Control of electric actuator for control valve

Electric actuator control of the regulating valve is performed using an analog or three-point signal from the controller. The types of control signals of the actuator and controller must match.

Analog and three-point signals equally effectively control the processes, so there are no recommendations on the use of any type of control signal in certain schemes.

Analog control (proportional) - the stem moves to a position proportional to the magnitude of the control signal (voltage or current). In analog control (direct), the position of the electric actuator stem depends on the magnitude of the applied voltage in the range from 0 to 10 volts (2-10V). For example, if the controller determines that the regulating valve controlled by the electric actuator should be half-open, it sends an analog control signal of 5 volts, and if the valve should be fully open, a control signal of 10 volts must be formed.

Three-point control (pulse) - the stem moves to a position proportional to the duration of the power signal. In three-point control, the position of the stem does not depend on the voltage, and a signal of opening or closing is sent to the electric actuator. In the case of three-point control, the magnitude of the control signal is constant, but it is sent through different channels.

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