in series with a dc power supply, and the current drawn from the supply is a 4 - 20 mA or output signal which is proportional to the input signal.

Remote mounting of the transmitter near the sensor is allowed by two-wire transmission in order to minimize the effects of noise and signal degradation to which low level sensor outputs are susceptible.

Environmental protection and screw terminal input and output connections are offered by a rugged metal enclosure ideal for field mounting. This enclosure may be either surface or standard relay track mounted.

Even though new models are now available that are linearized to the actual temperature, most temperature transmitters are linearized to the voltage signal produced by the thermocouple or RTD.

The thermocouple or RTD signal is converted to a 4 - 20 mA output signal by the temperature transmitters. Some models will convert to an RS-232C output. Transmitters are available with dip switch selection for several thermocouple types per model, as well as thermocouple and RTD selection on a single model.

RTD and thermocouple transmitters are available in either non-isolating or isolating models, and they also feature output ranging adjustments with zero and span adjustments over 80 to 100% (based on model) of the sensor range.

Some Information About USB pressure transmitter CPT2500

Applications

Calibration service companies/service industry

Quality assurance

Recording and monitoring of pressure processes

Measurement of pressure peaks

Special Features

Recording interval can be set from 1 ms ... 10 s

Measuring ranges from 0 ... 25 mbar to 0 ... 1,000 bar (0 ... 0.4 psi to 0 ... 14.500 psi)

Accuracy: 0.2 %, optional 0.1 % (incl. calibration certificate)

No external voltage supply required

Software for recording of measured values, calibration and evaluation

Description

Extensive application possibilities

The CPT2500 USB pressure transmitter is suitable for connection to any PC with a USB port, via the CPA2500 USB adapter.

For the USB adapter there are stainless steel pressure transmitters available with measuring ranges up to 1,000 bar. The USB adapter automatically detects the measuring range of the currently connected pressure transmitter and ensures a highly accurate pressure measurement.

Functionality

The measurement interval for pressure recording can be set in the range of 1 ms ... 10 s. With a recording interval of more than 5 ms the following data is recorded in addition to the current measured value:

the mean value over the recording interval

the maximum and minimum value during the recording interval

Thus pressure peaks within the overall recording interval can be very easily identified.

It is also possible to set start and stop conditions for the recording. In this way it is possible to detect pressure peaks with a resolution of up to 1 ms.

The CPT2500 is a thus very well suited to all applications where, over a limited time span, pressure processes must be recorded and analysed with high resolution.

Software

The USBsoft2500 and USB ScanSoft software are delivered as standard with the USB adapter. With it, all settings for recording the pressure process can be made. The recorded measured values can be graphically displayed and evaluated.

In addition to the USBsoft2500 and USB ScanSoft software, WIKA-CAL calibration software for calibration tasks is also available. Using this software, the data is automatically transferred into a printable calibration certificate.

Furthermore, WIKA-CAL also offers, over and above PC-supported calibration, the management of the calibration and instrument data in an SQL database. For data transfer, a USB interface is available.

Usage and benefits of simens sitarans aw210 - WirelessHART adapter

The WirelessHART adapter is a communications component which integrates different field devices in a WirelessHART network. The field devices will be connected via HART or 4 … 20 mA. The adapter supports the standard WirelessHART protocol.

Input: One-device input channel

One point-to-point connection with a HART device or a 4...20 mA device or up to eight externally powered HART devices operated in multidrop mode

Input: Communication type

HART communication in multi drop mode (standard HART V7.1), 4...20 mA current signal in point-to-point connection

Output

WirelessHART radio in 2.4 GHz

Benefits

Explosion proof type: Intrinsic safe, Explosion proof

HART/4...20 mA wireless signal transfer

No extra wiring costs with loop power supply

Up to eight devices connected in multi drop mode

Configurable with standard tools support EDD – e. g. SIMATIC PDM, HART handheld communicator

Supports burst mode and event notification for adapter and sub devices

Good and simple retrofitting or extension solution for wired devices

Do you know that what is pressure regulator and how it works?

Pressure regulator

A pressure regulator is a control valve that reduces the input pressure of a fluid to a desired value at its output. Regulators are used for gases and liquids, and can be an integral device with an output pressure setting, a restrictor and a sensor all in the one body, or consist of a separate pressure sensor, controller and flow valve.

Operation

A pressure regulator's primary function is to match the flow of gas through the regulator to the demand for gas placed upon it, whilst maintaining a constant output pressure.

If the load flow decreases, then the regulator flow must decrease also. If the load flow increases, then the regulator flow must increase in order to keep the controlled pressure from decreasing due to a shortage of gas in the pressure system.

A pressure regulator includes a restricting element, a loading element, and a measuring element:

The restricting element is a valve that can provide a variable restriction to the flow, such as a globe valve, butterfly valve, poppet valve, etc.

The loading element is a part that can apply the needed force to the restricting element. This loading can be provided by a weight, a spring, a piston actuator, or the diaphragm actuator in combination with a spring.

The measuring element functions to determine when the inlet flow is equal to the outlet flow. The diaphragm itself is often used as a measuring element; it can serve as a combined element.

In the pictured single-stage regulator, a force balance is used on the diaphragm to control a poppet valve in order to regulate pressure. With no inlet pressure, the spring above the diaphragm pushes it down on the poppet valve, holding it open. Once inlet pressure is introduced, the open poppet allows flow to the diaphragm and pressure in the upper chamber increases, until the diaphragm is pushed upward against the spring, causing the poppet to reduce flow, finally stopping further increase of pressure. By adjusting the top screw, the downward pressure on the diaphragm can be increased, requiring more pressure in the upper chamber to maintain equilibrium. In this way, the outlet pressure of the regulator is controlled.

Single stage regulator

High pressure gas from the supply enters into the regulator through the inlet valve. The gas then enters the body of the regulator, which is controlled by the needle valve. The pressure rises, which pushes the diaphragm, closing the inlet valve to which it is attached, and preventing any more gas from entering the regulator.

The outlet side is fitted with a pressure gauge. As gas is drawn from the outlet side, the pressure inside the regulator body falls. The diaphragm is pushed back by the spring and the valve opens, letting more gas in from the supply until equilibrium is reached between the outlet pressure and the spring. The outlet pressure therefore depends on the spring force, which can be adjusted by means of an adjustment handle or knob.

The outlet pressure and the inlet pressure hold the diaphragm/poppet assembly in the closed position against the force of the large spring. If the supply pressure falls, it is as if the large spring compression is increased allowing more gas and higher pressure to build in the outlet chamber until an equilibrium pressure is reached. Thus, if the supply pressure falls, the outlet pressure will increase, provided the outlet pressure remains below the falling supply pressure. This is the cause of end-of-tank dump where the supply is provided by a pressurized gas tank. With a single stage regulator, when the supply tank gets low, the lower inlet pressure causes the outlet pressure to climb. If the spring compression is not adjusted to compensate, the poppet can remain open and allow the tank to rapidly dump its remaining contents. In other words, the lower the supply pressure, the lower the pressure differential the regulator can achieve for a given spring setting.

Double stage regulator

Two stage regulators are two single stage regulators in one that operate to reduce the pressure progressively in two stages instead of one. The first stage, which is preset, reduces the pressure of the supply gas to an intermediate stage; gas at that pressure passes into the second stage. The gas now emerges at a pressure (working pressure) set by the pressure adjusting control knob attached to the diaphragm. Two stage regulators have two safety valves, so that if there is any excess pressure there will be no explosion. A major objection to the single stage regulator is the need for frequent torque adjustment. If the supply pressure falls, the outlet pressure increases, necessitating torque adjustment. In the two stage regulator, there is automatic compensation for any drop in the supply pressure. Single stage regulators may be used with pipe lines and cylinders. Two stage regulators are used with cylinders and manifolds.

Applications

Air compressors

Air compressors are used in industrial, commercial, and home workshop environments to perform an assortment of jobs including blowing things clean; running air powered tools; and inflating things like tires, balls, etc. Regulators are often used to adjust the pressure coming out of an air receiver (tank) to match what is needed for the task. Often, when one large compressor is used to supply compressed air for multiple uses (often referred to as "shop air" if built as a permanent installation of pipes throughout a building), additional regulators will be used to ensure that each separate tool or function receives the appropriate pressure it needs. This is important because some air tools, or uses for compressed air, require pressures that may cause damage to other tools or materials.

Aircraft

Pressure regulators are found in aircraft cabin pressurization, canopy seal pressure control, portable water systems, and waveguide pressurization.[1]

Aerospace

Aerospace pressure regulators have applications in propulsion pressurant control for reaction control systems (RCS) and Attitude Control Systems (ACS), where high vibration, large temperature extremes and corrosive fluids are present.[2]

Cooking

All modern pressure cookers will have a pressure regulator valve and a pressure relief valve as a safety mechanism to prevent explosion in the event that the pressure regulator valve fails to adequately release pressure. Some older models lack a safety release valve[citation needed]. Most home cooking models are built to maintain a low and high pressure setting. These settings are usually between 7 and 15 PSI. Almost all home cooking units will employ a very simple single-stage pressure regulator. Older models will simply use a small weight on top of an opening that will jiggle to allow excess pressure to escape. Newer models usually incorporate a spring-loaded valve that lifts and allows pressure to escape as pressure in the vessel rises. Some pressure cookers will have a quick release setting on the pressure regulator valve that will, essentially, lower the spring tension to allow the pressure to escape at a quick, but still safe rate. Commercial kitchens also use pressure cookers, in some case using oil based pressure cookers to quickly deep fry fast food. In this case, and in the case of cooking at home, pressurized vessels can be used to cook food much more rapidly than it would take to cook large amounts of food without pressure. Pressure vessels of this sort can also be used to sterilize small batches of equipment and in home canning operations.

Water pressure reduction

Often, water enters water-using appliances at fluctuating pressures, especially in remote locations, and industrial settings. This pressure often needs to be kept within a range to avoid damage to appliances, or accidents involving burst pipes/conduits. A single-stage regulator is sufficient in accuracy due to the high error tolerance of most such appliances. Also used in applications where the water supply reservoir is significantly higher in elevation to the end of the line. e.g. underground mine water supply.

Oxy-fuel welding and cutting

Oxy-fuel welding and cutting processes require gases at specific pressures, and regulators will generally be used to reduce the high pressures of storage cylinders to those usable for cutting and welding. Oxy-gas regulators usually have two stages: The first stage of the regulator releases the gas at a constant rate from the cylinder despite the pressure in the cylinder becoming less as the gas is released. The second stage of the regulator controls the pressure reduction from the intermediate pressure to low pressure. It is constant flow. The valve assembly has two pressure gauges, one indicating cylinder pressure, the other indicating hose pressure.

Propane/LP Gas

All propane and LP Gas applications require the use of a regulator. Because pressures in propane tanks can fluctuate significantly, regulators must be present to deliver a steady flow pressure to downstream appliances. These regulators normally compensate for tank pressures between 30 - 200PSI and commonly deliver 11 inches water column (0.4 PSI) for residential applications and 35 inches of water column (1.3 PSI) for industrial applications. Propane regulators differ in size and shape, delivery pressure and adjustability, but are uniform in their purpose to deliver a constant outlet pressure for downstream requirements. As is the case in all regulators, outlet pressure is lower than inlet pressure.

Gas powered vehicles

No matter what type of motor (internal combustion engine or fuel cell electric powertrain) a specific pressure regulator will be necessary to bring the stored gas (CNG, Hydrogen) pressure from 700, 500, 350 or 200 bar (or 70, 50, 35 and 20 MPa) to operating pressure in addressing all safety and operational requirements.

Recreational vehicles

For recreational vehicles with plumbing, a pressure regulator is a necessity. When camping, a source of water may have an enormous pressure level, particularly if it comes from a tank that is at a much higher elevation than the campground. Water pressure is dependent on how far the water must fall. Without a pressure regulator, the intense pressure encountered at some campgrounds in mountainous areas may be enough to burst the camper's water pipes or unseat the plumbing joints, causing flooding. Pressure regulators for this purpose are typically sold as small screw-on accessories that fit inline with the hoses used to connect an RV to the water supply, which are almost always screw-thread-compatible with the common garden hose.

Breathable air supply

Main article: Diving regulator

Pressure regulators are used with air tanks for SCUBA diving. The tank may contain pressures well in excess of 2,000 PSI, which could cause a fatal barotrauma injury to a person breathing it directly. A regulator allows only a sustained flow of air at the ambient pressure (which varies by depth in the water).

Mining Industry

As the pressure builds rapidly in relation to depth, underground mining operations require a fairly complex water system with pressure reducing valves. These devices must be installed at a certain distance interval, usually 600 feet (180 m).[citation needed] Without such valves, pipes would easily burst and pressure would be too great for equipment operation.

Working Principle Of Pressure Gauge

What is Pressure?

Pressure is defined as the amount of force applied to a unit area. Usually involving liquids and gases, Pressure is a critical component of a diverse array of applications, both those that rely on accurate pressure control as well as those that derive other values (such as depth/level or flow) based upon pressure.

Pressure measurements can be made in a number of units. Most commonly, we see PSI ( pounds per square inch) or bar. Other units of measure include kg/cm2, inH2O, mmHg, Pa, and many others.

There are also different types of pressure that are used in Pressure Measurement. The type of pressure refers to the zero reference point of a measurement. For example:

Gauge pressure:

The pressure gauge is referenced against atmospheric pressure so it does not include the effects of that pressure making it equal to absolute pressure minus ambient air pressure. Sealed gauge sensors may use a fixed pressure different than ambient atmospheric temperature.

Absolute pressure:

The pressure gauge is referenced against a perfect vacuum so it, therefore, includes the effects of atmospheric pressure. It is equal to gauge pressure plus atmospheric pressure.

Differential pressure:

The pressure gauge contains two process connections to measure the difference between two pressures, such as each side of a filter to measure pressure drop.

Pressure Gauge Technology:

Pressure gauges are fairly simple devices though there are many considerations that go into selecting the best instrument for your particular application. The most obvious difference, when looking at pressure gauges, is that some are digital while others are analog. While they fulfill the same basic role, analog and digital gauges use different technology and excel under different conditions.

Analog pressure gauges:

Most analog gauges rely on either of two measurement principles:

Bourdon Tube:

Gauges with bourdon tubes are the most well-known kind of simple gauges being used. Bourdon tubes depend on the rule that a bent tube has a tendency to rectify when subjected to pressure. The tube is associated with a pointing gadget so unobtrusive developments because of pressure variances are demonstrated on pressure aligned scale on the dial.

Bourdon tube pressure gauges work extremely well for most applications, especially those including medium to high pressures. They are straightforward in development, which keeps them economical and simple to utilize. Bourdon tubes additionally offer unrivaled linearity and can be exact up to ±0.1% making them appropriate for exactness estimations.

Bourdon tube pressure gauges likewise have impediments, however. They do not have the affectability for exceedingly precise readings at low pressures and can likewise be delicate to stuns and vibration and subject to hysteresis. Bourdon tubes can likewise react gradually, so applications including quick pressure vacillations are not perfect. Likewise, similar to every single simple gauge, Bourdon tubes can't make supreme pressure estimations nor are they especially adroit at accuracy estimations.

Bellows:

Bellows gauges are an awesome arrangement when measuring pressure runs underneath what is perfect for Bourdon tube gauges. Bellows gauges contain a versatile component that radially extends and contracts to react to pressure changes. The inner bellows are associated with a pointing gadget so inconspicuous developments because of pressure vacillations are shown on pressure adjusted scale on the dial.

Bellows gauges exceed expectations in low-pressure applications and have the exactness and affectability for exact estimation. Also, bellows gauges are tough and solid with low hysteresis and crawl. Like Bourdon tubes, bellows gauges are touchy to vibration and stun.

Simple gauges are boundless for a reason, they offer precision over the wide range at a decent cost. In spite of the fact that they can't coordinate the highlights of digital gauges, simple gauges are regularly accessible with temperature remuneration for more noteworthy precision, fluid fill to hose development of the pointer, numerous dial sizes to enhance perceivability and space necessities.

Digital pressure gauges:

Digital pressure gauges utilize propelled sensors and chip to show profoundly precise pressure readings on a digital marker. In spite of the fact that by and large more costly than simple gauges, digital gauges offer various highlights that make them appealing choices for various applications.

Digital gauges give snappy and simple to peruse comes about. As opposed to counting hashes to peruse the pressure, digital gauges give resolutions of up to 0.01 or 0.001 making them perfect for low pressures or little incremental pressure changes, for example, those found when spill testing, that would be difficult to relate to a simple gauge.

Digital pressure gauges have less moving parts than simple gauges making them more solid. Easy to work, they, in any case, can be customized for various pressure units and incorporate yields for sending results to a PC, information lumberjack, or different instruments for capacity or examination.

Most digital pressure gauges depend on one of two estimation innovations:

Strain gauge:

Strain gauge sensors depend on the piezoresistive impact which portrays changes in the electrical resistivity of a semiconductor or metal—generally silicon, polysilicon thin film, reinforced metal thwart, thick film, or sputtered thin film—when mechanical strain (pressure) is connected. Most regularly this innovation comprises of a stomach with designed metallic strain gauge implanted into it. Expanding pressure causes the stomach, and accordingly, the gauge to twist which impacts it's resistivity. That change is measured and changed over into an electrical flag corresponding to the pressure. By and large, strain gauges are associated with the frame a Wheatstone connect circuit to boost the yield of the sensor and to diminish affectability to blunders.

Piezoelectric sensors:

Piezoelectric sensors depend on the piezoelectric impact in specific materials, for example, quartz to gauge the strain upon the detecting system because of pressure. As pressure is connected a charge creates over the sensor in the extent to the force.

What to Consider When Choosing a Pressure Gauge?

What is the Magnitude of Pressure?

What precision is required?

What units of estimation are favored?

Which process association is required?

Are there any issues with material similarity or substance protection?

What is the temperature run? Is pay required?

What burst pressure is required?

What is the favored dial estimate?

We "Instronline" are the largest and biggest suppliers, traders, exporters, distributors of CALIBRATION INSTRUMENT, Pressure Calibrator, AUTOMATION SOLUTIONS, PLC, HMI, Recorder, data logger, controller, DRIVES, VFD, MVD, Softstarter, PRESSURE, Pressure Gauge, Transmitter Smart / Hart, Indicator, Digital Pressure gauge, Pressure Transmitter, Special Pressure Gauge, Diaphgram Seals, Pressure Accessories, Pressure Switch and much more Automation product. If You have any Querry regarding it please don't hesitate to contact us.

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Benefits of using Conductivity controllers

Conductivity controllers are used to monitor and control conductivity in process water or wastewater. Exceptional capabilities of the Conductivity controllers:-

These are Programmable wide measurement range
These devices are computerized temperature repayment
Set factors on the front panel
Huge vibrant red LED display screen
Twin heavy-duty output relays

Benefits OF dependable Conductivity Controllers

AC vs. DC Gear Motors: What’s the Difference, and Which Offers More Gear Motor Advantages?

Geared Motors

Helical geared automobiles are the conventional answer for your pressure software. Helical tools devices are coaxial units where the gear unit output shaft is in-line with the motor shaft. A solid shaft is always used as the output shaft. Additional additives – e.g. tools wheels or chain wheels to transfer the force to the driven load are therefore required. Solutions utilizing helical geared motors are able to an extreme variable speed variety. In lots of instances, helical geared motors constitute the most price-powerful solution for your power project.

· MOTOX helical geared vehicles are to be had for the electricity variety up to two hundred kW and rated tools unit torques up to 20,000 Nm.These geared motors are available in the following versions:

· Foot and flange-mounting variations

· Solid shaft

· Our most selling and maximum inexpensive unit, the BG gear motor, sets new requirements for reliability and financial system and consists of extraordinary preferred functions. An inverter pleasant design affords for easy integration now and a clearly future-proof answer. An inch or metric dimensioned output shafts are well-known presenting for clean integration into all your applications. The BG gear motor gives overall flexibility in mounting options consists of the foot, base, face, and flange answers. The motor terminal field may be mounted in alternative positions rotated in 90° steps around the motor body presenting for unheard of integration opportunities.

· BG tools motors follow North American and worldwide requirements, inclusive of NEMA, IEC, CSA, & CE, the BG series allows for global acceptance, a truly general solution for our global customers.

· Superior protection of IP65 acc. to IEC 529 assures you that the BG series is dust tight and hose evidence, and may be used outdoors or in moist and dusty environments without the usage of extra enclosures. The complete rated output is available on the output shaft of the unit.

If you are looking more products like Yokogawa Differential Pressure Transmitter, Yokogawa Flange Mounted Differential Pressure Transmitter, Yokogawa Absolute Pressure Transmitter these are available on instronline where you can Pressure Transmitter Dealers where you can find best quality Pressure Transmitter exporter, Yokogawa Differential Pressure Transmitter dealer in NCR

Difference between ac and Dc motor Gear Motor.

Given sufficient time, the engineer would possibly move directly to give an explanation for the technical factors that differentiate those two equipment motors. If speak me to a layperson, the engineer might start by means of explaining that AC stands for alternating modern-day, while DC stands for direct current. A more superior target market may get facts at the simple layout of each tool motor – an AC gear motor commonly features a rotor interior a stator with coils, while a DC gear motor would possibly have rotating armature windings with a stationary magnetic subject.

1. if you’re analyzing about gear motors, you’re probably an engineer yourself, so allows the pass to what might interest designers like you: AC gear motor blessings, in comparison to their DC counterparts.AC tools motor layout has advanced greatly in a previous couple of years, to the point where in an AC motor can provide a good deal or even more velocity manipulates than a DC motor. These days' AC cars can be regulated to within .1 percentage of the favored pace.

2. DC gear motors are nevertheless greater highly-priced, in common. A huge benefit of AC tools cars for manufacturers is their decrease price. These days, an AC motor and force collectively can cost the same as a DC motor on its personal.

3. Due to the fact they usually require less maintenance, an AC motor is a better preference for probably wet, tough-to-attain or otherwise unsafe environments.

4. Technological enhancements have added AC gear cars on top of things with DC automobiles. for example, cutting-edge AC vehicles can offer full torque without delay, at startup. That became impossible only some years ago.

5. Despite all of these blessings, there are a few conditions that also call for a DC equipment motor or an excessive overall performance AC motor. For one aspect, engine cooling is vital for lengthy-term overall performance, so a top class-efficient or power-green motor is usually recommended for adjustable-frequency drives.

Excessive starting masses and the call for constant horsepower whilst running a hundred and fifty percentages above base pace are a few different applications that demand specialized vehicles.

The pleasant manner to decide which gear motor is proper for you is to touch a custom motor producer together with Sinopec. After mastering approximately your needs and professional can advise the fine tools motor primarily based on its intended application.

The Most Appropriate Things About Electric Contact Pressure Gauge

The SE model contact pressures with electric alarm contacts are suitable for controlling or regulating process sequences. The contact opens and closes electric circuits when it comes to the location of the pointer at the strain gauge. Our touch strain gauges with bourdon tube system are used at technique pressures of about 1kg/cm2 and upwards. The materials used make the gauges suitable for chemically competitive gases or liquids, even though these won't be too viscous or be at risk of crystallization. The cheaper attempted and examined bourdon tube system coupled with cutting-edge modular precept offers a very dependable but much less luxurious contact pressure gauge. Electrically powered alarm touch is used as magnetic snap-motion contacts, mainly in harsh business conditions. The high contact strain and the selection of different electrical contact substances permit excessive currents to be switched reliably. If the electric switching areas of the alarm contacts are handed or not reached a relay is to be used to offer an appropriated modern rating. Inductive alarm contacts function without bodily contact and consequently don't have any detrimental consequences for the stress measuring machine on the identical time as having endless service lifestyles.

General specification of Electric Contact Pressure Gauge:-

A manipulate unit is usually had to carry out these contracts. Touch pressure gauges with inductive alarm touch can be applied in probably explosive atmospheres, supplied that the proper policies are complied with. .if you are looking for Food Process Industries / Hygienic Applications then find best electromagnetic flow meter Dealers which has the good information about Water treatment plants, Iron and Steel Industries, General Mechanical Engineering Industries, Rubber Molding / Processing Plants, Chemical process industries.They will help you out in choosing best Temperature Transmitter Suppliers and Temperature Transmitter Exporters.

EP model contact pressure gauges with electrical contacts are suitable for controlling and regulating process sequences. The contact opens and closes electrical circuits in relation to the position of the pointer on the pressure gauge. Contact pressure gauges with bourdon tube system are used at process pressures of approximately 1 kg/sq.cm and upwards. The materials used to make the gauges are suitable for chemically aggressive gases or liquids, although these may not be too viscous or be susceptible to crystallization which long lasting and very easy to use. The tried and tested bourdon tube system coupled with modular contacts provides a very reliable contact pressure gauge. Electrical alarm contacts which are used for magnetic snap action contacts, especially in harsh industrial conditions which are very tough, the high contact pressure and the choice of different electrical contact materials enables high currents to be switched reliably. If the electric switching capacities of the contacts are exceeded or now not reached, a relay is for use to provide the appropriated contemporary rating. If you are looking products dealers like Diaphragm pressure gauge dealer in Noida Best Pressure Transmitter Suppliers, Pressure Transmitter exporter, Pressure Transmitter supplier in Delhi NCR.

The benefit of Using Electric Pressure Gauge:-
1. The Modular construction system ensures high reliability and long service life.
2. Due to stainless steel design here is Chemical resistance Very good.
3. The Contact Accuracy of every class is near about 1,6 % of FS standard and Casing, Stainless Steel 304 standard.
5. Stainless Steel Measuring System which is very good looks wise.
6. Up to four-alarm contact possible as an option which is more comfortable.
7. This is well suitable for the programmable controller.

Area of Application:-
Widely used in Petroleum industries m, Thermal / Hydro Power Stations, Hydraulics and Pneumatics systems.

A magnetic flow meter

A magnetic Flow meter (magazine go with the flow meter) is a volumetric go with the flow meter which does now not have any shifting elements and is good for wastewater programs or any dirty liquid that's conductive or water based. Magnetic glide meters will usually now not paintings with hydrocarbons, distilled water and lots of non-aqueous answers). Magnetic flowmeters also are best for packages where low strain drop and low preservation are required.

Working Principle of Magnetic Flow Meter:-
Faraday’s law the operation of a magnetic flow meter or magazine meter is based upon Faraday's regulation, which states that the voltage brought about throughout any conductor as it moves at proper angles via a magnetic subject is proportional to the rate of that conductor.
to use this principle to waft dimension with a magnetic flow meter, it's miles essential first to the kingdom that the fluid being measured need to be electrically conductive for the Faraday principle to use.

Magmeter Selection Process:-
The key Point which needs to be answered before selecting a magnetic flow meter are:
1. Is the fluid conductive or water based?
2. Is the fluid or slurry abrasive?
3. Do you require an integral display or remote display?

Insertion Magmeter:-
Insertion type meters supplied with the aid of Omega Engineering have a well-known 2" NPT or suit into a particular size fitting. The FMG-550 collection is designed for 2" to forty-eight" in length with a floating price of zero.05 to ten m/sec (0.15 to 33 toes/sec). The FMG-550 collection gives an analog output with a quintessential show for float fee and tantalization. The FMG3000 collection offers corrosion resistant materials for pipes from zero.5 to 8". These insertion type flow meters are best for massive pipe packages.

Installation Considerations:-
Select a place for the sensor in which the drift profile is absolutely advanced and now not laid low with any disturbances. a minimum of 10 pipe diameters of heterosexual run upstream and 5 diameters downstream is recommended. Some conditions may additionally require 20 pipe diameters or greater upstream to ensure a completely evolved turbulent glide profile. The insertion Magmeter is sensitive to air bubbles on the electrodes. If there may be any query that the pipe is absolutely complete, mount the sensor at a 45 to a hundred thirty-five attitude.

Grounding requirements:-
Magnetic flow sensors are sensitive to electrical noise which is present in most piping systems. In the plastic piping systems, the fluid carries significant levels of static electricity that must be grounded for best Magmeter performance.Instructions are included with the installation manual on how to best ground the magnetic flow meter. If you are trying to find out best Low price electromagnetic flow meter Dealers, Siemens Electromagnetic flow meter Suppliers In Delhi NCR, Best Price Electromagnetic Flowmeters which is very cost effective.

In-Line Magmeter:-
The in-line type magnetic flow meters offer a higher accuracy. They can have accurate to 0.5% of the flow rate. The insertion styles offer a 0.5 to 1% accuracy. Omega's FMG-600 series line flange and wafer style meters offer higher flow rates of 1 to 10 m/sec. These inline meters are offered in pipe sizes up to 12".

Installation Considerations:-
In line flow meters do not require a great deal immediately pipe because of the insertion patterns. at the least, 5 to ten pipe diameters of straight run upstream and 1 to two diameters downstream is recommended. In vertical pipe runs, the flow has to continually run up and now not down. these go with the flow meters are very touchy to air bubbles. The magmeter cannot distinguish entrained air from the manner fluid; consequently, air bubbles will cause the Magmeter to read excessively.

Low Flow Magmeter:-
These low flow mag glide meters also are in line and offer three/8" to ½" NPT connections. The FMG200 collection provides glide quotes right down to 0.38 LPM (.1 GPM). A digital display with relay and analog outputs are fashionable. For decades sensors utilized in excessive reliability applications, consisting of the ones utilized in aerospace and military applications, relied upon connectors including the Mil-C-5015 or MIL-C-38999 connectors that supplied excessive reliability and cozy connections but at an excessive price. With the accelerated use of business automation structures, however, the quantity of sensors used have expanded dramatically, using the need for a reliable, value effective connection machine for those sensors.

Shop for Magnetic Flow Meters in India:-
The Instronline portal handles all inquiries and we’ve utility Engineers and Sale assist personnel equipped to assist you along with your technical questions, quotations, sand orders. A one-stop supply for system size and manage, Instronline presents guide thru internet chat, and email and Smartphone there are exceptional.
Pressure Transmitter Suppliers, Pressure Transmitter Exporters which will help you to choose right products.

How To Choose Control Valve

A control valve is a mechanical device that regulates the drift of the fluid in a pipeline with the aid of adjusting the size of the valve beginning according to signals controlled by using a controller. These sorts of valves control the drift price and related values as fluid stress, temperature, and stage. The opening and last of the valve, and it regulation, is finished by using the combined effect of a digital controller, a positioned and the actuator of the valve (which can be electric, pneumatic or hydraulic). Control valves are to be had in multiple shapes (maximum commonplace are globe, butterfly, and ball), material grades and sizes.

The most used type of actuator is the air-operated because it entails much less ancillary equipment (as cabling, switchgear) whilst as compared to different types of actuators. If you are looking best products like intelligent Level Controller, ultrasonic liquid level switches, with utility Control valves is increasing in the closing years, due to growing procedure automation in most industries. Those forms of valves are utilized in irrigation structures, water remedy flora, oil and fuel plants, energy technology, fireplace prevention structures, meals processing industries by streamlining the reaction to modifications in methods and offering greater safety to personnel and system.

TYPES OF CONTROL VALVES:-

Types of control valve almost any type of valve can be used for manage by way of becoming an actuator and positioned, even though care needs to be taken to make certain that there's no immoderate backlash gift and it will likely be recognized many will not showcase a good characteristic for precise manipulate.

Globe:-(Plug and Seat) those are the maximum traditionally used manage valves - commonly to be had from 12 to 400mm in all castable substances. Large sizes are available but it becomes greater commonplace to move to an attitude construction on these sizes.

Eccentric Plug: -A preferred purpose valve that offers price effective solutions over an extensive range of fashionable packages. It offers better CV values than globe - length for size with special features.

Butterfly:- The least expensive of all control valves. Sizes range from 50 to 3000mm. Pressure ratings are generally up to 1600 kappa (G). Temperatures are up to 100∞C. This valve is good for corrosive applications but does not handle high pressure drops well. It is the lightest valve available -size.

Diaphragm / Pinch:-These valves are inexpensive and very simple in operation. They are used extensively in the mining industry for control of slurries and Very good for low-pressure abrasive applications and you can this type product with Temperature Transmitter Suppliers which will help you out to choose right products. At Instronline radar level transmitter, electromagnetic flow meter Dealers, Siemens Electromagnetic flow meter Suppliers, Siemens Electromagnetic flow meter Dealers

Selection of accessories:-

Normally, the selection of accessories such as petitioners, transducers, boosters, solenoid valves, limit switches, hand wheels and travel stop, snubbers, regulators, transmission lines, is based on engineering specifications.

Cost is a major factor in material selection:-

Now not simply the value of fabric in bucks in keeping with the pound, however also the fee of fabrication and inspection contribute to the uninstalled cost valve. Set up cost consists of not best the fee of installation but additionally the cost of any harm from fallacious setup and value the inspection. The final includes things like analysis of material chemistry, radiographic and surface examination of castings and welds, and take a look at to see that the established valve is the precise one and that its miles nicely oriented.

The selection of the ideal or most reliable manage valve type relies upon on the particular take a look at of the pipe machine and the conditions of its fluid, however the length of the manipulate valve need to be such that stress drops through it and now not the drop of strain of the pipe is the one that controls the waft.If you are looking full specification of products like rf level transmitter, Ultrasonic Level Transmitter Dealers In Delhi NCR, low radar level transmitter Exporters of All valves, along with steam control valves, are designed to satisfy an allowable internal leakage preferred (FCI / ANSI) you can find these all on. The better the quality of products and updated price list on Instronline.

How SITRANS FM Magflo Mag5000 Transmitters Works

Transmitter MAG 5000/6000 compact version and 19“ insert model .The magazine 5000 and 6000 are microprocessor-based totally transmitters engineered for high performance, smooth set up, commissioning and upkeep. The transmitters compare the indicators from the Sitrans FM Magflo sensors kind mag 1100. You can find best SITRANS FM Electromagnetic Flow meters with the help of electromagnetic flow meter Dealers at Instoline where you will find Siemens Electromagnetic flow meter Suppliers ,Siemens Electromagnetic flow meter Dealers ,Siemens Electromagnetic flow meter Exporters.

Benefits of using SITRANS FM Magflo Mag5000:-
• Superior sign resolution for max turns down ratio.
• Virtual signal processing with many opportunities.
• computerized analyzing of SENSORPROM facts for smooth commissioning.
• User configurable operation menu with password safety.
• 3 strains, 20 characters show in eleven languages.
• go with the flow price in diverse units.
• Totalize for forward, opposite and internet glides as well as extra.

Information Available More About SITRANS FM Magflo Mag5000:-
• Multiple functional outputs for process control, minimum configuration
With analogue, pulse/frequency and relay output
(Status, flow direction, limits)
• Comprehensive self-diagnostic for error indication and error.
• Custody transfer approval: PTB, OIML R75, R117, R49.

Major Application of SITRANS FM Magflo Mag5000:-

The mag waft meters are appropriate for measuring the go with the flow of almost.
All electrically conductive drinks, pastes and slurries. the principle programs can be determined in:-
• Water and waste water.
• Chemical and pharmaceutical industries.
• Meals & beverage industries.
• Electricity technology and utility.

Design principle of SITRANS FM Magflo Mag5000

The transmitter is designed as either IP67 NEMA 4X/6 enclosure for compact or wall mounting or 19" version as a 19” insert as a base for use in:-
• 19" rack structures.
• Panel mounting IP65/NEMA 4.
• lower back of panel mounting IP20/NEMA 2.
• Wall mounting IP66/NEMA four.

Numerous options on 19” variations are to be had such as:-
• Transmitters for EEx ATEX authorized go with the flow sensors (incl. limitations).
• Transmitters with electrode cleansing unit.

Function of SITRANS FM Magflo Mag5000:-

The MAG 5000/6000 is microprocessor-based transmitters with a build-in alphanumeric display in several languages. The transmitters evaluate the signals from the associated electromagnetic sensors and also fulfill the task of a power supply unit which provides the magnet coils with a constant current.

Further information on connection, mode of operation and installation can be found in the data sheets for the sensors. FM Electromagnetic Flowmeters supplier at Instronline Electromagnetic flow sensor supplier in delhi NCR.

Mode of operation:-

The cleansing unit cleans the electrodes electro-chemically by using applying a voltage to the electrodes for approx. 60 seconds. While cleansing, the transmitter stores and holds the modern-day measured go with the flow studying at the show and additionally the sign outputs. After a further pausing period of 60 seconds the drift meter resumes regular dimension and the cleaning is now finished. The relay within the transmitter activates the cleaning cycle. Within the relay output menu (below cleansing) the cleansing c programming language can be set between 1 hour and 24 hours. Cleansing need to handiest take location with liquid in the pipe. This may be detected via the empty pipe feature. it's miles therefore encouraged to pick “empty pipe detection” ON while the use of the.

Cleaning:-

The cleaning collection also can be managed manually through the electrical enter of the transmitter. Earlier than that is executed, make certain that the measuring pipe is full.

Step by step installation instructions of High-quality pressure transmitter

Transmitters are used in the system enterprise environments to degree stress and other parameters. The plant operators rely upon those devices for correct measurements and manner optimization. The performance of those transmitters may also weaken with time due to numerous elements. That is once they need calibration. During calibration, an evaluation is made between the modern-day analyzing and the standard set studying. This allows plant operators decide the shift in readings and make important changes. The calibration techniques might also barely vary across the kinds of branded stress transmitters due to their designs. But, there are some standard steps to follow before calibrating your transmitter. At Instonline you can find all the type Sealed Diaphragm Gauge which will help in all type industry.

Some Basic Setup for Calibrating a Pressure Transmitter.

The transmitter can be easily calibrated following the manufacturer’s precise commands on calibration, supplied with the equipment. Study the preparation guide cautiously to recognize special steps concerned in the calibration. Additionally, you could refer diverse films to be had online to apprehend the technique. Arrange all instruments wished for the Calibration: the use of a proper device is a requisite of any calibration manner. Set up all devices wanted for calibration along with strain gauge, digital millimeter, stress source, and power supply module (24V). Make certain that the readout device and stress supply used are of exquisite accuracy than the transmitter to be calibrated. Correct measurements can't be performed, if low accuracy equipment is used for the calibration. The gadgets used for the calibration process must be regularly tested to make sure they may be running perfectly and serving their reason.

1. Transmitter Span

Most guidance manuals provide the connection diagram, or you could download the one from the net. Join all equipment as it should be as referred to inside the diagram. To keep away from any mistake, you can take several printouts of the diagram. You need to pay attention to a power supply as well as the polarity of the transmitter.

2. Prepare the tool for Calibration:
normally the calibration is done in either of the 2 ways:

3. Benchtop Calibration:
that is a manner, where the transmitter is calibrated at a bench using various calibration devices.

4. subject calibration:
this is a technique, where the real calibration is carried out as consistent with the tips referred to on this publish.

In each of the above-referred to types, the low port of the transmitter cell is vented to the ecosystem and the excessive port to a stressed supply. Examples of high port encompass pneumatic calibrator, pressure regulator, or a hand pump.

After putting in the relationship, turn on the power delivery, and pressurize the excessive port. Document the analyzing of present day (mA) and this can be the primary analyzing. Hold pressurizing the transmitter, and file readings in 5 points –zero%, 25%, 50%, 75%, and a hundred%. Take down readings for increasing, as well as lowering input values and corresponding output values. After the preliminary setup, you may start with the real calibration. Inside the next submit, we can talk steps for calibrating the pressure transmitter, Siemens Differential Pressure Transmitter dealer In Delhi NCR, Siemens Pressure Transmitter Exporter In Noida, instronline Compact pressure transmitter supplier, Pressure Transmitter Dealers which will help to find out best Differential Pressure Transmitter.

Get More Information About The Benefits Of Differential Pressure Transmitter.Click Here

Ultrasonic Vs Electromagnetic Flow Meters Which Is Used For Flow Measurement

Flow meters are extraordinarily essential gadgets for plenty industries in which it is vital to measure the charge or quantity of a fuel or liquid transferring through a pipe. There are specific styles of flow meters and there isn’t a ‘one-size-suits-all’ solution. On the subject of deciding on which device is high-quality for a particular application, it’s recommended that choices are based on the merits of the technology instead of looking to make the era match the software. It’s also by no means a great concept to priorities fee-financial savings over capabilities, and in case you’re selecting a float meter, Take into account that decrease-priced options may not have the capability to satisfy your necessities. Temperature Transmitter Suppliers with a high-quality product are crucial to recognize what the essential specs of the distinctive technologies are, so if you are considering a watt meter, the following dialogue on the important thing features of the primary sorts, namely ultrasonic float meters, and electromagnetic ones, could be beneficial.That two technology presently account for over 85% of the marketplace, with the growth of ultrasonic drift meters tipped to escalate in the future because of its many good advantages of buying the products with Pressure Transmitter Suppliers they will guide you for the best items.

Some crucial capabilities of Electromagnetic Flowmeters:-

All of the electromagnetic drift meter uses Faraday’s law of Electromagnetic Induction to measure float prices. it works by means of developing a magnetic subject by means of walking electric cutting-edge thru a coil surrounding the drift tube.

Designed for systems that move conductive liquids which include water, acids, caustic drinks and slurries
Performance isn’t inhibited via viscosity, temperature, and pressure Responds well to speedy adjustments in float
Suitable for drinks with heavy particulates.

A few important capabilities of ultrasonic go with the flow meters:-

Ultrasonic waft meters use ultrasound waves to calculate float thru a pipe and are used to measure an extensive style of fluids which includes water, natural gas, mineral oil, chemical substances and grimy liquids. it's miles an enormously accurate, non-intrusive procedure and the clamp-on devices can degree drift from the out of doors of plastic, steel or concrete lined pipes, regardless of their length. Ultrasonic level controller supplier presents a large array of products according to your choice and need.
• Relatively correct
• No moving parts meaning minimum, if any, renovation
• Easy to install and operate
• Fee-effective
• Clamp-on transducers are non-invasive, in order that they don’t obstruct the go with the flow, intervene with the stressor contaminate the procedure.

An ultrasonic go with the flow meter is an important non-adverse checking out tool in terms of ensuring constant product first-class, enhancing protection, optimizing techniques and protecting the environment. They offer accurate dimension of liquid and gas glide throughout a wide form of packages, each industrial and home, inclusive of method control, water useful resource management and effluent control in addition to inside the energy, chemical, meals and beverage, pharmaceutical, metals and mining, pulp and paper and oil and gas industries.

As cited in advance within the article, it's far important to pick the era which has the right attributes for your precise application. Getting professional advice from someone who's in reality interested in making sure that you have the proper answer may be hugely valuable over the lengthy-term, so it’ s worth speak me to us. Touch us nowadays a wide variety of products are available at Instronline.com here you will find a total solution related to automation of products.

How to choose the Right Temperature Controller

The way to choose the proper Temperature Controller for your system choosing the proper tool improves operations, saves money and makes for a safer gadget. Through Clayton Wilson, control gadgets manager at Yokogawa organization of the United States in many exclusive kinds of industries and applications, measuring and controlling temperature is vital for making sure quality and secure operations. Temperature controllers are used in studies laboratories, product improvement facilities, manner flowers and different commercial settings. In a smooth temperature-controlled lab setting, a cheaper off-the-shelf controller may be the proper product. But, these same controllers usually can’t live on the cruel situations common to heavy enterprise processes and faraway regions. Even as keeping temperature manipulate is imperative, it’s also one of the maximum difficult parameters to successfully manipulate.

A cheaper controller can be the pleasant one for an easy application, however, there are other vital elements to don't forget further to initial fee. Determining what controller to use can be perplexing because at a fundamental degree all controllers work in a similar way. The controller samples a fee transmitted from a temperature sensor typically in step with 2nd and compares this process variable in opposition to the set point. Whenever the process variable deviates from the set factor, the controller sends an output sign to have interaction other devices, together with heating and cooling mechanisms, to bring the temperature again to the set point. Notwithstanding being fairly similar on initial inspection, different controller kinds have capabilities and functions that provide vital benefits, relying on the sort of software. Braving the elements A evaluates of the input sensors is the excellent area to begin whilst choosing a controller for deployment in regions situation to dirt, excessive temperatures, and noise. Depending on the software—enter sensors may consist of thermocouples, RTDs and linear inputs such as mV and mA. For harsh environments, thermocouple or RTD sensors are the generally first-rate choice.

Thermocouple sensors are economical, rugged and provide accurate measurements for a wide range of temperature values. At instronline.com there are best available in multiple types and configurations, they work well in many different types of industrial installations.

ON-OFF Controllers:-

An ON-OFF controller is cheaper, but it may only determine if an output wishes to grow to become on or off. As an example, if the set point on a boiler is 245 stages and the method price temperature falls to 244 degrees, the controller will ship an ON sign. This sign might turn a heater on, open a steam valve, or take different action to grow the boiler temperature.

Braving the Elements:-

An assessment of the input sensors is the fine place to start while selecting a controller for deployment in areas problem to dirt, extreme temperatures, and noise. Relying on the software—enter sensors may include thermocouples, RTDs and linear inputs which includes mV and mA.For harsh environments, thermocouple or RTD sensors are the normally nice desire. Thermocouple sensors are low-priced, rugged and offer correct measurements for an extensive variety of temperature values. RTDs have a higher temperature restriction of about 1200 ranges Fahrenheit compared to 4200 stages Fahrenheit for thermocouples. something temperature sensor kind is chosen, the controller has to contain a "sensor ruin come across" feature. This signals the controller whilst a sensor is faulty or absent, permitting it to adjust the output to a preset value so as to save you damage to equipment and employees.

Protecting the Controller:-

Panel-installed controllers are presented with numerous front panel enclosure rankings, with charges growing alongside the degree of safety. The right Ingress protection (IP) score and the national electrical manufacturers association (NEMA) score should be selected depending on the particular utility.IP rankings are usually IP65 or higher for maximum commercial programs. This indicates the controller is absolutely covered with dirt, oil, and different non-corrosive fabric. The IP65 rating also guarantees entire protection from touch with the enclosed system, and from water projection by way of a nozzle from any path. More or less corresponding to an IP65 score could be a NEMA four or 4X rating. The 'X' in a NEMA 4X rating method that the controller's front panel might not corrode at some point of everyday running situations. Pressure Transmitter Dealers are providing full details and customer support for different Differential Pressure Transmitter and other products.

Highly Flexible Controllers:-

Single loop controllers typically have one input and one output. Multi-loop controllers have numerous inputs and outputs and can be used to simultaneously manage numerous loops, permitting the supervision of more procedure system functions. Furthermore, multi-loop controllers are compact and modular and can operate both in a stand- on my own mode or as a part of a complicated automation device together with a programmable good judgment controller, a programmable automation controller, of a disbursed manipulate structures.

Advanced controllers additionally offer higher conversation talents, letting them communicate with superior automation systems via virtual verbal exchange links. They can be configured speedy and without problems the use of computer-based total software, permitting configurations to be easily saved for future use. While related to the internet or to an intranet, those controllers may be accessed remotely, allowing full far-flung viewing, configuration and manage from any location with internet or intranet get entry to. At Our portal, you can also find Sealed Diaphragm Gauge Suppliers Sealed Diaphragm Gauge, Sealed Diaphragm Gauge Exporters.

HOW TO USE A ELECTROMAGNETIC FLOW METER

PRINCIPLE

SITRANS FM Electromagnetic Flow meter detects flow by victimization Faraday's Law of induction.

Inside the SITRANS FM Electromagnetic Flow meters, there's the associate degree electromagnetic coil that generates a field of force, and electrodes that capture emf (voltage). owing to this, though it should seem as if there's nothing within the flow pipe of SITRANS FM magnetic force Flow meter, flow is measured

Under Faraday's law of induction, moving semiconducting liquids within a field of force generates associate degree emf (voltage) during which the pipe inner diameter, field of force strength, and average flow rate are all proportional. In alternative words, the flow rate of liquid acquiring a field of force is regenerate into electricity. (E is proportional to V × B × D).As the flow changes, the emf (voltage) at bay by the electrodes changes as follows.

If you are interested in SITRANS FM Electromagnetic Flow meter and want to know more about SITRANS FM Electromagnetic Flow meter Dealers, FM Electromagnetic Flow meter Exporter, Electromagnetic Flow meter dealer In Delhi NCR, SITRANS FM Electromagnetic Flow meter Exporter In Noida. Then you can find in on Instronline.com

FEATURES OF SITRANS FM ELECTROMAGNETIC FLOW METER
Within the context of the principles listed higher than, SITRANS FM elElectromagneticlow meters typically have the subsequent options.

PROS
・Unaffected by the temperature, pressure, density,or body of the liquid.
・Able to sight liquids that embody contaminants (solids, air bubbles)
・There isn't any pressure loss.
・No moving elements (improves reliability)

CONS
・Cannot sight gases and liquids while not electrical conduction.
・A short section of straight pipe is needed

ELECTRICAL CONDUCTION
There is one necessary purpose once victimization SITRANS FM electromagnetic Flow meter as a result of SITRANS FM electromagnetic Flow meters are supported the laws of electromagnetic induction , semiconducting liquids are the sole liquids that flow is detected. whether or not it's a semiconducting liquid or not is decided by the presence of electrical conduction.So, simply what's electrical conductivity?

Electrical conduction typically could be a worth that expresses the benefit for electricity to flow. the other numerical worth is ohmic resistance, that expresses the amount of issue for electricity to flow. For units, S/cm (siemens per centimeter) is primarily used. to work out however simply electricity can flow, one cm² electrodes are placed one cm apart. victimization water at one hundred to two hundred μS/cm, drinking water at five hundred μS/cm or a lot of, and pure water at zero.1 μS/cm or less as samples, we are able to give samples of actual measured electrical conduction.

In order to calculate electrical conduction, it's necessary that conditions, like conductor space and therefore the distance between electrodes, are properly calculated. thanks to this, it's fairly troublesome to calculate. As a general thanks to make sure electrical conduction, associate degree electrical conduction meter (US$50-1000) is wont to perform this measure.

WHY WILL WATER CONDUCT ELECTRICITY?
H2O itself could be a stable molecule, and can not conduct electricity. So, why will electricity flow in water? the key is that the absence or presence of impurities within the water confirm its ability to conduct electricity.

Besides liquid (water molecules), Ca2+ (Calcium ions) and Mg2+ (Magnesium ions) exist among water. The terms H2O and H2O are determined by quantity|the quantity|the number} of ions found among a given amount of water. as a result of these ions conduct electricity among water, tap water, groundwater and alternative particle made waters possess a property that conducts electricity. Also, since pure water is merely liquid and doesn't contain any impurities, it cannot conduct electricity.

QUICK TECHNIQUE
When you would merely prefer to make sure the presence or absence of electrical conduction, a customary multi-meter is used. Place the tester in a very mode that measures resistance values and place each probes into the liquid. If the needle of the tester moves even slightly towards the zero aspect, it shows that electricity is flowing.Conversely, if the needle doesn't move from in the least, then there's no electrical conduction. It is judged that detection with SITRANS FM electromagnetic Flow meter.

Benefits Of Wireless HART Pressure Transmitter

Wireless’ hart pressure transmitter is meant to be used in rugged, industrial area unites wherever correct pressure measurements are required. Offered in powered and AC-powered versions, the wireless pressure transmitter includes the wireless transmitter, pressure detector, and self-contained power supply beat a light-weight, rugged aluminum enclosure to be used in industrial environments. The wireless pressure transmitter allows tank farms, pipelines, in-plant, and alternative industrial applications to control while not the constraints of arduous wiring. The system is meant to assist users avoid pricey cable and passage runs, lower labor and material installation prices, Associate with the monitoring devices wherever cabling is not an choice.

Wireless solutions supply way more edges than simply the elimination of cabling and installation prices. Users conjointly exploit considerably quicker commission and additional economical maintenance, still bigger flexibility and quality. And wireless technology ensures improvement of production quality and safety in plants. In the end, all of those benefits add up to bigger overall plant availableness. Wireless devices are terribly economical as a result of their distinctive energy management supported a extremist low power vogue. The significance or extended battery life can increase the dependableness of your network. Teeming faster update rates are potential.

The battery replacement intervals are going to be vastly reduced. Wireless instrumentation network deployment made easy Common HMI platform for easier network access, device parameterization and troubleshooting Wireless Differential Pressure Transmitter devices can be configured with common HART Handheld terminals. ALL the delivers pre-configured wireless devices for your network, for a quick, reliable and cost-effective deployment.You are looking Pressure Transmitter Dealers then you can find search online Instronline Differential Pressure Transmitter Exporter they will you to find the Siemens Differential Pressure Transmitter dealer In Delhi NCR ,Siemens Pressure Transmitter Exporter In Noida. Our best appealing model like, SITRANS P280 is a Wireless HART pressure transmitter that provides all type measurement processing values as well as diagnostic information, parameters and functions via radio.

The device is powered by an internal battery and designed for ultralow power consumption. The best part of this is that it had compact and rugged design which makes it especially suitable for direct mounting on tanks and pipes in remote parts of plants, and on moving or rotating equipment for process monitoring or asset management applications. You can find all type of Siemens Differential Pressure Transmitter dealer In Delhi NCR.

Benefits of using Wireless HART Pressure Transmitter

1. It gives LCD display with functional display items and icons, English and German display selectable
2. There are Practical push buttons: Three push buttons for maximum efficiency for setup, diagnostics, communication and security settings with no additional devices or tools
3. It provides Maintenance-friendly backlight function
4. There is Sleep mode for efficient battery life management
5. Physical HART maintenance port for commissioning

Application of Wireless HART Pressure Transmitter
1. This is field device for measuring absolute and gauge pressure.
2. The measuring ranges for absolute and gauge pressure measurements .The sensor is integrated into the transmitter housing.
3. It can be used in all Type industries and applications in non-explosive areas.

Get More Information About:-Tips For Choosing Right Temperature Transmitter:-Click Hear

Automation Globe Valve And Its Types

Globe valves could also be used for isolation and strangling services.Though these valves exhibit slightly higher pressure drops than straight through valves, they’ll be used wherever the pressure drop through the valve isn't a dominant issue.

Larger Glove valves would need that giant forces be exerted on the stem to open or shut the valve besieged.Globe valves square measure extensively utilized to regulate flow. The vary of flow management, pressure drop, and duty should be thought-about within the style of the valve to avert premature failure and to assure satisfactory service. Valves subjected to high-differential pressure-throttling service need specially designed valve trim. Valves with special trim could also be designed for applications prodigious these differential pressure limits. Many top brands are presenting very good glove value like Pneucon TEFLON LINED BALL VALVE WITH ROTARY ACTUATOR, Pneucon GLOBE 2 WAY VALVE (Piston Operated Valve) , you can find this products on instroline.

Types of Globe Valves
1. Tee Pattern globe valves have all-time low constant of flow and better pressure drop. They’re employed in severe choking services, like in bypass lines around an impact valve. Tee-pattern globe valves may additionally be employed in applications wherever pressure drop isn't a priority and choking is needed.

2. Wye Pattern globe valves, among globe valves, supply the smallest amount resistance to flow. They will be cracked open for long periods while not severe erosion. They're extensively used for strangulation throughout seasonal or startup operations. They will be rod through to get rid of rubble once employed in drain lines that area unit ordinarily closed.

3. Angle Pattern globe valves turn the flow direction by ninety degrees while not the utilization of Associate in Nursing elbow and one additional weld. They need a rather lower constant of flow than wye-pattern globe valves. They are employed in applications that have periods of beating flow due to their capability to handle the slugging impact of this kind of flow.

Working and Maintenance of Glove value
Globe valves sometimes have rising stems, and also the larger sizes ar of the surface screw-and-yoke construction. Parts of the world valve are like those of the gate valve. this sort of valve has seats in an exceedingly plane parallel or inclined to the road of flow.

Maintenance of globe valves is comparatively straightforward, because the discs and seats ar without delay refurbished or replaced. This makes globe valves notably appropriate for services that need frequent valve maintenance.

The principal variation in globe-valve style is within the styles of discs used. Plug-type discs have an extended, tapered configuration with a good bearing surface. this sort of seat provides most resistance to the erosive action of the fluid stream. Within the composition disc, the disc contains a flat face that's ironed against the seat gap sort of a cap. This sort of seat arrangement isn't as appropriate for prime differential pressure choking.

The conventional disc, in distinction to the plug sort, provides a skinny contact between the taper of the traditional seat and also the face of the disc. This slender contact space tends to interrupt down laborious deposits which will type on the seats and facilitates pressure-tight closure. This arrangement permits permanently seating and moderate choking. For higher pressures, disc guides ar forged into the valve body. The disc turns freely on the stem to forestall vexatious of the disc face and seat ring. The stem bears against a hardened thrust plate, eliminating vexatious of the stem and disc at the purpose of contact. Pneucon Rubber Lined Butterfly Valve, Pneucon Teflon Lined Butterfly Valve are very good and having very good qualities.

Advantages of using Globe Valve
1 provides very Good shut-off capability.
2. Moderate to good throttling capability.
3. Shorter stroke.

Disadvantages of using Globe Valve
1. Higher pressure drop.
2. It requires greater force or a larger actuator to seat the valve (with pressure under the seat).

How Differential Pressure Transmitter Are Beneficial For Industry

The pressure transmitter merchandise series supply most preciseness, hardiness, and ease-of-use. Compliant with business standards and international certifications, Siemens pressure measuring devices fulfill the more and more advanced tasks of the method business. Some versions, in addition, supply various medicine functions that assist you to invariably have your plant firmly in restraint.

The most common and useful industrial pressure instrument is that the differential pressure transmitter.This instrumentation will sense the excellence in pressure between a pair of ports associated end up associate degree signal with relevance a label pressure vary.

Pressure sensing element is housed in the bottom half, and the electronics are housed in the top half. It will have two pressure ports marked as “High” and “Low”. It is not always must that the high port will be always at high pressure and the low port always at low pressure. This labeling has its relation to the effect of the port on the output signal. Best Pressure Transmitter Suppliers are available on Instroline They can suggest you best Pressure Transmitter exporter which will help you in choosing best suitable Pressure Transmitter supplier in Delhi NCR .which will additionally expertise pressure within the variety of all weather This might be thought of the force being applied by the atmosphere on our heads. Because of the air pressure changes, therefore will the weather. Air mass sometimes referees to clear sunny days, whereas low produces cloudy ones.

If we have a tendency to refer back to our automobile types, two pressures are functioning on the wall of the type. The pressure of the atmosphere on the skin of the tire and also the pressure we have a tendency to browse on the gauge after we wired the type up.

The models of pressure transmitter likeYokogawa Differential Pressure Transmitter, Yokogawa Flange Mounted Differential Pressure Transmitter, Yokogawa Absolute Pressure Transmitter for general industrial Applications are the ideal solution for customers with demanding according to measuring requirements. It features a very good accuracy, a robust design and an exceptional number of These measuring ranges of Differential Pressure Transmitter, a be combined with almost multiple ways with all the standard industry output signals, the most common process connections and a wide number of electrical connections. Furthermore, it offers numerous options, such as different Accuracy classes, extended temperature ranges and customer-specific pin assignments.

Some Major Applications of Differential Pressure Transmitter :-
1. Machine building
2. Hydraulics and pneumatics
3. Pumps
4. Chemical industry

Benefits of Differential Pressure Transmitter for Industry:-
Differential Pressure has unlimited industrial applications Like Oil and Gas flow metering in onshore, offshore and subsea applications. One of the most popular uses is Water and effluent treatment plants. It is largely used to monitor filters in these plants. It is highly used to monitor Sprinkler Systems. Remote sensing of Heating Systems for Steam or Hot Water. We also used this for Pressure drops across valves can be monitored and Pump control monitoring.

Working Principles of Electromagnetic flow meter

The electromagnetic flow meter is one reasonably main flow instrument, widely apply to flow activity for several industrial department like fossil oil, industry, metallurgy, light and textile business, craft, atmosphere protection, food etc. and municipal management, water comes construction field.

A common magnetism flow meter is that the magnetic flow meter, additionally technically associate magnetism flow meter or a lot of unremarkably simply referred to as a magazine meter. A magnetic flux is applied to the tube, which ends up with potential proportional to the flow speed perpendicular to the flux lines. The physical principle of work is magnetic induction. The magnetic flow meter needs a conducting fluid, as an example, water that contains ions, associated an electrical insulating pipe surface, as an example, a rubber-lined steel tube.

If the magnetic field direction were constant, chemical science and alternative effects at the electrodes would create the potential tough to differentiate from the fluid flow induced potential. To mitigate this in fashionable magnetic flowmeter, the magnetic flux is consistently reversed, cancelling out the chemical science potential, that doesn't amendment direction with the magnetic flux. This but prevents the employment of permanent magnets for magnetic flow meters. If you are looking electromagnetic flowmeter online then you search best Temperature Transmitter Suppliers, Best Price Electromagnetic Flow meters on Instronline. Here you can also find best and updated Siemens Ultrasonic Level Transmitter Exporters, Siemens Ultrasonic Level.

Working Principle of Electromagnetic Flowmeter

The purpose of a flow meter system is to live the movement, or rate of flow, of a given volume of fluid Associate to specific it through an unambiguous electrical signal. a typical flow meter consists of a series of coupled parts that transmits signals indicating the degree, rate of flow, or volume of fluid moving through a particular channel, and it ideally functions with bottom interference from environmental conditions. A magnetic flow meter may be a comparatively noninvasive measuring system that's well-suited for rate of flow analysis as a result of its varying of functions.

A magnetic or electromagnetic force flowmeter are often put in relatively easy fashion to that degree as an existing pipe network are often reborn into a measuring system by applying external electrodes and magnets. These flow meters will track forward and reverse flow and are minimally laid low with flow disturbances associated with consistency or density. They’re linear devices which will be label to live a spread of various variables whereas additionally reacting to changes in fluid movement. Progress in flowmeter technology has targeted on manufacturing devices that are smaller, less costly, and capable of constructing additional refined measurements.

Faraday’s Law

Like several different electrical devices, magnetic flow meters operate underneath the principles of Faraday’s law of magnetic force induction. in step with this law, a conductor that passes through a field of force produces voltage proportional to the relative velocities between the field of force and also the conductor. The law is often applied to flowmeter systems as a result of several fluids are semi conductive to a precise degree. The quantities of voltage they generate as they move through a passage are often transmitted as a symptom measure quantity or flow characteristics.

Velocity and Voltage

When a flowmeter is installed and activated, its operations begin with a pair of charged magnetic coils. As energy passed through the coils, and then they produce a magnetic field that remains perpendicular to both the conductive fluid being measured and the axis of the electrodes take the measurements. The fluid moves along the longitudinal axis of the flowmeter, making any generated induced voltage perpendicular to the field and the fluid velocity. An increment in the flow rate of the conductive fluid will create a proportionate increase the voltage level.

Flow Profiles

Fluid movements within a flowmeter system are often characterized as sq., with a turbulent fluid velocity; distorted, with weak upstream flow; or parabolic, with a stratified speed. However notwithstanding the profile, a magnetic flowmeter can offer the common voltage from a metering cross-sectional, so the signal transmitted to operators tends to closely mirror the common speed of the flowing liquid. Given a set pipe diameter and a continuing magnetic flux, induced voltage can solely correlate to fluid speed. If the fluid has sensors connected to a circuit, the voltage can produce a current that may be translated as associate degree correct rate of flow measure.

Although flow meters area unit designed to produce as shut of a linear association between voltages and flow as potential, there are a unit various factors which can disrupt this relationship. Potential sources of interference include:

• Unintended extra voltage in the processing liquid.
• Electromechanical voltage accidentally induced in the electrodes or the fluid.
• Capacitive coupling between the signal circuit and the power source.
• Inductive coupling between the magnetic components in the system.
• Capacitive coupling between connective leads.

These and similar sources of external voltage or noise can disrupt normal flow measurement, so it may be worthwhile to set up a flowmeter under conditions as carefully controlled as possible.

How to Select an Ultrasonic Level Controller System

Integration of method controllers in several industries, level measure sensors conjures to main components. Purpose level measure sensors area unit accustomed mark one separate liquid height a planned level condition. Generally, these types of detector functions as a high alarm, sign degree fill up condition, or as a marker for a low alarm condition. Continuous level sensors area unit lots of delicate and will offer level observation of an entire system. They live fluid level among a spread, instead of at a purpose, manufacturing associate degree analog output that directly correlates to the amount within the vessel. To form tier management system, the sign is coupled to a method management loop and to a visible indicator. Siemens Pressure Transmitter Suppliers also offering miniature ultrasonic level Controller switch with a good price list.

The Siemens LUC500 Ultrasonic Level Controller is a complete, efficient answer for observance and management in water distribution and effluent assortment systems. It combines non-contacting supersonic technology, proprietary echo-processing techniques and established application code to produce correct level observance in liquids up to 15m (50 ft). It conjointly effectively monitors flow in flumes, weirs, and open channels. 5 relays management any combination of pumps, gate valves, and alarms. Any blessings embody fault signaling and knowledge work for analysis. It will log the time, date and volume of up to twenty occurrences of combined sewer overflows (CSO).

The ultrasonic level controller is very easy to install and configure the system, with fast start-up, reliable performance, and its maintenance is very low.

Benefits of using Ultrasonic Level Controller System
1. This provides Monitoring and control in one device.
2. This gives Integral telemetry interface (Modbus RTU/ASCII)
3. Due to the Patented algorithm for calculation of pumped volume provides 5% accuracy.
4. Expandable with I/Os, RAM for data logging, dual point, and SmartLinx
5. communications and RS-485 interface
6. Simple system configuration and diagnostics with Siemens Miltonic’s this is windows bases software system.
7. This works on AC or DC power supply
8. Best Suitable for indoor mounting. These are typically used in control rooms alongside other panel-mounted electrical equipment or where the space is less
9. This gives us Dual Point Function a second measuring point is provided on the LUC 500 to permit dual-point measurements. For existing installations, this function is made available by ordering a software access code. A dual point is available as a configuration option for new units. Please contact your Siemens supplier for details.
10. Communications The LUC 500 is offered with Modbus because It contains a standard feature RTU/ASCII as a Further industrial communications protocols are available with the addition of an optional Smarting card Siemens Ultrasonic Level Controller Dealers provides you to a large array of available devices.

How to Choose best Level Sensor according to your needed Correct Level Sensor

Numerous principles of operation and design variations together with the consideration of installation parameters, location and the economies of operation can make it a daunting task when choosing the right level sensor for a particular application. If you don’t know the difference between ultrasonic level, float level or buoyancy level technologies then you’re probably not going to make the right choice when it comes to selecting a level sensor.

Then you choose Instronline which will which will help to choose best Siemens LUC500 Ultrasonic Level Controller Suppliers, Siemens Ultrasonic Level Transmitter Suppliers
Now the main questions arise which ultrasonic level Controller you need to be considered before selecting a level measurement sensor:

1. What are the contents being measured like liquid or solid or slurry or powder?
2. What accuracy range is required for effective monitoring of the device?
3. What kind of output we required like analog, relay or other.
4. Monitoring and control in a single device.

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How to Work Electromagnetic Flow meters in Industry and what is the benefits

Electromagnetic flow measurement could be a well-established technique throughout industries for quite sixty years. This technique is applicable for all semiconducting liquids, like water, acids, alkalis, slurries and plenty of others. Typical applications area unit observance of fluids, filling, dosing and precise measurement in custody transfer. The 2 million megameters we’ve sold-out since 1977 would like no maintenance and provide seamless system integration into your processes. There is a unit a couple of areas wherever industrial flow measurement is very important, from a residential waste. With additional and additional specialize in protective the environment, the disposal and observation of waste is crucial as we try to make a cleaner and fewer contaminated world. Human’s area unit overwhelming large quantities of water and this may continue because the world population grows. SITRANS FM Electromagnetic Flow meters area unit crucial in each observation the residential effluent waste additionally as being Associate important a part of the method system in waste matter treatment plants.

Flow meters are an integral tool for measuring the flow of liquid, gas, or a mix of each in applications employed in the food and nutrient business, oil and gas plants, and chemical/pharmaceuticals. There are a large number of measures many various varieties of flow meters out there on the market. Fluid characteristics flow range, and also the want for correct measurements square measure key factors for decisive the correct flow meter for a specific application. Further concerns like mechanical restrictions and output connectivity choices additionally impact this alternative. The general accuracy of a flow meter depends to some extent on the circumstances of the applying. Electromagnetic flow meter Dealers can help to tell about pressure, temperature, fluid and other details related to Siemens Electromagnetic flow meter Exporters.

The effects of pressure, temperature, fluid, and dynamic influences will probably alter the measurement being taken. Industrial flow meters are utilized in environments wherever noise and sources of high-voltage surges proliferate. This implies that the analog front (AFE) has to operate at high common-mode voltages and have very sensible noise performance, additionally to process little electrical signals with high exactitude and repeatability. The 4- to 20-mA loop is that the most typical interface between flow transmitters and flow-control instrumentality like programmable logic controllers. Flow transmitters will either be supercharged by this loop or have a frenzied transmission line. Flow transmitters designed to use the loop have very tight power constraints, as all of the physics for signal acquisition/processing and transmission may have to work exclusively off the 4- to 20-mA loop.

Ultra-low-power processors like the Texas Instruments MSP430™ and TMS320C5000™ DSP families, in conjunction with high precision, low-power AFE solutions, are usually utilized in loop-powered transmitters. Transmitters with digital connectivity options like a method field bus (PROFIBUS), I/O links, and/or wireless property are more and more standard, as they scale back start-up times and supply continuous watching and fault medical specialty, FM Electromagnetic Flow meters supplier you can find on instronline.com where you can also search Siemens Electromagnetic flow meter Dealers , Siemens Electromagnetic flow meter Exporters ,where you will find more updated Features price list.

Principle working of Electromagnetic flow:-
Faraday’s law of induction states that a metal rod moving in a magnetic field induces an electrical voltage. This dynamo principle also governs the way electromagnetic flow meters work.

As soon as the electrically charged particles of a fluid cross the artificial magnetic field generated by two field coils, an electric voltage is induced. This voltage, tapped by two measuring electrodes, is directly proportional to the velocity of flow and thus to the flow volume.

Benefits of using Electromagnetic Flowmeters:-
· The measuring principle is virtually independent of pressure, density, temperature, and viscosity.
· Even fluids with entrained solids can be metered, e.g. ore slurry or cellulose pulp.
· Wide range of nominal diameters (DN 2 to 2400; 1/12 to 90").
· Free pipe cross-section: CIP/SIP cleanable, pig gable.
· No moving parts, maintenance-free.

Electromagnetic flowmeter advantages of straightforward structure, no moving components, and no obstruction of fluid flow throttle components, therefore once the fluid passage doesn't cause any extra pressure loss, and it doesn't cause such wear, blockage, especially for measure the suspension with solid particles, sewerage, and alternative liquid-solid two-phase body, and a range of viscous suspension soon.

Get more Information about How to install Level Transmitter click here

New L&T Electrical & Automation Cx 2000 Ac Drive With Best Features

An ac drive is a device that is used to control the velocity of an electrical motor. The velocity is managed via changing the frequency of the electrical deliver to the motor.

The three-segment voltage within the country wide electric grid linked to a motor creates a rotating magnetic field in it. The rotor of the electric motor will follow this rotating magnetic area.

An ac power converts the frequency of the community to anything between 0 to 300Hz or even higher, and therefore controls the rate of motor proportionally to the frequency.

The Cx2000 AC Drives is perfectly suited for conveyors, pumps, enthusiasts and textile equipment. It handles masses as much as eleven kW, and is engineered to hold your system operating at most advantageous efficiency, even in the hot, humid and dusty situations that signify India's business surroundings. Compact, lightweight, easy to put in, function and provider – the Cx2000 is perfectly suited for conveyors, pumps, enthusiasts and textile machinery.

It handles masses as much as 11 kW, and is engineered to keep your machine working at most beneficial performance, even in the warm, humid and dusty conditions that represent India's industrial environment. L&T Electrical & Automation Cx 2000 Ac Drive supplier guiding you for best L&T Electrical & Automation Cx 2000 Ac Drive.

Features:

V/F Control, Sensor less Vector Control, Slip Compensation
Starting Torque 150% at 3 Hz
Built-in Potentiometer
Conformal Coated PCB
Built-in RS485 Modbus
RPM Display
Draw Mode
Brake Control
Auto Tuning
Built-in PID
2nd Motor Operation
Built-in Safety circuit
Built-in Braking Chopper up to 11kW

The Cx2000 adds a new dimension to L&T's AC drive solutions. Built to L&T's stringent quality standards, the Cx2000 is tested and certified to meet global benchmarks, thus giving you the assurance of total reliability. Compact, lightweight, easy to install, operate and service – the Cx2000 is perfectly suited for conveyors, pumps, fans and textile machinery.

It handles loads up to 11 kW, and is engineered to keep your machine operating at optimum efficiency, even in the hot, humid and dusty conditions that characterize India's industrial environment.

Single Phase 230V - 0.1 to 2.2kW.
Three Phase 230V - 0.2 to 11kW.
Three Phase 415V - 0.75 to 11kW.

FEATURES of L&T CX2000 SERIES AC DRIVES

Built-in Potentiometer.
Conformal Coated PCB.
Built-in RS485 Modbus.
RPM Display.
Draw Mode.
Brake Control.
Auto Tuning.
Built-in PID.
Built-in Safety circuit.
Built-in Safety circuit.

Some Rating Operation of L&T CX2000 SERIES AC DRIVES

Designed to be used for heavy and normal duty applications.

Heavy duty operation: 150% of rated current for 60 sec.
Normal duty operation: 110% of rated current for 60 sec.

Possible to add reference from keypad and external signal.
Provides external potentiometer for easier frequency control.

Cx2000 has built-in PID which saves use of external PID.

Single AC Drive can maintain 2 motor parameters connected to 2 different loads with different Accel / Decal parameter setting.
For isolated operation of motors one VFD can be used in place of 2.

Tool-less replacement of Cooling Fan.

Built-in brake chopper which saves panel space.
L&T is one of the few switch L&T Electrical & Automation Cx 2000 Ac Drive dealer gear manufacturers in India with a dedicated, NABL-certified testing facility. Our products are tested for conformity to standards that exceed minimum requirements, giving you the assurance of high-quality performance. Our focus on continuous improvement ensures that our standards are on par with the best in the world. Repeat orders endorse the value that we deliver. You can find the Instronline Cx 2000 Ac Drive supplier on our portal where you can find very good range of Best Cx 2000 Ac Drive instrument which durable and On L&T Electrical & Automation Cx 2000 Ac Drive dealer

Endress Hauser temperature transmitter tmt162 How to work

Temperature is the maximum measured parameter in manner automation. Therefore, it comes as no wonder that temperature measurement generation is used throughout all industries. This warrants meeting an extensive variety of customer necessities. Endress+Hauser rises to the challenge with complete software guide from the strategy planning stage to set up and operation.

Unsurpassed reliability, accuracy and long-time period stability in vital methods over all industries. The configurable transmitter now not most effective transfer’s transformed alerts from resistance thermometers (RTD) and thermocouples (TC), it also transfers resistance and voltage indicators. Swift and smooth operation, visualization and preservation by means of a laptop the use of operating software program. Space-saving DIN rail mounting as per IEC 60715.Endress Hauser Temperature field transmitter, It visualizes the signals on its own backlit display.

1. Designated use:-
The device is a familiar and configurable temperature area transmitter with each one or two temperature sensor inputs for resistance thermometers (RTD), thermocouples (TC) and resistance and voltage transmitters. The unit is designed for mounting in the field. The manufacturer isn't chargeable for harm as a result of unsuitable or non-specified use.

2. Workplace safety:-
For work on and with the device: wear the required private defensive system in line with federal/country wide rules.

3. Operational safety:-
Operate the device in the proper technical situation and fail-safe circumstance simplest. The operator is liable for the interference-free operation of the device. energy delivery.The unit must best be powered with the aid of a strength deliver that operates the usage of an IEC 61010-1 compliant energy restricted circuit, "SELV or class 2 circuits". Conversions to the tool Unauthorized changes to the tool aren't permitted and may cause unforeseeable risks. If, in spite of this, changes are required, consult with Endress+Hauser.

Repair:-
To make certain continued operational safety and reliability, carry out maintenance on the tool best if they're expressly accepted. Study federal/countrywide guidelines concerning the repair of an electrical tool.

Hazardous area:-
To eliminate a hazard for men and women or for the facility while the tool is used within the dangerous area (e.g. explosion protection or protection gadget) based totally on the technical records on the nameplate, check whether or not the ordered tool is allowed for the meant use in the hazardous area. The nameplate may be located on the side of the transmitter housing. Look at the specs within the separate supplementary documentation that is an imperative a part of these instructions

4. Product safety:-
This measuring device is designed in accordance with good engineering practice to meet state-of-the-art safety requirements, has been tested. It meets general safety standards and legal requirements. It also complies with the EC directives listed in the device-specific EC Declaration of Conformity. Endress+Hauser confirm this by affixing the CE mark to the device.

5. IT security:-
We only provide an assurance if the tool is established and used as described within the operating commands. The tool is ready with safety mechanisms to guard it in opposition to any inadvertent changes to the device settings. IT safety features in line with operators' safety requirements and designed to provide extra safety for the tool and device facts transfer need to be carried out by using the operators themselves.

The unit is constructed using the most up-to-date production equipment and complies with the .safety requirements of the local guidelines. The temperature transmitter is fully factory tested. ITEMP TMT162 Temperature field transmitter, housing allows a direct connection in harsh process areas as well as in hygienic applications as the option.

Endress Hauser iTEMP TMT162 Temperature field transmitter dealer, Endress Hauser Temperature field transmitter, Endress Hauser TLSW1 Protection tube, Endress Hauser temperature thermocouples, According to the specifications indicated on the order. These entire Endress Hauser Transmitter heart supplier, You can find on Instronline.com, However, if it is installed incorrectly or is misused, certain application dangers can occur.

Installation, wiring, and maintenance of the unit must only be done by trained, skilled personnel who are authorized to do so by the plant operator. This skilled staff must have read and understood these instructions and must follow them to the Letter. The plant operator must make sure that the measurement system has been correctly wired to the connection schematics. Electrical temperature sensors such as RTD's and thermocouples produce low-level signals Proportional to their sensed temperature. The temperature transmitter converts the low-level sensor signal to a standard 4 to 20 mA DC signal that is relatively insensitive to lead length and electrical noise. This current signal is then transmitted to the control room via two wires.

Endress Hauser temperature Indicator Exporters, you can find on for temperature transmitter according to your need.The transmitter can be commissioned before or after installation. It may be useful to commission it on the bench, before installation, to ensure proper operation and to become familiar with its functionality. Endress Hauser Transmitter Smart / HART, Make sure the instruments in the loop are installed in accordance with intrinsically safe or non-incendive field wiring practices before connecting a HART communicator in an explosive atmosphere.

Smart Differential Pressure Transmitter with Display

The Smart differential pressure transmitter is a rugged, compact, light weight, loop powered instrument that is ideally suited for hazardous locations and hostile environments where space is limited. This versatile instrument may be used to reliably measure differential pressure, level or flow.

Some Major Applications of pressure sensors:

1. Pressure sensing:-
This is wherever the measuring of interest is pressure, expressed as a force per unit space. This can be helpful in weather instrumentation, aircraft, cars, and the other machinery that has pressure practicality enforced.

2. Altitude sensing:-
This is useful in aircraft, rockets, satellites, weather balloons, and many other applications. All these applications make use of the relationship between changes in pressure relative to the altitude.

3. Flow sensing:-
This is the utilization of pressure sensors in conjunction with the venturi impact to live flow. Differential pressure is measured between 2 segments of a measuring system that have a unique aperture. The pressure distinction between the 2 segments is directly proportional to the rate through the measuring system. an occasional pressure sensing element is nearly continuously needed because the pressure distinction is comparatively tiny.

4. Level / depth sensing:-
A pressure sensor may also be used to calculate the level of a fluid. This technique is commonly employed to measure the depth of a submerged body (such as a diver or submarine), or level of contents in a tank.

5. Leak testing:-
A pressure sensor may be used to sense the decay of pressure due to a system leak. This is commonly done by either comparison to a known leak using differential pressure, or by means of utilizing the pressure sensor to measure pressure change over time. In industrial applications, the measure purpose is mostly within the field, and therefore the show device or the management devices area unit typically within the room or management cupboard. The gap between the 2 is also a couple of dozen to a couple of hundred meters. Yokogawa Differential Pressure Transmitter supplier, Yokogawa Flange Mounted Differential Pressure Transmitter Exporter and Yokogawa EJA110E Diaphragm Sealed Differential Pressure Transmitter you can search with different different price they are widely used pressure transmitters which is very efficient.

Pressure Transmitter Working principle:-

Principle of capacitive pressure transmitter, capacitive pressure transmitter vital to the completion of the pressure / capacitance conversion chamber device and also the electrical device converts the two-wire 4-20mA electronic circuit card, and once the method pressure from either side of the ministration chamber (or side) is applied to the isolation diaphragm through the middle of gravity of the silicone polymer oil fill fluid transmitted chamber diaphragm, the middle of gravity of the diaphragm is tensioned diaphragm edge, fraught, the prevalence of the corresponding displacement, the displacement constitutes a differential capacitance changes, If you are buying Pressure Transmitter then you can prefer Instronline.com where a large series of Pressure Transmitters are available like Yokogawa EJA110E Diaphragm Sealed Differential Pressure Transmitter are fit for use.

Ceramic of pressure transmitters principle and liquid transfer, the indirect effects of pressure before the appearance of the ceramic diaphragm, the diaphragm occurrence huge deformation, thick film resistors printing the reverse side of the ceramic diaphragm pressure transmitter using anti-corrosion, converge into a Wheatstone bridge (closed bridge), due to the piezoresistive effect of the varistor, so that the bridge occurs a highly linear and inversely proportional to pressure.

The piezoelectric sensor can also be used to measure the internal engine combustion pressure measurement and the measurement of the degree of vacuum. Can also be used in the military industry, for example, use it to measure the moment of firing guns and bullets in the barrel bore pressure change and pressure of the shock wave of the muzzle. It can be used to measure a large pressure, can also be used to measure a minute pressure. Piezoelectric sensors are also widely used in biomedical measurements, for example, the ventricular catheter decline damper is made of piezoelectric sensors measure dynamic pressure is so common piezoelectric sensor applications is very broad. Pressure Transmitter Suppliers, Pressure Transmitter Exporters you can find online with a large no of price and model details.

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Digital temperature transmitter with hart quick installation guide

A temperature transmitter is an electrical device that interfaces a temperature sensor (e.g. thermocouple, RTD, or thermostat to a dimension or manipulate device (e.g. pec, DCS, laptop, loop controller, facts logger, show, recorder, and so on.). Usually, temperature transmitters isolate, enlarge, filter noise, linearism, and convert the input sign from the sensor then ship (transmit) a standardized output sign to the manipulate device. not unusual electrical output signals utilized in production vegetation are four-20mA or 0-10V DC ranges.

Some Applications where wide use of Temperature Transmitters Process industry and Machine building and plant construction.

Special features of Digital temperature transmitter:-
• Universally configurable via Windows PC, sensor simulation not required
• Insulation voltage AC 1,500 V between sensor and current loop
• Signaling configurable for sensor break and sensor short-circuit
• For 100 % relative humidity, condensation allowed

These temperature transmitters are designed for ordinary use in industrial applications. They provide high accuracy, galvanic isolation and safety towards electromagnetic influences (EMI).

similarly to the distinctive sensor kinds, e.g. sensors according with DIN EN 60751, JIS C1606, DIN 43760, DIN EN 60584 or DIN 43710, purchaser-precise sensor traits also can be described via the input of pairs of values.

The connection type is configurable, consequently making sure gold standard connecting cable reimbursement. a chilly junction compensation for thermocouples is built-in, while an outside cold junction also can be used.

The configurable errors signaling (e.g. sensor destroy, hardware errors, sensor over/below-variety) ensures a excessive degree of monitoring functionality. Wika Analogue temperature transmitter Configuration adjustments can be fast and easily transmitted to the T12 the use of the WIKA_T12 configuration software program (free download at www.wika.com) and the communication interface (programming unit), that's to be had as an accent. The bidirectional communiqué makes it viable to show the measured values additionally at the laptop/notebook. You can find theirs transmitter according your need but there are some good temperature transmitters are available like Wika HART field temperature transmitter. Wika Temperature Transmitter Exporters you can find through Instronline.com

The programming unit offers voltage to the temperature transmitter version T12, in order that no additional voltage deliver is required to configure the T12.

The scale of the top-established transmitter healthy the shape B DIN connecting heads with extended mounting area, e.g. WIKA model BSS. The transmitters in rail mounting cases are appropriate for all fashionable rails in accordance with IEC 60715.

The transmitters are brought with a basic configuration or configured in line with purchaser specifications.
You can check Temperature Transmitter Suppliers and Temperature Transmitter Exporters online on many other portals.

Except the selection of the sensor type and the measuring range, the software program allows the error signaling operation, damping and several measuring point descriptions to be stored. Furthermore, the WIKAsoft-TT software program gives a line recording functionality where the temperature profile for the sensor linked to the T15 can be displayed.

The model T15 transmitter additionally has diverse supervisory capabilities, which include the tracking of the sensor cord resistance and sensor-ruin detection in accordance with NAMUR NE89 in addition to tracking of the measuring range. Moreover, these transmitters have complete cyclic self-tracking capability.

How to mount the transmitter

Mount the transmitter at a high point in the conduit run to prevent moisture from draining into the transmitter housing. Transmitter with DIN plate style sensor.

1. Attach the thermo well to the pipe or process container wall. Install and tighten the thermo well before applying process pressure. LSL (Lower Sensor Limit) 2, 2, 1, 9 URV (Upper Range Value) 2, 2, 2, 4, 2 Message 2, 2, 3,1,3 USL (Upper Sensor Limit) 2, 2, 1, 8 Open Sensor Hold off 2, 2, 3, 4 Write Protect 2, 2, 3, 6 Percent Range 2, 2, 2, 3 2-Wire Offset 2, 2, 1, 5 Table 1. Programming Kit Spare Part Numbers Product description Part number Programming Software (CD) 00248-1603-0002 Rosemount 248 Programmer Kit - USB 00248-1603-0003 Rosemount 248 Programmer Kit - Serial 00248-1603-0004 Function Fast Keys Function Fast Keys 00825-0100-4825_12-27_RevHA.fm Page 5 Tuesday, January 17, 2017 10:56 PM January 2017 6 Quick Start Guide

2. Assemble the transmitter to the sensor. Push the transmitter mounting screws through the sensor mounting plate and insert the snap rings (optional) into the transmitter mounting screw groove.
3. Wire the sensor to the transmitter.

4. Insert the transmitter-sensor assembly into the connection head. Thread the transmitter mounting screw into the connection head mounting holes. Assemble the extension to the connection head. Insert the assembly into the thermo well.

5. Slip the shielded cable though the cable gland.

6. Attach a cable gland into the shielded cable.

7. Insert the shielded cable leads into the connection head through the cable entry. Connect and tighten the cable gland.

8. Connect the shielded power cable leads to the transmitter power terminals. Avoid contact with sensor leads and sensor connections.

9. Install and tighten the connection head covers.

The major components of the Rosemount 3051 are the sensor module and the electronics Housing. Wika Digital temperature transmitter with HART protocol are sensor module which contains the oil filled sensor system these electronics are installed within the sensor module and include a temperature sensor (RTD), a memory module, and the capacitance to digital signal converter (C/D converter). The electrical signals from the sensor module are transmitted to the output electronics in the electronics housing.

Working Principle of Digital Tachometer

A Tachometer is an instrument measuring the rotation pace of a shaft or disk, as in a motor or different machine. The device generally shows the revolutions in keeping with minute (RPM) on a calibrated analogue dial, how ever virtual presentations are increasingly more common. Essentially the phrases tachometer and speedometer have identical meaning: a device that measures speed. It’s far by way of arbitrary conference that within the automobile world one is used for engine and the other for vehicle velocity. In formal engineering nomenclature, more particular terms are used to differentiate the two.

It produces the voltage consistent with the velocity of the shaft. Power, accuracy, RPM range, measurements and display are the specifications of a tachometer. Tachometers may be analog or digital indicating meters; but, this text focuses handiest at the virtual tachometers. Digital tachometers are divided into four types primarily based at the information acquisition and size strategies.

Tachometers are used to estimate traffic speed and volume (flow). A vehicle is equipped with the sensor and conducts "tach runs" which record the traffic data. These data are a substitute or complement to loop detector data. To get statistically significant results requires a high number of runs, and bias is introduced by the time of day, day of week, and the season. However, because of the expense, spacing (a lower density of loop detectors diminishes data accuracy), and relatively low reliability of loop detectors (often 30% or more are out of service at any given time), tach runs remain a common practice.

Based on the data acquisition technique, the tachometers are of the two type Contact type, Non Contact types both type are available at Instronline.

There are a vast varieties of techno meter are available with a large array of products list like See-believe portable digital tachometer, Samson Check Valves, Conductivity Controller, conductivity meters. You can also find lockup valve Dealers at Instronline is portal where you can search and find best suitable model according to your need. ABUSTEK Interface converter is available in Delhi Ncr which is highly in demand Digital Tachometer is basically used for Space Shuttle, Motor Control, Assembly Systems, Data Recording Systems Petrochemical, Air compressors.

The working principle of an electronic tachometer is quite simple. The ignition device triggers a voltage pulse on the output of the tachometer electromechanical component whenever the spark plugs fires. The electromechanical element responds to the common voltage of the series of pulses. It indicates that the common voltage of the pulse teach is proportional to engine pace. The sign from the notion head is transmitted with the aid of general dual screened cable to the indicator.The tachometers are temperature compensated as a way to deal with operations over an ambient temperature range of – 20 to +70°C (-4 to +158°F). It’s all about revolution. Digital tachometers, and all tachometers, measure the revolutions of a spinning object to determine the rate at which it is spinning. Nearly all types of transportation vehicles, from planes to trucks to buses to trains to cars have tachometers. You’ll even find tachometers used for production line checks, monitoring turbines, measuring machine speeds, and maintaining quality control.

Laser Pocket Tachometer:-

What sets digital tachometers apart is the display that suggests a digital analyzing, which can be gathered by using an optical sensor. Optical virtual tachometers are non-contact and may be used to evaluate RPMs by measuring the variety of rotations a reflective floor makes in a minute. Photo tachometers, the use of laser beam era, are class II rated and allow users to measure objects up to fourteen ft away. A laser tachometer can perform in difficult-to-reach or remote places for introduced versatility.

Conversely, contact tachometers bodily contact a rotating or moving object to degree its linear speed or RPMs. Dual-type technology (or combination) styles are also available at instronline.

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Why We Use Process controllers

Control in process industries refers to the law of all components of the process. Unique manage of level, temperature, strain and glide is critical in many method programs. This module introduces you to govern in procedure industries, explains why control is critical, and identifies specific approaches wherein unique control is ensured. The following five sections are included in this module:

The importance of process control theory basics, Components of control loops and ISA symbology, Controller algorithms and tuning, Process control systems as you precede through the module, solution the questions within the activities column on the proper aspect of every web page. Also, be aware the utility packing containers (double-bordered containers) positioned throughout the module. Application packing containers provide key statistics about how you could use your baseline understanding within the area. Whilst you see the workbook exercise picture at the lowest of a page, visit the workbook to finish the distinctive exercising before shifting on in the module. Workbook sporting activities help you measure your progress closer to assembly every segment’s mastering goals.

Process control is an engineering subject that offers with architectures, mechanisms and algorithms for keeping the output of a selected manner within a favored variety. For example, the temperature of a chemical reactor may be managed to keep a steady product output.

Technique control is notably utilized in enterprise and allows mass production of constant merchandise from continuously operated processes such as oil refining, paper manufacturing, chemicals, energy plant life and lots of others. Process manipulate permits automation, through which a small team of workers of running personnel can perform a complex system from a valuable manage room.

Process Controllers are available in the market widely.Controller is Reliable and easy to use.There is large No of brands like, Honeywell process controller, Gefran1200-1300 Configurable controllers, Yokogawa UT35A/UT32A digital indicating controller.

Instronline is very good portal online that enable you to buy a Process controller online at just the right kind of prices that you might have been looking for. Instronline.com providing very good products in Worldwide including Delhi NCR.

Apart from their reliability, SIPART DR controllers excel due to their ease of use. Various software packages are available to make their handling easy and intuitive and to extend their scope of application. The standard version already offers comprehensive controller hardware. It can be upgraded quickly and easily for specific applications with a large number of optional input and output modules .control are often called hybrid applications.

All-round process controller for all processs specific tasks in 72x144 mm format, including mathematical calculations, logic operations, open-loop controls and time scheduled closed-loop controls. Up to four independent control loops.

Benefits of using These Controller:-
• Director sensor connection
• Integrated control program
• Continuous or step controller (K/S) (0/4 until 20mA / relays)

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Benefits of using Pneucon Automation Globe 3 Way Valve

A globe valve, special from BAL valve, is a sort of valve used for regulating glide in a pipeline, which includes a movable disk-type element and a stationary ring seat in a commonly spherical body. Globe valves are named for their spherical body shape with the 2 halves of the frame being separated via an inner baffle. This has an opening that bureaucracy a seat onto which a movable plug may be screwed in to shut (or shut) the valve. The plug is likewise called a disc or disk. In globe valves, the plug is attached to a stem that's operated by using screw motion the use of a hand wheel in manual valves. Generally, automatic globe valves use smooth stems in preference to threaded and are opened and closed by way of an actuator assembly.

Globe 3 Value control Valves are used to mix two flows or to divert flow into two outlets. They’re designed to replace and perform the capabilities of two single ported manage valves acting in contrary guidelines, in converging or diverging liquid waft provider. They may be used to manipulate the stream of water, oil, sea water or other liquids in heating or cooling programs related to warmth exchanger bypass manage.

They can also be used in blending systems and on-off selector systems.
Body Designed and Manufactured as per ASME B 16.34.
Body Form: Globe Type with Tail Piece to provide Third Port.
Body MOC -Cast Iron, Carbon Steel, Stainless Steel (Special on request).

3 way Glove control valves are used to combine two flows or to divert one flow into two outlets. They are designed to replace and perform the functions of two single ported control valves acting in opposite directions, in converging or diverging liquid flow service. They can be used to control the flow of water, oil, sea water or other liquid in heating or cooling applications involving heat exchanger bypass control. They can also be used in blending systems and on-off selector systems.

3-way Glove are High sensitivity and stability, With Simple zero and span adjustments.There is Field reversibility. And internal components are of stainless steel.

Benefit Of Pneucon Automation Globe 3 Way Valve:-
1. Heavy-duty design withstands impurities and thermal cycles and ensures extensive life time.
2. Unique balanced plug design reduces dynamic torque and allows accurate, stable control for the full 90 degrees rotation.
3. Effective, rotating Q-trim attenuator for cavitations and noise abatement is a self flushing design and capable to handle dirty fluids also.
4. Live loaded rotary packing ensures excellent control for fugitive emissions with long endurance.
5. Fire safe, fugitive emission and SIL certification to gether with anti-blowout shaft design meet the maximum stringent HSE requirements for manage valves control values.
6. Excellent reliability with low maintenance cost.
7. Versatile mounting orientations.

Pneucon Automation Globe 3 Way Valve is available worldwide.Instronline are the largest and biggest suppliers, of GLOBE 3 WAY VALVE.We cater globally including Delhi NCR.

Siemens Ultrasonic Level Controller

As the world's main issuer of ultrasonic degree size technology, Siemens gives a large choice of devices and helps you with size able application expertise. Our non-stop dimension portfolio consists of person-friendly and especially dependable transmitters, a huge variety of controllers from single-factor controllers to structures that monitor up to 10 measuring factors and plenty of unique transducers. As nicely, don’t neglect that the most secure engineered level size solution consists of switches for again-up, overfill, low level and dry run protection.

This ultrasonic level controller is known for its compatibility with six pumps, providing control and flow monitoring, which makes it suitable for various industry applications. In addition, if you are working with waste water plants, this economical solution which comes with low maintenance costs will also be of use. The digital communications and built-in Modbus RTU structures make the operation of this item greater dependable, while the compatibility with SIMATIC PDM permits for setup and configuration with the usage of a pc. If you are searching out reliability, performance and excessive nice, that is an object worth investing in.

Siemens Hydro Ranger 200 is an ultrasonic level controller for up to six pumps, and provides control, differential control, and open channel flow monitoring (MCERTS).For government, water and wastewater treatment works, Hydro Ranger 200 is a cheap, low-upkeep solution delivering manipulate efficiency and productiveness had to meet two days exacting requirements. It gives single- or dual-factor monitoring with 6 relays popular, in addition to virtual communications with built-in Modbus RTU via RS-485. 200 ultrasonic level controllers is compatible with SIMATIC PDM, allowing for PC configuration and set-up. Sonic Intelligence advanced echo-processing software provides increased reading reliability.

Ultrasonic level controller 200 hydro uses proven continuous ultrasonic echo ranging technology to monitor water and wastewater of any consistency up to 15 m (50 ft) in depth.Achievable resolution is 0.1% with accuracy to 0.25% of range. Unlike contacting devices, Hydro Ranger 200 is immune to problems caused by suspended solids, harsh corrosives, grease or silt in the effluent, reducing downtime. Hydro Ranger 200 ultrasonic level controller Dealer In Delhi NCR are providing you a wide range of controller which is held by instronline.com.

Water Metering Is The Process Of Measuring Water Use

In many countries water meters are used todegree the quantity of water utilized by residential and business buildingswhich might be supplied with water via a public water supply machine. Watermeters can also be used on the water supply, properly, or in the course of awater device to decide waft through a specific portion of the gadget. Inmaximum of the arena water meters measure drift in cubic metres (m3) or litres.a few electronic meter registers can display rate-of-float in addition tooverall usage. There are several types of water meters in common use. Thechoice depends on the flow measurement method, the type of end user, therequired flow rates, and accuracy requirements.

Types of metering devices.
There are two common approaches to flowmeasurement, displacement and velocity, each making use of a variety oftechnologies. Common displacement designs include oscillating piston andnutating disc meters. Velocity-based designs include single- and multi-jetmeters and turbine meters.

There are also non-mechanical designs, forexample electromagnetic and ultrasonic meters, and meters designed for specialmakes use of. Maximum meters in a standard water distribution system aredesigned to degree bloodless potable water best. Strong point hot water metersare designed with substances that can resist higher temperatures. Meters forreclaimed water have special lavender sign up covers to indicate that the watermust not be used for drinking.

Water meters are usually owned, read andmaintained by using a public water issuer which includes a town, rural waterassociation or personal water company. In some instances an proprietor of amobile domestic park, apartment complex or business constructing may be billedwith the aid of a software based totally on the studying of 1 meter, with theexpenses shared a number of the tenants based on some form of key (size offlat, quantity of population or by means of separately monitoring the waterintake of each unit in what is called sub metering).

Water meter in Belo Horizonte.
This type of water meter is most often used inresidential and small industrial packages and houses. Displacement meters arecommonly mentioned as Positive Displacement,or "PD" meters. Two common types are piston meters and nutating diskmeters. Either technique relies at the water to bodily displace thetransferring measuring element in direct share to the quantity of water thatpasses through the meter. The piston or disk movements a magnet that drives theregister.

Velocity water meters.
A velocity-type meter measures the velocity offlow through a meter of a known internal capacity. The speed of the flow can then be converted into volume of flow todetermine the usage. There are several types of meters that measure water flowvelocity, including jet meters (single-jet and multi-jet), turbine meters,propeller meters and mag meters. Most velocity-based meters have an adjustmentvane for calibrating the meter to the required accuracy.

Multi-jet meters.
Multi-jet meters are very accurate in smallsizes and are commonly used in ⅝" to 2" sizes for residential andsmall commercial users. Multi-jet meters use multiple ports surrounding aninternal chamber to create multiple jets of water against an impeller, whoserotation speed depends on the velocity of water flow Turbine meters.

Turbine meters are.
Turbine meters are less accurate thandisplacement and jet meters at low flow rates, but the measuring element doesnot occupy or severely restrict the entire path of flow. The flow direction isgenerally straight through the meter, allowing for higher flow rates and lesspressure loss than displacement-type meters. They are the meter of choice forlarge commercial users, fire protection and as master meters for the waterdistribution system. Strainers are generally required to be installed in frontof the meter to protect the measuring element from gravel or other debris thatcould enter the water distribution system. Turbine meters are generally available for 1-½" to 12" or higherpipe sizes. Turbine meter bodies are commonly made of bronze, cast iron or ductileiron. Internal turbine elements can be plastic or non-corrosive metal alloys.They are accurate in normal working conditions but are greatly affected by theflow profile and fluid conditions.

SITRANS F M MAG 8000 is Battery operated water meter which gives you the flexibility toinstall a reliable water flow meter virtually anywhere without sacrificing accuracy or performance. 8000 Battery-operated water meter, in this meter Nomains power is required. MAG 8000 complieswith the custody transfer approvals MID and OIML R49 water meter standards and isspecially engineered for stand-alone water applications such as abstraction,distribution network, revenue metering and irrigation.

The majorapplication of Battery-operatedwater meter MAG 8000 is mainly Abstraction anddistribution network, Revenue and bulk metering and Irrigations

An optional build-in GSM/GPRS WirelessCommunication Module opens up for receiving logged flow measurement data viaemail, SMS and to OPC server keeps the operator up-to-date regardless oflocation and makes it possible to change settings without visiting the site. Battery-operated water meter are available inworld wide. MAG 8000 Battery-operatedwater meter Dealer In Delhi NCR are also available.For information orbuying best water meter according to your comfortness on instronline.com

Siemens Digital Pressure Transmitter

Digital Pressure transmitter, is a transducer that converts pressure into an analog electricsignal. Despite the fact that there are numerous types of strain transducers,one of the most not unusual is the stress gage base transducer.

Pressure transmitter are used for control and monitoring in thousands of everyday applications. Pressure sensors can also be used to indirectly measure other variables such as fluid/gas flow, speed, water level,and altitude. Pressure sensors can alternatively be called pressure transducers, pressure transmitters, pressure senders,indicators and piezometers, manometers, among other names. Pressure sensors can vary drastically in technology, design, performance,application suitability and cost. There is also a category of pressure that is designed to measure in a dynamic mode for capturing very high speed changes in pressure. Example applications for this type of sensor would be in the measuring of combustion pressure in an engine cylinder or in a gas turbine.These sensors are commonly manufactured out of piezoelectric materials such as quartz. which has very goodperformance .Some Digital Pressure transmitter, such as those found insome traffic enforcement cameras, function in a binary (on/off) manner,i.e., when pressure is applied to a pressure sensor, the sensor acts tocomplete or break an electrical circuit.

The conversion ofpressure into an electrical signal is achieved via the bodily deformation ofpressure gages that are bonded into the diaphragm of the pressure transducerand careworn out right into a wheat stone bridge configuration. Stress carriedout to the strain transducer produces adeflection of the diaphragm which introduces pressure to the gages. The strainwill produce an electrical resistance alternate proportional to the stress. Thestrain transmitter merchandise in the SITRANS P series offer maximum precision,robustness and simplicity-of-use.

Our SITRANS P300 Digital Pressure Transmitter stand for measurementprecision, ruggedness and maximum user-friendliness. And of Course with regards to global approvals or industryrequirements, our measuring devices reliably meet the needs of the increasinglycomplicated tasks found in the manner industry.

In DigitalPressure Transmitter P300 every process, everyinfrastructure and every environmental condition brings with it specificrequirements. That’s why we provide you a complete device family with SITRANS Ppressure transmitters featuring a range of performance levels, load capacitiesand materials. Simens Digital Pressure Transmitter are Offering 100%Dependability under Pressure. From the basic model, the P310,through theadvanced SITRANS P410 to the Premium SITRANS P500.We cater globally. We arealso available in India. P300 DigitalPressure Transmitter Dealer In Delhi NCR are also available which have a big demand in market. Instronline.com will help to choosebest Pressure transmitter according to your requirement.

Siemens Single Converter Flow Meter

Accurate flow Meters is a essential factor of many commercial and industrial processes.The single flow meter is an instrument used to measure linear,nonlinear, mass or volumetric flow rate of a liquid or a gas. When choosing flow meters, one should consider such intangible factors as familiarity of plant personnel, their experience with calibration and maintenance, spare parts availability, and mean time between failure history and others. One of the most common flow measurement mistakes is the reversal of this sequence: Instead of selecting a sensor which will perform properly, an attempt is made to justify the use of a device because it is less expensive. Those "inexpensive" purchases can be the most costly installations. Instronline will help you for better flow meters, but you can also speak to our application engineers at anytime if you have any special flow measurement challenges.

The first step to flow Meter selection is to determine if the flow rate information should be continuous or totalized, and whether this information is needed locally or remotely. If remotely, ought to the transmission be analog, digital, or shared? And, if shared, what's the specified (minimum) information-update frequency? As soon as these questions are answered, an evaluation of the residences and float traits of the system fluid, and of the piping so as to accommodate the go with the flow meter. Vortex flow meter works on a principle known as the vonkármá effect. According to this principle, flow will alternately generate vortices when passing by a bluff body. A bluff body has a broad, flat front. In a vortex meter, the bluff body is a piece of material with a broad, flat front that extends vertically into the flow stream. Flow velocity is proportional to the frequency of the vortices. Flow rate is calculated by multiplying the area of the pipe times the velocity of the flow. The SITRANS FX300 vortex flowmeter provides accurate volumetric and mass flow measurement of steam, gases and liquids as an all-in-one solution with integrated temperature and pressure compensation.

Instronline held these products like flow meters, Digital Pressure Transmitter for the automotive industry and today services concrete, defense,chemical processing, mining, wastewater, energy, electronics, laboratories,medical, and many other industries. The vortex flowmeter product program consists of two types of flow meters, aflange and a sandwich version, making Siemens precise because it covers all possible applications. The flange version is available with Single or dual converter, while the sandwich model is simplest available with a Single converter. Both variations have the temperature sensor integrated and the strain sensor as a choice.

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Electromagnetic flow meters working principle

Thereason for a flow meter system is to quantify the movement, or flow rate, of agiven volume of liquid and to express it through an unambiguous electricalflag. A standard Yokogawaelectromagnetic flow meter comprises of a progression of connected segmentsthat transmits signals showing the volume, rate of flow, or volume of liquidtraveling through a particular channel, and it preferably works withinsignificant impedance from ecological conditions. A magnetic flow meter is agenerally noninvasive measuring gadget that is appropriate for flow rateinvestigation because of its direct scope of capacities.

An electromagneticflow meter by Instronline.com can beintroduced in a relatively straightforward manner seeing that a current pipesystem can be changed over into an estimation framework by applying outerterminals and magnets. The Yokogawaelectromagnetic flow meter can track forward and invert stream and arenegligibly influenced by stream unsettling influences identified withconsistency or thickness. They are straight gadgets that can be adjusted togauge a scope of various factors while additionally responding to changes insmooth motion. Progress in flow meter technology has concentrated on deliveringgadgets that are littler, less costly, and equipped for making more refinedestimations.

Faraday'sLaw
Inthe same way as other electrical gadgets, Yokogawaelectromagnetic flow meter work under the standards of Faraday's law ofelectromagnetic acceptance. As indicated by this law, a conductor that goesthrough an attractive field produces voltage corresponding to the relativespeeds between the attractive field and the conductor. The law can be connectedto flow meter frameworks in light of the fact that numerous liquids areconductive to a specific degree. The measure of voltage they produce as theytravel through a section can be transmitted as a flag measuring amount orstream qualities.

Speedand Voltage
Atthe point when a Yokogawaelectromagnetic flow meter is introduced and enacted, its operations startwith a couple of charged attractive loops. As vitality goes through the curls,they deliver an attractive field that remaining parts opposite to both theconductive liquid being measured and the hub of the anodes taking estimations.The liquid moves along the longitudinal hub of the electromagnetic flow meter, making any produced actuated voltageopposite to the field and the liquid speed. An expansion in the stream rate ofthe conductive liquid will make a proportionate increment the voltage level.

Essentials of Direction Control Valve

Bang-bangis the term regularly used to portray essential 2 way flow directional-control valves. It alludes to how the valvesmove - from completely open to completely shut. This more often than nothappens in a moment, making liquid quickly quicken and decelerate. Underspecific conditions, this can bring about liquid sledge, which sounds like amallet striking the water powered framework from inside. Thus, moving the valvestarting with one position then onto the next can deliver a blast sound.

Aless casual term to depict these segments is discrete valves. This term alludesto how the valves work: they move starting with one discrete position then ontothe next, for example, augment, withdraw, and non partisan. Relative valves,then again, control course and speed. Not with standing moving into discretepositions, they can move into middle of the road positions to control actuatorheading, speed, increasing speed, and deceleration.

Significantlymore fundamental than the discrete directional-control valve is the advancedvalve. As in computerized gadgets, advanced 2 way flow directional control valves work either on or off. Whilediscrete valves by and large utilize a spool to accomplish two, three, or morepositions, discrete valves utilize a plunger, poppet, or ball that sealsagainst a seat. The preferred standpoint to this kind of operation is that itgives a positive seal to avert cross-port spillage.

Thetwo essential qualities for selecting a GLOBEdirectional-control valve are the quantity of liquid ports and the quantityof directional states, or positions, the valve can accomplish. Valve ports givea way to liquid (air or pressure driven liquid) to flow to or from differentsegments. The quantity of positions alludes to the quantity of particularstream ways a valve can give.

A4-port, 3-position spool valve serves as an advantageous representation. Oneport gets pressurized liquid from the pump and one courses liquid back to thestore (or to the climate or fumes suppressor in pneumatic frameworks). Theother two ports are by and large alluded to as work ports and course liquid toor from the actuator. For this situation, one work port courses liquid to orfrom the rod end of the barrel, alternate courses liquid to or from the top end.

More Information About GLOBE directional-control valve Click Hear

SITRANS FM Electromagnetic Flowmeters Technology

Electromagneticflowmeters works under Faraday's Law of Electromagnetic Induction to decide theflow of fluid in a pipe. In SITRANS FM Electromagnetic Flow meters, amagnetic field is created and directed into the fluid coursing through thepipe. Taking after Faraday's Law, flow of a conductive fluid through the magneticfield will bring about a voltage flag to be detected by cathodes situated onthe stream tube wall. At the point when the liquid moves quicker, more voltageis created.

Faraday'sLaw expresses that the voltage produced is corresponding to the development ofthe flowing fluid. The electronic transmitter forms the voltage flag to decidefluid stream. Interestingly with numerous other SITRANS FM ElectromagneticFlow meters technologies, magneticflow meter innovation produces flags that are direct with stream. In thatcapacity, the turn down connected with Electromagnetic flow meters can approach20:1 or better without giving up accuracy.

Electromagneticflowmeters measure the speed of conductive fluids in channels, for example,water, acids, burning, and slurries. SITRANS FM ElectromagneticFlow meterscan gauge appropriately when the electrical conductivity of the fluid is morenoteworthy than around 5μS/cm. Utilizing Electromagnetic flow meters on liquidswith low conductivity, for example, deionized water, kettle bolster water, orhydrocarbons, can bring about the flow meter to kill and measure zero stream.

Applicationsfor dirty liquids are found in the water, wastewater, mining, mineral handling,power, mash and paper, and synthetic businesses. Water and wastewaterapplications incorporate authority move of fluids in compel mains betweenwater/wastewater locales. SITRANS FM Electromagnetic Flow metersare utilized as a part of water treatment plants to quantify treated anduntreated sewage, handle water, water and chemicals. Mining and mineral processindustry applications incorporate process water and process slurry streams andsubstantial media streams.

Withattention for materials of development, the flow of very destructive fluids,(for example, corrosive and harsh) and rough slurries can be measured. Corrosivefluid applications are generally found in the compound business forms, and insynthetic sustain frameworks utilized as a part of generally enterprises.Slurry applications are generally found in the mining, mineral preparing, mashand paper, and wastewater businesses.

More Information About Electromagnetic Flow meters:-Click Hear

HYDRAULIC DIRECTIONAL CONTROL VALVE

Inmost of control valves WIKA directionalcontrol valves are determined for the most part by the quantity of ports orways (lines joined to the symbol’s case) and the quantity of positions (boxesor envelopes in the image) they have. Other information about them incorporateswhether they are ordinarily shut (not passing liquid), typically open (passingliquid), how they are worked (solenoid, manual, or spring) and differentelements, for example, manual overrides, deplete ports, pilot ports, and soforth.

Somebroad standards for drawing symbols in Wika Hydraulic comparison test pump are:only draw flow lines to one box of the symbol continuously observe that streamways and course of stream in every crate is perfect on 4-way water powered valves,pipe the A port to the cap end of the barrel and the B port to the pole endattract all symbol their rest position. Indicate valves that are held incitedby a machine part in their moved condition, and give information, for example, pressuresettings, flow rates, orifice sizes, drive and rpm where relevant.

Asper this strategy for determining, check valves and pre-fill valves would be2-way valves since they have two ports. Be that as it may, on the grounds thatthese valves are essentially single function and have vastly factor streamways, their images and wording don't take after general directional controlvalve rules. A 2-way directional control valve works work in acircuit of Wika Hydraulic comparison test pump.

The instrument has two boxes (or envelopes) to show two positions.Every position is a flow path. The case with stream lines coming to it is thetypical or very still position of the valve. The ordinary or at rest positionis for the most part at the spring end of a spring-return valve as found in WikaHydraulic comparison test pump. The hydraulic term originates from the, liquidused to move the energy in a nearby circle. The pressure driven framework isthe place we utilize the media like, oil or water to exchange the constrainfrom one indicate other in the system. We utilize oil in this reason with someproperty like non compressive and grease.

Tocomprehend the water powered framework which is utilized as a part of ourindustry, we need to go inside the rudiments of pressure driven. At instronline.com you can get the bestdealer or supplier for all instruments.

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Automatic Diverter Valve

The auto controldivert wall is a licensed programmed check and deplete valve that worksinstantly on pump start up/close down. Before pump start up there is normalstream past the ESP. On ESP switch-on the ADV consequently works to close portsto the annulus and pumped generation starts to surface. Upon ESP trip/closedown, liquid and solids in the tubing string deplete into the annulus.Correspondence to the ESP is blocked anticipating solids entering the ESP. Atthe point when the ESP is restarted the autocontrol divert wall naturally works to close ports to annulus and ordinarycreation resumes.

This adaptable valve can be utilized to shield the pump fromfall back of solids or permit spill out of the annulus to the creation tubing.A typical reason for ESP disappointments is when solids in the tubing stringover the pump are permitted to fall once again into the pump after the ESP hasbeen turned off (either physically or naturally). Solids that settle in the topphases of the ESP frequently plug the pump.

The auto controldivert wall likewise permits a well to free-stream around a torpid ESP inwells that will stream normally; permitting the ESP to be sent amid theunderlying fruition and keeping a future work over. As a result of the ADV'scapacity to take into consideration programmed sidestep of a lethargic pump,double exemplified ESP frameworks (or Can frameworks) can be sent without extracontrol lines required for water driven sliding sleeves.

Highlightsand Benefits

Shield your pump from solids fall-back in sandy/solidsdelivering wells. Solids settling on pump stages can wreck your pump auto control divert wall securesagainst solids fall-back and maintains a strategic distance from:

- -Broken shafts/engine failure

- -Harmed upper stages

- -Plugged pump head

- -Reverse-pivot

Free-flow well before pump starts up in normal stream ordouble ESP applications. Stream past the pump:

- _Boosts creation by keeping away from pressure dropthrough torpid ESP

- -Takes out bearing harm

- -Takes out scale develop

Top Tip For Flowmeter Selection More Information Click Hear

Everything You Need To Know About SITRANS FM Ultrasonic Flowmeters

The SITRANSFM Ultrasonic Flowmeters/sensor is a non-intrusive volume flow measuringapparatus, which utilizes one of two fundamental standards of operation, to bespecific travel time and Doppler Effect innovations:

TravelTime Ultrasonic Flow Meters:
Ultrasonictravel time flow meters depend on the recurrence contrast among upstream anddownstream times of flight of an ultrasonic pulse that is anticipated into andover the pipe. This move in recurrence is corresponding to the stream speed.Travel time flow meters won't work with grimy or bubbly fluids and are in thisway commonly utilized for spotless and ultra-immaculate streams.

DopplerUltrasonic Flow Meters:
Anultrasonic Doppler flow meter utilizes the recurrence move of an ultrasonicflag when it is reflected by suspended particles or gas rises in movement. Thismove in recurrence is relative to the flow speed. All things considered,Doppler flow meters are ordinarily utilized as a part of messy applications,for example, squander water.

SITRANS FM UltrasonicFlowmeters Advantages:

- SITRANS FM UltrasonicFlowmeters are non-obtrusive and simple to install innovation
- Noprocedure contamination is processed in SITRANSFM Ultrasonic Flowmeters
- Applicableto destructive fluids
- Lowmaintenance device as no moving parts
- Zeropressure drops
- SITRANS FM UltrasonicFlowmeters can identify zero flow
- Applicableto little and expansive (up to 5 meters) channels
- Portable,battery controlled units accessible for remote or field applications
- Sensorsaccessible for throbbing flow
- Insensitiveto changes in temperature, consistency, thickness or pressure

SITRANS FM UltrasonicFlowmeters Limitations:

- SITRANS FM UltrasonicFlowmeters can experience the ill effects of pipe-wall impedance
- Accuracymight be influenced by any air spaces in the pipe
- Maybe contrary with certain pipe materials e.g. concrete, fiberglass and plasticlined channels
- Restrictedto applications with clean, bubble free fluids (travel time meters)
- In SITRANS FM Ultrasonic Flowmeters flows must contain particulates or rises of a lessconcentration and particulate size (Doppler meters)
- Accuracymight be influenced by molecule measure dispersion and any relative speed amongparticulates and the liquid (Doppler meters)
- Notappropriate for low stream fluid (Doppler meters)

Note: Beingnon-intrusive, SITRANS FM UltrasonicFlowmetershave a wide assortment of uses in the water, squander water, heating,ventilation and aerating and cooling, petroleum and general process markets

For More Information About:Piping Requirements for Flow Meter Installation Click Hear

Facts about Flow Meter

Flowmeter innovation is one of those advances that can either bolster or block thedevelopment of other innovations. Truth is told a great part of the advances inflow meter innovations is an immediate reaction to numerous necessities indifferent enterprises including fabricating, car and numerous others. Forexample we needed better autos and got them, now we need autos that are bothall the more effective and also more fuel proficient and it took more than amodest bunch of flow measuring, flow control, sensors and PC chips to conveythem.

Themost punctual uses for flow meters originate from a need to proportion outwater and exchange both strong and fluid products. A FM Electromagnetic Flowmeters in those days was as straightforwardas a substantial vat or other sort of holder that would be topped off toquantify the measure of water to apportion then discharged into a channel orother compartment. The requirement for great precision is not as it is today;giving somebody a pretty much was no major ordeal.

Todaywe measure the flow of fluids as well as of gasses and solids too. We measurethings in much little amount and our estimations should be as close to correctas would be prudent with every generation of gadgets beating the past one.Quite a bit of what we see around us today would not be conceivable without theadvances in flow meters.

Somebasic cases of FM ElectromagneticFlowmeters incorporate the pump at the service station, your family unitwater meter and your gas meter for normal gas. Your auto is brimming withstream control gadgets and more up to date autos incorporate stream control andsensors as a major aspect of its PC controller. SITRANS FM ElectromagneticFlowmeters for flow estimation is additionally utilized as a part where failurecould mean debacle including nuclear power plants, fabricating operations and aconsiderable number of something more.

Incorrectnessin FM Electromagnetic Flowmeters for flowestimation or misinterpreting estimations cannot just cost you an awesomemeasure of cash after some time, it can likewise spell debacle for hardware, productand even peril to life. This is the reason it is essential for all individualsthat work around or with FMElectromagnetic Flowmeters or the information gave by them to think aboutthe fundamental sorts of meters and how they function.

Fromvarious SITRANS FM ElectromagneticFlowmeters supplier that ought to know something of what they buy to theindividual that ranges the floors during the evening, all ought to think about thisSITRANS FM Electromagnetic Flowmeters.Instronline.com is set up to give the most fundamental prologue to Electromagnetic Flowmeters and show anabundance of other data.

More Information About:Piping Requirements for Flow Meter Installation Click Hear

Top Tips for flowmeter selection

The enormous cluster of flow innovation choices on offer can make selecting the right flowmeter for applications of stupefying errand. A wide scope of elements can impact flowmeter choice, of which cost is only one. An expert suggested rundown of top tips for selecting the best all round flowmeter systems for different applications.

1.Do you even need a flowmeter?
Numerous clients frequently simply need to know the rate at which a fluid or gas is traveling through a pipeline. In such cases, a basic flow indicator, accessible from any flowmeter supplier at a small amount of the cost of the simplest flowmeter, will normally suffice. Basic and simple to introduce and requiring no outside power, these instruments can be utilized to give nearby sign of flow.

Indeed, even where there is an interest for something more refined, for example, an indication of flow to inside 10%, there may at present be no compelling reason to buy any FM electromagnetic flowmeter. Numerous establishments regularly highlight curves or joints that can be promptly changed over into a rough flowmeter by buying a FM electromagnetic flowmeter and introducing sensors to quantify the distinction in pressure between two or more focuses. Given that alignment can be effectively accomplished, these disentangled flowmeters can accomplish a precision of around 5%.

2.Don't pick on cost alone?
With regards to selecting a flowmeter, least expensive is in no way, shape or form best. Despite the fact that it may appear the most ideal approach to spare cash in the short term, picking the least cost arrangement may conceivably bring about issues later down the line.

Be especially cautious where diminishments in the price tag have been accomplished by decreases up and ability. Eventually, the most financially savvy establishment will be the one where the FM electromagnetic flowmeter supplier can offer great specialized go down, autonomously traceable test offices, a set up reputation and a notoriety for high-unwavering quality items in view of sound innovative work.

3.Know your flow?
A key thing to recall while selecting any electromagnetic flowmeter is that each liquid or gas acts distinctively when coursing through the pipeline. The primary driver of this is thickness - how much the liquid opposes flow, which thus influences the speed of move through the pipeline.

By profiling the flow of a liquid or gas through the pipeline, it is conceivable to discover how it carries on and from that point to contract down the decision of flowmeters to those best ready to adapt to the states of the application.

4.Opt for the most extensive turndown?
Put basically, turndown is the proportion of the most extreme and least flow rates a flowmeter can gauge inside its predetermined precision go. The turndown of a flowmeter is especially vital in light of the fact that it is for all intents and purposes difficult to know ahead of time the correct scope of streams to be measured. Selecting a flowmeter that offers the amplest conceivable turndown will guarantee that it can cover all expected stream varieties.

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Santary Ball valve, Pneumatics Control, Suppliers, in India

The Santary ball valve is a valve with a circular circle, the part of the valve which controls the flow through it. The circle has a gap, or port, through the center so that when the port is in accordance with both closures of the valve, stream will occur. At the point when the valve is shut, the opening is opposite to the closures of the valve, and stream is blocked. The handle or lever will be in accordance with the port position giving you a chance to see the valve's position. The ball valve alongside the butterfly valve and attachment valve are a piece of the group of quarter turn valves.

Utilizing ball valves as a part of clean applications has some pros and cons. Maybe the best advantage of utilizing sanitary ball valves is that they for the most part work to accomplish impeccable shutoff even following quite a while of neglect. They are along these lines a phenomenal decision for shutoff applications and are regularly wanted to santary butterfly valves, diaphragm valves or seat valves. They don't offer the fine control that might be vital in throttling applications yet are once in a while utilized for this reason. The other enormous favorable position ball valves have is that they are the most elevated pressure appraised clean valves available.

Santary ball valves, as the name suggests, have a ball with a hole drilled through the inside swivel mounted with the valve body. Whenever the opening in the ball is situated in the same course as the funnel; this will bring about full stream rate. As the hole in the ball is situated far from the heading of the channel, the stream rate will be confined lastly cut off totally when the gap is arranged 90 degrees to the funnel course.

Like santary butterfly valves, most santary ball valves can be exceedingly mechanized. Ball valves are offered with stainless steel actuators for all sizes. There are distinctive switch bundles accessible which to mount to the actuators. Twofold rack and pinion pneumatic actuators are the standard for ball valves, since they are ¼ turn valves. Likewise the same as the butterfly valves, ball valves have a vast offering of various ¼ turn actuators available.

A wide range of santary ball valves manufacturers offer their variant of a ball valve in spite of the fact that the operational elements are fundamentally the same as. In the business sector of ball valves there are a wide range of option decisions so that potential clients are effortlessly ready to locate another decision. Hence it is critical to decode a client's requirements for the current application. This will make it conceivable to pick the one that will be a quality entertainer at a decent cost.

PNEUCON AUTOMATION GLOBE 3 WAY VALVE DESIGN FEATURE

Pneucon was advanced by the technocrats in last 90s, which are having an affair of more than four decade in control valve technology. The organization is occupied with the Design, Development and Manufacture of an exhaustive scope of Control Valves for all procedure, Power era and related ventures. The organization has the building and specialized mastery together with the offices to address the assorted computerization requests of the cutting edge process ventures. Standard, Special and Customized Control Valves are all accessible on interest for use in an extensive variety of uses and enterprises.

The best Globe 3 Way Control Valves are utilized to join two streams or to redirect stream into two outlets. They are intended to supplant and play out the elements of two single ported control valves acting in inverse headings, in meeting or wandering fluid stream administration. They can be utilized to control the course of water, oil, ocean water or different fluids in warming or cooling applications including heat exchanger sidestep control. All Globe 3 way valve exporters are providing best designed and featured instrument, Instronline is the best Pneucon automation Globe 3 way valve supplier in NCR that provides a full maintenance certificate and a grantee of on best design and performance. The Globe 3 Way Control Valve-Design Features are:
-High appraised Valve limits and range capacity
-Overwhelming – Duty ground and cleaned stems
-Extensive variety of exchangeable trim sizes
-Howl seals accessible for positive stem fixing
-Extensively planned and tried to guarantee its ideal execution for the intense procedure parameters indicated
More Information About Samson Vetec Rotary Control Valves:-Click Hear

Samson Vetec Rotary Control Valves: Instronline

The VETEC line of Rotary Plug Valves from Samson are the perfect decision for basic control valve applications that require free section, stable activity at little opening points, and high KVs values. Samson VETEC Rotary Plug Valves join the upsides of Dom Valves, Butterfly Valves, and conventional Control Valves into one minimized bundle. Thus, numerous applications that can't use conventional control valves can make utilization of VETEC Rotary Plug Valves. Samson VETEC Rotary Plug Valves have different focal points over conventional control valves too. VETEC Rotary Plug Valves don't require the media current to be redirected through the lodging divider (particularly helpful for grating/sticky media).

The high Kvs estimations of VETEC Plug Valves (up to 200% bigger than a valve of similar size) permit less costly, littler valve ostensible sizes to be utilized as a part of the spot of bulkier, customary control valves. This recovers both space and cash. Samson VETEC Rotary Plug Valves likewise have extraordinary range ability. Since the module VETEC valves does not dunk into the seat, the outline takes into consideration a noteworthy range ability increment contrasted with conventional models. While regular valves have range abilities of 1:30 to 1:50, VETEC Rotary Plug Valves achieve normal estimations of 1:200.

Apart from the description of this rotary plug valve if we talk about the best Samson VETEC Rotary Plug Valves exporter, then Instronline.com is the answer. Instronline is the Samson Check Valves Suppliers in NCR with various dealers and buyers in connections. The brand is as popular as Samson check valves exporter in Delhi/NCR.

More Information About SITRANS FUT1010 (Liquid and Gas) click Hear

DC Drives - Drive Monitoring Tool

To the extent the DC drives are concerned it's a free hard drive checking apparatus to screen hard drive and to show the general circle drive execution. With the assistance of this awesome contraption one can break down all your disk drives as far as disk movement, disk use, reading or writing rates, and file framework. The best part is that it demonstrates a rundown of all the disk drives and removable media associated with the PC, with all the fundamental subtle elements. What's more, the outcome is that it helps you to investigate and screen the execution. The Intronline is the main name in the Instrumentation and Automation Products which deals in supplying DC motor drives in Delhi and NCR.

According to the innovative progression these Drives Monitors are not just sufficiently competent to shows the execution of different circle drives associated with the PC, additionally offers different helpful settings. Instronline is the biggest Siemens DC drive supplier and Siemens DC drive manual dealer in Delhi with various standards.

1/2Hp, 1Hp, 3hp,5Hp, 10Hp Input Voltage:
• Input Voltage 110VAC • Input Voltage 220VAC • Input Voltage 440VAC Output Voltage:
• Armichar 180VDC • Armichar 380VDC • Field Voltage 220VDC

To provide the different necessity these drive monitoring tools are made available in fluctuated size and measurements. Prevalent quality info and most recent innovation are utilized as a part of the manufacture procedure and this makes the drive screens high popular in the universal field. To surpass the quality a falcon eye is kept up in the whole procedure so that the immaculate scope of Drive Monitor is conveyed at the customer end.

Our range of ability lies in the Proximity Sensors, Optical Sensors, Capacitive Type, Power Supply Relay Unit, Present Counter, Digital Timer, RPM Indicator and R T D Sensor. What's more, we likewise offer Eight Channel Relay Unit, Temperature Controller, DC Drives and Digital Tachometer. These items are figured in the universal field for their inflexible development, sturdy completion standard, solid execution and prevalent usefulness.

Inside a limited capacity to focus time organization have scaled new statures in the space. His sharp business keenness and rich industry encounter likewise help us in meeting customers' variegated prerequisites in auspicious way. The unassuming and adroit staff guarantees that the administrations would meet the clients' necessities in most ideal way.

The moral business practices, customer driven methodology and simple installment modes help Instronline in accomplishing complete customer driven methodology are Strategic arranging, Timely execution, Flexibility, Reliability, Promptness, Customized arrangements and Customer-situated methodology. Our products are reasonable and dependable as well.

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Electromagnetic flow meter in India Click Hear

Understanding how ultrasonic continuous level measurement works

The Ultrasonic sensors are easy to see, simple to introduce and cheap. It's anything but difficult to go to them as the careless sensor of decision for level applications, pretty much the same number of individuals goes to differential pressure level sensors. However, the same number of clients have found, ultrasonic sensors and transmitters are dubious monsters. Similarly as with some other field instrument, applying a ultrasonic level sensor too far outside the maker's prescribed application envelope is bound to come up short, and some of the time fall flat staggeringly. In any case, in the event that you take after these essential rules, you will have effective ultrasonic level establishments.

How it actually works:

Ultrasonic level sensors work by the "time of flight" guideline utilizing the pace of sound. The sensor transmits a high-recurrence beat, for the most part in the 20 kHz to 200 kHz reach, and afterward listens for the reverberation. The pulse is transmitted in a cone, more often than not around 6° at the summit. The pulse affects the level surface and is reflected back to the sensor, now going about as a collector, and after that to the transmitter for sign handling.

Essentially, the transmitter partitions the time between the pulse and its reverberation by two, and that are the separation to the surface of the material and Instronline. The transmitter is intended to listen to the most elevated adequacy return pulse (the reverberation) and cover out the various ultrasonic signs in the vessel.

As a result of the high plentifulness of the pulse, the sensor physically vibrates or "rings." Visualize a still chime struck by a mallet. A separation of about 12 in. to 18 in. (300 mm to 450 mm), called the "blanking separation" is intended to keep spurious readings from sensor ringing. This is imperative for establishment in zones where the separation over the level surface is insignificant.

Beyond this working of Ultrasonic Transmitter physical installation issues persists, one of the main and big physical installation issue is to ensure that the working temperature scope of the sensor is not surpassed on either the high or low temperature end. The materials of development may misshape or the piezoelectric gem may change its recurrence if the temperature extent is surpassed. The change in ambient temperature is generally adjusted, either by an installed temperature sensor, a remotely mounted temperature sensor or an objective of known separation that can be utilized to quantify the encompassing temperature.

Electromagnetic flow meter in India

Generally the flow transmitters precisely measure the stream rate of conductive fluids and slurries in shut channels. Because of basic and unbending configuration the flow transmitter is a deterrent less and support free instrument set up of customary mechanical stream measuring gadget.

The utilization of 'DC Pulse' innovation offers most elevated capacity and better measuring precision as electrical sign 4 - 20 mA DC directly relative to volumetric stream. The instrument depends on Faraday's law of electro-magnetic incitement. An attractive field is produced by the instrument in the stream tube.

The liquid moving through this attractive field creates a voltage that is corresponding to the stream speed. Relating electrical yield is given admiration to measuring voltage.

The SITRANS FM electromagnetic flow meters are intended for measuring the stream of electrically conductive mediums. The full SITRANS FM program comprises of three distinct sorts of flow meters making Siemens one of a kind in that it covers all conceivable applications where electromagnetic flow meters are an appropriate match.

Similarly, ABB is an another electromagnetic flow transmitter by Instronline built up world power in the outline and assembling of instrumentation for mechanical procedure control, stream estimation, gas and fluid investigation and natural applications. As a world pioneers in procedure computerization innovation our overall nearness, far reaching administration what's more, application situated expertise make ABB a main supplier of electromagnetic flow transmitters.

The Siemens are small scale controller based pedal to the metal sort electromagnetic flow transmitter uncommonly utilized for different mechanical applications.

Electromagnetic flow meters utilize Faraday's Law of Electromagnetic Induction to decide the stream of fluid in a funnel. In an electromagnetic flow meter by Instronline, an attractive field is produced and diverted into the fluid coursing through the funnel.

Taking after Faraday's Law, stream of a conductive fluid through the attractive field will bring about a voltage sign to be detected by terminals situated on the stream tube dividers. At the point when the liquid moves quicker, more voltage is created.

Faraday's Law expresses that the voltage created is relative to the development of the streaming fluid. The electronic transmitter forms the voltage sign to decide fluid stream.

See Believe Power Genex Positioner, Electropneumatic Positioner

MIEPL 10m Range Ultrasonic Level Transmitter

The MIEPL is the main ultrasonic level transmitter that utilizations dynamic GAP innovation with a specific end goal to find the right reverberates. The MIEPL uses the base measure of GAP (Gain, Amplitude, and Power) at each conceivable separation inside the estimation range. This basically implies we lessen the ability to give you the most precise perusing with a bar edge of just 3 degrees and after that enough energy to push through the dustiest situations.

The MIEPL 10m Ultrasonic Level Transmitter is the dependable and financially savvy, non-reaching estimation arrangement from MIEPL. Time demonstrated ultrasonic innovation with cutting edge programming and best in class hardware conveys high unwavering quality in a wide assortment of uses. The 10m level is the range model for basic level estimation. For risky zone applications, the 10m Ultrasonic Level Transmitter is confirmed inherently sheltered.

Ultrasonic Level Transmitter arrangement transmitters are 3 wire sort instruments. An ultrasonic wave pulses 5 times each second. The impression of this beat is gotten by the sensor. The time taken for the wave to go to the article and back to the sensor is corresponding to the separation of the item from the sensor. The conservative size, slender bar point and little dead band guarantees that these sensors will work dependably for little tanks.

Temperature Instruments and Controllers Dealers

As the name infers, a temperature controller is an instrument used to control temperatures, mostly without broad administrator association. A controller in a temperature controlling system will acknowledge a temperature sensor, for example, a thermocouple or RTD as information and contrast the real temperature with the coveted control temperature, or set point. It will then give a yield to a control component.

A decent illustration would be an application where the controller takes a contribution from a temperature sensor and has a yield that is associated with a control component, for example, a warmer or fan. The controller is normally only one a player in a temperature control framework, and the entire framework ought to be broke down and considered in selecting the best possible controller.

Simillarly, Digital temperature transmitter is an electrical instrument that interfaces a temperature sensor to an estimation or control gadget. Normally, temperature transmitters segregate, intensify, channel clamor, linearize, and change over the info signal from the sensor then send an institutionalized yield sign to the control gadget. There are various Digital temperature instrument dealer in and around Delhi/ NCR. Instronline is best temperature Instruments and Controllers Dealers, temperature transmitter exporters who supplies various electrical and other instruments like Wika temperature transmitter, Wika Hand-held temperature calibrator, Temperature Gauge Exporters,Digital Temperature Humidity Indicator etc.

Automation Solutions by Instronline.com

Automation or programmed control, is the utilization of different control frameworks for working hardware, for example, apparatus, forms in production lines, boilers and heat treating broilers, switching on phone network, controlling and adjustment of boats, air ship and different applications with insignificant or decreased human mediation.

A few procedures have been totally mechanized. The greatest advantage of automation solutions is that it spares work; in any case, it is additionally used to spare vitality and materials and to enhance quality, exactness and accuracy.

Automation has been accomplished by different means including mechanical, water driven, pneumatic, electrical, electronic gadgets and PCs, more often than not in blend. Complicated automation frameworks, for example, modern processing plants, planes and ships ordinarily utilize all these joined methods. Instronline.com gives a full support in proving various product for backing of automation solutions, as it is the best automation service provider in India.

Our uncommon experience, mastery and commitment to appropriately built and introduced automation control system guarantees our client's prosperity while executing another outline, redesigning a current control, or overhauling a current framework.

The automation solutions provided by Instronline are fully based on their techniques, offering a wide assortment of arrangements and services to different buyers and users.

We have all latest technology based products that not only helps in various field to buyers but also assets to empower conveyance of assembling arrangements that give the most noteworthy efficiency and payback for your application.

Our nature and involvement with Robots, Motion Controls, PLCs, appropriated I/O, HMI interfaces, PC Based Controls, SCADA, Servo Motors, Hydraulics, Pneumatic, and a wide range of machine outlines permits us to best help you succeed.

We are the best automation instruments dealer and can help in the features, designs and procedure to install your next automation device and can make Instronline the best automation solutions supplier.

Ultrasonic Level transmitter Frequently Asked Question

Sonic is the range of audible sound that we can listen. Ultrasonic is the sound above human listening to run. Human can hear greatest up to a recurrence of 20 KHz. Ultrasonic frequencies are above 20 KHz. Ultrasonic level transmitter is contact less guideline and most reasonable for level estimations of warm, destructive and bubbling fluids. On the other hand Instronline is one of the biggest Ultrasonic Level Transmitter exporter across the globe. The most of the transmitter suppliers do not provide the answers to the queries of the buyers, but Instronline is here to answer the frequently asked questions by the buyers. Some FAQs by buyers to various Ultrasonic Level Transmitter exporter are:

What is the principle of Ultrasonic Level transmitters?

Ultrasonic waves identify an article similarly as Radar does it. Ultrasonic level transmitter utilizes the sound waves, and Radar utilizes radio waves. At the point when ultrasonic pulse sign is focused on towards a point, it is reflected by the point and reverberation comes back to the sender. The time travelled by the ultrasonic pulse is figured, and the separation of the item is found. Bats utilize understood technique to gauge the separation while voyaging. Ultrasonic level estimation guideline is additionally used to discover fish positions in sea, find submarines beneath water level, likewise the position of a scuba jumper in ocean.

Advantages of Ultrasonic Level transmitters?

The ultrasonic level transmitter has no moving parts, and it can quantify level without reaching the item. This common normal for the transmitter is valuable for measuring levels in tanks with destructive, bubbling and unsafe chemicals. The precision of the perusing stays unaffected even after changes in the substance synthesis or the dielectric consistent of the materials in the process liquids.

Limitations of Ultrasonic Level transmitters?

The ultrasonic level transmitters are the best level measuring gadgets where the got reverberation of the ultrasound is of worthy quality. It is not all that advantageous if the container profundity is high or the reverberation is retained or scattered. The object ought not be sound retaining sort. It is additionally unsatisfactory for the keeper with an excess of smoke or high thickness dampness.

Cross correlation flow meter?

Cross correlation flow meter? these are my queries
1. what is cross correlation flow meter?
2. which is the sensor used?
3. how it differs from ultrasonic and differential pressure or are they same??????????
more Product about flow meter Click here...

How is mechanical energy converted into electrical energy?

A generator is used to convert mechanical energy to electrical energy. A motor converts electrical energy to mechanical energy. An electric generator is a device used to convert mechanical energy into electrical energy.

The controls on the animation allow you to control the speed and direction of the generator and turn portions of the animation on and off for greater clarity. You can also use the radio buttons to show a direct current, or DC generator (with commutator) or an alternating current, or AC generator (without commutator).

Electromagnetic Flow Meter Devices

Instronline is famous for Selling various Electromagnetic flow meter devices. we sell various electronic devices and components. So many companies participate in the buying and selling process of these devices instronline works in global.

Ultrasonic Switches

Ultrasonic switches are a financially savvy solution for your applications.Establishment requires mounting the sensor (strung or flanged) to the vessel, interfacing the force and control wires, and applying force.There is no extra set-up or alignment required. Since it is an electronic instrument with no moving parts, preventive support is constrained to a yearly visual assessment. The just prescribed extra part is the "board" at an amount of one board for each 10 units. A specialist with fundamental electrical abilities (wiring)can administration the instrument.

Principle Of Ultrasonic Switches

A ultrasonic switch is a gadget that uses imperceptible high-recurrence sound (ultrasound) to recognize the vicinity or nonattendance of a fluid at an assigned point. The gadget comprises of an electronic control unit and a sensor.

Ultrasonic level switches utilize the properties of sound transmission in vapor and fluids to recognize fluid level. At the point when sound goes in air, it loses a lot of sign quality. At the point when going in fluid, sound holds the greater part of its sign quality.

To identify fluid level, we must figure out whether there is a fluid or gas (air) in the crevice. Since fluids have a higher thickness than gasses, it is less demanding to transmit sound through them. One side of the sensor hole transmits sound, the other side distinguishes it. At the point when fluid is available, a high measure of sound is gotten at the recognition side. Whenever gas (air) is available, a little measure of sound is gotten. The gadgets recognize this distinction and switch a hand-off likewise.

Ultrasonic changes are easy to apply and utilize. There are just a couple of restrictions to their utilization:

The media must be fluid.
Process temperature between - 40 and 250F.
The media must have under 5% suspended solids.
No air circulation in liquids with a thickness of 100cP (30W engine oil) or more.

Electronic pressure measurement

Electronic pressure measurement adds to the sheltered, exact and vitality sparing control of procedures. Close by temperature estimation, it is the most essential and most usually utilized innovation for checking and controlling plants and apparatus. Especially in pneumatic and water power, estimation and control of the framework weight is the most vital essential for protected and financial operation. Amid the previous 20 years, electronic weight estimation has been presented in a huge number of utilization, and new applications are included each day. On the other hand, the requests on the instruments are as different as the applications. This is likewise reflected in the vast number of items. In the beginning of electronic weight estimation the client could just look over a little number of variations, produced by a modest bunch of suppliers. Today the client is defied with a large number of specialized arrangements by various suppliers, and must in this way depend on able help with the determination.

Keeping in mind the end goal to have the capacity to make an appropriate choice of the suitable electronic weight measuring instrument, the clients or designers ought to have Variety of utilization and instruments Instrument determination Suitability information about the physical standards of

Weight estimation, the focal points and disservices of distinctive sensor innovations in connection to the specific application, further more about the key nuts and bolts of instrument innovation. The determination of the suitable weight measuring instrument is based,in addition to other things, on such criteria as the weight territory, the weight or process association, the electrical association, the yield sign and the measuring precision. This book introduces the foundation information required to comprehend and think about information in the information sheets in a straightforward and clear way.

Pressure and pressure measurement :

In procedure frameworks two of the most essential process variables to gauge are temperature what's more, weight. The normal weights measured are the hydro static weight of a fluid section what's more,the air weight. All in all, weight is characterized as takes after:if a power per unit territory is connected in a heading opposite to a surface, then the proportion of the power esteem F to the surface territory An is called weight P: P=F/A

To transmit pressure, in compressible media for example, fluids are suitable. To store vitality in the type of weight work, compressible media for example, gasses are utilized.

What is Tachometer ?

Tachometers are basically used to measure the rotation speed of shafts or discs in motor or any other machine.For more details about Tachometer, visit Instronline.

Properties of Transmitter

Our company Instronline is famous for selling various electronic devices and components. So many companies participates in the buying and selling process of these devices.For more details, visit Instronline.

Pressure Calibrator

The manufacturing of the precision pressure gauges and calibrators has been relocated from Germany and are now being done in the U.S. by WIKA Instrument Corporation. They are certified to NIST Standards before shipment.
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Encoder

Due to their sturdy bearing construction in Safety-Lock Design, the Sendix 5000 and 5020 offer high resistance against vibration and installation errors. The rugged housing, high protection level of up to IP67, as well as the wide temperature range of -40°C up to +85°C, make this product range the perfect encoder for all applications.
For more details about Encoder, visit Instronline.

Volume Booster

Volume booster relay, YT-305 is used in pneumatic control valve which receives positioner’s output signal and supply air pressure actuator to reduce response and adjusting time.
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Pressure Transmitter

The SITRANS transmitters P200, P210 and P220 are compact single-range-transmitters for measurement of absolute and gauge pressure. In this series we use two different kinds of pressure sensors: two stainless steel sensors and one ceramics sensor.
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Temperature Transmitter

The ABUS Fr Block Series is a head-mounted version of the Fixed Range Temperature Transmitter. Fr Block Series is used for RTD Pt-100 sensor input and Thermocouple input, converts a temperature sensor signal into a 4 to 20 mA DC current loop powered signal with excellent linearity and load driving capability.
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New battery composed of lots of nanobatteries

We’re increasingly dependent upon our batteries, so finding ways of building ones with enhanced lifetimes would make a lot of people happy.
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Smart positioners in safety instrumented systems

The operation of many industrial processes, especially those within the chemical and oil and gas industries, involves inherent risk due to the leaking of dangerous chemicals or gases.

Pneumatics System

In a pneumatic system, energy is stored in a potential state under the form of compressed air. Working energy (kinetic energy and pressure) results in a pneumatic system when the compressed air is allowed to expand.
For more details about Pneumatics System, visit Instronline.

Flow Transmitter

MASS 6000 is based on the latest developments within digital signal processing technology engineered for high performance, fast flow step response, fast batching applications, high immunity against process noise, easy to install, commission and maintain.
For more details about Flow Transmitter, visit Instronline.

Importance of Pressure Transmitter

The advancement of the technology is seen in industrial processes during present days with a very high speed. The facilities like operations,guarantee of process optimization, the performance and operational safety are assured.
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Process Loop Calibration Optimises Plant Stability

The calibration of analogue signals from myriad sensors and transducers in a process plant is essential not only to ensure correct readings on instruments but also for the feedback signals required for stable process plant operation.

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Controller

The DC1000 Series are microprocessor based controllers designed with a high degree of functionality and reliability at a competitive price.
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Pressure Indicator

The product can support a wide application range to accept and display analog inputs. In process control industry the product finds use to display process parameters from various sensors such as Pressure, Flow, Level, Temperature etc.

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Hydraulic Test Pumps

Test pumps are used to generate pressure for testing, adjusting and calibrating mechanical and electronic pressure measuring instruments by means of comparison measurements.

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Programmable Logic Controller

Masibus signal isolator is a rugged 4 wire isolator available in compact DIN rail mounting enclosure designed to accept custom built and wide range of voltage and current input signals.

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INTEGRATED SIGNAL AND POWER ISOLATION

Robust and accurate measurements and controls are important for industrial instrumentation and process control. Various industrial sensors such as RTD or thermocouples usually require input isolation, not only to prevent ground loops that can compromise measurement accuracy, but also to prevent voltage transients that can cause permanent damage to the instrument.

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HOW TO SAVE MONEY ON ELECTRIC BILLS

Saving money can be difficult so you want to cut costs wherever possible to increase your savings. Lowering your electric bill can save a few dollars each month which adds up to extra money in your pocket. But how can we cut our electric bill without making major sacrifices or investing extra money to see some savings? More Information Click Hear

Electro-Pneumatic Positioners

Electromechanical positioners are conventional pneumatic positioners that have an additional integrated electro-pneumatic transducer. The transducer receives the DC analogue input signal from the control system and converts it to a proportional pneumatic signal which is then sent to the conventional positioner Almost every Fisher pneumatic positioner has the option of adding an integrated electro-pneumatic transducer.

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