Valve assembly with reversible stop

Abstract

A valve assembly 20 includes a housing or bonnet 22 and a stem 24. The valve assembly 20 further includes a thrust washer 26, an O-ring 28, 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 complete the components of the valve assembly 20. The rotatable disk 36 is assembled by a tight fit with the coupler 34 which, in turn is assembled with a drive bar 90 of the stem 24 by a tight fit. The assembled stem 24, coupler 34 and rotatable disk 36 are assembled 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. The fixed disk 38 is assembled fixedly within the bore 52 of the housing 22 in facing engagement with the rotatable disk 36. The seal 40 is assembled within an opening 54 of the housing and is placed in sealing and retaining engagement with the fixed disk 38. The retainer 32 is placed on the exposed shank portion 74 of the stem 24 and the reversible stop 30 is moved over the shank portion 74 and past the retainer 32 for engagement with splines 82 on the shank portion. The retainer 32 precludes unintentional removal of the stop 30 from the stem 24 while allowing intentional removal thereof.