On-Board Refueling Vapor
Recovery(ORVR) system is properly designed to prevent the fuel tank
vapor(HC) emission during refueling at the gas station. This system
consists of fill vent valve(ORVR), fuel shut-off valve, fuel cut
valve(roll over), two way valve(pressure/vacuum relief), fuel liquid/vapor
separator which is installed beside the filler pipe, charcoal canister
which is mounted under the rear floor LH side member with protector, tubes
and miscellaneous connections. While refueling, the flow and column of the
refueling draws the ambient air into the filler pipe so as not to emit
fuel vapor in the air. The fuel vapor in the tank is then forced to flow
into the canister via the fill vent valve and the fuel liquid/vapor
separator which isolates liquid fuel ingredient and transfers the pure
vapor to the carbon canister. While the engine is operating, the trapped
vapor emission in the canister is drawn and fed by the intake manifold
vacuum into the engine combustion chamber. According to this purge
process, the carbon canister is purged and recovers its absorbing
capability.
