On-Board Refueling Vapor Recovery (ORVR)

ORVR system recovers and stores hydrocarbon fuel vapor during refueling. Non-ORVR vehicles vent fuel vapors from the tank venting line back to the filler neck and in many states reclaimed by a vacuum receiver on the filling station fuel pump nozzle. When refueling, the pressure of the fuel entering the tank forces the hydrocarbon vapors through the tank refuelling breather hose to liquid/vapor expansion tank and into the active charcoal canister. HC vapors are stored in active charcoal canister and the system can then "breathe" through Diagnostic Module Tank Leakage (DMTL) and air filter.