Device for accumulation and evaporation of liquid fuel originated from condensation of fuel vapours in the vent conduit of a motor-vehicle tank

A fuel tank for a motor-vehicle comprises a vent conduit (5) connected to a canister arranged outside of the tank (1) for absorbing fuel vapors. The vent conduit (5) has a portion arranged inside the tank (1) with an intermediate portion located at a lowermost position, which creates a siphon-like zone (5a) in which liquid fuel tends to stagnate (7), which is originated from condensation of the vapors inside the vent conduit (5). The tank further comprises a conduit (8) for draining said liquid fuel (7) originated from condensation of vapors present within the vent conduit (5). The draining conduit (8) extends downwardly starting from said siphon-like zone (5a) and ends with a closed end portion (8a) acting as accumulator and evaporator of the fuel. The closed end portion (8a) is arranged at an area which can reach a temperature sufficient for causing evaporation of the condensed fuel and elimination thereof by a flow in an opposite direction through the draining conduit (8) and then through the vent conduit (5) towards the canister.