Curiosii for ever!: Car repair manuals for everyone.

Evaporative and ORVR Emission Control System

EVAPORATIVE AND ORVR EMISSION CONTROL SYSTEM

DESCRIPTION




On-Board Refuelling Vapor Recovery (ORVR) system is properly designed to prevent 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), fuel liquid/vapor separator (which is installed on the fuel tank), charcoal canister (which is mounted under the rear floor LH side member with protector), tubes and miscellaneous connections.

During refueling, the flow and column of the refueling fuel draws the ambient air into filler pipe so as not to emit fuel vapor in the air. The fuel 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.