Abstract: The invention relates to a method and device for extracting fuel vapour displaced during the simultaneous operation of at least two fuel-dispensing units using a gas pump device. Each fuel-dispensing unit comprises a vapour extraction conduit in which a control valve is arranged. The different vapour extraction conduits are connected to a single gas pump device. The underpressure to be created by the gas pump device and essential for discharge of the correct quantity of vapour is determined, whereafter the control valves are adjusted such that they each allow through the correct quantity of vapour at the specific underpressure.

Abstract: The invention relates to a pumping device for volatile liquid, comprising a closed pump housing having an intake connected to a supply reservoir and at least one discharge connected to a delivery means. The device further comprises a liquid pump with a liquid inlet drawing into the interior of the pump housing and a pressure outlet connected to the discharge, a gas pump with a gas inlet drawing into the pump housing at a high level and a gas outlet debauching outside the pump housing and wherein the liquid pump is a hydrodynamic pump such as a centrifugal pump.