Patent ID: 6767002
Filing Date: 2004-07-27
Classification: F16K,F17C,Y10T

Abstract:
A check valve for a tap of a gas or a liquefied gas cylinder including a housing having a bore therein having an inner circumferential surface, said bore having an axis and a mouth opening in a housing end surface; a valve body member axially movable in the housing bore between a check valve open and a check valve dosed position and having a proximal annular portion defining a proximal annular end surface facing the housing bore mouth opening and a distal portion remote from said mouth opening, and said valve body member having gas flow passageway means therein opening out through said proximal portion of said valve body member and being in fluid communication, through the outer circumferential surface of the valve body member, with an annular interfacial gap defined between the outer circumferential surface of the valve body member and the inner circumferential surface of the housing bore; axially spaced primary and secondary seal means on the valve body member, said primary seal means being adapted to sealingly engage an associated generally axially extending primary sealing surface portion on the housing bore inner surface surrounding the valve body member, and said secondary seal means being adapted to sealingly engage at least one associated secondary sealing surface portion on said housing bore inner surface surrounding the valve body member, the primary seal means being on the outer circumferential surface of the valve body member distally of where the gas flow passageway means communicates with said annular interfacial gap, and the secondary seal means being on the valve body member proximally of where the gas flow passageway means communicates with said interfacial gap; spring means urging the valve body member in a proximal direction to the check valve closed position in which the primary seal means is in gas tight engagement with its associated axially extending primary sealing surface portion to prevent gas flow between the gas flow passageway means and a distal plenum chamber delimited between said housing bore and the valve body member, the valve body member being movable in an opposite, distal direction to said check valve open position wherein the primary seal means is distally disengaged from its associated primary sealing surface portion to permit gas flow between the plenum chamber and the gas flow passageway means through said annular interfacial gap; said valve body member having an annular contact surface extending around the gas passageway means at the proximal portion of the valve body member and adapted to be gas tightly engaged by an annular gas ducting member of an actuator means urging the valve body member against the spring force in the opposite, distal direction towards the open position.