Abstract: A system for vapor recovery in fuel filling installations without the use of seal members between the delivery gun and the filler pipe of the vehicle to be refuelled, comprising control means which in response to electrical signals indicative of the volumetric fuel delivery rate render the volumetric draw-in rate of said recovery means always greater than said volumetric fuel delivery rate; a preferred embodiment of said control means is also described.

Abstract: A vapor recovery system for a fuel filling installation in which the recovered air-vapor mixture is pumped to the submerged end of a discharge pipe. The discharge pipe is connected to a closed tube which extends along the bottom of an underground fuel tank. The closed tube has a porosity that generates very small bubbles from the air-vapor mixture that flows through the fuel within the tank. A vent pipe for the underground tank separates air from the air-vapor mixture through decreasing density separation by means of a large cross-section for the vent pipe and by providing baffles in the pipe interior.

Abstract: A volumetric meter for liquids and/or gases in which rolling rollers are mutually repelled magnetically to press in a sealed manner against the inner surface of the outer casing of the meter, said rollers being housed in circumferential grooves in the rotor, which is mounted eccentric to said outer casing, said grooves being inclined forwards to the direction of rotation of the rotor.

Abstract: A system for safe vapor recovery, particularly for fuel filling installations, in which a positive displacement pump effects controlled drawing of a vapor-air mixture into a vapor return pipe which extends to the bottom of the underground tank of the installation. The system is provided with a non-return valve downstream of the pump and a special circuit for effecting the controlled in-drawing based on the quantity of fuel delivered, the difference in temperature between the underground tank and the recovered mixture, and especially on the density of the mixture, by which its degree of explosiveness is determined. Structure are also provided for preventing or limiting explosion propagation.