If the valve is in a large throttling range, the back of the butterfly valve plate is prone to cavitation, which will increase the possibility of valve damage. Therefore, generally speaking, pneumatic butterfly valves are used outside 15 °.

Common faults of pneumatic butterfly valve and solutions! Test and adjustment of pneumatic butterfly valve
1. The manual, pneumatic, hydraulic and electric parts of butterfly valve have been strictly debugged before leaving the factory. When rechecking the sealing performance, the user should evenly fix both sides of the inlet and outlet, close the butterfly valve, apply pressure to the inlet side, and observe whether there is leakage at the outlet side. Before the strength test of the pipeline, the disc should be opened to prevent damage to the sealing pair.
2. Although the pneumatic butterfly valve has been strictly inspected and tested before delivery, some products have automatic screw displacement during transportation, which requires readjustment, pneumatic, hydraulic, etc. Please read the operating instructions of the supporting drive device.
3. The electric drive butterfly valve has adjusted the opening and closing travel of the control mechanism before delivery. In order to prevent the power supply from being connected in the wrong direction, after the first power supply is connected, the user should first turn on the manual switch to the half open position, and then press the electric switch to check that the direction of the indicator plate is consistent with the closing direction of the valve.