High stress valve seal and valves

Claim 2

In a valve, the combination of: a seat member having a flow passage therein, a rigid seating surface thereon surrounding the flow passage, and an annular groove between the seating surface and the flow passage, said groove having an open side facing said flow passage; a movable valve member for opening and closing said flow passage and having a rigid surface thereon adapted to engage said seating surface and overlie said groove when the valve is closed; and an annular seal of relatively soft elastic material bonded in said groove to form a seal between said members around the flow passage when the valve is closed, said seal having: a first portion continuously exposed at the open side of said annular groove; a sealing engagement, load bearing portion protruded beyond said seating surface, to be engaged by the valve member, whereby the seal is placed under a high state of stress when the valve is closed and is s distorted outwardly from said groove at the open side thereof; said seal having a thickness, in its relaxed state, substantially less than the length of the protruded sealing engagement, load bearing portion thereof, and said seal further having a relieved portion adjacent said seating surface to minimize damage to said seal when the valve member is being moved to a closed position; and wherein said seal is a rubber composition having a durometer of between about 60 and about 70.

Claim 3

A valve as defined in claim 1 wherein the maximum thickness of said seal is no greater than one-fourth the length of the protruded sealing engagement, load bearing portion thereof in the relaxed condition of the seal.

Claim 4

A valve as defined in claim 1 wherein the maximum thickness of the seal is no greater than one-eighth the length of the protruded, sealing engagement, load bearing portion thereof in the relaxed condition of the seal.

Claim 5

A valve as defined in claim 1 wherein the thickness of the portion of the seal protruding beyond said seating surface is about one-third the total thickness of the seal.

Claim 6

A valve as defined in claim 1 wherein the portion of the seal protruding beyond said seating surface extends from the inner periphery of the seal to said relieved portion, and the surface thereof facing the valve member is parallel with said seating surface.

Claim 7

A valve as defined in claim 1 wherein the seal overlaps and is bonded to the inner periphery of the seat member.

Claim 8

A valve as defined in claim 1 wherein said seat member has a second annular groove therein surrounding said seating surface, and characterized further to include a second annular seal of relatively soft material bonded in said second groove having a thickness, in its relaxed state, substantially less than the length thereof, and having a portion thereof protruding beyond said seating surface to be engaged by the valve member, whereby said second seal is placed in a state of high strEss when the valve is closed.

Claim 9

A valve as defined in claim 7 wherein said second seal further includes a relieved portion adjacent said seating surface.

Claim 10

In a valve, the combination of: a seat member having a flow passage therein, a rigid seating surface thereon surrounding the flow passage, and an annular groove between the seating surface and the flow passage, said groove having an open side facing said flow passage; a movable valve member for opening and closing said flow passage and having a rigid surface thereon adapted to engage said seating surface and overlie said groove when the valve is closed; and an annular seal of relatively soft elastic material bonded in said groove to form a seal between said members around the flow passage when the valve is closed, said seal having: a first portion continuously exposed at the open side of said annular groove; a sealing engagement, load bearing portion protruded beyond said seating surface, to be engaged by the valve member, whereby the seal is placed under a high state of stress when the valve is closed and is distorted outwardly from said groove at the open side thereof; said seal having a thickness, in its relaxed state, substantially less than the length of the protruded sealing engagement, load bearing portion thereof, and said seal further having a relieved portion adjacent said seating surface to minimize damage to said seal when the valve member is being moved to a closed position; and wherein the surface of the seal facing the valve member increasingly protrudes beyond said seating surface from the inner periphery of the seal to said relieved portion.

Claim 11

In a valve, the combination of: a seat member having a flow passage therein, a rigid seating surface thereon surrounding the flow passage, and an annular groove between the seating surface and the flow passage, said groove having an open side facing said flow passage; a movable valve member for opening and closing said flow passage and having a rigid surface thereon adapted to engage said seating surface and overlie said groove when the valve is closed; and an annular seal of relatively soft elastic material bonded in said groove to form a seal between said members around the flow passage when the valve is closed, said seal having: a first portion continuously exposed at the open side of said annular groove; a sealing engagement, load bearing portion protruded beyond said seating surface, to be engaged by the valve member, whereby the seal is placed under a high state of stress when the valve is closed and is distorted outwardly from said groove at the open side thereof; said seal having a thickness, in its relaxed state, substantially less than the length of the protruded sealing engagement, load bearing portion thereof, and said seal further having a relieved portion adjacent said seating surface to minimize damage to said seal when the valve member is being moved to a closed position; and wherein the surface of the seal facing the valve member increasingly protrudes beyond said seating surface from the inner periphery of the seal to said relieved portion.

Claim 12

A valve as defined in claim 9 wherein the surface of the seal facing the valve member adjacent the inner periphery of the seal does not protrude into the path of movement of the valve member.

Claim 13

A valve as defined in claim 9 wherein the depth of said groove increases from the inner to the outer periphery thereof.

Claim 14

In a valve, the combination of: a seat member having a flow passage therein, a rigid seating surface thereon surrounding the flow passage, and an annular groove between the seating surface and the flow passage, said groove having an open side facing said flow passage; a movable valve member for opening and closing said flow passage and having a rigid surface thereon adapted to engage said seating surface and overlie said groove when the valve is closed; and an annular seal of relatively soft elastic material bonded in said groove to form a seal between said members around the flow passage when the valve is closed, said seal having: a first portion continuously exposed at the open side of said annular groove; a sealing engagement, load bearing portion protruded beyond said seating surface, to be engaged by the valve member, whereby the seal is placed under a high state of stress when the valve is closed and is distorted outwardly from said groove at the open side thereof; said seal having a thickness, in its relaxed state, substantially less than the length of the protruded sealing engagement, load bearing portion thereof, and said seal further having a relieved portion adjacent said seating surface to minimize damage to said seal when the valve member is being moved to a closed position; and wherein said relieved portion includes an annular groove in the surface of the seal facing the valve member wherein the bottom of the groove is substantially parallel with said seating surface.

Claim 15

In a valve, the combination of: a seat member having a flow passage therein, a rigid seating surface thereon surrounding the flow passage, and an annular groove between the seating surface and the flow passage, said groove having an open side facing said flow passage; a movable valve member for opening and closing said flow passage and having a rigid surface thereon adapted to engage said seating surface and overlie said groove when the valve is closed; and an annular seal of relatively soft elastic material bonded in said groove to form a seal between said members around the flow passage when the valve is closed, said seal having: a first portion continuously exposed at the open side of said annular groove; a sealing engagement, load bearing portion protruded beyond said seating surface, to be engaged by the valve member, whereby the seal is placed under a high state of stress when the valve is closed and is distorted outwardly from said groove at the open side thereof; said seal having a thickness, in its relaxed state, substantially less than the length of the protruded sealing engagement, load bearing portion thereof, and said seal further having a relieved portion adjacent said seating surface to minimize damage to said seal when the valve member is being moved to a closed position; and wherein said relieved portion includes an annular groove in the surface of the seal facing the valve member wherein the bottom of the groove is substantially parallel with said seating surface.

Claim 16

In a valve, the combination of: a seat member having a flow passage therein, a rigid seating surface thereon surrounding the flow passage, and an annular groove between the seating surface and the flow passage, said groove having an open side facing said flow passage; a movable valve member for opening and closing said flow passage and having a rigid surface thereon adapted to engage said seating surface and overlie said groove when the valve is closed; and aN annular seal of relatively soft elastic material bonded in said groove to form a seal between said members around the flow passage when the valve is closed, said seal having: a first portion continuously exposed at the open side of said annular groove; and a sealing engagement, load bearing portion protruded beyond said seating surface, to be engaged by the valve member, whereby the seal is placed under a high state of stress when the valve is closed and is distorted outwardly from said groove at the open side thereof; said seal having a thickness, in its relaxed state, substantially less than the length of the protruded sealing engagement, load bearing portion thereof, and said seal further having a relieved portion adjacent said seating surface to minimize damage to said seal when the valve member is being moved to a closed position; and wherein said relieved portion includes an annular groove in the surface of the seal facing the valve member wherein the bottom of the groove is spaced from the path of movement of the valve member in the relaxed state of the seal.

Claim 17

In a valve, the combination of: a seat member having a flow passage therein, a rigid seating surface thereon surrounding the flow passage, and an annular groove between the seating surface and the flow passage, said groove having an open side facing said flow passage; a movable valve member for opening and closing said flow passage and having a rigid surface thereon adapted to engage said seating surface and overlie said groove when the valve is closed; and aN annular seal of relatively soft elastic material bonded in said groove to form a seal between said members around the flow passage when the valve is closed, said seal having: a first portion continuously exposed at the open side of said annular groove; and a sealing engagement, load bearing portion protruded beyond said seating surface, to be engaged by the valve member, whereby the seal is placed under a high state of stress when the valve is closed and is distorted outwardly from said groove at the open side thereof; said seal having a thickness, in its relaxed state, substantially less than the length of the protruded sealing engagement, load bearing portion thereof, and said seal further having a relieved portion adjacent said seating surface to minimize damage to said seal when the valve member is being moved to a closed position; and wherein said relieved portion includes an annular groove in the surface of the seal facing the valve member wherein the bottom of the groove is spaced from the path of movement of the valve member in the relaxed state of the seal.

Claim 18

In a valve, the combination of: a seat member having a flow passage therein, a rigid seating surface thereon surrounding the flow passage, and an annular groove between the seating surface and the flow passage, said groove having an open side facing said flow passage; a movable valve member for opening and closing said flow passage and having a rigid surface thereon adapted to engage said seating surface and overlie said groove when the valve is closed; and an annular seal of relatively soft elastic material bonded in said groove to form a seal between said members around the flow passage when the valve is closed, said seal having: a first portion continuously exposed at the open side of said annular groove; and a sealing engagement, load bearing portion protruded beyond said seating surface, to be engaged by the valve member, whereby the seal is placed under a high state of stress when the valve is closed and is distorted outwardly from said groove at the open side thereof; said seal having a thickness, in its relaxed state, substantially less than the length of the protruded sealing engagement, load bearing portion thereof, and said seal further having a relieved portion adjacent said seating surface to minimize damage to said seal when the valve member is being moved to a closed position; and wherein the thickness of the seal progressively increases from the inner periphery of the seal to said relieved portion.

Claim 19

In a valve, the combination of: a seat member having a flow passage therein, a rigid seating surface thereon surrounding the flow passage, and an annular groove between the seating surface and the flow passage, said groove having an open side facing said flow passage; a movable valve member for opening and closing said flow passage and having a rigid surface thereon adapted to engage said seating surface and overlie said groove when the valve is closed; and an annular seal of relatively soft elastic material bonded in said groove to form a seal between said members around the flow passage when the valve is closed, said seal having: a first portion continuously exposed at the open side of said annular groove; and a sealing engagement, load bearing portion protruded beyond said seating surface, to be engaged by the valve member, whereby the seal is placed under a high state of stress when the valve is closed and is distorted outwardly from said groove at the open side thereof; said seal having a thickness, in its relaxed state, substantially less than the length of the protruded sealing engagement, load bearing portion thereof, and said seal further having a relieved portion adjacent said seating surface to minimize damage to said seal when the valve member is being moved to a closed position; and wherein the thickness of the seal progressively increases from the inner periphery of the seal to said relieved portion.

Claim 20

In a valve, the combination of: an annular seat member having a flow passage therethrough and a rigid seating surface thereon surrounding the flow passage; a valve ball member having a rigid seating surface thereon sized to engage the seating surface on the seat member when the valve is closed; means in one of said members forming an annular groove arranged to face a portion of the seating surface on the other member when the valve is closed and terminating at one end in a shoulder defining one boundary of the respective seating surface, and open at its other end; and an annular seal of relatively soft elastic material bonded in said groove to form a seal between said members around said flow passage when the valve is closed: a portion of said seal being protruded beyond the seating surface of the member in which the seal is secured, whereby the seal is placed under a high state of stress when the valve is closed, and the peripheral portion of the seal adjacent the seating surface of the member in which the seal is secured being relieved to minimize damage to the seal when the ball member is being turned to a closed position; and said seal having a thickness, in its relaxed state, substantially less than the length of the protruded portion thereof.

Claim 21

In a valve, the combination of: an annular seat member having a flow passage therethrough and a rigid seating surface thereon surrounding the flow passage; a valve ball member having a rigid seating surface thereon sized to engage the seating surface on the seat member when the valve is closed; means in one of said members forming an annular groove arranged to face a portion of the seating surface on the other member when the valve is closed and terminating at one end in a shoulder defining one boundary of the respective seating surface, and open at its other end; and an annular seal of relatively soft elastic material bonded in said groove to form a seal between said members around said flow passage when the valve is closed: a portion of said seal being protruded beyond the seating surface of the member in which the seal is secured, whereby the seal is placed under a high state of stress when the valve is closed, and the peripheral portion of the seal adjacent the seating surface of the member in which the seal is secured being relieved to minimize damage to the seal when the ball member is being turned to a closed position; and said seal having a thickness, in its relaxed state, substantially less than the length of the protruded portion thereof.

Claim 22

A valve, comprising: a body having a valve chamber therein and an inlet and an outlet communicating with the valve chamber; a valve baLl mounted in the valve chamber and adapted to be turned between open and closed positions; an annular seat in the valve chamber encircling the inlet and having an annular, rigid seating surface shaped to mate with the valve ball and having an annular groove therein extending from the seating surface to the inner periphery of the seat; an annular seal of relatively soft elastic material bonded in said groove to form a seal between the seat and ball when the valve is closed, said seal having an exposed portion at the inner periphery of the seat; a sealing engagement, load bearing portion of said seal, spaced from said seating surface, being protruded beyond said seating surface in the relaxed state of the seal, whereby the seal is placed under a high state of stress when the valve is closed; and said seal having a relieved portion adjacent said seating surface to minimize damage to the seal when the valve ball is being moved to a closed position; said seal having a thickness, in its relaxed state, not more than one-eighth the length of said sealing engagement, load bearing protuberant portion thereof.

Claim 23

A valve, comprising: a body having a valve chamber therein and an inlet and an outlet communicating with the valve chamber; a valve baLl mounted in the valve chamber and adapted to be turned between open and closed positions; an annular seat in the valve chamber encircling the inlet and having an annular, rigid seating surface shaped to mate with the valve ball and having an annular groove therein extending from the seating surface to the inner periphery of the seat; an annular seal of relatively soft elastic material bonded in said groove to form a seal between the seat and ball when the valve is closed, said seal having an exposed portion at the inner periphery of the seat; a sealing engagement, load bearing portion of said seal, spaced from said seating surface, being protruded beyond said seating surface in the relaxed state of the seal, whereby the seal is placed under a high state of stress when the valve is closed; and said seal having a relieved portion adjacent said seating surface to minimize damage to the seal when the valve ball is being moved to a closed position; said seal having a thickness, in its relaxed state, not more than one-eighth the length of said sealing engagement, load bearing protuberant portion thereof.

Claim 24

A valve as defined in claim 16 characterized further to include: a second annular seat in the valve chamber encircling the outlet having an annular, rigid seating surface shaped to mate with the valve ball and having an annular groove therein extending from the respective seating surface to the inner periphery of the respective seat; an annular seal of relatively soft elastic material bonded in the groove in said second seat to form a seal between the second seat and the valve ball when the valve is closed; a portion of said last mentioned seal, spaced from the respective seating surface, being protruded beyond the respective seating surface in the relaxed state of the seal, whereby the last-mentioned seal is placed under a high state of stress when the valve is closed; and said last-mentioned seal having a relieved portion adjacent the respective seating surface to minimize damage to the seal when the valve ball is being moved to a closed position, and said last-mentioned seal having a thickness in its relaxed state not more than one-eighth the length of said protruded portion of said last mentioned seal.

Claim 25

A valve as defined in claim 17 characterized further to include means journaling the valve ball in the valve chamber on a fixed axis of rotation.

Claim 26

A valve as defined in claim 17 characterized further to include means supporting the valve ball in the valve chamber for movement toward and away from said second seat.

Claim 27

A valve seat assembly, comprising: a seating ring formed of relatively rigid material having a valve seating surface on one face thereof and an annular groove in said one face coterminous with said seating surface and opening at the inner periphery of said seating ring; an annular seal of relatively soft elastic material bonded in said groove having a sealing engagement portion thereof, spaced from said seating surface, protruding beyond said seating surface in the relaxed state of the seal, and said annular seal having a relieved portion between the protruding portion and said seating surface; said seal having said sealing engagement portion thereof of a length substantially greater than the thickness of said seal in its relaxed state; and wherein said seal is a rubber composition having a durometer of between about 60 and about 70.

Claim 28

A valve seat assembly, comprising: a seating ring formed of relatively rigid material having a valve seating surface on one face thereof and an annular groove in said one face coterminous with said seating surface and opening at the inner periphery of said seating ring; an annular seal of relatively soft elastic material bonded in said groove having a sealing engagement portion thereof, spaced from said seating surface, protruding beyond said seating surface in the relaxed state of the seal, and said annular seal having a relieved portion between the protruding portion and said seating surface; said seal having said sealing engagement portion thereof of a length substantially greater than the thickness of said seal in its relaxed state; and wherein said seal is a rubber composition having a durometer of between about 60 and about 70.

Claim 29

An assembly as defined in claim 20 wherein the maximum thickness of said seal is no greater than one-fourth the length of the sealing engagement portion thereof in the relaxed condition of the seal.

Claim 30

An assembly as defined in claim 20 wherein the maximum thickness of said seal is no greater than one-eighth the length of the sealing engagement portion thereof in the relaxed condition of the seal.

Claim 31

An assembly as defined in claim 20 wherein the thickness of the portion of the seal protruding beyond said seatIng surface is about one-third the total thickness of the seal.

Claim 32

An assembly as defined in claim 24 wherein the portion of the seal protruding beyond said seating surface extends from the inner periphery of the seal to said relieved portion and the surface thereof adapted to face a valve member is parallel with said seating surface.

Claim 33

A valve seat assembly, comprising: a seating ring formed of relatively rigid material having a valve seating surface on one face thereof and an annular groove in said one face coterminous with said seating surface and opening at the inner periphery of said seating ring; and an annular seal of relatively soft elastic material bonded in said groove having a sealing engagement portion thereof, spaced from said seating surface, protruding beyond said seating surface in the relaxed state of the seal, and said annular seal having a relieved portion between the protruding portion and said seating surface; said seal having said sealing engagement portion thereof of a length substantially greater than the thickness of said seal in its relaxed state; and wherein said relieved portion includes an annular groove in the surface of the seal adapted to face a valve member wherein the bottom of said last-mentioned groove is substantially parallel with said seating surface.

Claim 34

A valve seat assembly, comprising: a seating ring formed of relatively rigid material having a valve seating surface on one face thereof and an annular groove in said one face coterminous with said seating surface and opening at the inner periphery of said seating ring; and an annular seal of relatively soft elastic material bonded in said groove having a sealing engagement portion thereof, spaced from said seating surface, protruding beyond said seating surface in the relaxed state of the seal, and said annular seal having a relieved portion between the protruding portion and said seating surface; said seal having said sealing engagement portion thereof of a length substantially greater than the thickness of said seal in its relaxed state; and wherein said relieved portion includes an annular groove in the surface of the seal adapted to face a valve member wherein the bottom of said last-mentioned groove is substantially parallel with said seating surface.

Claim 35

A valve seat assembly, comprising: a seating ring formed of relatively rigid material having a valve seating surface on one face thereof and an an annular groove in said one face coterminous with said seating surface and opening at the inner periphery of said seating ring; and an annular seal of relatively soft elastic material bonded in said groove having a sealing engagement portion thereof, spaced from said seating surface, protruding beyond said seating surface in the relaxed state of the seal, and said annular seal having a relieved portion between the protruding portion and said seating surface; said seal having said sealing engagement portion thereof of a length substantially greater than the thickness of said seal in its relaxed state; and wherein said relieved portion includes an annular groove in the surface of the seal adapted to face the valve member wherein the bottom of said last-mentioned groove is spaced inwardly, with respect to the seating ring, from said seating surface.

Claim 36

A valve seat assembly, comprising: a seating ring formed of relatively rigid material having a valve seating surface on one face thereof and an an annular groove in said one face coterminous with said seating surface and opening at the inner periphery of said seating ring; and an annular seal of relatively soft elastic material bonded in said groove having a sealing engagement portion thereof, spaced from said seating surface, protruding beyond said seating surface in the relaxed state of the seal, and said annular seal having a relieved portion between the protruding portion and said seating surface; said seal having said sealing engagement portion thereof of a length substantially greater than the thickness of said seal in its relaxed state; and wherein said relieved portion includes an annular groove in the surface of the seal adapted to face the valve member wherein the bottom of said last-mentioned groove is spaced inwardly, with respect to the seating ring, from said seating surface.

Claim 37

A valve seat assembly, comprising: a seating ring formed of relatively rigid material having a value seating surface on one face thereof and an annular groove in said one face coterminous with said seating surface and opening at the inner periphery of said seating ring; and an annular seal of relatively soft elastic material bonded in said groove having a sealing engagement portion thereof, spaced from said seating surface, protruding beyond said seating surface in the relaxed state of the seal, and said annular seal having a relieved portion between the protruding portion and said seating surface; said seal having sealing engagement portion thereof of a length substantially greater than the thickness of said seal in its relaxed state; and wherein the thickness of the seal progressively increases from the inner periphery of the seal to said relieved portion.

Claim 38

A valve seat assembly, comprising: a seating ring formed of relatively rigid material having a value seating surface on one face thereof and an annular groove in said one face coterminous with said seating surface and opening at the inner periphery of said seating ring; and an annular seal of relatively soft elastic material bonded in said groove having a sealing engagement portion thereof, spaced from said seating surface, protruding beyond said seating surface in the relaxed state of the seal, and said annular seal having a relieved portion between the protruding portion and said seating surface; said seal having sealing engagement portion thereof of a length substantially greater than the thickness of said seal in its relaxed state; and wherein the thickness of the seal progressively increases from the inner periphery of the seal to said relieved portion.

Claim 39

A valve seat assembly, comprising: a seating ring formed of relatively rigid material having a valve seating surface on one face thereof and an annular groove in said one face coterminous with said seating surface and opening at the inner periphery of said seating ring; and an annular seal of relatively soft elastic material bonded in said groove having a sealing engagement portion thereof, spaced from said seating surface, protruding beyond said seating surface in the relaxed state of the seal, and said annular seal having a relieved portion between the protruding portion and said seating surface; said seal having said sealing engagement portion thereof of a length substantially greater than the thickness of said seal in its relaxed state; and wherein the surface of the seal adapted to face a valve member increasingly protrudes beyond said seating surface from the inner periphery of the seal to said relieved portion.

Claim 40

A valve seat assembly, comprising: a seating ring formed of relatively rigid material having a valve seating surface on one face thereof and an annular groove in said one face coterminous with said seating surface and opening at the inner periphery of said seating ring; and an annular seal of relatively soft elastic material bonded in said groove having a sealing engagement portion thereof, spaced from said seating surface, protruding beyond said seating surface in the relaxed state of the seal, and said annular seal having a relieved portion between the protruding portion and said seating surface; said seal having said sealing engagement portion thereof of a length substantially greater than the thickness of said seal in its relaxed state; and wherein the surface of the seal adapted to face a valve member increasingly protrudes beyond said seating surface from the inner periphery of the seal to said relieved portion.

Claim 41

An assembly as defined in claim 20 wherein the seal overlaps and is bonded to the inner periphery of the seating ring.

Claim 42

A gate valve seat assembly, comprising: a seating ring of high strength material having concentric grooves in one end face thereof, one of said grooves extending from the inner periphery of the seating ring and the other of said grooves extending from the outer periphery of the seating ring, and said end face between said grooves being formed substantially flat to form an annular gate seating surface; and a seal ring of relatively soft elastic material in each of said grooves, each of said seal rings having a thickness, in its relaxed condition, to protrude beyond said seating surface and having a length, measured radially with respect to the seal ring and along the portion thereof which protrudes beyond said seating surface, substantially greater than the thickness in the relaxed condition of the seal ring.

Claim 43

A gate valve seat assembly, comprising: a seating ring of high strength material having concentric grooves in one end face thereof, one of said grooves extending from the inner periphery of the seating ring and the other of said grooves extending from the outer periphery of the seating ring, and said end face between said grooves being formed substantially flat to form an annular gate seating surface; and a seal ring of relatively soft elastic material in each of said grooves, each of said seal rings having a thickness, in its relaxed condition, to protrude beyond said seating surface and having a length, measured radially with respect to the seal ring and along the portion thereof which protrudes beyond said seating surface, substantially greater than the thickness in the relaxed condition of the seal ring.

Claim 44

A valve seat assembly, comprising: a seating ring formed of relatively rigid material having a valve seating surface on one face thereof and an annular groove in said one face coterminous with said seating surface and extending from said seating surface to the inner periphery of said seating ring, said groove increasing in depth from the inner to the outer periphery thereof; and an annular seal of relatively soft elastic material bonded in said groove and having a portion thereof, spaced from said seating surface, protruding beyond said seating surface in the relaxed state of the seal, and having a relieved portion between the protruding portion and said seating surface; said seal having a length substantially greater than the thickness thereof in its relaxed state.

Claim 45

A valve seat assembly, comprising: a seating ring formed of relatively rigid material having a valve seating surface on one face thereof and an annular groove in said one face coterminous with said seating surface and extending from said seating surface to the inner periphery of said seating ring, said groove increasing in depth from the inner to the outer periphery thereof; and an annular seal of relatively soft elastic material bonded in said groove and having a portion thereof, spaced from said seating surface, protruding beyond said seating surface in the relaxed state of the seal, and having a relieved portion between the protruding portion and said seating surface; said seal having a length substantially greater than the thickness thereof in its relaxed state.