An air-operated valve, also known as a pneumatic valve, is a type of power-operated pipe valve that uses air pressure to perform a function similar to a solenoid. As air pressure is increased, the compressed air starts to push against the piston or diaphragm walls which causes the valve to actuate. Air operated valves (or air piloted valves) make use of air pressure to control compressed air, liquids or gas by means of a pneumatic system. Manufacturers prefer these valves because they do not require additional electrical current or labor to operate.
Pneumatic valve actuator generally require minimal maintenance. Pneumatic actuators can often be designed smaller, lighter and more responsive because air compressibility has little or no resistance. When additional stroking power is needed, cylinder sizes can be enlarged. Unlike a pressure relief valve, an air release valve is open at atmospheric pressure, then closes automatically when liquid is present. Degassing Valve — Designed for periodically venting trace amounts of gas as it occurs. Like an air release valve, this normally-open valve closes once liquid rises in the system.
Three very common types of control valves: (l-r) manual valve, solenoid-operated valve, and air-piloted valve. In the pneumatic world, valves are the equivalent of relays controlling the flow of electricity in automation systems.
