Evaporative Check Valve: Description and Operation

Evaporative Emission System

Evaporative Emission System - Duratec Engine:

Duratec Engine

Evaporative Emission System - Zetec Engine:

Zetec Engine

Principles of Operation

Evaporative Emission (EVAP) Check Valve
The check valve vent is normally closed When the EVAP system enters a purge cycle, the valve forces the purge air, being drawn in, to enter the system through the remote canister vent tube. During refueling the valve vent opens allowing the displaced air to vent freely to the atmosphere through a more direct and lower resistance path.