(under subclass 561) Device comprising a valve controlled flow line and valve controlled exhaust passage connected to the line downstream of the flow control valve, whereby the supply through the flow line may be cut off and the downstream portion of the line may be drained through the exhaust passage.
SEE OR SEARCH THIS CLASS, SUBCLASS:
61, for low temperature responsive supply and exhaust.
62, for low temperature responsive drains.
74, for drain outlets with heat fusible closures.
102+, for supply and exhaust type self-correlating systems, especially subclass 107 for waste valves responsive to flow stoppage.
143, for vent type siphon breakers. 216+, for air vents in liquid flow line for back flow prevention.
226, for coaxial inflation and relief valves for pressure controlled tire inflation.
281, and 302+, for supply and exhaust valves associated with hydrants.
312+, for apparatus for collecting leakage or drip.
570, and 733+, especially subclasses 735+ and 738+ for drain valves mounted on well pipes and similar valve mountings.
589, for outlet lines extending downwardly from a valve and vented for draining.
599+, for systems comprising a flow passage which is divided and recombined, including by-passes, and see the search notes thereto.
625.2+, for valve units of the supply and exhaust stop and vent or drain types.
627.5, for supply and exhaust valves having an intermediate position in which both valves are closed.
631+, for valves with cyclic action or actuators, and see the search notes to subclass 631.
SEE OR SEARCH CLASS 222, Dispensing,
424.5+, for measuring traps of the stationary type which are filled and drained through multiple or multiway valves.
251, Valves and Valve Actuation, appropriate subclasses, especially subclasses, 23, 89, 94, 110 for valves of the stop and waste, stop and vent, or drain types.
