Butterfly valve is a commonly used valve in vacuum systems, typically used to control gas flow in vacuum systems.
The structural butterfly valve has a simple structure, small volume, and light weight, consisting of only a few parts. Its main structure includes valve body, valve plate, valve stem, sealing ring and other parts.
Working principle: When the valve plate and valve seat are fully in contact through the sealing mechanism, gas cannot pass through the valve and the valve is in a closed state. When the valve plate rotates a certain angle, gas can pass through the valve and the valve is in an open state. It only needs to rotate 90 ° to quickly open and close, and the operation is simple. When the butterfly valve is in the fully open position, the thickness of the butterfly plate is the resistance of the medium flowing through the valve body, so the pressure drop generated by this valve is very small (flow resistance is small), and it has certain flow control characteristics.
There are two types of sealing methods and classifications for butterfly valves: elastic sealing and metal sealing. For elastic sealing valves, the sealing ring can be embedded on the valve plate or attached to the periphery of the butterfly plate. There are three ways to drive the valve stem movement: manual, electric, and pneumatic.
Advantages of butterfly valve
① Quick opening and closing, low flow resistance
② Simple structure, small size, light weight, material saving
③ Can be used for flow control, but the flow adjustment range is not large. When the opening reaches 30%, the flow will increase by more than 90%
Disadvantages of butterfly valves
① Due to the limitations of butterfly valve structure and sealing materials, it is not suitable for use in high-temperature and high-pressure pipeline systems
② The sealing performance is relatively poor compared to plug valves and globe valves, so it is used in places where sealing requirements are not very high
③ When applying valves, it is necessary to leave space for the valve plate to open, which increases the volume to be pumped out
④ Due to the limitation of the valve plate sealing and compression device, the flow direction of the medium is restricted
Post time: Apr-12-2025