Patent ID: 8636025

Claim:
A dual check valve device comprising: a housing; a first check valve positioned in the housing to allow fluid flow through a first passageway between an upstream source fluidly coupled to a first inlet of the first check valve and a downstream source fluidly coupled to a first outlet of the first check valve; and a second check valve located in the housing adjacent the first check valve and in substantial axial alignment with the first check valve such that a second inlet of the second check valve is to be fluidly coupled to a second passageway and a second outlet of the second check valve is in fluid communication with the first inlet of the first check valve, the second check valve to control fluid flow through the second passageway different from the first passageway, the second check valve to allow fluid flow between the second passageway and a portion of the first passageway upstream from the first inlet of the first check valve and to the upstream source when a pressure differential between the first portion of the first passageway and the second passageway causes the second check valve to move to an open position.