Ball valve seal for high temperature operation

Claim 2

A ball valve seat ring assembly comprising: an inner holder ring, a generally radial leading surface and an annular extension on said inner seat ring, an outer holder ring secured around said inner holder ring, and an internal cylindrical surface on said outer holder ring intersecting at the trailing end thereof with said leading surface, an inward radial extension at the forward end of said outer holder ring, and a seal member of a yieldable material, carried on said holder rings, generally radial trailing and forward surfaces and inner and outer cylindrical surfaces on said seal member engagable by said leading surface, said inward extension, said annular extension and said internal cylindrical surface, respectively, said inner and outer holder rings being secured together by interlocking engagement of a V-shaped radial extension around said inner holder ring, and a V-groove around said internal cylindrical surface.

Claim 3

The Seat ring assembly defined by claim 1 including: a generally conical surface on said seal member intersecting said inner cylindrical and forward radial surfaces to engage a valve ball closure member.

Claim 4

The seat ring assembly defined by claim 1 wherein: the trailing portion of the outer holder ring is reduced in thickness and tapered outward rearward from said V-groove so that said trailing portion may be cammed outward by said radial extension to snap said extension into and out of said V-groove.

Claim 5

The seat ring assembly defined by claim 1 wherein: the leading edge of the annular extension on said inner seat ring is formed on a taper.

Claim 6

The seat ring assembly defined by claim 1 including: an external conical surface on said inner holder ring tapering inward rearward of said leading surface, a back seal ring of yieldable material carried on said inner holder ring, and complementary conical and cylindrical surfaces on said seal ring slidable on said external conical and cylindrical surfaces of said inner holder ring.

Claim 7

The seat ring assembly defined by claim 5 including: said back seal ring extends rearward of said inner holder ring and is adapted for sealing engagement with the bottom wall of a valve body recess.

Claim 8

A valve structure comprising: a valve body with flow passages therethrough, a closure member mounted in said body and having a flow blocking surface thereon movable into and out of alignment with one of said flow passages, a recess in said valve body around said one flow passage, and a seat ring assembly slidably received in said recess, an external conical surface on said seat ring assembly tapering inward toward the back thereof, a trailing external cylindrical surface extending rearward from said external conical surface, a back seal ring of yieldable material, and complementary conical and cylindrical surfaces on said back seal ring slidable on said external conical and cylindrical surfaces on said seat ring assembly.

Claim 9

A valve structure comprising: a valve body with flow passages therethrough, a closure member mounted in said body and having a flow blocking surface thereon movable into and out of alignment with one of said flow passages, a recess in said valve body around said one flow passage, and a seat ring assembly slidably received in said recess, an external conical surface on said seat ring assembly tapering inward toward the back thereof, a trailing external cylindrical surface extending rearward from said external conical surface, a back seal ring of yieldable material, and complementary conical and cylindrical surfaces on said back seal ring slidable on said external conical and cylindrical surfaces on said seat ring assembly.

Claim 10

The valve structure defined in claim 7 including: a generally radial bottom wall in said valve body recess, said back seal ring being in sealing engagement with said recess bottom wall.

Claim 11

The valve structure defined by claim 8 including: a cylindrical wall in said valve body recess, and a complementary outer cylindrical surface on said back seal ring in sliding engagement with said cylindrical wall.

Claim 12

A ball valve seat ring assembly for high temperature operation comprising: an inner holder ring, a generally radial leading surface and an annular extension on said inner seat ring, an outer holder ring secured around said inner holder ring, and an internal cylindrical surface on said outer holder ring intersecting at the trailing end thereof with said leading surface, an inward radial extension at the forward end of said outer holder ring, and a seal ring of a yieldable material, having a greater coefficient of thermal expansion than that of the inner and outer holder rings carried on said holder rings, generally radial trailing and forward surfaces and inner and outer cylindrical surfaces on said seal ring engagable by said leading surface, said inward extension, said annular extension and said internal cylindrical surface, respectively, to be substantially confined thereby, a groove around said seal ring of an area in cross-section sufficient to accommodate greater thermal expansion of said seal member relative to said inner and outer holder rings.

Claim 13

A ball valve seat ring assembly for high temperature operation comprising: an inner holder ring, a generally radial leading surface and an annular extension on said inner seat ring, an outer holder ring secured around said inner holder ring, and an internal cylindrical surface on said outer holder ring intersecting at the trailing end thereof with said leading surface, an inward radial extension at the forward end of said outer holder ring, and a seal ring of a yieldable material, having a greater coefficient of thermal expansion than that of the inner and outer holder rings carried on said holder rings, generally radial trailing and forward surfaces and inner and outer cylindrical surfaces on said seal ring engagable by said leading surface, said inward extension, said annular extension and said internal cylindrical surface, respectively, to be substantially confined thereby, a groove around said seal ring of an area in cross-section sufficient to accommodate greater thermal expansion of said seal member relative to said inner and outer holder rings.