ELECTRIC ACTUATOR FOR FLUID CONTROL VALVES

摘要

An electro-mechanical actuator (10) for operating a fluid control valve (12) and controlling the operation of one or more field instruments, including other valve actuators. An electro-mechanical actuator has a drive unit (22) and an electric motor (16) driving the drive unit to open and close a fluid control valve to the fully opened and fully closed states under the control of monitoring limit open and limit closed sensors. Auxiliary control output lin es (50) connected to other field instruments from the electro-mechanical actuat or drive associated fluid control valves to fully open and fully closed states. Limit open sensors and limit closed sensors monitor the valve open and close d state of the other respective field instruments and through a respective pai r of auxiliary travel input lines (52) to the electro-mechanical control the field instrument.