Lubricated valve assembly

Claim 2

A valve assembly comprising a body formed with upstream and downstream fluid flow passages opening at their inner ends into an internal valve closure member space, a valve closure member displaceable in said space between positions where it respectively blocks and provides fluid communication between said passages, a relatively rigid seat ring mounted at the inner end of at least said upstream passage and having an annular recess opening toward said closure member in said space, and an annular seat of elastically deformable material anchored in said recess and projecting through the open end of said recess, said seating being characterized in that it is formed with a pair of spacedapart annular, differently diametered sealing lips disposed beyond said recess and compressed against said closure member, one of said lips normally being sufficiently compressed against said closure member to seal against flow of fluid in both directions between said upstream passage and said space regardless of fluid pressure variations in said upstream passage and said space, and the other of said lips normally being compressed against said closure member to a lesser degree than said one lip to be less effective than said one of said lips to seal against upstream fluid flow toward said space when said one lip is effective to provide a fluidtight seal against said closure member, and means for increasing the compression of said other lip against said closure member to seal against fluid flow in both directions between said upstream passage and said space when said one lip fails to seal against fluid flow from said upstream passage to said space.

Claim 3

The valve assembly defined in claim 1 wherein said valve closure member is a trunnioned, ported, ball-type valve plug rotatable between said positions within said space and having a spherically contoured surface engaged by said lips.

Claim 4

The valve assembly defined in claim 2 wherein both of said lips are coaxial with the longitudinal axis of said rigid seat ring, and wherein said one lip is of larger diameter than said other lip and projects from an annular face of said seat axially beyond said other lip.

Claim 5

The valve assembly defined in claim 3 wherein saId other lip is sufficiently thin in cross section that it is deformable outwardly and away from said surface of said valve plug by fluid pressure in said upstream passage when the upstream pressure acting on one side of said other lip exceeds the pressure acting on the opposite side of said other lip by a predetermined magnitude.

Claim 6

The valve assembly defined in claim 4 wherein said annular seat is formed with an annular groove between said lips, and wherein said valve assembly further comprises means for introducing pressurized plastic material into said groove for distribution between said one lip and said surface of said plug, said pressurized material in said groove being effective to deform said other lip against said plug sufficiently to seal against fluid flow in both directions between said upstream passage and said groove.

Claim 7

The valve assembly defined in claim 3 comprising means in said body for supporting said ring for limited axial displacement toward and away from said plug, and an annulus of elastically deformable material anchored on said rigid seat ring and reacting against an internal surface in said body for biasing said rigid seat ring together with said annular seat toward said plug and to a position where said lips are deformed against said plug, the fluid pressure in said upstream passage acting upon said annulus and said seat ring to apply predetermined force for urging the assembly of said annulus, said rigid seat ring, and said annular seat toward said plug, and said other lip being exposed to fluid pressure in said upstream passage and being sufficiently thin in cross section that it is deformable outwardly into the region between said lips and away from said plug to admit upstream fluid into said region when the pressure of fluid in said upstream passages exceeds fluid pressure in said region by a predetermined amount, the pressure of fluid in said region being effective to oppose said force.

Claim 8

The valve assembly defined in claim 6 wherein said annular seat is stiffer than said annulus.

Claim 9

The valve assembly defined in claim 6 wherein said annulus is formed with a circumferentially extending lip deformed against the interior of said body to provide an annular seal between said seat ring and said body, with an annular axially extending land engaging said internal surface of said body to bias said assembly toward said plug, and with grooves in said annular land for introducing upstream fluid to a space between said land and said circumferential lip where it compresses the circumferential lip of said annulus against the interior of said body.

Claim 10

The valve assembly defined in claim 1 wherein said seat is formed from polyurethane.

Claim 11

The valve assembly defined in claim 7 wherein both said seat and said annulus are formed from polyurethane.

Claim 12

A valve assembly comprising a body formed with upstream and downstream fluid flow passages opening at their inner ends into an interval valve closure member space, a valve closure member displaceable in said space between positions where it respectively blocks and provides fluid communication between said passages, and a seat ring assembly comprising a rigid seat ring mounted within said body at the inner end of at least one of said passages and having an annular recess opening toward said closure member, and an annular seat of elastically deformable material anchored in said recess and projecting beyond said recess, said seat having an annular surface facing said closure member and being characterized in that it is formed with a pair of spaced apart, annular, differently diametered sealing lips projecting from said surface and being compressed against said closure member and being sufficiently stiff to maintain said ring and the remaining surface of said seat spaced from said closure member at least up to the maximum pressure differential for which said assembly is rated.

Claim 13

A valve assembly comprising a body formed with upstream and downstream fluid flow passages opening at their inner ends into an interval valve closure member space, a valve closure member displaceable in said space between positions where it respectively blocks and provides fluid communication between said passages, and a seat ring assembly comprising a rigid seat ring mounted within said body at the inner end of at least one of said passages and having an annular recess opening toward said closure member, and an annular seat of elastically deformable material anchored in said recess and projecting beyond said recess, said seat having an annular surface facing said closure member and being characterized in that it is formed with a pair of spaced apart, annular, differently diametered sealing lips projecting from said surface and being compressed against said closure member and being sufficiently stiff to maintain said ring and the remaining surface of said seat spaced from said closure member at least up to the maximum pressure differential for which said assembly is rated.

Claim 14

The valve assembly defined in claim 11, wherein said closure member is a ported, ball-type plug, and wherein saiD valve assembly further comprises trunnion means journaling said plug for rotation between said positions and confining said plug against displacement toward and away from the inner end of each of said passages, and means axially biasing said assembly toward said plug and to a position where said lips are deformed against a spherical surface on said plug.

Claim 15

In a valve assembly having a body formed with upstream and downstream fluid flow passages opening at their inner ends into an internal valve closure member space and a valve closure member displaceable in said space between positions where it respectively blocks and provides fluid communication between said passages, seat ring means mounted within said body at the inner end of at least one of said passages and comprising a rigid ring formed with an annular recess opening toward said member and an annular seat of elastically deformable material anchored in said recess and projecting beyond said recess for engagement with said closure member, said seat being formed at its surface facing said closure member with spaced-apart differently diametered annular sealing lips compressed against said member, with one of said lips normally being compressed against said member more tightly and over a greater sealing contact area than the other of said lips.

Claim 16

In a valve assembly having a body formed with upstream and downstream fluid flow passages opening at their inner ends into an internal valve closure member space and a valve closure member displaceable in said space between positions where it respectively blocks and provides fluid communication between said passages, seat ring means mounted within said body at the inner end of at least one of said passages and comprising a rigid ring formed with an annular recess opening toward said member and an annular seat of elastically deformable material anchored in said recess and projecting beyond said recess for engagement with said closure member, said seat being formed at its surface facing said closure member with spaced-apart differently diametered annular sealing lips compressed against said member, with one of said lips normally being compressed against said member more tightly and over a greater sealing contact area than the other of said lips.

Claim 17

A valve assembly comprising a body formed with upstream and downstream fluid flow passages opening at their inner ends into an internal valve closure member cavity, a trunnioned valve closure member rotatable in said cavity between positions where it respectively blocks and provides fluid communication between said passages, seat ring means mounted within said body for limited axial displacement at the inner end of at least said upstream passage and being formed with an annular recess opening toward said closure member, an annular seat of elastically deformable material anchored in said recess, said seat projecting from said recess and being formed with a pair of spaced apart, annular, differentially diametered, sealing lips engaging said closure member, means applying a force for axially urging the assembly of said seat ring means and said seat towards said closure member to compress said lips against said closure member, with one of said lips normally being compressed with greater tightness against said member than the other of said lips to provide a bidirectional fluidtight seat-to-closure member seal around the inner end of said upstream passage at least up to the maximum pressure differential for which the valve assembly is rated, and means effective upon failure of said one lip to prevent fluid leakage in a predetermined direction for increasing said force to deform at least said other lip with greater tightness against said closure member.

Claim 18

A valve assembly comprising a body formed with upstream and downstream fluid flow passages opening at their inner ends into an internal valve closure member cavity, a trunnioned valve closure member rotatable in said cavity between positions where it respectively blocks and provides fluid communication between said passages, seat ring means mounted within said body for limited axial displacement at the inner end of at least said upstream passage and being formed with an annular recess opening toward said closure member, an annular seat of elastically deformable material anchored in said recess, said seat projecting from said recess and being formed with a pair of spaced apart, annular, differentially diametered, sealing lips engaging said closure member, means applying a force for axially urging the assembly of said seat ring means and said seat towards said closure member to compress said lips against said closure member, with one of said lips normally being compressed with greater tightness against said member than the other of said lips to provide a bidirectional fluidtight seat-to-closure member seal around the inner end of said upstream passage at least up to the maximum pressure differential for which the valve assembly is rated, and means effective upon failure of said one lip to prevent fluid leakage in a predetermined direction for increasing said force to deform at least said other lip with greater tightness against said closure member.

Claim 19

The valve assembly defined in claim 13, wherein said one lip is of larger diameter than said other lip.

Claim 20

In a valve assembly having a body formed with upstream and downstream fluid flow passages opening at their inner ends in a valve closure member space, a valve closure member displaceable in said space between positions where it respectively blocks and provides fluid communication between said passages and seat ring means for said closure member and comprising rigid, metallic holder means mounted in said body and formed with an annular recess opening toward said valve closure member, the improvement comprising an annular seat defined by a plurality of separately formed elastically deformable annular sections, one of said sections being received in only the inner part of said recess and anchored to said holder means, the other of said sections being bonded at least to said one section and projecting through the outer part of said recess for seating engagement with said valve closure member, said other section having a thermal coefficient of expansion which is greater than that of said metallic holder means, and said one section having a thermal coefficient of expansion which is also greater than that of said holdeR means but which is less than that of said other section.

Claim 21

In a valve assembly having a body formed with upstream and downstream fluid flow passages opening at their inner ends in a valve closure member space, a valve closure member displaceable in said space between positions where it respectively blocks and provides fluid communication between said passages and seat ring means for said closure member and comprising rigid, metallic holder means mounted in said body and formed with an annular recess opening toward said valve closure member, the improvement comprising an annular seat defined by a plurality of separately formed elastically deformable annular sections, one of said sections being received in only the inner part of said recess and anchored to said holder means, the other of said sections being bonded at least to said one section and projecting through the outer part of said recess for seating engagement with said valve closure member, said other section having a thermal coefficient of expansion which is greater than that of said metallic holder means, and said one section having a thermal coefficient of expansion which is also greater than that of said holdeR means but which is less than that of said other section.

Claim 22

The valve assembly defined in claim 16, wherein said closure member is a ported, ball-type valve plug, and wherein said valve assembly further comprises trunnion means journaling said plug for rotation between said positions and confining said plug against displacement toward and away from the inner end of each of said passages, and mans axially biasing the assembly of said holder means and said seta toward said plug and to a position where the other of said sections is deformed against a spherical surface on said plug, said one of said sections filling the inner part of said recess and said other of said sections filling the remainder of said recess.

Claim 23

The valve assembly defined in claim 16, wherein said one of said sections has embedded therein relatively hard material for reducing its thermal coefficient of expansion to a value that is less than that of the other of said sections.

Claim 24

The valve assembly defined in claim 16, wherein said one of said sections has embedded therein glass fibers for reducing its thermal coefficient of expansion to a value that is less than that of the other of said sections.

Claim 25

The valve assembly defined in claim 16, wherein both sections are formed for polyurethane and wherein said one of said sections has a material embedded therein for reducing its thermal coefficient of expansion to a value that is less than that of the other of said sections.

Claim 26

In a valve assembly, a body formed with upstream and downstream fluid flow of passages opening at their inner ends into an internal valve closure member space, a valve closure member displaceable within said space between position where it respectively blocks and provides fluid communication between said passages, rigid seat ring mounted within said body at the inner end of at least one of said passages and being formed at its inner surface facing said member with an annular recess opening toward said member, and an annular seat of elastically deformable material anchored in and projecting beyond said recess for engagement with said member, the portion of said inner surface disposed radially outwardly from said recess defining an annular axially extending lip, and said seat having an annular extension hooked over the end face and outer peripheral surface of said lip and bonded to said lip to secure said seat against dislodgement from said recess.

Claim 27

In a valve assembly, a body formed with upstream and downstream fluid flow of passages opening at their inner ends into an internal valve closure member space, a valve closure member displaceable within said space between position where it respectively blocks and provides fluid communication between said passages, rigid seat ring mounted within said body at the inner end of at least one of said passages and being formed at its inner surface facing said member with an annular recess opening toward said member, and an annular seat of elastically deformable material anchored in and projecting beyond said recess for engagement with said member, the portion of said inner surface disposed radially outwardly from said recess defining an annular axially extending lip, and said seat having an annular extension hooked over the end face and outer peripheral surface of said lip and bonded to said lip to secure said seat against dislodgement from said recess.

Claim 28

A valve assembly comprising a body formed with upstream and downstream fluid flow passages opening at their inner ends into an internal valve closure member cavity, a trunnioned valve closure member rotatable in said cavity between positions where it respectively blocks and provides fluid communication between said passages, a relatively rigid seat ring mounted for limited axial displacement between said closure member and an opposing internal surface of said body at least at the inner end of said upstream passage, said seat ring being formed with an annular recess opening toward said closure member, an annular valve closure member of elastically deformable material seat anchored in said recess and extending beyond said recess toward said closure member, said annular seat having an annular surface disposed beyond said recess and facing said closure member, and said annular seat having an annular groove defined by a pair of spaced apart, differently diametered annular lips which are integral with said seat and which extend from said annular surface, means for axially biasing said seat ring toward said closure member to initially compress and thereby preload said lips against said closure member in absence of a fluid pressure differential across the assembly of said set ring and said annular seat, with one of said lips being sufficiently deformed against said closure member to provide a seat-to-closure member seal, means for introducing pressurized plastic material into said groove, the other of said lips being deformed against said closure member by the pressure of plaStic material in said annular groove to seal against flow of said platic material between said other lip and said closure member and to thereby enable the pressure of the plastic material in said annular groove to build up sufficiently for effecting the distribution of said plastic material between said one lip and said closure member, said lips being sufficiently stiff to normally maintain said closure member spaced from said seat ring and the remaining surface of said annular seat.

Claim 29

A valve assembly comprising a body formed with upstream and downstream fluid flow passages opening at their inner ends into an internal valve closure member cavity, a trunnioned valve closure member rotatable in said cavity between positions where it respectively blocks and provides fluid communication between said passages, a relatively rigid seat ring mounted for limited axial displacement between said closure member and an opposing internal surface of said body at least at the inner end of said upstream passage, said seat ring being formed with an annular recess opening toward said closure member, an annular valve closure member of elastically deformable material seat anchored in said recess and extending beyond said recess toward said closure member, said annular seat having an annular surface disposed beyond said recess and facing said closure member, and said annular seat having an annular groove defined by a pair of spaced apart, differently diametered annular lips which are integral with said seat and which extend from said annular surface, means for axially biasing said seat ring toward said closure member to initially compress and thereby preload said lips against said closure member in absence of a fluid pressure differential across the assembly of said set ring and said annular seat, with one of said lips being sufficiently deformed against said closure member to provide a seat-to-closure member seal, means for introducing pressurized plastic material into said groove, the other of said lips being deformed against said closure member by the pressure of plaStic material in said annular groove to seal against flow of said platic material between said other lip and said closure member and to thereby enable the pressure of the plastic material in said annular groove to build up sufficiently for effecting the distribution of said plastic material between said one lip and said closure member, said lips being sufficiently stiff to normally maintain said closure member spaced from said seat ring and the remaining surface of said annular seat.

Claim 30

A valve assembly comprising a body formed with upstream and downstream fluid flow passages opening at their inner ends into a valve plug cavity, a trunnioned, ported, ball-type valve plug rotatable in said cavity between positions where it respectively blocks and provides fluid communication between said passages, a relatively rigid seat ring mounted for limited axial sliding movement between said plug and an opposing internal surface of said body at the inner end of at least said upstream passage, said seat ring being formed with an annular recess opening toward said plug in said cavity, an annular seat of elastically deformable material anchored in said recess and extending beyond said recess, said annular seat having an annular surface at its end disposed beyond said recess and facing said plug, a pair of spaced apart, differently diametered annular lips formed integral with said annular seat and extending from said annular surface for engagement with said plug, means for axially biasing said seat ring toward said plug to deform said lips against said plug, the grater diametered one of said lips normally being sufficiently deformed against said plug to provide a primary bidirectional seat ring-to-plug seal for preventing flow of fluid in either direction between said upstream passage and said cavity, the smaller diametered one of said lips being configured and normally deformed against said plug to a lesser degree than said larger diametered seal to provide a secondary seat ring-to-plug seal which is less effective than said primary seal for preventing fluid flow from said upstream passage toward said cavity as long as said larger diametered lip is effective to establish said primary seal, and means including surface means forming a part of the assembly of said biasing means, said seat ring and said annular seat and coacting with fluid pressure in said body for sufficiently increasing the deformation of said smaller diametered lip against said plug to establish a bidirectional seat ring-to-plug seal preventing fluid flow in either direction between said upstream passage and said cavity whenever said larger diametered lip becomes ineffective to provide its fluidtight seal for preventing flow of fluid from said upstream passage to said cavity whereby the action of said primary seal is transferred to said smaller diametered lip whenever said larger diametered lip fails to seal against flow of fluid at least from said upstream passage to said cavity.

Claim 31

A valve assembly comprising a body formed with upstream and downstream fluid flow passages opening at their inner ends into a valve plug cavity, a trunnioned, ported, ball-type valve plug rotatable in said cavity between positions where it respectively blocks and provides fluid communication between said passages, a relatively rigid seat ring mounted for limited axial sliding movement between said plug and an opposing internal surface of said body at the inner end of at least said upstream passage, said seat ring being formed with an annular recess opening toward said plug in said cavity, an annular seat of elastically deformable material anchored in said recess and extending beyond said recess, said annular seat having an annular surface at its end disposed beyond said recess and facing said plug, a pair of spaced apart, differently diametered annular lips formed integral with said annular seat and extending from said annular surface for engagement with said plug, means for axially biasing said seat ring toward said plug to deform said lips against said plug, the grater diametered one of said lips normally being sufficiently deformed against said plug to provide a primary bidirectional seat ring-to-plug seal for preventing flow of fluid in either direction between said upstream passage and said cavity, the smaller diametered one of said lips being configured and normally deformed against said plug to a lesser degree than said larger diametered seal to provide a secondary seat ring-to-plug seal which is less effective than said primary seal for preventing fluid flow from said upstream passage toward said cavity as long as said larger diametered lip is effective to establish said primary seal, and means including surface means forming a part of the assembly of said biasing means, said seat ring and said annular seat and coacting with fluid pressure in said body for sufficiently increasing the deformation of said smaller diametered lip against said plug to establish a bidirectional seat ring-to-plug seal preventing fluid flow in either direction between said upstream passage and said cavity whenever said larger diametered lip becomes ineffective to provide its fluidtight seal for preventing flow of fluid from said upstream passage to said cavity whereby the action of said primary seal is transferred to said smaller diametered lip whenever said larger diametered lip fails to seal against flow of fluid at least from said upstream passage to said cavity.

Claim 32

A valve assembly comprising a body formed with upstream and downstream fluid flow passages opening at their inner ends into an internal valve plug cavity, a trunnioned valve plug rotatable in said cavity between positions where it respectively blocks and provides fluid communication between said passages, means comprising a first annular lip of elastically deformable material compressed against said plug at the inner end of said upstream passage for establishing a first bidirectional seal against fluid flow in either direction between said upstream passage and said cavity when said plug is in its fluid-blocking position and means comprising a second annular lip of elastically deformable material compressed against valve plug for establishing a second bidirectional seal against fluid flow in either direction between said upstream passage and seal cavity in response to a failure of said first lip to seal against flow of fluid from said upstream passage to said cavity.

Claim 33

A valve assembly comprising a body formed with upstream and downstream fluid flow passages opening at their inner ends into an internal valve plug cavity, a trunnioned valve plug rotatable in said cavity between positions where it respectively blocks and provides fluid communication between said passages, means comprising a first annular lip of elastically deformable material compressed against said plug at the inner end of said upstream passage for establishing a first bidirectional seal against fluid flow in either direction between said upstream passage and said cavity when said plug is in its fluid-blocking position and means comprising a second annular lip of elastically deformable material compressed against valve plug for establishing a second bidirectional seal against fluid flow in either direction between said upstream passage and seal cavity in response to a failure of said first lip to seal against flow of fluid from said upstream passage to said cavity.

Claim 34

The valve assembly defined in claim 24, wherein said means comprIsing said second annular lip further includes means for continuously venting fluid in said cavity to said downstream passage whenever the pressure of fluid in said cavity exceeds the pressure of fluid in said downstream passage by a predetermined magnitude.

Claim 35

A valve assembly comprising a body formed with upstream and downstream fluid flow passages opening at their inner ends into a valve closure member space, a trunnioned, ported, ball-type valve plug rotatable in said space between positions where it respectively blocks and provides fluid communication between said passages, a relatively rigid seat ring mounted at the inner end of at least one of said passages for limited axial sliding movement between said plug and an opposing internal surface of said body, an elastically deformable seat carried by said ring for engagement with said plug and an annulus of elastically deformable material anchored on the end of said ring remote from said closure member and being characterized in that it seals against said body to keep fluid in said one passage from flowing around the outer periphery of said ring and into said space, but provides for fluid in said space to flow around the outer periphery of said ring and into said one passage whenever the fluid pressure in said space exceeds the fluid pressure in said one passage by a predetermined magnitude, said annulus being formed with an annular land, a circumferential sealing lip and an annular groove between said land and said lip, said land projecting beyond the end face of said seat ring remote from said plug and having a radial surface deformed against said opposing internal surface of said body for axially biasing said seat ring toward said plug to deform said seat against said plug, said circumferential lip being seated against the interior of said body to establish a seal between said body and said ring for sealing against flow of fluid from said one passage to said space when the fluid pressure in said space does not exceed the pressure in said one passage by said predetermined magnitude, said land having groove means to establish fluid communication between said one passage and said annular groove, and said lip being deformable into said annular groove by fluid pressure in said space when it exceeds the fluid pressure in said one passage by said predetermined magnitude to provide fluid communication between said space and said annular groove.

Claim 36

A valve assembly comprising a body formed with upstream and downstream fluid flow passages opening at their inner ends into a valve closure member space, a trunnioned, ported, ball-type valve plug rotatable in said space between positions where it respectively blocks and provides fluid communication between said passages, a relatively rigid seat ring mounted at the inner end of at least one of said passages for limited axial sliding movement between said plug and an opposing internal surface of said body, an elastically deformable seat carried by said ring for engagement with said plug and an annulus of elastically deformable material anchored on the end of said ring remote from said closure member and being characterized in that it seals against said body to keep fluid in said one passage from flowing around the outer periphery of said ring and into said space, but provides for fluid in said space to flow around the outer periphery of said ring and into said one passage whenever the fluid pressure in said space exceeds the fluid pressure in said one passage by a predetermined magnitude, said annulus being formed with an annular land, a circumferential sealing lip and an annular groove between said land and said lip, said land projecting beyond the end face of said seat ring remote from said plug and having a radial surface deformed against said opposing internal surface of said body for axially biasing said seat ring toward said plug to deform said seat against said plug, said circumferential lip being seated against the interior of said body to establish a seal between said body and said ring for sealing against flow of fluid from said one passage to said space when the fluid pressure in said space does not exceed the pressure in said one passage by said predetermined magnitude, said land having groove means to establish fluid communication between said one passage and said annular groove, and said lip being deformable into said annular groove by fluid pressure in said space when it exceeds the fluid pressure in said one passage by said predetermined magnitude to provide fluid communication between said space and said annular groove.

Claim 37

In a valve assembly having a body formed with upstream and downstream fluid flow passages opening at their inner ends into a valve plug cavity, and a ported, ball-type valve plug rotatable in said cavity between positions where it respectively blocks and provides fluid communication between said passages, a seat ring assembly mounted in said body at least at the inner end of said upstream passage and comprising a rigid seat ring having an annular recess opening toward said plug, an annular seat of elastically deformable material anchored in said recess and projecting therefrom, said annular seat having an annular surface facing said plug, means forming an annular groove in said surface and opening toward said plug, and means including passage means for introducing plastic material under pressure into said groove for distribution as a band around the surface of said plug, said annular groove forming means comprising a deflectable annular lip projecting from said surface and engaging said plug, said lip having inner and outer peripheral surfaces, with said outer peripheral surface defining the inner peripheral side of said groove, said outer peripheral surface having a slope in cross section which is appreciably greater than that of said inner peripheral surface to provide a greater amount of elastically deformable material supporting said lip against outward deflection and into said groove as compared with the amount of elastically deformable material supporting said lip against inward deflection into the inner end of said upstream passage, said seat ring being formed with an inner, Annular end face extending radially between said recess and the inner periphery of said ring, and said annular seat extending at its inner periphery appreciably axially beyond said end face, to provide freedom for said lip to flex inwardly.

Claim 38

In a valve assembly having a body formed with upstream and downstream fluid flow passages opening at their inner ends into a valve plug cavity, and a ported, ball-type valve plug rotatable in said cavity between positions where it respectively blocks and provides fluid communication between said passages, a seat ring assembly mounted in said body at least at the inner end of said upstream passage and comprising a rigid seat ring having an annular recess opening toward said plug, an annular seat of elastically deformable material anchored in said recess and projecting therefrom, said annular seat having an annular surface facing said plug, means forming an annular groove in said surface and opening toward said plug, and means including passage means for introducing plastic material under pressure into said groove for distribution as a band around the surface of said plug, said annular groove forming means comprising a deflectable annular lip projecting from said surface and engaging said plug, said lip having inner and outer peripheral surfaces, with said outer peripheral surface defining the inner peripheral side of said groove, said outer peripheral surface having a slope in cross section which is appreciably greater than that of said inner peripheral surface to provide a greater amount of elastically deformable material supporting said lip against outward deflection and into said groove as compared with the amount of elastically deformable material supporting said lip against inward deflection into the inner end of said upstream passage, said seat ring being formed with an inner, Annular end face extending radially between said recess and the inner periphery of said ring, and said annular seat extending at its inner periphery appreciably axially beyond said end face, to provide freedom for said lip to flex inwardly.

Claim 39

The valve assembly defined in claim 27, wherein pressure of plastic material introduced into said groove is effective to deform said lip against the periphery of said plug to provide under predetermined conditions a fluidtight seal against fluid flow into said cavity.