Patent ID: 7257940

Claim:
A method of pumping a fluid, comprising: providing a pressurizer for pressurizing the fluid, the pressurizer comprising: at least two storage tanks, wherein, for each storage tank, the pressurizer further comprises: a propellant entrance valve connected to and associated with the storage tank; a propellant exit valve connected to and associated with the storage tank; a pressurant entrance valve connected to and associated with the storage tank; and a pressurant exit valve connected to and associated with the storage tank, wherein each of the storage tanks is configured to be filled with the fluid under a low pressure when its associated propellant entrance and pressurant exit valves are open and its associated propellant exit and pressurant entrance valves are closed, and to be drained of the fluid under a high pressure by the force of a pressurant when its associated propellant entrance and pressurant exit valves are closed and its associated propellant exit and pressurant entrance valves are open; and for each storage tank, opening and closing its associated valves in cycles to sequentially fill and drain the storage tank of the fluid, the cycles each having a cycle time between approximately 1 and 500 milliseconds.