Ventilation device for fuel system of hybrid vehicle

The device (8) has a first chamber (II) comprising a first channel (2) connected to a canister inlet and a fuel tank and a blocking device (O) closed to seal the first channel. The first channel is separated from a second channel (1) of a second chamber (I). One/two pressure/vacuum safety valves (PVSV) is/are located in/attached to a bypass of the second channel to establish connection between ends of the second channel when a sealing device (F) is closed and overpressure/negative pressure exists at sides of the second channel, respectively. The chambers are integrated in a common case. An independent claim is also included for a fuel system.