Different valves work for different conditions. It is more than wrong If you think that valve is just a simple switch to cut off the flow just like a faucet (though faucet is actually a valve in some terms). But let explore further about how the valve works and how to select the right valve for the specific purpose!

The valve used to cut off the flow

The straight-through valve, with a relatively small flow resistance, is usually used to cut off the flow. On the contact, downward-closing valves like globe valve and plunger valve, which have a tortuous path, have higher flow resistance than other valves. Because of that, this kind of valve is used to control flow where high flow resistance is allowed.

The valve used for flow control

Usually we choose the valve that is easy to adjust the flow as the flow control. The downward-closing valve mentioned above works in this condition because its seat size is proportional to the stroke of the wedge. Rotary valve (plug valve, butterfly valve, ball valve), pinch valve and diaphragm valve can also be used to control the flow. But they are only applied within a limited valve diameter range. The gate valve uses a disc-shaped gate to make a transverse movement to the circular valve seat. It can control the flow rate only when it is about to close, so it cannot be used for flow control.

Valve used to reverse and divert the flow

In accordance with the need of reversing and diverting, this kind of valve has three or more channels. Plug valves and ball valves are more suitable for this. However, in some cases, other types of valves can also be used for reversing and diverting as long as two or more valves are properly connected to each other.

Valve used for medium with particles

Speak of transferring medium with floating particles in it, the best choice is to choose the valve whose disc slides along the sealing surface. The disc will wipe this area while it moves. If the disc moves vertically along the seat ring, particles may be stuck at the sealing part. Ball valve and plug valve will clean its sealing surface when they are working, hence, they can be put in particle-mixed medium transportation.

At present, no matter in the pipeline system of petroleum, chemical industry, or in other industries, the application, operation frequency and service of the valve are ever-changing. To control or eliminate even the smallest leakage, the most important and critical equipment is the valve. The ultimate control of the pipeline is the valve, which plays a unique and reliable role in various fields.