(under the class definition) Apparatus in which the pump fluid is liquid, the pump including a port or valve other than the ports or valves necessary to the normal operation of the pump, said port or valve being positioned in the pump chamber or pump fluid conduit to allow pump fluid therein to flow through said port or upon actuation of said valve to drain said pumping chamber or conduits.
(1) Note. When the drain means comprises a valve, the valve may not be of the type which cyclically controls the discharge of pump fluid as a consequence of operation of the pump and must be disclosed as for the purpose of draining the pump after termination of the use thereof.
SEE OR SEARCH THIS CLASS, SUBCLASS:
435, for a separate port or noncyclic valve for venting or filling a pump portion.
440+, for a separate selectively controlled noncyclic valve for a purpose other than draining a pump portion.
443+, for a pressure responsive distributor opened in response to pumping member position.
446, for means for selectively holding a pressure responsive distributor open. 447, for a pressure responsive distributor which is
constantly biased open.
493+, for a pumping member controlled inlet or outlet port including plural cyclically controlled inlet or outlet flow paths.
503, for multiple cyclic outlet paths.
SEE OR SEARCH CLASS
137, Fluid Handling,
565.36, for a valve means for draining a pump tube. Class 417 takes a valve designed to drain a pump tube or chamber where the pump is claimed or when some structure peculiar to a pump is claimed. The mere claiming of a pump barrel or cylinder does not preclude classification in Class 137.
166, Wells,
316+, for well structure having a valve means associated therewith and operable to drain a portion of the well structure.
251, Valves and Valve Actuation,
142+, for a fluid flow path combined with a means to control the flow of fluid through said flow path, particularly subclasses 149.1+ for a valve operated by joining the flow path sections together and subclasses 145+ for a valve for controlling a port in a pipe side where the flow path sections or the pipe constitute an inlet or discharge pipe of a pump.
