Patent attributes
A valve body and seal assembly comprises a valve body symmetrical about a longitudinal axis and comprising a circumferential seal retention groove and a frusto-conical valve body impact area for contacting a valve seat. An elastomeric seal is cast-in-place in the circumferential seal retention groove. Each seal comprises first and second seal sections in contact via an intra-seal interface, the interface simultaneously extending radially outward and longitudinally. First seal sections may comprise a first polyurethane having a higher modulus than a second polyurethane of which second seal sections may be comprised. First seal sections are cast and partially cured in a mold which is rotating about the longitudinal axis. Second seal sections are cast after the first seal sections are partially cured, resulting in the intra-seal interface shape described above. Cross-linking between first and second seal sections across the intra-seal interface is thus facilitated.
