Safety and ventilation valve

Safety and ventilation valve

This valve is located in the fuel filler cap and carries out the following functions:

• discharging the excess pressure outwards which forms inside the tank (safety function); the pressure acts on the plate (2) and, overcoming the spring (1) loading, allows the excess vapours to be discharged outwards;
• allowing the flow of outside air in the tank when an excessive vacuum is formed inside the tank through the effect of the fuel consumption (ventilation function): when the vacuum exceeds the loading of the spring (4), it moves the valve (3), allowing the intake of air.

Active charcoal filter

This is made up of granules of charcoal (4) which trap the vapours entering through the inlet (5).

The scavenging air which enters through the inlet (1), passes through the paper filter (3), comes into contact with the charcoal granules removing the vapours and directs them towards the outlet (2) and from there towards the filter valve.

The air, having entered through the inlet (5) can also be sent by the vacuum into the tank for ventilation.

The partition (6) ensures that the warm scavenging air drawn in comes into contact with all the granules of charcoal.

There are also two springs (7) which allow the expansion of the mass of granules when the pressure increases.

Charcoal filter solenoid valve

This valve, of the normally closed type, controls the flow of vapours reaching the inlet manifold and is operated by the control unit with duty-cycle operation.

NOTE The inlet which has the word CAN (canister) written on it should be connected to the charcoal filter.

1. From the charcoal filter
2. To the inlet manifold