Patent ID: 8322435

Claim:
A method of manufacturing a pressure driven pumping system, the method comprising: providing a separating member within a first bore of a housing to separate a process chamber from a working chamber, the separating member being movable within the housing; providing a rod member in contact with the separating member and to extend into a reduced pressure chamber, the reduced pressure chamber being sealed from the working chamber and configured for sustaining a pressure less than a pressure in the working chamber; attaching one or more working fluid ports to pass through the housing to the working chamber; and fluidly connecting one or more working fluid valves to the one or more working fluid ports for controlling flow through the one or more working fluid ports, wherein the separating member comprises a first face exposed to a process fluid and a second face exposed to a working fluid, the first face having an effective area greater than an area of the second face, wherein the working chamber is sandwiched between the process chamber and the reduced pressure chamber such that the rod member extends through the entire working chamber, and wherein at least one of the working fluid ports is in fluid communication with a pump for passing working fluid into the working chamber.