Published: August 1,
Last updated: December 30,
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Knowing what makes a valve the right choice
Valves control gas and liquid flow in almost every process and system. As common as they are, choosing the right valve can sometimes be time consuming and confusing.
Begin valve selection by first gathering some basic information on system performance requirements. Knowing this will make it easier to find the right valve. The five tips in this article focus on how to match valve features with these requirements.
Tip 1 &#; Valve size and type
Choose the right valve type. Every valve needs to perform one or more basic functions:
Function determines the design of standard valve types. These are some of the most common valve types:
Properly sizing the valve is also important. The right valve choice means matching the valve&#;s size to expected flow through the system.
Common Valve Types at VMA, Valve Manufacturers Association of America
How to Select the Right Valve (with Pros and Cons) at Indelac Controls
Tip 2 &#; Materials of construction
Know the chemical compatibility requirements. The valve materials need to be compatible with the gases or liquids flowing through it. Plastic valves usually resist harsh or corrosive chemicals better than metal valves.
Miniature Ball Valves: Plastic, Brass or Stainless Steel? at ISM, Industrial Specialties Mfg.
Chemical Compatibility Chart at ISM, Industrial Specialties Mfg.
Tip 3 &#; Performance requirements
Determine the pressure and temperature requirements. Find out both the temperature and pressure ranges where the valve will be installed. Metal valves tend to withstand higher temperatures and pressures than plastic valves. Metal valves are also usually best for pressurized gases. This is because they tend to be stronger than plastic valves.
A Selection Criterion for Pump and Valve Reliability at Processing Magazine
Tip 4 &#; Check valves have special requirements
Be sure the new check valve will work as expected. Look at the response time needed as well as the cracking pressure required to open the valve.
Another consideration is normally closed vs normally open. There are basic check valve designs that require positive downstream pressure to open. These are usually referred to as normally closed check valves. There are other designs that require a positive backpressure to close. These are usually called normally open check valves. An appropriate choice between these two can improve check valve reliability. It is usually best to base this decision on whether the valve is usually open more or usually closed more during normal system operation.
Some check valve types may not work properly if mounted vertically instead of horizontally. Flow direction (upwards vs downwards) and fluid density both matter for check valve designs that can be mounted vertically.
Checking Out Check Valves &#; An Introduction at ISM, Industrial Specialties Mfg.
Tip 5 &#;Maintenance
Don't forget to consider ongoing maintenance. Any valve choice should include attention to maintenance requirements. This is important for both valve reliability and application stability.
A good example of this are ball valves. They resist clogging, jamming or malfunctioning. But they are not suitable for adjusting flow. Using them to control flow can lead to leaking or premature failure.
Valve connection type affects the ease and speed of repair or replacement. Each connection type (threaded, barbed, push-in, Luer, and so on) has its pros and cons.
For more information, please visit plastic flow adjustment valve.
Plant and Equipment Maintenance at HSE, Health and Safety Executive
Knowing where to start makes valve choice faster and easier
There it is. Knowing particular information beforehand, makes choosing the right valve easier and more certain. There will always be complications like application requirements, operating conditions and chemical compatibility. Starting with basic valve requirements will simplify and speed up valve selection:
Some additional resources
How ISM can help you find the right miniature valve for your application
Personalized customer service and resources available at the ISM website can be a great help when selecting a valve. Available online resources include chemical compatibility reference guides, dimensional drawings and product data sheets. Our online and PDF flow control valve catalogs provide access to a wide variety of miniature valve types, connection types, materials and sizes:
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We offer a line of ideas, so if you don't see it - ask for it. Let us turn your ideas for pneumatic or fluidic circuitry assemblies into reality &#; from conception to finished product.
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In the simplest terms, a valve is a device used to control the flow of a medium &#; liquid, gas or solid &#; through a piping system. Most commonly, valves are used to stop and start the flow of media. Some valves are also able to control the rate of flow, these are commonly referred to as control valves.
Because there are so many different uses for valves, they are available in a wide range of mechanical variations. Using the appropriate valve in a given scenario means your application will run smoothly and safely, accomplishing the intended goal most efficiently.
Though there are many different valve classifications, most valves fall within three categories: rotary, linear and self-actuated.
Rotary valves utilize a rotating closure component to block flow within a piping system. Most often, this rotation is limited to 90 degrees, which is why rotary valves are also commonly referred to as quarter-turn valves. These types of valves are closed at 0 degrees and open at 90 degrees.
Some rotary valves can operate with a larger degree of rotation and include more than two positions. Common examples of rotary valve types are butterfly, plug and ball valves.
Linear valves use a flow obstructer &#; such as a disc, slat or diaphragm &#; that moves in a straight line to start, stop or adjust flow through a piping system. These valves can be separated into two distinct types: rising stem (multi-turn) and axial.
Multi-turn linear valves work particularly well in control applications and include globe valves, gate valves and needle valves. Axial valves, such as coaxial and angle seat valves, are fast-acting and used primarily in on/off process applications.
Compared to other categories of valves, linear motion valves tend to have longer cycle times than rotary valves.
Unlike linear and rotary valves, self-actuated valves do not require direct input from the operator. Instead, they use the pressure within the process line to open or close a pressure control valve. This valve type is commonly used as a pressure relief valve and only opens once maximum allowable pressure is reached within the system. As a result of this mechanism, self-actuated valves are common safety requirements in certain applications.
Common self-actuated valves include relief valves, safety valves, check valves and steam traps.
For more plastic flow control valveinformation, please contact us. We will provide professional answers.