Patent ID: 7905247

Claim:
A vacuum actuated check valve for delivery of a fluid from a pressurized fluid source to a downstream processing tool, comprising: a valve base having a pin inserted there through for communication with a bellows chamber downstream, wherein the pin and the valve base form a passageway there-between, the pin is adapted for reciprocal movement to bias a spring bushing, the valve base having a counterbore therein, with a sleeve forming a passageway between said pin and sleeve, and an o-ring disposed concentrically around the lower section of the pin and sleeve combination wherein said sleeve is disposed between the circumference of the pin shaft and the inside radius of said o-ring within the counterbore of the valve base, where the pin is firmly held in place by the spring bushing adapted to movement between a sealing position that blocks fluid flow along the passageway and an open position that permits fluid between the pin and sleeve, along the passageway; and the bellows chamber disposed downstream of the valve base and pin, wherein the bellows chamber defines an interior volume isolated from the pressure condition upstream of the pin, the bellows chamber is adapted to expand when communication with a discharge path produces a vacuum condition around the bellows and forces a contact plate to impinge onto the pin so as to bias the spring bushing away from the valve base to an open position to allow fluid flow through the passageway in the valve base.