How to select pneumatic actuators for valves

Pneumatic actuators, also called pneumatic devices, pneumatic heads, and cylinders, are devices that are installed on the valve so that the valve can control the switch or submit through the air source. Take Theoborn, which is often selected as a shortlisted brand by bidding projects, as an example, general pneumatic actuators are used with ball valves, butterfly valves, and regulating valves, the ball valve with Theoborn pneumatic actuator is called pneumatic ball valve, the butterfly valve with Theoborn pneumatic actuator is called Pneumatic Butterfly Valve, and the regulating valve with Theoborn pneumatic actuator is called pneumatic control valve.

The following aspects must be considered when selecting Pneumatic Actuators:
A. Air source pressure or power supply voltage of actuator; The general air source pressure is 4-8Bar, and the power supply voltage generally refers to the voltage of the Solenoid Valve, and the common power supply voltage of the Theoborn Solenoid Valve is AC220V, DC24V;
B. The operating torque of the valve plus the manufacturer's recommended safety factor / according to the operating condition; Generally, it is the actual operating torque of the valve plus 20% of the safety factor.
C. The type of pneumatic actuator: double-acting or single-acting (spring return) and the output torque under a certain air source or the output torque under the rated voltage;
D. Its steering and failure mode (fault on or off fault) It is very important to choose an actuator correctly, if the actuator is too large, the valve stem may be too stressed. Conversely, if the actuator is too small, the side will not be able to generate enough torque to fully operate the valve. The torque required to operate the valve comes from the friction between the metal parts of the valve and the seals. Depending on the occasion of the valve's use, the operating temperature, the operating frequency, the pipe and the differential pressure, the flowing medium (lubrication, drying, mud), many factors affect the operating torque.