Working principle diagram of single and double acting pneumatic actuator

Pneumatic actuator, also known as pneumatic actuator or pneumatic device, but generally popular as "pneumatic head", it is through the use of gas source to drive the pressure to open or close or adjust the valve actuator. Compared with the electric actuator, the pneumatic actuator performs very quickly and reaches 0.05 seconds / sec! Pneumatic actuators are divided into single action and double action according to the different forms of action, the difference and principle are different!


Double acting actuator is mainly gas open air shut type, that is, whether the valve is opened or closed, need to use the gas source, usually expressed as ventilation open, ventilation closed, lost gas source, the valve remained in the state at that time, after the gas source re connected, the valve can continue to work.



The single acting actuator has the function of spring reset. According to the working conditions, the normally open and normally closed type can be selected. The situation is 1:: when the gas is opened, the gas is automatically reset to the initial closing state when the gas source is lost. Situation 2: ventilation closed, lost gas source, automatically reset to the initial open state.

Double acting pneumatic actuator is generally used in the condition of low leakage requirements, while the single acting pneumatic actuator is used more frequently in dangerous conditions, and the valve can be quickly closed or opened when the sudden failure occurs when the gas supply fails. On the price, the single acting pneumatic actuator will be higher than the double acting.