Four functions of valves in pipelines

Newsway Valve Company (NSW) valves are widely used in various fields of pipeline, it can meet the following requirements for pipeline valves

1. Cut off and release the medium

This is the most basic function of the valve. Usually, a valve with a straight-through flow path is selected, and its flow resistance is small.

Bottom-closed valves (Globe valves, plunger valves) are rarely used because of their tortuous flow passages and higher flow resistance than other valves. Where a higher flow resistance is allowed, a closed valve can be used.

 

2. Control flow

Usually, a valve that is easy to adjust the flow is selected as the flow control. A downward closing valve (such as a globe valve) is suitable for this purpose because its seat size is proportional to the stroke of the closing member.

Rotary valves (Plug valves, butterfly valves, ball valves) and flex-body valves (pinch valves, diaphragm valves) can also be used for throttling control, but they are usually only applicable within a limited range of valve diameters.

The gate valve uses a disc-shaped gate to make a cross-cutting movement to the circular valve seat opening. It can control the flow well only when it is close to the closed position, so it is usually not used for flow control.

 

3. Reversing and shunting

According to the needs of reversing and shunting, this kind of valve can have three or more channels. Plug valves and 3 way ball valves are more suitable for this purpose. Therefore, most of the valves used for reversing and dividing flow select one of these valves.

But in some cases, other types of valves can also be used for reversing and shunting as long as two or more valves are properly connected to each other.

 

4. Medium with suspended particles

When there are suspended particles in the medium, it is most suitable to use a valve with a wiping effect on the sliding of the closing member along the sealing surface.

If the back and forth movement of the closing member to the valve seat is vertical, it may hold particles. Therefore, this valve is only suitable for basic clean media unless the sealing surface material allows particles to be embedded. Ball valves and plug valves have a wiping effect on the sealing surface during the opening and closing process, so they are suitable for use in media with suspended particles.


Post time: Aug-06-2021