Filter assembly with automatic shut-off and quick-connect filter cartridge

A filter cartridge for containing filter media and for cooperating with a valve head assembly, the filter cartridge comprising:

• a body with an interior space for receiving filter media, the body having an upper end, and a lower end;
• a cap attached to the body near the upper end for enclosing the interior space, the cap having a cap top surface, a cap bottom surface, a generally cylindrical neck protruding vertically upward from the cap top surface, and a generally cylindrical protrusion extending downward from the cap bottom surface and being generally coaxial with said neck;
• wherein the neck comprises a neck top surface with a center and a perimeter edge, and a plurality of generally vertical fluid holes extending through the cap from the neck top surface near the perimeter edge to the cap bottom surface;
• wherein the cap further has a return hole extending through said center of the neck and through said protrusion, the return hole being generally coaxial with said neck and said protrusion, and wherein said protrusion has a generally cylindrical inside surface surrounding and defining the return hole through said protrusion;
• a return tube received in the body interior space and generally coaxial with the return hole, said return tube having a top end received in said return hole inside said protrusion;
• a sealing member located between and contacting the return tube top end and the protrusion inside surface to seal the return tube to the protrusion inside surface;
• and
• a seal retainer ring received in and generally coaxial with the return hole in said protrusion, the retainer ring being positioned directly above said sealing member to retain said sealing member between said return tube and said protrusion inside surface, and the retainer ring having an inner rim extending inwardly directly above the top end of the return tube to provide a stop for positioning the return tube.