(under subclass 409) Apparatus in which the float controls the application of another source of power for operating the flow controlling means rather than acting directly through a mechanical connection.
SEE OR SEARCH THIS CLASS, SUBCLASS:
191, and 195, for servo control with sinking type floats in pressure systems containing diverse fluids.
SEE OR SEARCH CLASS
91, Motors: Expansible Chamber Type, appropriate subclasses for fluid servo-motors.
251, Valves and Valve Actuation,
25+, for fluid pressure servo-motor operation of valves (and see the search notes to subclass 25), subclasses 68+ for electrical actuation of biased trip type valves, and subclasses 129+ for electrical actuation of valves, especially subclass 131 for remote control of such actuators.
