Abstract: A cryogenic pump is disclosed for pumping liquified gas from one container to another container or a point of use. The pump comprises a series of chambers and coupling valves for progressively pumping a liquified gas from an inlet end located within and adjacent to the bottom of the container to an outlet conduit. The pump arrangement allows the container to be substantially emptied thereby avoiding waste of the contained liquified gas.

Abstract: A cryogenic pump capable of operating with a sub-zero net positive suction head includes a reciprocating piston positioned in a cylindrical housing for dividing the interior of the housing into a supercharger chamber and an evacuation chamber on opposite sides of the piston. A supercharger chamber valve, positioned directly behind the reciprocating piston, controls the flow of liquified gas from a gas inlet into the supercharger chamber. A fixed piston, extending into the evacuation chamber, engages a cylindrical skirt carried by the reciprocating piston to form a high pressure chamber between the two pistons. Liquified case from the high pressure chamber is supplied to a gas outlet via a passageway in the fixed piston.

Abstract: A vane pump particularly adapted for pumping cryogenic liquids has a plurality of vanes, each of which comprises a composite of at least two vane plates mounted in slots of a rotor of the pump, and sealingly pressed toward one another by the pressure differential existing on the opposite sides of the vanes, while the vanes are under pumping load. Each plate of the vanes comprises at least two parts which are mounted to one another and incorporate a biasing device, such as a spring, which urges the parts away from one another in a direction substantially parallel with the rotational axis of the rotor, and into sealing relationship with the end walls of a stator chamber in which the rotor is rotating. As an additional feature, the interior surface of the stator chamber, has a circular cross section in the area where the vanes move under a pumping load.