(under subclass 12) Subject matter wherein the fluid pressure actuator for the valve is connected by a closed fluid line to a control station at which is located a means for varying the pressure in the fluid line, which means takes the form of an expansible chamber device such as a pump, pulsator, piston and chamber or diaphragm and chamber.
SEE OR SEARCH THIS CLASS, SUBCLASS:
29, for fluid pressure actuated valves of the servo-motor type, the operation of which is controlled from a distant point by means of a valve for the power fluid, and subclass 41 for other types of remote pilot valve actuation.
131, for remote control of electrical valve actuators.
SEE OR SEARCH CLASS
60, Power Plants,
533+, for a fluid link or column, per se, or actuating a nominal load other than a valve.
137, Fluid Handling,
82+, for pressure modulating relays or followers including fluid links, but not including valve or the motor means which is actuated by it.
