This type of actuator is paired with a positioner so the actuator can move to the required position accurately. There are several basic types of valve actuators: manual, electric, pneumatic, and ...
Some water valves are actuated manually, by a hand wheel or crank, or with mechanical devices such floats and cams. Others are actuated by electric, pneumatic, electro-hydraulic, or hydraulic methods.
The standard also provides a guide to assist the user in specifying electric valve actuators. ISA96.03 – The basic requirements for pneumatic valve actuators of the single- and double-acting types ...