On-Board Refueling Vapor Recovery System (ORVR): Notes

The ORVR system controls the volume of vaporized fuel released into the atmosphere from the fuel tank during fuel replenishment. Additionally, the system provides optimum fuel line diameter to prevent vaporized fuel from reaching The atmosphere through the fuel neck during replenishment. Vaporized fuel is instead purged to the canister through the shut-off-valve (SOV). Purge volume varies with conditions inside the fuel tank.