Pneumatic actuators, commonly known as pneumatic heads, also called pneumatic actuators (Pneumatic actuator), are divided into three main categories: pneumatic, electric and hydraulic. They have their own characteristics and are suitable for different occasions. The pneumatic actuator is a category in the actuator.


Pneumatic actuators can also be divided into two types: single action and double action. The switch actions of actuators are driven by gas source, called DOUBLE ACTING (double action). The SPRINGRETURN (single action) actuator is only open or closed to the gas source, and the opposite action is reset by the spring.


The actuator and regulating mechanism of the pneumatic [1] actuator are unified as a whole. The actuator has a film type, a piston type, a fork type and a gear and rack type. The piston stroke is long, which is suitable for the situation requiring large thrust; while the thin film stroke is small, it can only drive the stem directly. The [2] fork pneumatic actuator has the characteristics of large torque and small space, and the torque curve is more consistent with the torque curve of the valve, but it is not very beautiful. It is commonly used on the valve with large torque. The rack and pinion pneumatic actuator has the advantages of simple structure, stable and reliable action, and safety and explosion-proof. It has wide applications in power plants, chemical industry, refining and other safety requirements.


When compressed air enters the pneumatic actuator from the A pipe nozzle, the gas pushes the two pistons to the ends (Gang Gaiduan) in a straight line motion. The rack on the piston drives the gear on the rotating shaft to rotate 90 degrees counterclockwise, and the valve is opened. At this time the gas at both ends of the pneumatic actuating valve is discharged with the B tube.

On the contrary, when the compressed air enters the two ends of the pneumatic actuator from the B pipe nozzle, the gas pushes the double plug to the middle straight line movement. The rack on the piston drives the gear on the rotating shaft to rotate 90 degrees clockwise, and the valve is closed. At this time the gas in the middle of the pneumatic actuator is discharged with the nozzle of the A tube.

The above is the standard type of transmission principle. According to the needs of users, pneumatic actuators can be installed as opposed to the standard ones. That is to say, the alignment axis is turned clockwise to open the valve, and the counterclockwise direction is turned to close the valve. The single action (spring reset) pneumatic actuator A tube is the inlet, and the B tube is the exhaust hole (the B tube nozzle should be installed the muffler). A nozzle inlet to open the valve, cut off the gas valve is closed by spring force.