Why is the pneumatic butterfly valve easy to vibrate under the condition of small opening?
For single core, when the medium is open flow type, the valve has good stability; When the medium is closed, the stability of the valve is poor. The pneumatic butterfly valve has two slide valves, the sliding valve is closed and the upper slide valve is open. In this way, when working at a small opening, the flow passage valve core is likely to cause valve vibration, which is why the pneumatic butterfly valve cannot be used for small opening operation.
The advantage of the pneumatic butterfly valve core is the force balance structure, and the allowable pressure difference is large, while its prominent disadvantage is that the two sealing surfaces cannot contact well at the same time, resulting in large leakage. If it is used for cutting off artificially and compulsorily, the effect is obviously not good. Even if many improvements have been made to it (such as double seal sleeve valve), it is not advisable.
