On-board refueling vapor recovery function - GF47.10-P-3004V

MODEL 203 with ENGINE 272.920 with CODE (494) USA version 

MODEL 211 with ENGINE 272.922 with CODE (494) USA version 

MODEL 203, 209 with ENGINE 272.940 with CODE (494) USA version 

MODEL 203 with ENGINE 272.941 with CODE (494) USA version 

MODEL 171 with ENGINE 272.942 with CODE (494) USA version 

MODEL 211 with ENGINE 272.943 with CODE (494) USA version 

MODEL 211 with ENGINE 272.944 with CODE (494) USA version 

MODEL 251 with ENGINE 272.945 with CODE (494) USA version 

MODEL 221 with ENGINE 272.946 with CODE (494) USA version 

MODEL 203, 209 with ENGINE 272.960 with CODE (494) USA version 

MODEL 171 with ENGINE 272.963 with CODE (494) USA version 

MODEL 211, 219 with ENGINE 272.964 with CODE (494) USA version 

MODEL 221 with ENGINE 272.965 with CODE (494) USA version 

MODEL 230 with ENGINE 272.966 with CODE (494) USA version 

MODEL 164, 251 with ENGINE 272.967 with CODE (494) USA version 

MODEL 203 with ENGINE 272.970 with CODE (494) USA version 

MODEL 211 with ENGINE 272.972 with CODE (494) USA version 

MODEL 221 with ENGINE 272.975 with CODE (494) USA version 

MODEL 221 with ENGINE 273.922 with CODE (494) USA version 

MODEL 164 with ENGINE 273.923 with CODE (494) USA version 

MODEL 221 with ENGINE 273.924 with CODE (494) USA version 

MODEL 164 with ENGINE 273.943 with CODE (494) USA version 

MODEL 211, 219 with ENGINE 273.960 with CODE (494) USA version 

MODEL 216, 221 with ENGINE 273.961 with CODE (494) USA version 

MODEL 211 with ENGINE 273.962 with CODE (494) USA version 

MODEL 164, 251 with ENGINE 273.963 with CODE (494) USA version 

MODEL 230 with ENGINE 273.965 with CODE (494) USA version 

MODEL 209 with ENGINE 273.967 with CODE (494) USA version 

MODEL 221 with ENGINE 273.968 with CODE (494) USA version 

Fig 1: On-Board Refueling Vapor Recovery Function Diagram

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

The legislator demands: 

• Refueling vapors in the vehicle must be recovered (ORVR = O  n-board R  efueling V  apor R  ecovery)
• Fuel and refueling gases must be separated in order to prevent fuel from flowing into the activated charcoal canister due to inappropriate refueling or a defective nozzle.

Thanks to its shape, the fuel filler neck functions as a suction jet pump. The fuel out of the nozzle accelerates through this in the filler neck and air is suctioned around the nozzle.

As a result of this air intake (in the fuel tank) around the nozzle, refueling vapors are not able to rise up at the fuel filler neck and escape into the atmosphere.

The refueling gases are stored in the activated charcoal canister.

When the canister is regenerated (purge control valve actuated), the refueling vapors are drawn off by the engine and burned together with the fuel vapors from the fuel evaporation control system.

Stop refueling when the nozzle is switched off and the fuel tank is full! On no account overfilling fuel tank as a result of refueling nozzle being switched on several times.

Fuel tank in luggage compartment (model 171, 230) 

If the fuel tank is full, the float with the flap (45/2) closes the fuel filler neck at the bottom. This ensures that the refueling nozzle shuts off rapidly and overfilling is largely prevented. A check valve (45/1) prevents the quick increase of fuel in the filler neck.

Two safety valves (rollover valves) (75/1) located in the fuel tank (75). If fuel flows to the high mounted safety valves they close the vent line to the activated charcoal canister (77). Through powerful braking, accelerating or cornering the valves can also close briefly.

If an excessively high pressure exists in the activated charcoal canister, the pressure relief valve (77/1) opens. In this special case the removal of pressure is performed via the activated charcoal canister shutoff valve (Y58/4) into the open air.

Fuel tank on frame floor assembly 

(Model 164, 203, 209, 211, 219, 216, 221, 251) 

The refueling vapors flow along the vent line to the expansion reservoir and on from there to the activated charcoal canister. A filler neck with valves is not necessary.