addition the tank ventilation valve 8 is opened by a control unit 11 when the fuel tank 1 is refueled with fuel through a filler neck 12 to prevent leakage of fuel vapors through the filler neck 12 also inserted into the ventilation line 7 is a controllable pressure valve 13 is which opens automatically when the gas pressure in the activated carbon filter 4 rises when opening the tank ventilation valve 8 further the pressure valve 13 on one hand is opened along with the tank ventilation valve 8 when refueling the fuel tank 1 and on the other hand during a regeneration of the activated carbon filter 4 a controllable valve 14 is inserted into the regeneration line 6 which is opened in defined operating conditions in a pulsed manner together with the pressure valve 13 in the ventilation line 7 to aspirate ambient air through the activated carbon filter 4 and the intake manifold for combustion in the internal combustion engine to decrease loading of the activated carbon filter 4 with hydrocarbons and thereby allow extending the time period between successive regeneration processes of the activated carbon filter without the risk of bleed emission or to decrease the required size of the activated carbon filter 4 the fuel tank 1 of the exemplary embodiments in the fig1 to 3 includes a heat pipe 15 which serves for cooling and condensing fuel vapors heat pipes are known per se and usually have the shape of a tube with a hermetically sealed hollow inner volume which is partially filled with a liquid.