What are the types electrical actuators?

There are commonly two types of electrical actuators in control valve system.

Solenoid actuated valve:

This on/off valve is used to remotely open or shut a flow line. These valves normally come in small sizes. It is often used for the control of air supply lines etc. in Emergency Shut-Down (ESD) systems.

The actuator of the valve inside the valve is moved when a current is passed through the solenoid. The control signal is passed to the control valve in the form of electrical signal. When the solenoid energizes, it magnetise and move the magnetic plunger in the valve, thus produce a control action

The Motor Operated Valve (MOV):

A motor operated valve can be used to as control valve with more control positions other than ON/OFF.

The valve stem end is manufactured with the worm gear and also the motor stem. Both are connected together in a way that when the motor rotates the valve stem moves up and down. The control action is given to the motor as electrical signal then it converts it into mechanical energy.