An electric actuator in the valve automation field is a device that converts electrically generated high speed low rotary motor torque into low speed high rotary torque which, when coupled to a part-turn or multi-turn valve, drives the valve.
rotary actuators
What is a Butterfly Valve?
A butterfly valve is a designed to isolate the flow in pipes using a disc which, when aligned with the pipe allows flow, but when perpendicular isolates it.