Multi-purpose valve

MULTI-PURPOSE VALVE

The purposes of this valve are:

• To send the fuel vapours to the canister
• Ventilate the fuel tank
• Prevent the fuel from spilling

When the pressure of the vapours in the tank reaches 0.038 ÷ 0.053 bar, a diaphragm countered by a spring allows them to be released to the canister.

To ventilate the tank with vacuum ratings below -0.020 bar, a centre cup acts on the above-mentioned diaphragm countered by another spring and lets air into the tank.

1. Fuel vapour relief valve to canister
2. Tank ventilation valve
3. Needle valve

In the lower part of the body there is a taper housing on which a ball of suitable weight is housed. This ball rolls on its housing and under the centrifugal thrust received from the car, it raises and closes a needle valve to prevent the fuel from spilling when the car sways and when it is parked on sloping ground. The needle valve also acts as an anti-rollover valve.

REMOVAL/REFITTING

- Remove the fuel tank (see specific paragraph).

1. Remove the multi-purpose valve from the fuel tank.

FUEL VAPOUR FILTER (CANISTER)

The filtering element comprises active carbons enclosed in a plastic container which absorb the fuel vapours leading from the fuel tank.