A valve comprising a valve body including a first end and a second end spaced apart along a longitudinal axis, a central portion disposed between the first end and the second end, wherein the first end and the second end define a first flow passageway and a second flow passageway, respectively, and wherein the central portion defines an interior chamber, a stem rotatably supported by the valve body about a rotation axis, wherein the stem includes a polygonal end, and a disc disposed within the interior chamber and including a polygonal aperture to receive the polygonal end of the stem.