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.