DD15 Engine

Section 3.5 Low Pressure Fuel Pump

Section 3.5
Low Pressure Fuel Pump

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 1. Relief Valve for Low Pressure Pump‪

 7. Fuel Before Quantity Control Valve‪

 2. Low Pressure Pump‪

 8. Lubrication Fuel‪

 3. Fuel Inlet from Tank‪

 9. Two-stage Valve‪

 4. Bypass‪

10. Fuel Return‪

 5. Quality Control Valve‪

11. From Low Pressure Pump‪

 6. Fuel Inlet from Filter (to High Pressure Pump)‪

The low pressure fuel pump (2) is mounted on the high pressure fuel pump. The fuel pump (2) pulls fuel from the fuel tank through the fuel heat exchanger for the MCM.‪

The low pressure fuel pump (2) is designed as a gear pump and is driven by the high pressure fuel pump. As soon as the engine starts and runs, the right gearwheel in the fuel pump is driven by the drive plate on the high pressure fuel pump camshaft. The fuel is suctioned up due to the rotational movement of both gearwheels and the design of the pump chamber.‪

Section 3.5.1
Pressure Relief Valve

A pressure relief valve (1) is incorporated into the low pressure fuel pump. If the system pressure is too high, the pressure relief valve (1) will open allowing the fuel pressure side (B) to be connected to the fuel suction side (A). This will prevent further build-up of fuel pressure. The pressure limiting valve (1) is designed to open at 13 bar absolute (189 psi).‪


DD15 Fuel System Technician's Guide - DDC-SVC-MAN-0037
Generated on 10-13-2008

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