Basic Classification of Valves – ITC Engineering Company

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The following are some of the commonly used valve classifications, based on mechanical motion:

Linear Motion Valves. The valves in which the closure member, as in gate, globe, diaphragm, pinch, and lift Check Valves, moves in a straight line to allow, stop, or throttle the flow.

Rotary Motion Valves. When the valve-closure member travels along an angular or circular path, as in butterfly, ball, plug, eccentric- and Swing Check Valves, the valves are called rotary motion valves.

Quarter Turn Valves. Some rotary motion valves require approximately a quarter turn, 0 through 90°, motion of the stem to go to fully open from a fully closed position or vice versa.

Classification of Valves based on Motion

Valve Types Linear Motion Rotary Motion Quarter Turn
Gate YES NO NO
Globe YES NO NO
Plug NO YES YES
Ball NO YES YES
Butterfly NO YES YES
Swing Check NO YES NO
Diaphragm YES NO NO
Pinch YES NO NO
Safety YES NO NO
Relief YES NO NO
Valve Types Linear Motion Rotary Motion Quarter Turn

Class Ratings

Pressure-temperature ratings of valves are designated by class numbers. ASME B16.34, Valves-Flanged, Threaded, and Welding End is one of the most widely used valve standards. It defines three types of classes: standard, special, and limited. ASME B16.34 covers Class 150, 300, 400, 600, 900, 1500, 2500, and 4500 valves.

Summary

On this page are defined a number of basic information from valves.

As you may have seen in the main Menu “Valves”, you can find also information about several and often applied valves in Petro and chemical industry.
It can give you an impression, and good understanding of the differences between the various types of valves, and how these differences affect the valve function. It will help to a proper application of each type of valve during the design and the proper use of each type of valve during operation.