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There are two types of actuators: electric and pneumatic.
Taking pneumatic as an example, it is divided into single acting (spring reset) and double acting. Drive the screw rod to rotate the valve stem through compressed air.
1. Select the actuator based on the size of the gas source (instrument gas)
2. The output torque of pneumatic actuators depends on the torque required by the valve
The torque required for valve opening and closing determines the output torque of the electric actuator. Generally, it is proposed by the user or selected by the valve manufacturer. As the actuator manufacturer, they are only responsible for the output torque of the actuator. The torque required for normal valve opening and closing is determined by factors such as valve diameter size and working pressure. However, due to differences in processing accuracy and assembly technology among valve manufacturers, the torque required for valves of the same specification produced by different manufacturers also varies. Even valves of the same specification produced by the same valve manufacturer may have different torques. If the torque of the actuator is selected too small, it will cause the valve to be unable to open and close normally. Therefore, pneumatic actuators must choose a reasonable torque range. (Shanghai Jinzexin Pneumatic Valve Co., Ltd.)
2. The torque required to rotate the valve is too small to move, and too large will result in a shorter lifespan of the valve. Generally, leaving a 30% margin for torque is sufficient.
The difference is that when selecting a type, if the torque of the actuator is too small, it will cause the valve to fail to open and close normally. Therefore, pneumatic actuators must choose a reasonable torque range.
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