Patent ID: 6986303

Claim:
An apparatus for pumping flowable material, comprising: a first barrel; a first piston movable within the first barrel, thereby dividing the first barrel into a first head-side chamber and a first rod-side chamber; a second barrel; a second piston movable within the second barrel, thereby dividing the second barrel into a second head-side chamber and a second rod-side chamber; a pump for delivering fluid to the first and second barrels; a valve fluidly coupled between the pump and the first and second barrels, the valve movable between a first position wherein an outlet of the pump alternately communicates with the first and second rod-side chambers, and a second position wherein the outlet of the pump alternately communicates with the first and second head-side chambers; one or more sensors for measuring a parameter related to the fluid delivered by the pump to the first and second barrels; and a controller coupled to the valve and the one or more sensors, the controller moving the valve between the first and second positions based upon the measured parameter.