(under subclass 244) Apparatus in which the pumped fluid is controlled prior to, during or after being acted upon by the pumping units, the control operating in response to the occurrence of a condition or a change in condition.
(1) Note. The fluid may be controlled by controlling an inlet or discharge valve (e.g., by holding an inlet or discharge valve open), a bypass valve or a clearance space.
(2) Note. This definition includes direct acting relief valves and the like, but excludes a mere cyclic distributor valve (e.g., inlet or discharge check valve) of an expansible chamber pump.
SEE OR SEARCH THIS CLASS, SUBCLASS:
252, for multistage pumps with an interstage pressure responsive discharge for pumped fluid.
