The cartridge shuttle valve permits flow from either of two inlet ports to a common outlet. Similar to the Kep-O-seal inline version, a free floating metal ball shuttles according to the relative pressure at the two inlets. The higher pressure inlet flows through the valve and moves the ball to close the opposite inlet. Kepner's Flexible Seal Seat™ ensures bubble-tight shutoff of liquid or gas, and long service life. Shuttle valves can also flow in the reverse direction, and relieve system pressure when input is removed. Standard and specialty valves handle a wide variety of applications, and are ideal for use in manifolds, subplates, or cylinder heads.