Single Canister System

Single Canister System:

This system uses a single charcoal canister with a pressure control valve between the canister and the fuel tank vapour outlet. A vacuum control pipe is connected from the engine intake induction elbow to the pressure control valve. The vapour outlet from the fuel tank is taken via a safety rollover valve fitted to the removable flange at the top of the tank.

With the engine stopped, the pressure control valve is closed, maintaining a slight positive pressure in the tank: any further increase in pressure causes the valve to open and release vapour to the canister.

When the engine is running, manifold depression (via the vacuum control pipe) holds the pressure control valve open. Air is drawn into the tank to maintain atmospheric pressure as fuel is used and vapourised fuel is deposited in the charcoal canister.
Canister purge operation is as described in Evaporative Emissions Control System (EVAP).

Evaporative Flange Assembly:

The evaporative loss flange assembly is fitted to the top of the tank via a seal and locking ring. The assembly is removable complete with the fitted components.

The vapour vent / rollover valve is a push fit via a sealing grommet. The fuel pump connector is push fitted and crimped into a location tube on the underside of the flange.