High pressure pumping apparatus with coupled volumes in a pump working chamber

Abstract

A pumping apparatus (10), for delivering liquid at a high pressure at which compressibility of the liquid becomes noticeable, comprises a piston (20) adapted for reciprocation in a pump working chamber (30), wherein a movement of the piston (20) into a first direction (40) decreases a first volume (V1) in the pump working chamber (30) and increases a second volume (V2) in the pump working chamber (30), and a movement of the piston (20) into a second direction (50) opposite to the first direction (40) increases the first volume (V1) and decreases the second volume (V2). A coupling (70, 80, 90, 100) is provided for coupling the first volume (V1) with the second volume (V2) as long as a pressure (Psup) in the first volume (V1) exceeds a pressure in the second volume (V2). An outlet valve (120) is provided for coupling the second volume (V2) with an outlet (110) of the pumping apparatus (10) as long as a pressure in the second volume (V2) exceeds a pressure (Psys) at the outlet (110).

Dependencies are inferred from the claim text.