Three-position pneumatic actuator has two types:

  1.    0-45-90 degree

  2.    0-90-180 degree.

The piston will move toward both ends after the air enters from the gas port(2);

for the actuator that is fixed with auxiliary pistons for reach the middle position by

mechanical limit,you can adjust the middle angle simply using the external adjusting bolts at both ends,such as 20,30,50,75 degree as well as 95,120,130,150 and 175 degree.