Patent ID: 8444399

Claim:
A pump system for conveying a first fluid using a second fluid, the system comprising: at least a first pump, said first pump comprising at least a first rigid outer casing defining a first interior space and a first flexible tube structure accommodated in the first interior space, wherein the interior of the first flexible tube structure is arranged for receiving one of said first or second fluids, the region of the first interior space surrounding the first flexible tube structure is arranged for receiving said other of said first and second fluids, and the first flexible tube structure is movable between laterally expanded and collapsed conditions for varying the volume of the interior of the first flexible tube structure, thereby imparting sequential discharge and intake strokes on said first fluid, a second pump, said second pump comprising at least a second rigid outer casing defining a second interior space and a second flexible tube structure accommodated in the second interior space, wherein the interior of the second flexible tube structure is arranged for receiving one of said second or a third fluid being displaced by said imparted sequential discharge and intake strokes of said first pump, the region of the second interior space surrounding the second flexible tube structure is arranged for receiving said other of said second and third fluids being displaced by said imparted sequential discharge and intake strokes of said first pump, and the second flexible tube structure is movable between laterally expanded and collapsed conditions for varying the volume of the interior of the second flexible tube structure, thereby imparting sequential discharge and intake strokes on said third fluid; and at least one pumping device arranged for pressurizing said one of said first or second fluids.