Patent ID: 7325577

Claim:
A tank venting system comprising a base formed to include a tank passageway adapted to be coupled in fluid communication to a fuel tank and a canister passageway adapted to be coupled in fluid communication to a vapor recovery canister and arranged to open into the tank passageway, the base also being formed to include a valve seat at a fluid-conducting interface between the tank and canister passageways, a diaphragm valve having a first side exposed to fuel vapor extant in the tank and canister passageways and an opposite second side exposed to outside air, the diaphragm valve being mounted for movement relative to the base to a closed position wherein the first side engages the valve seat to block flow of fuel vapor between the tank and canister passageways and an opened position wherein the first side disengages the valve seat to allow flow of fuel vapor between the tank and canister passageways, and hydrocarbon recovery means for receiving any diffused hydrocarbon material associated with fuel vapor extant in the tank and canister passageways that has diffused through pores extant in the diaphragm valve and exited through the pores opening on the opposite second side of the diaphragm valve and for discharging such diffused hydrocarbon material into the canister passageway for delivery to the vapor recovery canister upon exposure of the canister passageway to a purge vacuum sufficient to apply a suction force to the first side of the diaphragm valve to move the diaphragm valve to assume the closed position so that negative pressure extant in the canister passageway is not applied to the fuel tank via the tank passageway.