Self-cleaning orifice check valve

Claim 1

An orifice-type check valve for providing a restricted flow in a first direction and an unrestricted flow in a second direction opposite to the first direction comprising a valve body, a bore in the valve body, a seat provided at one end of the bore, a first conduit means for communicating fluid to said one end of the bore, a second conduit means intersecting the bore transversely therewith and at a point remote from said first conduit means, a valve element slidably disposed in the bore, said valve element comprising a spool having first and second spaced lands defining an annular recess therebetween on said spool and wherein said first land is disposed between the first and second conduit means, said annular recess continually communicating with the second conduit means, means urging the valve element against the seat producing parallel abutting surfaces disposed transversely relative to said first conduit means, at least one of said surfaces having a groove formed thereon to provide an orifice when the valve is closed, said groove being disposed in a position to be flushed by the flow of fluid through the valve when it is opened, said first land having Flats on the periphery thereof communicating with the groove and the annular recess.