A ventilation device including: a first enclosure including a first passage configured to be connected to a canister outlet and the atmosphere, and a normally closed shutter device configured to open to release the first passage; a second enclosure including a second passage configured to be connected to the canister inlet and a fuel tank, and a normally open shutter device configured to close to shut the second passage, the second passage being separate from and not in communication with the first passage; and a combined pressure/vacuum relief valve or OPR and UPR valve pair situated in or fastened to a bypass of the first passage configured to establish a connection between ends of the first passage when the shutter device is closed and when there is over- or under-pressure in the ends. A fuel system can include the device and a hybrid vehicle can include the fuel system.