Method and device for controlling the pressure inside a fuel tank

The method involves partially releasing pressure (p) in a fuel tank by a mechanical high pressure valve during reaching a preset upper high pressure-threshold value. The valve is automatically opened when the pressure reaches the preset upper high pressure-threshold value. The pressure release is smaller than 5 percentage of the preset upper high pressure-threshold value. The pressure in the fuel tank is controlled by the high pressure valve and a mechanical low pressure valve during operation of an internal combustion engine. An independent claim is also included for a device for controlling pressure inside a fuel tank of an internal combustion engine of a motor vehicle.