Valve disk assembly having single orientation

Abstract

A valve assembly 20 includes a housing 22, a stem 24, a reversible stop 30 and a retainer 32. A coupler 34, a rotatable ceramic disk 36, a fixed ceramic disk 38 and a bottom seal 40. Also form components of the valve assembly 30. The rotatable disk 36, the coupler 34 and a drive bar 90 of the stem 24 are assembled and are located within a bore 52 of the housing 22 with a shank portion 74 of the stem 24 extending outward from an opening 56 of the housing 22. A pair of ears 148 and 150 extend radially from a side 144 on diametrically opposite sides of the fixed disk 38. The ear 148 is located symmetrically about a centerline which passes through both ears 148 and 150. The ear 150 is wider than the ear 148, and includes a portion which is offset from the centerline. The bore 52 is formed with a pair of slots 70 and 72, which are complementary to the ears 148 and 150, respectively, for receipt of the fixed disk 38. Due to the offset portion of the ear 150 and the location of the ears 148 and 150 about the centerline, and the accommodating size and location of the slots 70 and 72 of the housing 22, the fixed disk 38 can be located within the bore 52 in only a single orientation and only a single position.