Actuators
An air operated mechanical device used to open and close or modulate a valve. The actuator is designed to convert air pressure into mechanical force sufficient to operate the valve.
Actuator - Terminology
(a) Diaphragm
A flexible pressure responsive element which transmits the force to the actuator stem
A flexible pressure responsive element which transmits the force to the actuator stem
(b) Actuator stem
The extension of the diaphragm plate or piston for connection to the valve plug stem
The extension of the diaphragm plate or piston for connection to the valve plug stem
(c) Actuator spring
The spring enclosed in the yoke is to move the actuator stem in a direction opposite to that created by the diaphragm pressure
The spring enclosed in the yoke is to move the actuator stem in a direction opposite to that created by the diaphragm pressure
(d) Piston
A movable pressure responsive element which transmits force to the operating fluid
A movable pressure responsive element which transmits force to the operating fluid
(e) Yoke
The structure by which the diaphragm case is supported rigidly on the bonnet.
The structure by which the diaphragm case is supported rigidly on the bonnet.
(f) Travel indicator
A pointer to indicate the travel of the valve plug.
A pointer to indicate the travel of the valve plug.
(g) Travel indicator scale
A graduated scale attached to the yoke for indication of the travel.
A graduated scale attached to the yoke for indication of the travel.
