System components (page 2 of 2)

The mixed, two-stage electric fuel pump is fitted with a turbine for low pressures and rollers for high pressures. Fuel is taken up from the tank under low pressure and sent to the engine at high pressure.

Because it is fitted in the fuel tank, this pump performs the initial function of vapour separation. An impeller separates vapour from fuel inside the pump by means of centrifugal force. A vapour separator optimises output of heated fuel and forces it back to the fuel tank. Fuel then flows from the vapour separation assembly to the pump high pressure module. This module is designed expressly to ensure fuel delivery from tank to injection system at the required pressure.

Fuel is then forced towards the engine through the terminal assembly (cover) of the pump and the outlet pipe. The terminal assembly comprises a valve and an RPI (radio frequency interference) suppression module. The valve maintains fuel feed pressure when the engine stops running. The RFI circuit prevents noise due to pump operation that interferes with radio frequencies.

Output is about 90 l/h with pump pressure relief valve setting of 4.5-6.5 bar.

The electric pump consists of:

1. Case
2. Two-stage pumping section
3. Low-pressure turbine
4. High pressure roller
5. Pump motor
6. Cover assembly
7. Safety valve
8. Retaining valve
9. Fuel outlet
10. Fuel intake
11. Vapour exhaust