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Small Hydraulic Proportional Valve

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Small Hydraulic Proportional Valve

Small Hydraulic Proportional Valve

gr3ggh3ad

(Mechanical)

(OP)

6 Dec 22 01:35

Hi - The goal of my project is spool high-strength wire on to a drum at a fixed tension. To do so, I am considering controlling a small, hydraulic proportional valvehydraulic proportional valve using a PLC that will essentially feed a hydraulic brake. I will have a 4-20mA input (line tension feedback) to a programmable controller , a display to enter my setpoint (desired line tension), then vary the hydraulic valve output accordingly to control pressure only (no flow... the pressure output will feed a hydraulic brake to adjust line tension). The max pressure is probably less than 500 psi. I do not have a ton of experience with hydraulics, however I do have experience with PLC controls. I am mainly looking for help in pointing me toward a proportional valve that will meet these requirements, but any other tips or knowledge of a small PID controller that will do the job would be appreciated, too. Also, if you have a lead on a small scale hydraulic pump to feed the valve, please let me know as well. Thanks! Gregg

RE: Small Hydraulic Proportional Valve

srini

(Electrical)

8 Dec 22 08:12

https://continentalhydraulics.com/product_items/ve...

I have some experience in similar applications but using pneumatic proportional pressure control valve not hydraulic.So, check this thoroughly.

This is what i could get from what i understand of the application. The pressure can be varied from 15 to psi using a 0-10V or a 4-20mA signal. You write a code in the PLC for the scaling between the strain gauge input and the signal output to tune the PID.I have some experience in similar applications but using pneumatic proportional pressure control valve not hydraulic.So, check this thoroughly.

RE: Small Hydraulic Proportional Valve

PNachtwey

(Electrical)

8 Dec 22 19:14
Is this a new installation?
Normally one controls the tension by controlling the torque on the winder. Also, you need something to lay the wire smoothly back and forth on the spool/drum. Nothing is said about the source of the wire. Sometimes there is a tension loop between the source and destination spool.
There are electric winding machines that cost less than the valve and machine is put together.
https://www.vevor.com/automatic-coil-winder-c_...
There are many such machines. I would look around and see if you can buy something off the shelf before trying to re-create the wheel.
BTW, I sell motion controller that have done applications like this but the reason why our motion controller was chosen is because they were winding very thick copper that was rectangular in shape so a custom machine was necessary. Unless you are doing something that is not normal you should look for something off the shelf.

The valve described by gr3ggh3ad will work if the rest of the system is good.Is this a new installation?Normally one controls the tension by controlling the torque on the winder. Also, you need something to lay the wire smoothly back and forth on the spool/drum. Nothing is said about the source of the wire. Sometimes there is a tension loop between the source and destination spool.There are electric winding machines that cost less than the valve and machine is put together.There are many such machines. I would look around and see if you can buy something off the shelf before trying to re-create the wheel.BTW, I sell motion controller that have done applications like this but the reason why our motion controller was chosen is because they were winding very thick copper that was rectangular in shape so a custom machine was necessary. Unless you are doing something that is not normal you should look for something off the shelf.

Peter Nachtwey
Delta Computer Systems
http://www.deltamotion.com
http://forum.deltamotion.com/
IFPS Hall of Fame Member

RE: Small Hydraulic Proportional Valve

LittleInch

(Petroleum)

8 Dec 22 21:09

Look up how automatic car brakes work?

I think you need to vary the air pressure over a hydraulic chamber or piston and not the hydraulics itself as you have no flow.Look up how automatic car brakes work?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: Small Hydraulic Proportional Valve

gr3ggh3ad

(Mechanical)

(OP)

8 Dec 22 22:25

Thank you all for the replies. Forgive me as this is my first post... I do not see a way to reply to individual responses, only 'reply to the post'. Allow me to clarify my scenario:

We have trucks with 15K+ feet of wire spooled on for oil, gas, and geothermal well service work. Occasionally we spool new line [under tension] on the trucks. Our current method is open-loop: an operator has one hand on a pack- off pump which applies hydraulic pressure to a capstan brake [to vary the tension], and an eye on the line-tension display. If the line tension decreases, he pumps the pack-off pump to increase the drag at the capstan. If the tension increases, he bleeds off a little pressure to reduce the tension.

I want to automate this and make it closed-loop. I'll fabricate a portable box that we place at the truck when spooling new line. I'll use a 4-20mA output from the line-tension sensor on the truck and bring it into the 'box' as my feedback. A small display on 'the box' will allow the operator to enter the setpoint (desired tension). The 'box' will have small hydraulic pump, and a variable valve to control the pressure out to the brake on the capstan; I think this should keep the line tension fairly constant.

I know enough about controls to make it happen [in theory]... I just do not have the hydraulic experience to choose a valve.

Thanks again!

RE: Small Hydraulic Proportional Valve

zeusfaber

(Military)

14 Dec 22 20:31

Here are two approaches you might try.

You could connect a single direction valve in series with a fixed orifice and tap off the pressure at the junction between them - the hydraulic analogue of a potentiometer. This approach can be made to give you something that responds very quickly, but is wasteful of energy.

The other is to use a bidirectional valve to charge or discharge an accumulator - much more analogous to your existing approach. Although the response is slower, pressure control will be smoother and you might even get away with bang-bang control rather than a proportional valve.

However, making your chosen valve control pressure is only the start of the job. You've still got to sort out how your valve arrangement is going to get a suitable and reliable supply of hydraulic fluid. It isn't enough just to clag in a small hydraulic pump, switch it on and then turn the tap on and off. To a first approximation (Peter will tell you how misleading this is, but for a first approximation, it will do), cheap hydraulic pumps are constant flow devices. That means that when your valves aren't demanding flow, you need to choose a suitable place for that constant flow to go (suitable doesn't mean out through a new hole in the side of the pump). In the motion-control world, it's common to find that the proportional control valve that does the simple job you wanted in the first place ends up supported by six or seven additional valves and a handful of orifices - without which the system will overheat, self-destruct, refuse to work, or some combination of the three.

If a handpump and bleed valve worked well enough in the first place, perhaps you could just replace the handpump with a small electrically driven pump with a check valve on the output and then only run the motor when you need to increase pressure. Replace the bleed valve with a solenoid valve and an orifice to limit the flow. Add an accumulator if you want to slow the process down.

A.

As LittleInch suggested, readily available solenoid valves (even proportional ones) are not very good at controlling pressure directly. To a first approximation, what they control is flow (and, if you haven't got some sort of mechanism for maintaining a constant pressure drop across the valve, even that's a pretty poor approximation).Here are two approaches you might try.However, making your chosen valve control pressure is only the start of the job. You've still got to sort out how your valve arrangement is going to get a suitable and reliable supply of hydraulic fluid. It isn't enough just to clag in a small hydraulic pump, switch it on and then turn the tap on and off. To a first approximation (Peter will tell you how misleading this is, but for a first approximation, it will do), cheap hydraulic pumps are constant flow devices. That means that when your valves aren't demanding flow, you need to choose a suitable place for that constant flow to go (suitable doesn't mean out through a new hole in the side of the pump). In the motion-control world, it's common to find that the proportional control valve that does the simple job you wanted in the first place ends up supported by six or seven additional valves and a handful of orifices - without which the system will overheat, self-destruct, refuse to work, or some combination of the three.If a handpump and bleed valve worked well enough in the first place, perhaps you could just replace the handpump with a small electrically driven pump with a check valve on the output and then only run the motor when you need to increase pressure. Replace the bleed valve with a solenoid valve and an orifice to limit the flow. Add an accumulator if you want to slow the process down.A.

RE: Small Hydraulic Proportional Valve

gr3ggh3ad

(Mechanical)

(OP)

14 Dec 22 23:26

zeusfaber (and littleinch) - The lightbulb went on. I get it now that it would be difficult to control the pressure directly with hydraulics. The idea of air pressure over the hydraulic chamber makes perfect sense. Now I need to find out how I can regulate the air pressure with a controller. Thanks again!

RE: Small Hydraulic Proportional Valve

73lafuite

(Industrial)

15 Dec 22 08:52

Hello,
It's easy to regulate the hydraulic pressure. If you gave more details on the current hydraulic circuit and on the brake, the answer would obviously be more appropriate.
If currently your pump runs constantly and it does not heat the oil too much: then you are using a proportional pressure relief valve. example: RZM Atos; DBE Bosch rexroth; PDB Hydac
If the pump stops and there is an accumulator then use a proportional 3-way pressure reducer. example: ZGO Atos; DRE Bosch rexroth; PDR Hydac
Cordially

RE: Small Hydraulic Proportional Valve

LittleInch

(Petroleum)

15 Dec 22 10:36

You could do this with a two stage hydraulic accumulator system as well - high pressure supply into a decent sized accumulator so you pump it up and leave it. Solenoid valve with a flow control set by you ( needle valve) into a second hydraulic system connected to your brake with a small accumulator with a return path to a reservoir via a second solenoid valve also with a small needle valve. Then your PID loop either opens one valve for more tension or opens the second for less. Then all you really need to control or measure is the tension which you increase or decrease as required to maintain your set point.

You might find something like this where you can vary pressure via a 4-20, but if you want to build it yourself then the option above might be worth looking at, but this really mirrors your current system, just via a PID loop.

Just an idea.

Depends on your hydraulic pressure on the brake really.You could do this with a two stage hydraulic accumulator system as well - high pressure supply into a decent sized accumulator so you pump it up and leave it. Solenoid valve with a flow control set by you ( needle valve) into a second hydraulic system connected to your brake with a small accumulator with a return path to a reservoir via a second solenoid valve also with a small needle valve. Then your PID loop either opens one valve for more tension or opens the second for less. Then all you really need to control or measure is the tension which you increase or decrease as required to maintain your set point.You might find something like this where you can vary pressure via a 4-20, but if you want to build it yourself then the option above might be worth looking at, but this really mirrors your current system, just via a PID loop.Just an idea.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: Small Hydraulic Proportional Valve

gr3ggh3ad

(Mechanical)

(OP)

16 Dec 22 23:10

The attached image [below] shows the basics of the existing set up: the brakes on a capstan are currently being controlled with a hand pack-off pump; the greater the pressure on the brakes, the greater the capstan causes tension on the line being pulled around it. The hydraulic pressure required to obtain the tension I want is only on the order of 50-100 psi.

The second part of the image shows my proposed test. I bought a precision, relieving regulator (0-150psi) and 0.5 gal tank good for 200 psi. I'll fill the tank approx. half full of hydraulic fluid, then use the air regulator to vary the pressure over the hyd. fluid, which varies the brakes, which varies the tension on my line as I am spooling it onto the truck.

If this works well enough, I'll leave it with just the regulator [open loop]. If it really well and we want to go to the next level, I'll get a small PID controller and an Electronically Controlled Precision Compressed Air Regulator like this one from McMaster Carr and attempt to do it closed loop. ([link

Again... thank you for the input.The attached image [below] shows the basics of the existing set up: the brakes on a capstan are currently being controlled with a hand pack-off pump; the greater the pressure on the brakes, the greater the capstan causes tension on the line being pulled around it. The hydraulic pressure required to obtain the tension I want is only on the order of 50-100 psi.The second part of the image shows my proposed test. I bought a precision, relieving regulator (0-150psi) and 0.5 gal tank good for 200 psi. I'll fill the tank approx. half full of hydraulic fluid, then use the air regulator to vary the pressure over the hyd. fluid, which varies the brakes, which varies the tension on my line as I am spooling it onto the truck.If this works well enough, I'll leave it with just the regulator [open loop]. If it really well and we want to go to the next level, I'll get a small PID controller and an Electronically Controlled Precision Compressed Air Regulator like this one from McMaster Carr and attempt to do it closed loop. ([link s/maximum-pressure~100-psi/regulator-style~relieving/" target="_blank">https://www.mcmaster.com/precision-air-regulator*!...]Link[/link])

RE: Small Hydraulic Proportional Valve

LittleInch

(Petroleum)

18 Dec 22 14:09

Let us know how it goes.

I thought you might need more than 100 psi but that's well within a simple air compressor range.

That should work. The reaction time might be a bit slower than the hydraulic oil version but that might be a good thing?Let us know how it goes.I thought you might need more than 100 psi but that's well within a simple air compressor range.

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News

Table of Contents

1. Type of Valve

2. Actuator Type

3. Material Compatibility

4. Pressure and Temperature Ratings

5. Flow Requirements

6. Sealing Performance

7. Control and Connectivity

8. Maintenance and Repair

9. Certifications and Standards

10. Cost of Ownership

Actuated valves are critical components in various industries, controlling the flow of liquids and gases with precision. Whether you're in the pharmaceutical, food processing, petrochemical, or water treatment industry, selecting the right actuated valve is crucial for your operations. This comprehensive guide will outline the top 10 factors to consider, ensuring you make an informed decision that enhances efficiency, safety, and productivity.

1. Type of Valve

When delving into the intricacies of actuated valves, understanding the various types available and their specific applications is paramount. This knowledge ensures the selection of the most appropriate valve, which is a critical determinant of your system&#;s efficiency, reliability, and safety. Here, we explore the common types of valves used in actuated systems, highlighting their unique features, advantages, and typical applications. For example:

Ball Valves

Ball valves feature a spherical disc with a hole through it, which controls the flow through the valve when the ball is turned. This design allows for full, unrestricted flow with a quarter turn of the valve handle, leading to minimal pressure drop. Ball valves are renowned for their durability and excellent sealing capabilities, making them a preferred choice for applications requiring tight shut-off. They can handle a wide range of fluids, pressures, and temperatures, making them versatile for many industries.

Butterfly Valves

Butterfly valves consist of a disc mounted on a rotating shaft. When the valve is closed, the disc is turned so that it completely blocks off the passageway; when it is open, the disc is rotated a quarter turn to allow nearly unrestricted flow. This type of valve is known for its compact design and low weight, which makes it easy to install and requires less support. Butterfly valves are suitable for handling large flow volumes and are commonly used in water and wastewater treatment, as well as in HVAC applications.

... & Many More! (which you can view HERE)

2. Actuator Type

Actuators are the mechanisms that operate the valve, and they can be pneumatic, electric, or hydraulic. Pneumatic actuators are known for their fast response time and are suitable for explosive environments. Electric actuators offer precise control and are ideal for remote operation. Hydraulic actuators provide high force with minimal space requirements. The choice of actuator will depend on your operational requirements, including speed, force, and control needs. For example:

Pneumatic Actuators

Pneumatic actuators use compressed air to generate force to move the valve. They are characterised by their fast response time and reliability. These actuators are particularly well-suited for environments where spark prevention is critical, making them a safe choice for explosive or flammable atmospheres. Pneumatic actuators are cost-effective for applications requiring a large amount of force, such as large valve operations in the oil and gas industry.

Electric Actuators

Electric actuators use an electric motor to operate the valve mechanism. These actuators offer precise control over valve positioning and are easily integrated into digital control systems, making them ideal for applications requiring accurate flow modulation. Electric actuators are suitable for a wide range of environments, including hazardous areas, provided they are equipped with the appropriate enclosures. They are typically used in water treatment plants, HVAC systems, and anywhere precise electronic control is needed.

Hydraulic Actuators

Hydraulic actuators use fluid pressure to generate force to move the valve. They are capable of producing a very high force output from a relatively small footprint, making them suitable for heavy-duty industrial applications where space is limited. Hydraulic actuators provide smooth, consistent control over valve movement and can maintain valve position even when hydraulic pressure is removed, offering a fail-safe operation. They are commonly used in applications where reliability and high force are crucial, such as in the petrochemical industry.

Factors to Consider When Choosing an Actuator Type

• Speed and Response Time: Pneumatic actuators typically offer the fastest response time, followed by electric and hydraulic actuators.
• Control and Precision: Electric actuators provide the highest level of control and precision, especially beneficial for modulating valves.
• Force Requirements: Hydraulic actuators are unmatched in their ability to generate high force, making them ideal for moving large, heavy valves.
• Environment: Consider the operational environment, including the presence of explosive gases, which may favour pneumatic or specially enclosed electric actuators.
• Availability of Utilities: Electric actuators require electricity, while pneumatic actuators need compressed air, and hydraulic actuators depend on a supply of hydraulic fluid.
• Cost: Initial installation costs, operational costs, and maintenance needs vary across actuator types, influencing the total cost of ownership.

3. Material Compatibility

Material compatibility is a cornerstone consideration in selecting actuated valves, directly impacting their durability, functionality, and suitability for specific applications. The materials chosen for both the valve body and the internal components must be able to withstand the operational environment, including the type of media flowing through the valve, the temperature range, and any potential corrosive or abrasive conditions. Let&#;s explore the importance of material compatibility in more depth and the considerations involved in selecting the right materials for your actuated valves.

Understanding Material Compatibility

Material compatibility is critical for ensuring the long-term performance and reliability of actuated valves. The right material selection can prevent common issues such as corrosion, erosion, and material degradation, which can lead to valve failure, leakage, and operational inefficiencies.

Common Valve Materials

• Stainless Steel: Highly resistant to corrosion and can withstand a wide range of temperatures, making it suitable for a variety of applications, from water to harsh chemicals.
• Brass: Often used in applications where corrosion resistance is needed but at a lower cost than stainless steel. Suitable for water, gas, and some mild corrosive environments.
• PVC (Polyvinyl Chloride) and CPVC (Chlorinated Polyvinyl Chloride): Plastic materials that offer excellent resistance to corrosion and chemical attack. Ideal for applications in water treatment and chemical processing where metallic valves might corrode.

Factors Influencing Material Selection

• Type of Media: The chemical properties of the fluid or gas, such as acidity (pH level), corrosiveness, and solvent properties, dictate the material choice to ensure compatibility.
• Temperature and Pressure: High temperatures and pressures can compromise the integrity of some materials. It&#;s essential to choose materials that can maintain their properties under the expected operational conditions.
• Abrasion and Wear: For applications involving abrasive materials, such as slurry services, material selection must consider resistance to wear and erosion.

4. Pressure and Temperature Ratings

Understanding the pressure and temperature ranges within your system is vital. Actuated valves are rated for specific operating pressures and temperatures. Choosing a valve with inappropriate ratings can lead to failure, posing safety risks and operational downtime. Always ensure the valve you select can withstand the maximum expected pressure and temperature of your system.

Pressure Ratings

Pressure ratings indicate the maximum pressure at which a valve can safely operate without risking damage or failure. These ratings are determined by various factors, including the valve's material, design, and size. Exceeding these ratings can lead to catastrophic valve failure, posing safety risks and potential damage to the broader system.

Factors Affecting Pressure Ratings:

• Material Strength: Different materials can withstand different levels of stress. For instance, metal valves typically have higher pressure ratings than plastic valves.
• Valve Design: The design and thickness of the valve body and components affect its ability to withstand pressure.
• Temperature: The valve's pressure rating can change depending on the temperature, as materials may weaken or expand at higher temperatures.

Temperature Ratings

The temperature rating specifies the range of temperatures within which the valve can operate effectively. It is determined by the materials used in the valve's construction, including the body and sealing elements. High temperatures can affect the elasticity of seals, leading to leaks, and can alter the material properties of the valve body.

Considerations for Temperature Ratings:

• Thermal Expansion: Materials expand at different rates when heated. This expansion can affect the fit and sealing capabilities of valve components.
• Material Degradation: Prolonged exposure to high temperatures can cause materials to degrade or change properties, potentially leading to failure.
• Seal Material: The type of seal material (e.g., PTFE, EPDM, Viton) has a significant impact on the valve's temperature tolerance. Each material has its own strengths and temperature range.

5. Flow Requirements

Understanding and accommodating flow requirements is essential when selecting actuated valves, as it ensures the valve not only fits within the system but also performs its intended function efficiently and effectively. The flow requirements of a system dictate the size and type of valve needed to manage the fluid dynamics appropriately. Here&#;s an in-depth look at the considerations surrounding flow requirements.

Understanding Flow Coefficient (Cv)

The flow coefficient (Cv) is a critical specification that measures how much fluid can pass through a valve at a given pressure drop. It's defined as the number of gallons of water at 60°F that can flow through a valve per minute with a pressure drop of 1 psi. The Cv value is an essential indicator of the valve's capacity to deliver the required flow rate for your application.

Sizing the Valve

Correctly sizing the valve is pivotal to meeting the flow requirements of the system. An undersized valve can lead to excessive pressure drop, reduced flow rate, and inefficiency in the system operation. Conversely, an oversized valve may cause control issues, including poor regulation or valve hunting, leading to instability in the system.

Factors Influencing Valve Sizing:

• Flow Rate: The desired flow rate of the medium (liquid, gas, or steam) through the system is the starting point for determining the appropriate valve size.
• Pressure Drop: The acceptable pressure drop across the valve when it is fully open is a key factor. A higher allowable pressure drop can permit the use of a smaller valve, but this needs to be balanced against the overall system requirements and efficiency.
• Type of Media: The physical properties of the media (viscosity, density) affect flow characteristics and must be considered when selecting and sizing the valve.

Type of Operation

The intended function of the valve within the system also influences the flow requirements. Valves can be used for on/off control, throttling, or as part of a safety mechanism. For example, a valve used for throttling purposes will need precise control over a wide range of flow rates, whereas an on/off valve may only need to minimise pressure drop when fully open.

6. Sealing Performance

Leakage can significantly impact process efficiency and safety. When selecting an actuated valve, consider the sealing technology it uses. Soft seals, such as PTFE, offer tight sealing but may wear out faster with high-temperature applications. Metal seals withstand higher temperatures but might not provide as tight a seal. The right choice will balance sealing performance against operational conditions.

Types of Seals in Actuated Valves

• Soft Seals: Made from materials such as PTFE (Polytetrafluoroethylene), EPDM (Ethylene Propylene Diene Monomer), and NBR (Nitrile Butadiene Rubber), soft seals are known for their excellent sealing capabilities at lower pressures and temperatures. They provide tight shut-off but may wear faster under harsh conditions or with frequent cycling.
• Metal Seals: Constructed from stainless steel, alloy, or other metals, metal seals are suitable for high-temperature and high-pressure applications. While they offer durability and can withstand aggressive media, metal seals might not provide as tight a shut-off as soft seals and could require greater actuation force.

Considerations for Seal Selection

• Media Compatibility: The seal material must be compatible with the media being handled to prevent degradation, swelling, or other forms of deterioration that could impair sealing performance.
• Pressure and Temperature: The operating pressure and temperature range of the system influence seal selection. High pressures and temperatures may necessitate the use of metal seals or specially engineered soft seals.
• Valve Cycling Frequency: Valves that open and close frequently require durable seals that can withstand wear and tear without degrading the sealing performance.
• Regulatory and Environmental Concerns: In applications where leakage could have serious environmental or health impacts, such as in the chemical or pharmaceutical industries, the choice of seal and its performance is especially critical.

7. Control and Connectivity

In the context of actuated valves, control and connectivity encompass the methods and technologies used to operate, monitor, and integrate valves into broader system controls and automation strategies. As industries advance towards more automated and intelligent systems, the importance of sophisticated control and connectivity options for actuated valves has significantly increased. Here&#;s a closer look at the nuances of control and connectivity for actuated valves.

Control Mechanisms

• On/Off Control: The most basic form of valve control, where the valve is either fully open or fully closed. This is commonly used in applications requiring simple flow shutoff or isolation.
• Proportional Control: Enables the valve to modulate flow by adjusting the valve position between fully open and fully closed. This is critical in applications requiring precise flow control, such as in process industries where maintaining specific process conditions is essential.
• PID Control (Proportional, Integral, Derivative): A more advanced form of control that adjusts the valve position based on the difference between a setpoint and the process variable. PID control is used for maintaining precise control over complex processes by correcting overshoot and stabilising the process flow.

Connectivity Options

• Wired Connections: Traditional connectivity method involving direct wiring to control systems. This includes 4-20 mA signals for analog control or digital signals like HART, Foundation Fieldbus, and Profibus, which offer the advantage of transmitting data along with control signals for diagnostics and monitoring.
• Wireless Technologies: Emerging technologies like WirelessHART and ISA100.11a allow for remote control and monitoring of valves. Wireless solutions reduce installation costs, improve flexibility in system design, and enhance the ability to access hard-to-reach or hazardous locations.
• Ethernet/IP and Modbus TCP/IP: For integrating valves into industrial networks, protocols like Ethernet/IP and Modbus TCP/IP facilitate communication over industrial Ethernet. This connectivity supports high-speed data exchange and enables integration with modern Industrial Internet of Things (IIoT) platforms.

8. Maintenance and Repair

Maintenance and repair considerations are pivotal in ensuring the long-term reliability and efficiency of actuated valves within any industrial system. The ease with which a valve can be maintained and repaired impacts not only its operational lifespan but also the overall productivity and safety of the system it serves. An effective maintenance strategy minimises downtime, reduces operational costs, and prolongs the service life of the valve.

Importance of Maintenance

Regular maintenance is essential for detecting and mitigating wear and potential failures before they escalate into more significant issues. It involves routine inspections, cleaning, lubrication, and adjustments to ensure optimal performance and to prevent unexpected shutdowns.

Predictive Maintenance

Advancements in sensor technology and connectivity have paved the way for predictive maintenance strategies. By monitoring key performance indicators such as temperature, pressure, and flow rates, as well as specific valve conditions like stem movement and actuator performance, operators can predict potential failures before they occur, scheduling repairs at convenient times to minimise operational impact.

Accessibility

The design and installation of actuated valves should consider ease of access for maintenance and repair activities. Valves that are difficult to reach or require extensive disassembly of the system for access can significantly increase maintenance time and costs. Modular designs that allow for the easy replacement of components without the need for complete valve disassembly are highly beneficial.

9. Certifications and Standards

Certifications and standards play a pivotal role in ensuring the quality, safety, and compatibility of actuated valves with specific industry requirements. Adherence to recognised standards and obtaining the relevant certifications signify that a valve has been rigorously tested and meets the established criteria for performance, durability, and safety. This not only facilitates trust in the product's reliability but also aids in compliance with regulatory and industry-specific requirements. Here&#;s a closer exploration of the importance of certifications and standards for actuated valves.

Why Certifications and Standards Matter

• Quality Assurance: Certifications provide assurance that the valve has been manufactured to meet high-quality standards, ensuring reliability and performance in critical applications.
• Safety Compliance: Safety standards ensure that valves are capable of operating safely under the designated conditions, protecting both personnel and the environment from potential hazards.
• Regulatory Compliance: Many industries are subject to stringent regulations that require the use of certified valves. Compliance with these standards is crucial for legal operation and avoiding potential fines.
• Interoperability: Standards ensure compatibility between valves and other components within a system, facilitating integration and smooth operation.

Common Certifications and Standards for Actuated Valves

• ISO (International Organisation for Standardisation): ISO provides various standards for quality management systems (ISO ), environmental management systems (ISO ), and specific product standards for industrial valves (ISO for valve testing, ISO for actuator mounting).
• API (American Petroleum Institute): API standards are crucial in the oil and gas industry, with specifications like API 6D and API 598 governing pipeline valves and valve inspection and testing, respectively.
• ANSI (American National Standards Institute)/ASME (American Society of Mechanical Engineers): ANSI/ASME standards such as B16.34 provide specifications for valve materials, design, and pressure-temperature ratings, ensuring valves are suitable for their intended service conditions.
• PED (Pressure Equipment Directive) in the European Union and ASME Boiler and Pressure Vessel Code in the United States: These regulations govern the design, manufacture, and testing of pressure equipment, including valves, to ensure they are safe for use at specified pressures and temperatures.
• ATEX and IECEx for Explosive Atmospheres: Certifications ensuring that equipment, including actuated valves, is safe to use in potentially explosive environments by preventing ignition sources.
• NSF/ANSI Standards: Particularly relevant in the food, water, and pharmaceutical industries, these standards ensure that valves do not contaminate the media they control and are safe for use in these critical applications.

10. Cost of Ownership

The cost of ownership of actuated valves encompasses not only the initial purchase price but also a variety of other expenses incurred throughout the valve's life cycle. This holistic view of costs is crucial for making informed purchasing decisions that optimise both financial outlay and operational performance. Understanding and effectively managing these costs can lead to significant savings and more efficient system operations over time. Here's a comprehensive look at the factors contributing to the total cost of ownership for actuated valves.

Initial Purchase Price

• Acquisition Costs: The upfront cost of purchasing the valve, which can vary significantly based on the type, size, material, and specific features of the valve.

Installation and Commissioning Costs

• Installation: Costs associated with integrating the valve into the system, including any necessary modifications to piping or infrastructure.
• Commissioning: Expenses related to the initial setup, calibration, and testing of the valve to ensure it operates correctly within the system.

Operating Costs

• Energy Consumption: For electrically actuated valves, the cost of electricity to operate the actuator can impact overall expenses, especially in systems with frequent cycling.
• Compressed Air: Pneumatic actuators require compressed air, the production of which can contribute to operating costs.

Maintenance and Repair Costs

• Routine Maintenance: Regular inspections, cleaning, lubrication, and adjustments are necessary to keep the valve functioning efficiently.
• Unscheduled Repairs: Costs associated with unexpected breakdowns or failures, including parts replacement, labor, and potential system downtime.
• Spare Parts: Inventory costs for keeping essential spare parts on hand to minimise downtime during repairs.

Downtime Costs

• Production Losses: The loss of productivity or output due to system shutdowns for valve maintenance or repairs.
• Operational Inefficiencies: Costs incurred from operating the system at reduced capacity or efficiency while dealing with valve issues.

Strategies to Optimise Total Cost of Ownership

• Selecting Quality Products: Investing in higher-quality valves may have a higher initial cost but can lead to lower maintenance and repair costs, longer service life, and better performance.
• Preventive and Predictive Maintenance: Implementing a maintenance strategy that prevents failures and predicts issues before they occur can significantly reduce downtime and repair costs.
• Energy Efficiency: Choosing valves and actuators that are energy-efficient can lower operating costs, especially in systems with high usage rates.
• Standardisation: Using standardised valves across a facility can reduce spare parts inventory costs, simplify maintenance procedures, and streamline training for maintenance personnel.

Thank you for reading! Learnt something new? Consider subscribing to the End Connections newsletter to stay up-to-date with all valve, actuator, & industrial-related news.

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Small Hydraulic Proportional Valve

Small Hydraulic Proportional Valve

gr3ggh3ad

(Mechanical)

(OP)

6 Dec 22 01:35

Hi - The goal of my project is spool high-strength wire on to a drum at a fixed tension. To do so, I am considering controlling a small, hydraulic proportional valve using a PLC that will essentially feed a hydraulic brake. I will have a 4-20mA input (line tension feedback) to a programmable controller , a display to enter my setpoint (desired line tension), then vary the hydraulic valve output accordingly to control pressure only (no flow... the pressure output will feed a hydraulic brake to adjust line tension). The max pressure is probably less than 500 psi. I do not have a ton of experience with hydraulics, however I do have experience with PLC controls. I am mainly looking for help in pointing me toward a proportional valve that will meet these requirements, but any other tips or knowledge of a small PID controller that will do the job would be appreciated, too. Also, if you have a lead on a small scale hydraulic pump to feed the valve, please let me know as well. Thanks! Gregg

RE: Small Hydraulic Proportional Valve

srini

(Electrical)

8 Dec 22 08:12

https://continentalhydraulics.com/product_items/ve...

I have some experience in similar applications but using pneumatic proportional pressure control valve not hydraulic.So, check this thoroughly.

This is what i could get from what i understand of the application. The pressure can be varied from 15 to psi using a 0-10V or a 4-20mA signal. You write a code in the PLC for the scaling between the strain gauge input and the signal output to tune the PID.I have some experience in similar applications but using pneumatic proportional pressure control valve not hydraulic.So, check this thoroughly.

RE: Small Hydraulic Proportional Valve

PNachtwey

(Electrical)

8 Dec 22 19:14
Is this a new installation?
Normally one controls the tension by controlling the torque on the winder. Also, you need something to lay the wire smoothly back and forth on the spool/drum. Nothing is said about the source of the wire. Sometimes there is a tension loop between the source and destination spool.
There are electric winding machines that cost less than the valve and machine is put together.
https://www.vevor.com/automatic-coil-winder-c_...
There are many such machines. I would look around and see if you can buy something off the shelf before trying to re-create the wheel.
BTW, I sell motion controller that have done applications like this but the reason why our motion controller was chosen is because they were winding very thick copper that was rectangular in shape so a custom machine was necessary. Unless you are doing something that is not normal you should look for something off the shelf.

The valve described by gr3ggh3ad will work if the rest of the system is good.Is this a new installation?Normally one controls the tension by controlling the torque on the winder. Also, you need something to lay the wire smoothly back and forth on the spool/drum. Nothing is said about the source of the wire. Sometimes there is a tension loop between the source and destination spool.There are electric winding machines that cost less than the valve and machine is put together.There are many such machines. I would look around and see if you can buy something off the shelf before trying to re-create the wheel.BTW, I sell motion controller that have done applications like this but the reason why our motion controller was chosen is because they were winding very thick copper that was rectangular in shape so a custom machine was necessary. Unless you are doing something that is not normal you should look for something off the shelf.

Peter Nachtwey
Delta Computer Systems
http://www.deltamotion.com
http://forum.deltamotion.com/
IFPS Hall of Fame Member

RE: Small Hydraulic Proportional Valve

LittleInch

(Petroleum)

8 Dec 22 21:09

Look up how automatic car brakes work?

I think you need to vary the air pressure over a hydraulic chamber or piston and not the hydraulics itself as you have no flow.Look up how automatic car brakes work?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: Small Hydraulic Proportional Valve

gr3ggh3ad

(Mechanical)

(OP)

8 Dec 22 22:25

Thank you all for the replies. Forgive me as this is my first post... I do not see a way to reply to individual responses, only 'reply to the post'. Allow me to clarify my scenario:

We have trucks with 15K+ feet of wire spooled on for oil, gas, and geothermal well service work. Occasionally we spool new line [under tension] on the trucks. Our current method is open-loop: an operator has one hand on a pack- off pump which applies hydraulic pressure to a capstan brake [to vary the tension], and an eye on the line-tension display. If the line tension decreases, he pumps the pack-off pump to increase the drag at the capstan. If the tension increases, he bleeds off a little pressure to reduce the tension.

I want to automate this and make it closed-loop. I'll fabricate a portable box that we place at the truck when spooling new line. I'll use a 4-20mA output from the line-tension sensor on the truck and bring it into the 'box' as my feedback. A small display on 'the box' will allow the operator to enter the setpoint (desired tension). The 'box' will have small hydraulic pump, and a variable valve to control the pressure out to the brake on the capstan; I think this should keep the line tension fairly constant.

I know enough about controls to make it happen [in theory]... I just do not have the hydraulic experience to choose a valve.

Thanks again!

RE: Small Hydraulic Proportional Valve

zeusfaber

(Military)

14 Dec 22 20:31

Here are two approaches you might try.

You could connect a single direction valve in series with a fixed orifice and tap off the pressure at the junction between them - the hydraulic analogue of a potentiometer. This approach can be made to give you something that responds very quickly, but is wasteful of energy.

The other is to use a bidirectional valve to charge or discharge an accumulator - much more analogous to your existing approach. Although the response is slower, pressure control will be smoother and you might even get away with bang-bang control rather than a proportional valve.

However, making your chosen valve control pressure is only the start of the job. You've still got to sort out how your valve arrangement is going to get a suitable and reliable supply of hydraulic fluid. It isn't enough just to clag in a small hydraulic pump, switch it on and then turn the tap on and off. To a first approximation (Peter will tell you how misleading this is, but for a first approximation, it will do), cheap hydraulic pumps are constant flow devices. That means that when your valves aren't demanding flow, you need to choose a suitable place for that constant flow to go (suitable doesn't mean out through a new hole in the side of the pump). In the motion-control world, it's common to find that the proportional control valve that does the simple job you wanted in the first place ends up supported by six or seven additional valves and a handful of orifices - without which the system will overheat, self-destruct, refuse to work, or some combination of the three.

If a handpump and bleed valve worked well enough in the first place, perhaps you could just replace the handpump with a small electrically driven pump with a check valve on the output and then only run the motor when you need to increase pressure. Replace the bleed valve with a solenoid valve and an orifice to limit the flow. Add an accumulator if you want to slow the process down.

A.

As LittleInch suggested, readily available solenoid valves (even proportional ones) are not very good at controlling pressure directly. To a first approximation, what they control is flow (and, if you haven't got some sort of mechanism for maintaining a constant pressure drop across the valve, even that's a pretty poor approximation).Here are two approaches you might try.However, making your chosen valve control pressure is only the start of the job. You've still got to sort out how your valve arrangement is going to get a suitable and reliable supply of hydraulic fluid. It isn't enough just to clag in a small hydraulic pump, switch it on and then turn the tap on and off. To a first approximation (Peter will tell you how misleading this is, but for a first approximation, it will do), cheap hydraulic pumps are constant flow devices. That means that when your valves aren't demanding flow, you need to choose a suitable place for that constant flow to go (suitable doesn't mean out through a new hole in the side of the pump). In the motion-control world, it's common to find that the proportional control valve that does the simple job you wanted in the first place ends up supported by six or seven additional valves and a handful of orifices - without which the system will overheat, self-destruct, refuse to work, or some combination of the three.If a handpump and bleed valve worked well enough in the first place, perhaps you could just replace the handpump with a small electrically driven pump with a check valve on the output and then only run the motor when you need to increase pressure. Replace the bleed valve with a solenoid valve and an orifice to limit the flow. Add an accumulator if you want to slow the process down.A.

RE: Small Hydraulic Proportional Valve

gr3ggh3ad

(Mechanical)

(OP)

14 Dec 22 23:26

zeusfaber (and littleinch) - The lightbulb went on. I get it now that it would be difficult to control the pressure directly with hydraulics. The idea of air pressure over the hydraulic chamber makes perfect sense. Now I need to find out how I can regulate the air pressure with a controller. Thanks again!

RE: Small Hydraulic Proportional Valve

73lafuite

(Industrial)

15 Dec 22 08:52

Hello,
It's easy to regulate the hydraulic pressure. If you gave more details on the current hydraulic circuit and on the brake, the answer would obviously be more appropriate.
If currently your pump runs constantly and it does not heat the oil too much: then you are using a proportional pressure relief valve. example: RZM Atos; DBE Bosch rexroth; PDB Hydac
If the pump stops and there is an accumulator then use a proportional 3-way pressure reducer. example: ZGO Atos; DRE Bosch rexroth; PDR Hydac
Cordially

RE: Small Hydraulic Proportional Valve

LittleInch

(Petroleum)

15 Dec 22 10:36

You could do this with a two stage hydraulic accumulator system as well - high pressure supply into a decent sized accumulator so you pump it up and leave it. Solenoid valve with a flow control set by you ( needle valve) into a second hydraulic system connected to your brake with a small accumulator with a return path to a reservoir via a second solenoid valve also with a small needle valve. Then your PID loop either opens one valve for more tension or opens the second for less. Then all you really need to control or measure is the tension which you increase or decrease as required to maintain your set point.

You might find something like this where you can vary pressure via a 4-20, but if you want to build it yourself then the option above might be worth looking at, but this really mirrors your current system, just via a PID loop.

Just an idea.

Depends on your hydraulic pressure on the brake really.You could do this with a two stage hydraulic accumulator system as well - high pressure supply into a decent sized accumulator so you pump it up and leave it. Solenoid valve with a flow control set by you ( needle valve) into a second hydraulic system connected to your brake with a small accumulator with a return path to a reservoir via a second solenoid valve also with a small needle valve. Then your PID loop either opens one valve for more tension or opens the second for less. Then all you really need to control or measure is the tension which you increase or decrease as required to maintain your set point.You might find something like this where you can vary pressure via a 4-20, but if you want to build it yourself then the option above might be worth looking at, but this really mirrors your current system, just via a PID loop.Just an idea.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: Small Hydraulic Proportional Valve

gr3ggh3ad

(Mechanical)

(OP)

16 Dec 22 23:10

The attached image [below] shows the basics of the existing set up: the brakes on a capstan are currently being controlled with a hand pack-off pump; the greater the pressure on the brakes, the greater the capstan causes tension on the line being pulled around it. The hydraulic pressure required to obtain the tension I want is only on the order of 50-100 psi.

The second part of the image shows my proposed test. I bought a precision, relieving regulator (0-150psi) and 0.5 gal tank good for 200 psi. I'll fill the tank approx. half full of hydraulic fluid, then use the air regulator to vary the pressure over the hyd. fluid, which varies the brakes, which varies the tension on my line as I am spooling it onto the truck.

If this works well enough, I'll leave it with just the regulator [open loop]. If it really well and we want to go to the next level, I'll get a small PID controller and an Electronically Controlled Precision Compressed Air Regulator like this one from McMaster Carr and attempt to do it closed loop. ([link

Again... thank you for the input.The attached image [below] shows the basics of the existing set up: the brakes on a capstan are currently being controlled with a hand pack-off pump; the greater the pressure on the brakes, the greater the capstan causes tension on the line being pulled around it. The hydraulic pressure required to obtain the tension I want is only on the order of 50-100 psi.The second part of the image shows my proposed test. I bought a precision, relieving regulator (0-150psi) and 0.5 gal tank good for 200 psi. I'll fill the tank approx. half full of hydraulic fluid, then use the air regulator to vary the pressure over the hyd. fluid, which varies the brakes, which varies the tension on my line as I am spooling it onto the truck.If this works well enough, I'll leave it with just the regulator [open loop]. If it really well and we want to go to the next level, I'll get a small PID controller and an Electronically Controlled Precision Compressed Air Regulator like this one from McMaster Carr and attempt to do it closed loop. ([link s/maximum-pressure~100-psi/regulator-style~relieving/" target="_blank">https://www.mcmaster.com/precision-air-regulator*!...]Link[/link])

RE: Small Hydraulic Proportional Valve

LittleInch

(Petroleum)

18 Dec 22 14:09

Let us know how it goes.

I thought you might need more than 100 psi but that's well within a simple air compressor range.

That should work. The reaction time might be a bit slower than the hydraulic oil version but that might be a good thing?Let us know how it goes.I thought you might need more than 100 psi but that's well within a simple air compressor range.

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Also: If you get a response it's polite to respond to it.

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News

Table of Contents

1. Type of Valve

2. Actuator Type

3. Material Compatibility

4. Pressure and Temperature Ratings

5. Flow Requirements

6. Sealing Performance

7. Control and Connectivity

8. Maintenance and Repair

9. Certifications and Standards

10. Cost of Ownership

Actuated valves are critical components in various industries, controlling the flow of liquids and gases with precision. Whether you're in the pharmaceutical, food processing, petrochemical, or water treatment industry, selecting the right actuated valve is crucial for your operations. This comprehensive guide will outline the top 10 factors to consider, ensuring you make an informed decision that enhances efficiency, safety, and productivity.

1. Type of Valve

When delving into the intricacies of actuated valves, understanding the various types available and their specific applications is paramount. This knowledge ensures the selection of the most appropriate valve, which is a critical determinant of your system&#;s efficiency, reliability, and safety. Here, we explore the common types of valves used in actuated systems, highlighting their unique features, advantages, and typical applications. For example:

Ball Valves

Ball valves feature a spherical disc with a hole through it, which controls the flow through the valve when the ball is turned. This design allows for full, unrestricted flow with a quarter turn of the valve handle, leading to minimal pressure drop. Ball valves are renowned for their durability and excellent sealing capabilities, making them a preferred choice for applications requiring tight shut-off. They can handle a wide range of fluids, pressures, and temperatures, making them versatile for many industries.

Butterfly Valves

Butterfly valves consist of a disc mounted on a rotating shaft. When the valve is closed, the disc is turned so that it completely blocks off the passageway; when it is open, the disc is rotated a quarter turn to allow nearly unrestricted flow. This type of valve is known for its compact design and low weight, which makes it easy to install and requires less support. Butterfly valves are suitable for handling large flow volumes and are commonly used in water and wastewater treatment, as well as in HVAC applications.

... & Many More! (which you can view HERE)

2. Actuator Type

Actuators are the mechanisms that operate the valve, and they can be pneumatic, electric, or hydraulic. Pneumatic actuators are known for their fast response time and are suitable for explosive environments. Electric actuators offer precise control and are ideal for remote operation. Hydraulic actuators provide high force with minimal space requirements. The choice of actuator will depend on your operational requirements, including speed, force, and control needs. For example:

Pneumatic Actuators

Pneumatic actuators use compressed air to generate force to move the valve. They are characterised by their fast response time and reliability. These actuators are particularly well-suited for environments where spark prevention is critical, making them a safe choice for explosive or flammable atmospheres. Pneumatic actuators are cost-effective for applications requiring a large amount of force, such as large valve operations in the oil and gas industry.

Electric Actuators

Electric actuators use an electric motor to operate the valve mechanism. These actuators offer precise control over valve positioning and are easily integrated into digital control systems, making them ideal for applications requiring accurate flow modulation. Electric actuators are suitable for a wide range of environments, including hazardous areas, provided they are equipped with the appropriate enclosures. They are typically used in water treatment plants, HVAC systems, and anywhere precise electronic control is needed.

Hydraulic Actuators

Hydraulic actuators use fluid pressure to generate force to move the valve. They are capable of producing a very high force output from a relatively small footprint, making them suitable for heavy-duty industrial applications where space is limited. Hydraulic actuators provide smooth, consistent control over valve movement and can maintain valve position even when hydraulic pressure is removed, offering a fail-safe operation. They are commonly used in applications where reliability and high force are crucial, such as in the petrochemical industry.

Factors to Consider When Choosing an Actuator Type

• Speed and Response Time: Pneumatic actuators typically offer the fastest response time, followed by electric and hydraulic actuators.
• Control and Precision: Electric actuators provide the highest level of control and precision, especially beneficial for modulating valves.
• Force Requirements: Hydraulic actuators are unmatched in their ability to generate high force, making them ideal for moving large, heavy valves.
• Environment: Consider the operational environment, including the presence of explosive gases, which may favour pneumatic or specially enclosed electric actuators.
• Availability of Utilities: Electric actuators require electricity, while pneumatic actuators need compressed air, and hydraulic actuators depend on a supply of hydraulic fluid.
• Cost: Initial installation costs, operational costs, and maintenance needs vary across actuator types, influencing the total cost of ownership.

3. Material Compatibility

Material compatibility is a cornerstone consideration in selecting actuated valves, directly impacting their durability, functionality, and suitability for specific applications. The materials chosen for both the valve body and the internal components must be able to withstand the operational environment, including the type of media flowing through the valve, the temperature range, and any potential corrosive or abrasive conditions. Let&#;s explore the importance of material compatibility in more depth and the considerations involved in selecting the right materials for your actuated valves.

If you want to learn more, please visit our website hydraulic solenoid valve suppliers.

Understanding Material Compatibility

Material compatibility is critical for ensuring the long-term performance and reliability of actuated valves. The right material selection can prevent common issues such as corrosion, erosion, and material degradation, which can lead to valve failure, leakage, and operational inefficiencies.

Common Valve Materials

• Stainless Steel: Highly resistant to corrosion and can withstand a wide range of temperatures, making it suitable for a variety of applications, from water to harsh chemicals.
• Brass: Often used in applications where corrosion resistance is needed but at a lower cost than stainless steel. Suitable for water, gas, and some mild corrosive environments.
• PVC (Polyvinyl Chloride) and CPVC (Chlorinated Polyvinyl Chloride): Plastic materials that offer excellent resistance to corrosion and chemical attack. Ideal for applications in water treatment and chemical processing where metallic valves might corrode.

Factors Influencing Material Selection

• Type of Media: The chemical properties of the fluid or gas, such as acidity (pH level), corrosiveness, and solvent properties, dictate the material choice to ensure compatibility.
• Temperature and Pressure: High temperatures and pressures can compromise the integrity of some materials. It&#;s essential to choose materials that can maintain their properties under the expected operational conditions.
• Abrasion and Wear: For applications involving abrasive materials, such as slurry services, material selection must consider resistance to wear and erosion.

4. Pressure and Temperature Ratings

Understanding the pressure and temperature ranges within your system is vital. Actuated valves are rated for specific operating pressures and temperatures. Choosing a valve with inappropriate ratings can lead to failure, posing safety risks and operational downtime. Always ensure the valve you select can withstand the maximum expected pressure and temperature of your system.

Pressure Ratings

Pressure ratings indicate the maximum pressure at which a valve can safely operate without risking damage or failure. These ratings are determined by various factors, including the valve's material, design, and size. Exceeding these ratings can lead to catastrophic valve failure, posing safety risks and potential damage to the broader system.

Factors Affecting Pressure Ratings:

• Material Strength: Different materials can withstand different levels of stress. For instance, metal valves typically have higher pressure ratings than plastic valves.
• Valve Design: The design and thickness of the valve body and components affect its ability to withstand pressure.
• Temperature: The valve's pressure rating can change depending on the temperature, as materials may weaken or expand at higher temperatures.

Temperature Ratings

The temperature rating specifies the range of temperatures within which the valve can operate effectively. It is determined by the materials used in the valve's construction, including the body and sealing elements. High temperatures can affect the elasticity of seals, leading to leaks, and can alter the material properties of the valve body.

Considerations for Temperature Ratings:

• Thermal Expansion: Materials expand at different rates when heated. This expansion can affect the fit and sealing capabilities of valve components.
• Material Degradation: Prolonged exposure to high temperatures can cause materials to degrade or change properties, potentially leading to failure.
• Seal Material: The type of seal material (e.g., PTFE, EPDM, Viton) has a significant impact on the valve's temperature tolerance. Each material has its own strengths and temperature range.

5. Flow Requirements

Understanding and accommodating flow requirements is essential when selecting actuated valves, as it ensures the valve not only fits within the system but also performs its intended function efficiently and effectively. The flow requirements of a system dictate the size and type of valve needed to manage the fluid dynamics appropriately. Here&#;s an in-depth look at the considerations surrounding flow requirements.

Understanding Flow Coefficient (Cv)

The flow coefficient (Cv) is a critical specification that measures how much fluid can pass through a valve at a given pressure drop. It's defined as the number of gallons of water at 60°F that can flow through a valve per minute with a pressure drop of 1 psi. The Cv value is an essential indicator of the valve's capacity to deliver the required flow rate for your application.

Sizing the Valve

Correctly sizing the valve is pivotal to meeting the flow requirements of the system. An undersized valve can lead to excessive pressure drop, reduced flow rate, and inefficiency in the system operation. Conversely, an oversized valve may cause control issues, including poor regulation or valve hunting, leading to instability in the system.

Factors Influencing Valve Sizing:

• Flow Rate: The desired flow rate of the medium (liquid, gas, or steam) through the system is the starting point for determining the appropriate valve size.
• Pressure Drop: The acceptable pressure drop across the valve when it is fully open is a key factor. A higher allowable pressure drop can permit the use of a smaller valve, but this needs to be balanced against the overall system requirements and efficiency.
• Type of Media: The physical properties of the media (viscosity, density) affect flow characteristics and must be considered when selecting and sizing the valve.

Type of Operation

The intended function of the valve within the system also influences the flow requirements. Valves can be used for on/off control, throttling, or as part of a safety mechanism. For example, a valve used for throttling purposes will need precise control over a wide range of flow rates, whereas an on/off valve may only need to minimise pressure drop when fully open.

6. Sealing Performance

Leakage can significantly impact process efficiency and safety. When selecting an actuated valve, consider the sealing technology it uses. Soft seals, such as PTFE, offer tight sealing but may wear out faster with high-temperature applications. Metal seals withstand higher temperatures but might not provide as tight a seal. The right choice will balance sealing performance against operational conditions.

Types of Seals in Actuated Valves

• Soft Seals: Made from materials such as PTFE (Polytetrafluoroethylene), EPDM (Ethylene Propylene Diene Monomer), and NBR (Nitrile Butadiene Rubber), soft seals are known for their excellent sealing capabilities at lower pressures and temperatures. They provide tight shut-off but may wear faster under harsh conditions or with frequent cycling.
• Metal Seals: Constructed from stainless steel, alloy, or other metals, metal seals are suitable for high-temperature and high-pressure applications. While they offer durability and can withstand aggressive media, metal seals might not provide as tight a shut-off as soft seals and could require greater actuation force.

Considerations for Seal Selection

• Media Compatibility: The seal material must be compatible with the media being handled to prevent degradation, swelling, or other forms of deterioration that could impair sealing performance.
• Pressure and Temperature: The operating pressure and temperature range of the system influence seal selection. High pressures and temperatures may necessitate the use of metal seals or specially engineered soft seals.
• Valve Cycling Frequency: Valves that open and close frequently require durable seals that can withstand wear and tear without degrading the sealing performance.
• Regulatory and Environmental Concerns: In applications where leakage could have serious environmental or health impacts, such as in the chemical or pharmaceutical industries, the choice of seal and its performance is especially critical.

7. Control and Connectivity

In the context of actuated valves, control and connectivity encompass the methods and technologies used to operate, monitor, and integrate valves into broader system controls and automation strategies. As industries advance towards more automated and intelligent systems, the importance of sophisticated control and connectivity options for actuated valves has significantly increased. Here&#;s a closer look at the nuances of control and connectivity for actuated valves.

Control Mechanisms

• On/Off Control: The most basic form of valve control, where the valve is either fully open or fully closed. This is commonly used in applications requiring simple flow shutoff or isolation.
• Proportional Control: Enables the valve to modulate flow by adjusting the valve position between fully open and fully closed. This is critical in applications requiring precise flow control, such as in process industries where maintaining specific process conditions is essential.
• PID Control (Proportional, Integral, Derivative): A more advanced form of control that adjusts the valve position based on the difference between a setpoint and the process variable. PID control is used for maintaining precise control over complex processes by correcting overshoot and stabilising the process flow.

Connectivity Options

• Wired Connections: Traditional connectivity method involving direct wiring to control systems. This includes 4-20 mA signals for analog control or digital signals like HART, Foundation Fieldbus, and Profibus, which offer the advantage of transmitting data along with control signals for diagnostics and monitoring.
• Wireless Technologies: Emerging technologies like WirelessHART and ISA100.11a allow for remote control and monitoring of valves. Wireless solutions reduce installation costs, improve flexibility in system design, and enhance the ability to access hard-to-reach or hazardous locations.
• Ethernet/IP and Modbus TCP/IP: For integrating valves into industrial networks, protocols like Ethernet/IP and Modbus TCP/IP facilitate communication over industrial Ethernet. This connectivity supports high-speed data exchange and enables integration with modern Industrial Internet of Things (IIoT) platforms.

8. Maintenance and Repair

Maintenance and repair considerations are pivotal in ensuring the long-term reliability and efficiency of actuated valves within any industrial system. The ease with which a valve can be maintained and repaired impacts not only its operational lifespan but also the overall productivity and safety of the system it serves. An effective maintenance strategy minimises downtime, reduces operational costs, and prolongs the service life of the valve.

Importance of Maintenance

Regular maintenance is essential for detecting and mitigating wear and potential failures before they escalate into more significant issues. It involves routine inspections, cleaning, lubrication, and adjustments to ensure optimal performance and to prevent unexpected shutdowns.

Predictive Maintenance

Advancements in sensor technology and connectivity have paved the way for predictive maintenance strategies. By monitoring key performance indicators such as temperature, pressure, and flow rates, as well as specific valve conditions like stem movement and actuator performance, operators can predict potential failures before they occur, scheduling repairs at convenient times to minimise operational impact.

Accessibility

The design and installation of actuated valves should consider ease of access for maintenance and repair activities. Valves that are difficult to reach or require extensive disassembly of the system for access can significantly increase maintenance time and costs. Modular designs that allow for the easy replacement of components without the need for complete valve disassembly are highly beneficial.

9. Certifications and Standards

Certifications and standards play a pivotal role in ensuring the quality, safety, and compatibility of actuated valves with specific industry requirements. Adherence to recognised standards and obtaining the relevant certifications signify that a valve has been rigorously tested and meets the established criteria for performance, durability, and safety. This not only facilitates trust in the product's reliability but also aids in compliance with regulatory and industry-specific requirements. Here&#;s a closer exploration of the importance of certifications and standards for actuated valves.

Why Certifications and Standards Matter

• Quality Assurance: Certifications provide assurance that the valve has been manufactured to meet high-quality standards, ensuring reliability and performance in critical applications.
• Safety Compliance: Safety standards ensure that valves are capable of operating safely under the designated conditions, protecting both personnel and the environment from potential hazards.
• Regulatory Compliance: Many industries are subject to stringent regulations that require the use of certified valves. Compliance with these standards is crucial for legal operation and avoiding potential fines.
• Interoperability: Standards ensure compatibility between valves and other components within a system, facilitating integration and smooth operation.

Common Certifications and Standards for Actuated Valves

• ISO (International Organisation for Standardisation): ISO provides various standards for quality management systems (ISO ), environmental management systems (ISO ), and specific product standards for industrial valves (ISO for valve testing, ISO for actuator mounting).
• API (American Petroleum Institute): API standards are crucial in the oil and gas industry, with specifications like API 6D and API 598 governing pipeline valves and valve inspection and testing, respectively.
• ANSI (American National Standards Institute)/ASME (American Society of Mechanical Engineers): ANSI/ASME standards such as B16.34 provide specifications for valve materials, design, and pressure-temperature ratings, ensuring valves are suitable for their intended service conditions.
• PED (Pressure Equipment Directive) in the European Union and ASME Boiler and Pressure Vessel Code in the United States: These regulations govern the design, manufacture, and testing of pressure equipment, including valves, to ensure they are safe for use at specified pressures and temperatures.
• ATEX and IECEx for Explosive Atmospheres: Certifications ensuring that equipment, including actuated valves, is safe to use in potentially explosive environments by preventing ignition sources.
• NSF/ANSI Standards: Particularly relevant in the food, water, and pharmaceutical industries, these standards ensure that valves do not contaminate the media they control and are safe for use in these critical applications.

10. Cost of Ownership

The cost of ownership of actuated valves encompasses not only the initial purchase price but also a variety of other expenses incurred throughout the valve's life cycle. This holistic view of costs is crucial for making informed purchasing decisions that optimise both financial outlay and operational performance. Understanding and effectively managing these costs can lead to significant savings and more efficient system operations over time. Here's a comprehensive look at the factors contributing to the total cost of ownership for actuated valves.

Initial Purchase Price

• Acquisition Costs: The upfront cost of purchasing the valve, which can vary significantly based on the type, size, material, and specific features of the valve.

Installation and Commissioning Costs

• Installation: Costs associated with integrating the valve into the system, including any necessary modifications to piping or infrastructure.
• Commissioning: Expenses related to the initial setup, calibration, and testing of the valve to ensure it operates correctly within the system.

Operating Costs

• Energy Consumption: For electrically actuated valves, the cost of electricity to operate the actuator can impact overall expenses, especially in systems with frequent cycling.
• Compressed Air: Pneumatic actuators require compressed air, the production of which can contribute to operating costs.

Maintenance and Repair Costs

• Routine Maintenance: Regular inspections, cleaning, lubrication, and adjustments are necessary to keep the valve functioning efficiently.
• Unscheduled Repairs: Costs associated with unexpected breakdowns or failures, including parts replacement, labor, and potential system downtime.
• Spare Parts: Inventory costs for keeping essential spare parts on hand to minimise downtime during repairs.

Downtime Costs

• Production Losses: The loss of productivity or output due to system shutdowns for valve maintenance or repairs.
• Operational Inefficiencies: Costs incurred from operating the system at reduced capacity or efficiency while dealing with valve issues.

Strategies to Optimise Total Cost of Ownership

• Selecting Quality Products: Investing in higher-quality valves may have a higher initial cost but can lead to lower maintenance and repair costs, longer service life, and better performance.
• Preventive and Predictive Maintenance: Implementing a maintenance strategy that prevents failures and predicts issues before they occur can significantly reduce downtime and repair costs.
• Energy Efficiency: Choosing valves and actuators that are energy-efficient can lower operating costs, especially in systems with high usage rates.
• Standardisation: Using standardised valves across a facility can reduce spare parts inventory costs, simplify maintenance procedures, and streamline training for maintenance personnel.

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