A vapor emission control system suitable for gasoline and other fuel delivery systems, adapted to eliminate the escape of fuel vapors to the atmosphere, and permit utilization of these vapors by the system. The disclosed embodiment of the control system includes a delivery conduit or line having a fuel delivery nozzle, an annular sealing means encircling the nozzle adapted to seal the nozzle within the opening to the container or tank, a vapor return line which may be vacuum operated, and a filter or other means adapted to store the vapors. In the disclosed embodiment of the nozzle assembly, the sealing means includes a flexible annular sleeve which is received within the container opening. The sleeve is expandable in one of the disclosed embodiments to seal the tank opening. In another embodiment, the sealing means is provided with a spring-tensioned annular sealing ring adapted to seal the opening to the tank. In the latter embodiment, the vapors are conducted through apertures in the sleeve to the vapor return line.