Brief introduction of auxiliary structures of pneumatic control valve
We have introduced the structure of pneumatic control valve before, mainly including regulating valve body, pneumatic actuator and various accessories. Today we mainly introduce the subsidiary structures of pneumatic control valve.
The auxiliary structural devices of pneumatic control valve can realize various functional requirements for it, mainly including electric pneumatic converter, valve positioner, air filter pressure reducer, amplifier and hand wheel, etc.
1. Electro pneumatic converter is usually composed of circuit, magnetic circuit, pneumatic balance part, etc. it is a device that converts current signal into air pressure signal.
2. Valve positioner is a device that converts electrical signals into pressure signals.
3. The air filter pressure reducer is used to purify the air source from the air compression system, remove dust and impurities in the air, and adjust the air source pressure from the compressed air system to the required pressure value.
4. Some valves of the amplifier require short opening and closing time, and the size of the pneumatic actuator diaphragm of these valves is very large. Therefore, it is necessary to install an amplifier between the pneumatic actuator and the valve positioner to improve the operation of the valve. Its function is to increase the air inlet / outlet volume of the pneumatic actuator.
5. The handwheel mechanism is used with the pneumatic control valve. In case of air source (signal) pressure failure, diaphragm, spring and seal of actuator damaged, handwheel mechanism can be used to operate the valve to maintain the regulating function of the regulating valve.