In the selection of valve electric actuator, besides the matching of valve and other components, the control mode of valve electric actuator should also be considered. In the control mode of valve electric actuator, there are two common types of valve electric actuator: On-off valve electric actuator and modulating valve electric actuator. The difference is that the function of valve switch control is different.
1. On-off type valve electric actuator:
On-off type valve actuator is also known as open-loop control valve actuator. This actuator only opens and closes two actions when performing valve operation, that is to say, it can only make the valve open or close completely. On-off type valve electric actuator can not control the amplitude of the valve switch, so it can not accurately control the medium flow.
2. Modulating type valve electric actuator:
Modulating type valve electric actuator is also called closed-loop valve electric actuator. This kind of valve electric actuator not only has the control function of valve switch, but also can control the opening of valve accurately, so as to achieve the accurate control of medium flow. The modulating type valve electric actuator is equipped with signal loss protection. When the actuator is unable to accept the signal due to line failure or other reasons, it will automatically control the valve opening and closing state, usually the valve is fully open, fully closed or retains position.