Patent ID: 7231937

Claim:
An automatic shutoff valve comprising: a housing having an inlet, an outlet, and a reservoir; a check valve portion located in the housing and in communication with the inlet on an upstream side of the check valve portion and the reservoir on an downstream side of the check valve portion, said check valve portion preventing flow from the inlet to the reservoir in the absence of a pressure differential across the check valve portion in a shut configuration, said check valve portion having an open configuration allowing flow from the inlet to the reservoir when fluid pressure upstream of the check valve portion exceeds pressure downstream of the check valve portion by a first predetermined amount and said check valve preventing flow from the outlet to the inlet when in the shut configuration; and a shutoff valve portion in the housing having a first chamber in pressure communication with the inlet and a second chamber in fluid communication with the reservoir and the outlet in a first position, said first and second chamber separated by a shutoff actuator, said shutoff actuator moveable from the first position to a second position wherein when in the second position the shutoff actuator prevents fluid communication from the reservoir to the outlet, and a higher pressure at the inlet than at the outlet provides increased pressure in the first chamber relative to the second chamber thereby moving the shutoff actuator from the first position toward the second position, and wherein flow from the reservoir passes through second chamber prior to proceeding out of the outlet.