More and more factories adopt automatic control, and manual operation is replaced by machinery or automation equipment. It is required that the electric actuator can play an interface between the control system and the mechanical movement of valves, and the electric actuator is required to enhance the safety performance and environmental protection performance. In some dangerous situations, automatic actuator device can reduce personal injury.
So what problems should be considered in the selection of the electric valve actuator?
The following points should be paid attention to when choosing valve electric actuator correctly
1、 Operating torque: the operating torque is the most important parameter to select the valve electric device, and the output torque of the electric actuator should be 1.2-1.5 times of the maximum operating torque of the valve.
2、 There are two main structures for operating the electric device of thrust valve: one is to output torque directly without thrust disc; the other is to configure thrust disc, and the output torque is converted into output thrust through the stem nut in the thrust disc.
3、 Rotation number of output shaft: the number of rotation turns of output shaft of valve electric actuator is related to the nominal diameter of valve, the pitch of valve stem and the number of thread heads.
4、 If the maximum valve stem diameter allowed by the electric device can not pass through the valve stem of the valve, it can not be assembled into an electric valve. Therefore, the inner diameter of the hollow output shaft of the electric device must be larger than the outer diameter of the stem of the rising stem valve. For the Non rising stem valves in partial rotary valves and multi rotary valves, the diameter of the stem and the size of the keyway should be fully considered in the selection of valves, so that they can work normally after assembly.
5、 Output speed: if the opening and closing speed of the valve is too fast, it is easy to produce water hammer. Therefore, the appropriate opening and closing speed should be selected according to different service conditions.
6、 After the specification is determined, the control torque is also determined. Generally, the motor will run within a predetermined time, and the motor will not be overloaded.
7、 Control form: valve electric actuator is divided into on-off type and modulating type, and regulating type actuator signal is also divided into current signal and voltage signal.
8、 Control voltage: conventional electric actuator voltage has AC220V, AC380V, DC24V, etc.