Patent ID: 7475701

Claim:
A valve system for use in a system comprising a first source of a first pressurized fluid and a second source of a second pressurized fluid, the valve system comprising: a valve housing comprising a first inlet port adapted to be placed in fluid connection with the first source, a second inlet port adapted to be placed in fluid connection with the second source and an outlet port; and a backflow prevention system comprising a deformable sealing member having a first portion and a second portion, the deformable sealing member biased to prevent flow of the first pressurized fluid through the second inlet and to prevent flow of the second pressurized fluid through the first inlet port, wherein the valve system is adapted to provide a fluid path between at least the first inlet port and the outlet port to enable fluid to be drawn from the outlet port to the first inlet port, and further wherein flow of the second pressurized fluid into the second inlet port at a first pressure deforms the first portion of the sealing member to block flow into the first inlet port and flow of the second pressurized fluid into the second inlet port at a second pressure higher than the first pressure deforms the second portion of the sealing member to open a fluid path between the second inlet port and the outlet port.