Control valve common failure and reasons

For the regulating valve itself, the following faults may occur:

The stem of the regulating valve is deformed. Caused by improper transportation or improper conditions of use (pressure difference beyond the allowable range). Excessive leakage. Due to insufficient force. Or there are impurities deposited on the sealing surface to destroy the fit of the spool and the seat.

The valve body and the valve cover, or the valve cover and the alarm rod joint is not tight. The reason is that the tightness of the parts is not proper, or the selected packing is not suitable for the working conditions.

The spool (or disc valve plate) guide system is worn. It is caused by large pressure difference and strong force.

Possible failure of pneumatic actuator:

The rubber gasket seal area is leaking due to worn fittings. The diaphragm is ruptured. It is caused by poor quality of rubber, uneasy installation or poor quality of metal contact surface (with sharp edges). The spring is broken. It is caused by excessive force or improper processing (improper heat treatment).

The membrane head and connecting air duct are not tight. It is due to uneven force or improper connection when the film head is tightened.

For electric actuators, possible failures are:

Travel limits are irregular. Caused by improper transportation or installation.

The coupling weakness caused by the same reasons mentioned above and the motor overheating are caused by the improper installation position of the motor.