Patent ID: 8323003
Filing Date: 2012-12-04
Classification: F04B

Abstract:
1. A pressure driven pumping element, comprising: a housing having a bore at least partially bounded by first and second housing walls; a static separating member positioned within the bore; a first dynamic separating member movably disposed within the bore between the first housing wall and the static separating member to define a first outer chamber between the first housing wall and the first dynamic separating member and a first inner chamber between the first dynamic separating member and the static separating member; a second dynamic separating member movably disposed within the bore between the second housing wall and the static separating member to define a second outer chamber between the second housing wall and the second dynamic separating member and a second inner chamber between the second dynamic separating member and the static separating member; and a coupling member coupling the first and second dynamic separating members and sealingly passing through the static separating member, such that the first and second dynamic separating members are movable together to vary the volumes of the outer chambers and the inner chambers; a first inlet valve for controlling flow into the first outer chamber; and a second inlet valve for controlling flow into the first outer chamber, the second inlet valve being configured to pass flow at a slower rate than the first inlet valve, wherein one of the first inner chamber and the first outer chamber is configured to receive process fluid and the other of the first inner chamber and the first outer chamber is configured to receive working fluid, and wherein one of the second inner chamber and the second outer chamber is configured to receive damping fluid and the other of the second inner chamber and the second outer chamber is configured to receive working fluid.