The working principle of the pneumatic actuators:

1. Pneumatic piston type actuator for double action:

The double action locator output air pressure signal respectively input actuator piston left, right two gas chamber, due to the input piston left, right two chamber air pressure is different, formation pressure difference, and promote the piston as linear motion. Through the gear, rack drive, the linear motion of the piston into actuator the spindle rotation movement until the left, right chamber pressure balance, the motion stops. In the executing agency for the rotary motion and drive the valve rod, valve core make the rotary motion, in order to change the valve core and valve seat room of the circulation area to regulate purpose.

2. Pneumatic piston type actuator for monoculture when:

By the single-acting locator output of gas pressure signal input to the actuator no spring side of the chamber, air signal pressure acting on piston, formed on the thrust and spring force is the difference between the value, under the action of cylinder piston for linear motion, through the gear, rack drive. Until gas signal pressure formation of thrust and spring force balance, the motion stops. In the actuator spindle make the rotary motion and drive the valve rod, valve core make the rotary motion, thus change the valve core and valve seat between the circulation area, to regulate purpose.