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Do you know the structure and principle of pneumatic butterfly valve?


Release time:

2022-09-05

Wuxi xinming automatic control valve industry co., ltd. tells you the structure and principle of pneumatic butterfly valve

Do you know the structure and principle of pneumatic butterfly valve?

Wuxi Xinming automatic control valve industry co., ltd tells youpneumatic butterfly valvestructure and principle

The little braid takes you to understandpneumatic butterfly valve.
The pneumatic valve is composed of a cylinder and a valve body. There are three attachments on the cylinder:
1. Solenoid valve (mainly used for switching gas source)
2. Limit switch (long distance know whether the valve is open or closed)
3. Filter pressure reducing valve (filter the moisture in the air source, because the air source is not pure gas, the air source of the air compressor generally has moisture, so use the filter pressure reducing valve to ensure that there will not be a lot of moisture in the cylinder.
The butterfly valve is called a butterfly valve because of its shape like a butterfly. The structure of the butterfly valve is divided into three categories.




气动蝶阀
① Middle line butterfly valve.
② Double partial pain butterfly valve.
③ Three partial pain butterfly valve.
Midline butterfly valve.
The center butterfly valve is a rod in the center wrapped with a butterfly plate. The disc is switched by a central shaft. The center butterfly valve has no partial pain. It is straight. Generally, it will open a little when leaving the factory. Because the central shaft is straight, its seal will squeeze the rubber at both ends, and the switch will be in place when it is used.
Double partial pain butterfly valve
The point of the double-sided butterfly valve is that the oblique angle of the sealing surface of the central plate is painful, and the valve seat (the valve seat is also sealed) is also painful. The butterfly plate sealing surface can be quickly separated from the valve seat cone when it is opened and closed. When the valve shaft rotates clockwise, the butterfly plate moves in the closed direction. When the valve shaft rotates clockwise by 90 °, the butterfly plate sealing surface and the valve seat sealing surface are closed. Positive pressure uses the effect principle of double partial pain. At this time, the butterfly plate will become tighter and tighter under the effect of medium pressure.
Three-side pain butterfly valve
Three partial pain is more than double partial pain, and the valve stem is more painful. The primary effect of partial pain is to stabilize the valve seat and disc.
Butterfly valve seal classification.
Butterfly valve is mainly divided into soft seal and hard seal.
Soft sealing.
Soft seal refers to the sealing ring. The middle line butterfly valve is mostly soft seal, and the middle line butterfly valve has no hard seal.
There are three commonly used materials for soft seal valves.













气动蝶阀
1. ball milled cast iron.
The second is cast steel.
Three is stainless steel.
Seat seals are commonly used.
1. nitrile rubber.
1. EPDM (widely used, the same material as automobile tires, good wear resistance)
3. fluorine rubber.
2. PTFE (commonly used)
The valve plate corresponds to the valve body and is commonly used.
1. ball mill casting.
The second is cast steel.
Three is stainless steel.
3. There are also some working conditions that can use Luo Mo steel.
Stem (butterfly valve also called spool)
Generally 416 (equivalent to stainless steel, hardness), followed by 314, 316.
Hard seal.
The hard seal body is also the valve body, valve plate and valve core. The primary material is divided into cast steel and stainless steel. The valve plate is also cast stainless steel, and the valve core is generally at least 304L or 316L. Hard seal does not have cast iron, and the use of hard seal is different from soft seal. Usually choose hard seal walking mostly steam, some switching frequency is higher, the use of hard seal demand longer product life.
The commonly used hard seal is a metal sandwich graphite seal (graphite is resistant to high temperature, up to 800 degrees or more), and a kind of PTFE (PTFE can not be steam, instantly.

















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