Patent ID: 7007708

Claim:
A valve mechanism to control fluid flow between a fluid pumping device and a system, comprising: an inlet from the fluid pumping device, a first valve, a second valve, and a first outlet fluidly connected to the system; wherein the second valve is operable to substantially completely check fluid flow through the valve to the first outlet when fluid pressure at the inlet is less than a first predetermined pressure; wherein the second valve is operable to permit fluid flow from the fluid pumping device to the inlet and subsequently through the first outlet to the system only when fluid pressure at the inlet is greater than the first predetermined pressure; wherein the first valve is operable to prevent backflow of fluid from the system substantially immediately subsequent to the fluid pumping device discontinuing pumping fluid to the system; and, wherein the second valve is operable to prevent fluid pressure in the system from substantially exceeding a second predetermined pressure when the pumping device is not pumping fluid to the system.