DA type pneumatic actuator refers to the output moment of the double-acting pneumatic actuator gear-rack actuator, which is obtained by multiplying the piston pressure (supplied by the air pressure) by the pitch radius (force arm). And the friction resistance is small and the efficiency is high. The output torque of clockwise and counterclockwise rotation is linear. Under normal operating conditions, the recommended safety factor of double-acting actuator is 25-50%.