3232836 - 1040A fuel tank and components
CONSTRUCTION FEATURES
Immersed pump unit complete with fuel gauge sender unit
It mainly consists of:
- a roller type electric pump
- a fuel gauge sender unit
- a fuel filter.
Electric fuel pump
The electric pump immersed in the fuel is the positive-displacement roller type with a permanent-magnet brush motor.The impeller (1) rotates, driven by the motor, creating volumes (2) which move from the inlet port (3) to the supply port (4).These volumes are defined by rollers (5) which, whilst the motor is rotating, adhere to the outer ring (6).The pump has two valves, one single-acting valve to prevent the fuel circuit from being drained (with the pump not working) and a second excess pressure valve (7) which recirculates the supply when the pressure exceeds 5 bar.Multifunction valve
The multi-purpose valve has the following functions:
- pressurizing the tank
- retention
- seal in the event of roll-over.
The multi-function valve is thermowelded and so cannot be replaced individually. |
Pressurizing the tank
The tank is maintained at a pressure of 55-75 mbar by means of a fluorosilicone rubber valve, which rests on a sealing edge.The valve is supported by a stainless steel plate and counteracted by a spring.When the pressure in the tank exceeds the specified value, it overcomes the resistance of the spring and the valve is able to rise, allowing vapours to flow to the canister.When the pressure returns to the correct limits, the valve closes again.Retention
Under particular driving conditions, a vacuum could be created in the tank because of:
- temperature changes
- fuel consumption.