On-Board Refueling Vapor Recovery (ORVR - DM TL Equipped Vehicles)

The ORVR system recovers and stores hydrocarbon fuel vapor during refueling. When refueling the E60, the pressure of the fuel entering the tank forces the hydrocarbon vapors through the Filling Vent Valve (14) and the large tank ventilation line into the Carbon Canister (17). The HC's are stored in the Carbon Canister and the system can then "breathe" through the DM TL and the fresh air filter.

NOTE: A small diameter connection to the filler neck is provided and is necessary for checking the filler cap/neck during Evaporative Leak Testing.

The ventilation continues until the rising fuel level lifts the float in the Filling Vent Valve (14) and closes the outlet. When the ventilation outlet is closed, a pressure cushion (vapor area) is created in the fuel tank. This creates a backup of fuel into the filler neck and the tank is full.

This leaves a vapor area of approximately 6 liters above the fuel level. This area provides integral liquid/vapor separation. The vapor condensates separate and drain back into the fuel. The remaining vapors exit the fuel tank (when sufficient pressure is present) through the Service Vent Valves (15 & 16) to the Carbon Canister.

NOTE: The Service Vent Valves are also equipped with protection floats in the event of an "overfill" situation.