Electric actuator

There are two types of electric actuators, generally divided into partial turn electric valve actuators and multi turn electric valve actuators. The former mainly controls valves that require partial rotation, such as ball valves and butterfly valves, while the latter requires valves that require multiple turns, such as gate valves.
Electric driven multi turn actuators are one of the most commonly used and reliable types of actuators. Use a single-phase or three-phase electric motor to drive gears or worm gears and finally drive the valve stem nut, which causes the valve stem to move and open or close the valve. The multi turn electric actuator can quickly drive large-sized valves. To protect the valve from damage, a limit switch installed at the end of the valve stroke will cut off the power supply to the motor. At the same time, when the safety torque is exceeded, the torque sensing device will also cut off the power supply to the motor. The position switch is used to indicate the opening and closing status of the valve. The handwheel mechanism installed with the clutch device can manually operate the valve in case of power failure.
The main advantage of this type of actuator is that all components are installed in one housing, integrating all basic and advanced functions within this waterproof, dustproof, and explosion-proof housing. The main drawback is that in the event of a power failure, the valve can only remain in its original position. Only by using a backup power system can the valve achieve a fail safe position (fail open or fail close).
This type of actuator is similar to an electric multi turn actuator, with the main difference being that the final output of the actuator is a motion of 1/4 turn to 90 degrees. The new generation of electric single turn actuators combines the complex functions of most multi turn actuators, such as parameter setting and diagnostic functions using a non entry user-friendly operating interface. The single rotary actuator has a compact structure and can be installed on small-sized valves, usually with an output torque of up to 800 kilograms per meter. In addition, the required power supply should be small, and they can be installed with batteries to achieve fault safe operation.