Patent ID: 8454325

Claim:
A pumping apparatus, comprising: a housing; a first inlet disposed within the housing, the first inlet having an inlet valve; an outlet disposed within the housing; an internal power fluid column disposed within the housing, the internal power fluid column having a second inlet; and a transfer piston reciprocatingly mounted about the power fluid column, the transfer piston slidably and sealingly extending between the power fluid column and an interior wall of the housing; a product fluid chamber positioned above the transfer piston and at least partially defined by the interior wall of the housing; a transfer chamber positioned below the transfer piston and at least partially defined by the interior wall of the housing; a sealable channel in the transfer piston fluidly connecting the product fluid chamber and the transfer chamber, the sealable channel having a transfer piston valve; and at least one passageway fluidly connecting the power fluid column with a power fluid chamber.