Abstract: A reciprocating pump (10) comprises a first upright leg (12), a second upright leg (14), a first cross-over conduit (18), a second cross-over conduit (18), a lower valve assembly (20) and an upper drive assembly (22). The drive assembly includes plungers (30) which exert alternating downward pumping forces on columns of liquid in the legs (12, 14). The valve assembly is located in a reservoir of water (55) and includes suction openings (80, 64) in the water, which lead into the cross-over conduits (18) and (18), respectively. The valve assembly includes a system of valves and pistons (74, 76) for controlling flow of water into the legs (12, 14) via the cross-over conduits (12, 14) when pumping forces are alternately applied to columns of wafer in the legs (12, 14) wherein water in the legs is raised and lowered in alternating pendulum fashion.

Abstract: A reciprocating pump (10) comprises a first upright leg (12), a second upright leg (14), a first cross-over conduit (18), a second cross-over conduit (18), a lower valve assembly (20) and an upper drive assembly (22). The drive assembly includes plungers (30) which exert alternating downward pumping forces on columns of liquid in the legs (12, 14). The valve assembly is located in a reservoir of water (55) and includes suction openings (80, 64) in the water, which lead into the cross-over conduits (18) and (18), respectively. The valve assembly includes a system of valves and pistons (74, 76) for controlling flow of water into the legs (12, 14) via the cross-over conduits (12, 14) when pumping forces are alternately applied to columns of wafer in the legs (12, 14) wherein water in the legs is raised and lowered in alternating pendulum fashion.