VALVE ACTUATORSDOE-HDBK-1018/2-93ValvesSummaryThe important information in this chapter is summarized below.Valve Actuators SummaryManual actuators are the most common type of valve actuators. Manual actuatorsinclude handwheels attached to the valve stem directly and handwheels attachedthrough gears to provide a mechanical advantage.Electric motor actuators consist of reversible electric motors connected to thevalve stem through a gear train that reduces rotational speed and increases torque.Pneumatic actuators use air pressure on either one or both sides of a diaphragmto provide the force to position the valve.Hydraulic actuators use a pressurized liquid on one or both sides of a piston toprovide the force required to position the valve.Solenoid actuators have a magnetic slug attached to the valve stem. The force toposition the valve comes from the magnetic attraction between the slug on thevalve stem and the coil of the electromagnet in the valve actuator.ME-04Rev. 0Page 50
Integrated Publishing, Inc. - A (SDVOSB) Service Disabled Veteran Owned Small Business