The actuator is divided into electric and pneumatic.
Taking pneumatics as an example, pneumatics are divided into single-acting (spring return) and double-acting. Compressed air pushes the screw to drive the valve stem to rotate.
1. Select the actuator according to the size of the gas source (instrument gas)
2. The output torque of the pneumatic actuator depends on the torque required by the valve
The torque required to open and close the valve determines the output torque of the electric actuator, which is generally proposed by the user or selected by the valve manufacturer. As the actuator manufacturer, it is only responsible for the output torque of the actuator, which is required for the normal opening and closing of the valve. The torque is determined by the valve diameter, working pressure and other factors, but due to the difference in the processing accuracy and assembly process of valve manufacturers, the torque required for valves of the same specification produced by different manufacturers is also different, even if the same valve manufacturer produces the same torque. The torque of the valve is also different. When the torque of the actuator is too small, the valve cannot be opened and closed normally. Therefore, the pneumatic actuator must choose a reasonable torque range. (Shanghai Jinzexin Pneumatic Valve Co., Ltd.)
2. The torque required to turn the valve is too small to rotate, and the valve life is not long if it is too large. Generally, a 30% margin for torque is OK.
The difference is that when the torque selection of the actuator is too small, it will cause the valve to be unable to open and close normally, so the pneumatic actuator must choose a reasonable torque range.
