Abstract: A flow isolation system for connecting a source of pressurized fluid to plumbing for using the fluid. A generally vertical flow chamber extends from a lower end to an upper end, with an inlet for a pressurized fluid is disposed in a sidewall of the vertical chamber in a position near but paced above the lower end, and an outlet disposed in a sidewall of the vertical chamber in a position near but below the upper end. An evacuation tube extends from an open end near the lower portion of the vertical chamber to an evacuation valve disposed in the upper end. A gas inlet may be disposed in the upper end. When both the exit and inlet are closed, the system may be evacuated by connecting pressurized gas to the gas inlet to force fluid up the evacuation tube and out the evacuation valve.