How to choose pneumatic actuators

electrical and pneumatic actuators have. In the case of pneumatic, pneumatic and single acting ( Spring return) And dual role. By compressed air driven screw drive pneumatic valve rod rolling. 。 According to the source ( Instrument air) To choose the size of the actuator. Rolling torque requirements for a pneumatic valve, turn small still, too large pneumatic valve life is not long. Generally the torque to set aside the % margin with respect to OK. 。 Installation platform, has the scale, as long as according to looking for pneumatic valve dimensions can't be wrong.