Patent ID: 7566358

Claim:
A system for managing pressure in a fuel storage tank to prevent fugitive emissions, comprising: a carbon canister, comprising: a canister having an inlet port and an outlet port wherein the inlet port is coupled to the fuel storage tank; and hydrocarbon adsorbing activated carbon located inside the canister; a flow limiter coupled to the outlet port of the carbon canister to control a flow rate of air flow exiting from and entering into the outlet port of the carbon canister; wherein when the fuel storage tank is overpressurized, a hydrocarbon air mixture from the fuel storage tank enters into the inlet port of the carbon canister and the carbon adsorbs hydrocarbon in the hydrocarbon air mixture leaving a substantially cleansed air residual from the hydrocarbon air mixture that is vented through the outlet port and the flow limiter; and wherein when the fuel storage tank is underpressurized, outside air enters through the flow limiter and into the outlet port and the hydrocarbon adsorbed by the carbon is purged and returned back to the fuel storage tank.