Pneumatic butterfly valve is mainly composed of pneumatic actuator and butterfly valve, according to the requirements of users to install pneumatic accessories, switch type pneumatic butterfly valve needs to cooperate with the solenoid valve and limit switch, regulatory pneumatic butterfly valve needs to cooperate with the locator and filter decompression device. Therefore, when the pneumatic butterfly valve fails, the following reasons should be investigated:
1. Pneumatic actuator: no air source;Insufficient air source pressure; Cylinder piston aging fracture; Rack wear of piston gears; Single acting actuator spring aging rust.
2. Body: stem twisted or broken; Medium leakage caused by the valve stem rust; Impurities in the medium cause disc and seat to become jammed.
3. Solenoid valve: the wiring head becomes loose or falls off; Coils burnt out;When there are impurities or too little lubricating oil, the solenoid valve is easy to get stuck; Solenoid valve leakage caused by insufficient air source pressure.
4. Locator: air source is not open;Freezing of air source in winter causes blockage of air duct and filter; The regulator fails to adjust the retinal membrane damage.