PURPOSE: To return the whole vapor regardless of the flow rate of hydrocarbon by providing a comparator comparing the liquid flow rate in a first pipe with the gas flow rate in a second pipe, a valve fitted in between the comparator of the second pipe and a pump, and a control means controlling the opening of a valve as a function of the comparison.

CONSTITUTION: A vapor recovery device 22 fitted to both a hose 14 and a vapor recovery pipe or duct 16 is provided in the inside of the housing 20 of a dispenser. The vapor flow rate along the pipe 16 is subject to a standard value depending on the liquid flow rate along a main pipe 30 by a servo control loop of the device. When the vapor flow rate is more than the liquid flow rate, the valve member 92 is closed to lessen the vapor flow rate, and when the vapor flow rate becomes less than the liquid flow rate, the valve member is again opened by a correcting action of deformable systems 72, 76. In this way, if a pump 24 can carry out sufficient suction, the vapor flow rate can be controlled regardless of the flow rate of the liquid flow rate.