GB1563924A

GB1563924A - Sealing rings

Info

Publication number: GB1563924A
Application number: GB3288276A
Authority: GB
Original assignee: David Brown Vosper Offshore Ltd
Current assignee: David Brown Vosper Offshore Ltd
Priority date: 1977-08-24
Filing date: 1977-08-24
Publication date: 1980-04-02

Description

(54) SEALING RINGS (71) We, DAVID BROWN-VOSPER (OFF SHORE) LIMITED, a British Company, of Graphic House, Castle Street, Portchester, Hampshire P016 9PH, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to sealing rings and it is an object of this invention to provide an improved sealing ring.

According to this invention, there is provided an annular sealing ring which, in cross section, is hollow and rectangular and which comprises a ring which is U-shaped in cross section with the sides of the "U" intended to engage the surfaces to be sealed and an annular closure member fitted to the Ushaped ring so as to close the opening of the U-shaped ring, the arrangement being that, when the sealing ring has three of its sides resting against annular surfaces, fluid pressure against the fourth side will urge the first three sides against the respective annular surfaces.

An embodiment of this invention may serve as a seal between two concentric cylindrical surfaces. The cylindrical surfaces may be parts of, for example, a fluid swivel. Another application of this embodiment is to provide sealing between two concentric cylindrical surfaces in a joint where one pipe may move axially relative to another pipe as in an expansion joint.

Another embodiment of this invention is designed as a face seal.

By a face seal is meant a seal for use when the surfaces to be sealed lie in parallel planes transverse to the length of members to be sealed together; the two members may be relatively rotatable as in a swivel or may be fixed in which case the sealing ring serves as a static joint such as between flanges or in a screw joint.

The sealing ring may be pre-stressed by an internal rubber spring. As an alternative to a rubber spring, the sealing ring may be prestressed by a metallic spring ring of the type normally known as a crinkle spring. In this case it is desirable that the metallic spring should act against internal split rings which protect the internal surfaces of the sealing ring.

The sealing ring may be formed with one or more apertures to permit the entry under fluid under pressure, the action of which is to expand the ring to improve the sealing action.

Preferably the aperture or apertures are through a radially inner wall of the sealing ring.

Embodiments of this invention will now be described, by way of example only, with reference to the drawings accompanying the Provisional Specifications of Applications Nos. 32882/76 and 2163/77.

In the drawings accompanying the Provisional Specification of Application No.

32882/76:- Figure 1 is a part sectional elevation of a pipe swivel incorporating a sealing ring in accordance with this invention; Figure 2 is a sectional elevation through the sealing ring excluding a pre-stressing ring; and Figure 3 is a sectional elevation through the pre-stressing ring.

In the drawings accompanying the Provisional Specification of Application No.

2163/77: Figure 1 is a part sectional elevation of a part of a sealing ring in accordance with this invention; Figures 2 and 3 are respectively a part plan view and a part sectional elevation on the line Z-Z of Figure 2 of a spring ring used in.

the sealing ring of Figure 1; Figure 4 is a sectional elevation of an annular ring forming part of the sealing ring shown in Figure 1; and Figure 5 is a part plan view of a split ring 2 utilised in the embodiment shown in Figure 1.

The embodiment illustrated in the drawings accompanying the Provisional Specification of Patent Application No. 32882/76 will be described first and in Figure 1 of those drawings there is illustrated a fluid swivel com prising a flange 1 welded to a pipe 2; a coaxial pipe 4 is welded to a ring 5 which provides the inner race 6 of a ball race, one ball being visible at 7. Two coaxial rings 8 and 9 surround the ring 5 and are bolted to the flange 1 and together define the outer race 10 of the ball race. Rotation of the pipe 2 in relation to the pipe 4 is thus permitted by the ball race.

Annular seals 11 and 12 are formed on opposite sides of the ball race to prevent egress of the fluid flowing through the pipe, the main seal 12 which receives the full pressure of the fluid within the pipes as that fluid can flow in the transverse gap 3 between the ring 5 and the flange 1. The seal 12 is in accordance with this invention and is seated on a layer 13 formed on a portion 14 of reduced diameter of the ring 5 and also engages the resultant shoulder 15 on the ring 5.

A layer 16 is formed on the surface of the ring 9 surrounding the layer 13 and is also engaged by the seal 12.

Referring now also to Figures 2 and 3 the seal 12 is generally rectangular in cross section. The radially inner and outer surfaces of the seal 12 are formed with protuberances 17 and 18 which are each a segment of a circle in cross-section and which engage respectively the layers 16 and 13. The annular ring is made up of a ring 19 which is U-shaped in cross section and is closed by means of a flat closure 20, the ring 19 and the closure 20 both being of P.T.F.E. The protuberances 17 and 18 are formed on the sides of the ring 19.

To pre-stress the sealing ring, the sides of the ring 19 on which the protuberances 17 and 18 are formed are urged outwardly by means of an internal rubber spring 21 shown in cross section in Figure 3.

Fluid pressure on the base of the ring 19, i.e. the surface facing the flange 1 increases the pressure between the protuberances 17 and 18 and the layers 16 and 13 respectively and also increases the pressure between the closure 20 and the shoulder 15.

The provision of the internal spring permits a higher rate of recovery than would be achieved by the use of a solid P.T.F.E. ring as the sealing ring.

In the drawings accompanying the Provisional Specification of Application No.

2163/77, the sealing ring which serves as a face seal is denoted by numeral 1 and is generally rectangular in cross section. The side Surfaces of the ring 1 are formed with protuberances 2 and 3 which are a segment of a circle in cross-section and are intended to engage the surfaces to be sealed. The annular ring 1 is made up of an outer ring 4 which is U-shaped in cross section and is closed by means of a short cylindrical closure 5 fotrtril with six equispaced holes 6; the ring 4 and sure 5 are of P.T.F.E. To pre-stress the soa ring, the sides of the ring 4, on which the protuberances 2 and 3 are formed, are urged outwardly by means of a spring 7 which is in the form of a crinkle spring acts against split rings 8 resting against the inner sides of the ring 4.

This embodiment is designed for both ambient and cryogenic applications within a swivel system and the pre-stressing spring ring 7 could be replaced by such a rubber prestressing spring.

Fluid pressure within the pipes coupled by the swivel act against the radially inner surface of the ring 4 and urges the protuberances 2 and 3 against the faces they are intended to seal.

To illustrated sealing rings may be compatible with almost all known chemicals and have a very low coefficient of friction and may have an exceptionally good wear resistance.

The seals will cater for a high degree of misalignment giving the seals a greater tolerance than that of a conventional "0" ring seal.

The embodiment illustrated in the drawings accompanying the Provisional Specification of Application No. 32882j76 has the advantage that the P.T.F.E. ring 19 and closure 20 are compatible with most known chemical products. The rubber pre-stressing spring 21 is not compatible with many chemical products but the seal is so designed to permit the use of the rubber pre-stressing ring 21 while completely sealing it from the product by virtue of the ring 19 and closure 20 which are of P.T. F. E.

WHAT WE CLAIM IS: 1. An annular sealing ring which, in cross section, is hollow and rectangular and which comprises a ring which is U-shaped in cross section with the sides of the "U" intended to engage the surfaces to be sealed and an annular closure member fitted to the Ushaped ring so as to close the opening of the U-shaped ring, the arrangement being that, when the sealing ring has three of its sides resting against annular surfaces, fluid pressure against the fourth side will urge the first three sides against the respective annular surfaces 2. A sealing ring as claimed in claim 1, which is designed to provide a seal between two concentric surfaces.

3. A sealing ring as claimed in claim 1 or claim 2, which has protuberances on the radially inner and outer surfaces of the Ushaped ring.

4. A sealing ring as claimed in claim 1, which is designed as a face seal.

5. A sealing ring as claimed in claim 4 which has outwardly projecting protuberances on opposite sides of the U-shaped ring.

6. A sealing ring as claimed in any preceding claim which is pre-stressed by an internal ring spring.

7. A sealing ring as claimed in claim 6 wherein the internal spring is of rubber.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **.

prising a flange 1 welded to a pipe 2; a coaxial pipe 4 is welded to a ring 5 which provides the inner race 6 of a ball race, one ball being visible at 7. Two coaxial rings 8 and 9 surround the ring 5 and are bolted to the flange 1 and together define the outer race 10 of the ball race. Rotation of the pipe 2 in relation to the pipe 4 is thus permitted by the ball race.

Annular seals 11 and 12 are formed on opposite sides of the ball race to prevent egress of the fluid flowing through the pipe, the main seal 12 which receives the full pressure of the fluid within the pipes as that fluid can flow in the transverse gap 3 between the ring 5 and the flange 1. The seal 12 is in accordance with this invention and is seated on a layer 13 formed on a portion 14 of reduced diameter of the ring 5 and also engages the resultant shoulder 15 on the ring 5.

A layer 16 is formed on the surface of the ring 9 surrounding the layer 13 and is also engaged by the seal 12.

Referring now also to Figures 2 and 3 the seal 12 is generally rectangular in cross section. The radially inner and outer surfaces of the seal 12 are formed with protuberances 17 and 18 which are each a segment of a circle in cross-section and which engage respectively the layers 16 and 13. The annular ring is made up of a ring 19 which is U-shaped in cross section and is closed by means of a flat closure 20, the ring 19 and the closure 20 both being of P.T.F.E. The protuberances 17 and 18 are formed on the sides of the ring 19.

To pre-stress the sealing ring, the sides of the ring 19 on which the protuberances 17 and 18 are formed are urged outwardly by means of an internal rubber spring 21 shown in cross section in Figure 3.

Fluid pressure on the base of the ring 19, i.e. the surface facing the flange 1 increases the pressure between the protuberances 17 and 18 and the layers 16 and 13 respectively and also increases the pressure between the closure 20 and the shoulder 15.

The provision of the internal spring permits a higher rate of recovery than would be achieved by the use of a solid P.T.F.E. ring as the sealing ring.

In the drawings accompanying the Provisional Specification of Application No.

2163/77, the sealing ring which serves as a face seal is denoted by numeral 1 and is generally rectangular in cross section. The side Surfaces of the ring 1 are formed with protuberances 2 and 3 which are a segment of a circle in cross-section and are intended to engage the surfaces to be sealed. The annular ring 1 is made up of an outer ring 4 which is U-shaped in cross section and is closed by means of a short cylindrical closure 5 fotrtril with six equispaced holes 6; the ring 4 and sure 5 are of P.T.F.E. To pre-stress the soa ring, the sides of the ring 4, on which the protuberances 2 and 3 are formed, are urged outwardly by means of a spring 7 which is in the form of a crinkle spring acts against split rings 8 resting against the inner sides of the ring 4.

This embodiment is designed for both ambient and cryogenic applications within a swivel system and the pre-stressing spring ring 7 could be replaced by such a rubber prestressing spring.

Fluid pressure within the pipes coupled by the swivel act against the radially inner surface of the ring 4 and urges the protuberances 2 and 3 against the faces they are intended to seal.

To illustrated sealing rings may be compatible with almost all known chemicals and have a very low coefficient of friction and may have an exceptionally good wear resistance.

The seals will cater for a high degree of misalignment giving the seals a greater tolerance than that of a conventional "0" ring seal.

The embodiment illustrated in the drawings accompanying the Provisional Specification of Application No. 32882j76 has the advantage that the P.T.F.E. ring 19 and closure 20 are compatible with most known chemical products. The rubber pre-stressing spring 21 is not compatible with many chemical products but the seal is so designed to permit the use of the rubber pre-stressing ring 21 while completely sealing it from the product by virtue of the ring 19 and closure 20 which are of P.T. F. E.

WHAT WE CLAIM IS:

1. An annular sealing ring which, in cross section, is hollow and rectangular and which comprises a ring which is U-shaped in cross section with the sides of the "U" intended to engage the surfaces to be sealed and an annular closure member fitted to the Ushaped ring so as to close the opening of the U-shaped ring, the arrangement being that, when the sealing ring has three of its sides resting against annular surfaces, fluid pressure against the fourth side will urge the first three sides against the respective annular surfaces

2. A sealing ring as claimed in claim 1, which is designed to provide a seal between two concentric surfaces.

3. A sealing ring as claimed in claim 1 or claim 2, which has protuberances on the radially inner and outer surfaces of the Ushaped ring.

4. A sealing ring as claimed in claim 1, which is designed as a face seal.

5. A sealing ring as claimed in claim 4 which has outwardly projecting protuberances on opposite sides of the U-shaped ring.

6. A sealing ring as claimed in any preceding claim which is pre-stressed by an internal ring spring.

7. A sealing ring as claimed in claim 6 wherein the internal spring is of rubber.

8. A sealing ring as claimed in claim 6

wherein the internal spring is metallic.

9. A sealing ring as claimed in claim 8 wherein the internal ring is a crinkle spring.

10. A sealing ring as claimed in claim 8 or claim 9 wherein the spring ring acts against internal split rings which protect the internal surfaces of the sealing ring.

11. A sealing ring as claimed in any preceding claim which is formed with at least one aperture to permit the entry of the fluid under pressure.

12. A sealing ring as claimed in claim 13 wherein the aperture or apertures are formed through a radially inner wall of the sealing ring.

15. A sealing ring substantially as hereinbefore described with reference to the drawings accompanying the Provisional Specification of Application No. 32882/76 or the drawings accompanying the Provisional Specification of Application No. 2163/77.