Patent attributes
A valve body and seal assembly comprising a top-stem-guided valve body having at least one cast-in-place elastomeric seal insert in a peripheral seal retention groove and a cast-in-place top guide stem sleeve is made by pouring and curing liquid elastomer in at least one mold comprising the peripheral seal retention groove and the top guide stem. Mold surfaces contacting the poured elastomer are adhesion-inhibiting surfaces which reduce or eliminate background elastomer stress due to shrinkage during curing of the elastomer, and which allow limited relative movement of cast-in-place elastomer with respect to the valve body. Serrations on each of the opposing walls of the seal retention groove are offset to moderate differing stress concentrations in the groove walls.
