Patent ID: 6918547

Claim:
A device for pressurizing fluid, the device having an inlet end and an outlet end, the fluid exiting from the device at the outlet end and moving into a pressure chamber, the device comprising: a hollow piston having a piston axis, said hollow piston providing a path for fluid through the device; a closure member, wherein said hollow piston comprises a widened portion at an inlet end of said hollow piston and a remainder portion, said closure member coupled to said widened portion; a valve member located in the closure member having a valve axis, said valve member configured for axial movement wherein the valve axis remains parallel to the piston axis, said valve member movable between an open position and a closed position; a stop means for limiting axial movement of said valve member; and a sealing surface located in the closure member for sealing an inlet end of said valve member so that said valve member is sealed when in the closed position, wherein fluid flows through the device into the pressure chamber when said valve member is in the open position, and moving said valve member from the open position to the closed position pressurizes fluid in the pressure chamber.