GB1562691A

GB1562691A - Joint sealing devices

Info

Publication number: GB1562691A
Application number: GB5279575A
Authority: GB
Original assignee: SIBEX Ltd
Current assignee: SIBEX Ltd
Priority date: 1976-12-24
Filing date: 1976-12-24
Publication date: 1980-03-12

Description

(54) IMPROVEMENTS RELATING TO JOINT SEALING DEVICES (71) We, SIBEX (CONSTRUCTIONS) LIMITED of 159, Holton Road, Barry, South Glamorgan, a British Company, 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 joint sealing devices for insertion between opposed flanges at the ends of pipeline sections. It is primarily concerned with those devices which have a sealing compound injected through the joint to complete the seal.

Such sealing devices are known, but the problem with many of them is removal for re-use. If alterations are made requiring the seal to be broken, the whole device generally has to be scrapped. They are very expensvie items when used in large pipelines, and this scrapping is wasteful. It is an object of this invention to provide a sealing device of which at least the major part is re-usable.

According to the present invention there is provided a sealing device for insertion between opposed end flanges of adjacent pipeline sections, comprising a split ring with an annular sealing member mounted therein to be exposed at one axially facing side, and cam means operable from the radially outward side for urging said sealing member outwardly, in the axial direction, from said ring.

In a preferred embodiment the cam means includes screw means entered through the ring to engage the reverse, unexposed side of the sealing member, which provides a cam surface. Conveniently each screw means includes a screw and a balled element between said reverse side and the radially inner end of the screw.

Each ring section may be an integral member or the ring may be formed from inner and outer ring members, the inner one carrying the sealing member and the outer having the screws engaged therein.

Provision will generally be made for injecting sealing compound radially inwardly through the ring.

For a better understanding of the invention some embodiments will now be described, by way of example, with reference to the accompanying drawing, in which: Figure 1 is an end view, half in crosssection, of a sealing device for insertion between opposed flanges in a pipeline, Figure 2 is a section on the line II-II of Figure 1, and Figure 3 is a section, similar to Figure 2, but of an alternative sealing device.

The device of Figures 1 and 2 includes a split outer ring 1 of circular cross-section with a internally facing groove 2. A split inner ring 3 seats in the groove 2 by means of a narrow outer portion 4, and it has a wider inner portion 5 with opposed faces in radial planes and an annular groove 6 in one of those faces. A sealing ring 7 is housed in this groove 6, its exposed face 8 being in a radial plane while its opposite face 9 is shallow frusto-conical and engaged at intervals around the ring by ball-bearings 10.

These can be urged radially inwards by adjusting screws 11 which screw-threadedly engage in radial bores in the outer ring 1, and which have extension pins 12 projecting through narrower bores in the inner ring 3 to engage the ball-bearings. The correct registry of these bores is obtained by means of two diametrically opposed locating screws 13, also engaged in the outer ring 1 and projecting into depressions in the inner ring 3. Injection holes 14 for sealing compound are also provided at diametrically opposed points, these consisting of a wide screw-threaded portion 15 in the outer ring 1, to receive the nozzle of an injection gun, and a narrow passage 16 through the inner ring 3.

The two parts of the split outer ring 1 can be clamped together by means of screws or bolts 17 engaged in and through lugs 18, and the inner ring 3 and sealing ring 7 are also halved so that they can be fitted around an existing joint.

In use, the inner ring 3 is placed between opposed flanges at the adjacent ends of two pipeline sections, with the sealing ring 7 retracted so that its face 8 is almost flush with the adjacent radial face of the wide portion 5 of the ring 3. The outer ring 1 is placed around the inner ring and located by means of screws 13, and the whole assembly is then clamped in place. Each screw 11 is hardened down on a ball bearing previously inserted into the associated radial bore and the ball bearings 10 are thereby urged radially inwards over the inclined face 9.

The sealing ring is so shaped and initially positioned that when first inserted a ball bearing cannot enter fully into the groove 6 and thus possibly escape circumferentially.

When it is pressed further in, friction, and possibly a recessed end face on the screw, will keep the ball bearing in position. The resulting cam action forces the sealing ring 7 partially out from the ring 3 in the axial direction so that its face 8 is pressed tightly against one of the pipe flanges, while the opposed face of the ring portion 5 is urged by reaction in the opposite direction tightly against the end flange of the other pipe section. It will be appreciated that slight misalignment of pipe sections can be tolerated, for the sealing ring can be made to project varying amounts around the inner ring 3. When the screws 11 are fully hardened down, sealing compound is injected through the holes 14. and internal pressure in the pipe will ensure that the sealing compound spreads out and permeates into any interstices that remain, including the part of the groove 6 not occupied by the sealing ring.

The device shown in section in Figure 3 is identical in operation. It differs in construction in that the inner and outer ring sections are made integral so that there is a single split ring 19. The adjusting screws, ball bearings and sealing rings are referenced similarly to Figure 2.

These devices are largely re-usable, although the sealing rings themselves may need replacement. However, they are only a relatively small part to replace.

WHAT WE CLAIM IS: 1. A sealing device for insertion between opposed end flanges of adjacent pipeline sections, comprising a split ring with an annular sealing member mounted therein to be exposed at one axially facing side, and cam means operable from the radially outward side for urging said sealing member outwardly. in the axial direction, from said ring.

2. A sealing device as claimed in claim 1, wherein the cam means includes screw means entered through the ring to engage the reverse, unexposed side of the sealing member, which provides a cam surface.

3. A sealing device as claimed in claim 2, wherein each screw means includes a screw and a balled element between said reverse side and the radially inner end of the screw.

4. A sealing device as claimed in claim 1, 2 or 3, wherein each ring section is integral.

5. A sealing device, as claimed in claim 3, wherein in addition to being split, the ring is formed from inner and outer ring members, the inner one carrying the sealing member and the outer having the screws engaged therein.

6. A sealing device as claimed in any preceding claim, wherein provision is made for injecting sealing compound radially inwardly through the ring.

7. A sealing device substantially as hereinbefore described with reference to Figures 1 and 2, or Figure 3 of the accompanying drawing.

8. A pipeline comprising sections with end flanges, between at least one opposed pair of which is fitted a sealing device as claimed in any preceding claim.

9. A method of sealing a pipeline comprising sections with end flanges, wherein a device as claimed in any one of claims 1 to 7 is fitted between an opposed pair of flanges.

10. A method as claimed in claim 9, as appended to claim 6, wherein a sealing compound is injected subsequent to the fitting.

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. The two parts of the split outer ring 1 can be clamped together by means of screws or bolts 17 engaged in and through lugs 18, and the inner ring 3 and sealing ring 7 are also halved so that they can be fitted around an existing joint. In use, the inner ring 3 is placed between opposed flanges at the adjacent ends of two pipeline sections, with the sealing ring 7 retracted so that its face 8 is almost flush with the adjacent radial face of the wide portion 5 of the ring 3. The outer ring 1 is placed around the inner ring and located by means of screws 13, and the whole assembly is then clamped in place. Each screw 11 is hardened down on a ball bearing previously inserted into the associated radial bore and the ball bearings 10 are thereby urged radially inwards over the inclined face 9. The sealing ring is so shaped and initially positioned that when first inserted a ball bearing cannot enter fully into the groove 6 and thus possibly escape circumferentially. When it is pressed further in, friction, and possibly a recessed end face on the screw, will keep the ball bearing in position. The resulting cam action forces the sealing ring 7 partially out from the ring 3 in the axial direction so that its face 8 is pressed tightly against one of the pipe flanges, while the opposed face of the ring portion 5 is urged by reaction in the opposite direction tightly against the end flange of the other pipe section. It will be appreciated that slight misalignment of pipe sections can be tolerated, for the sealing ring can be made to project varying amounts around the inner ring 3. When the screws 11 are fully hardened down, sealing compound is injected through the holes 14. and internal pressure in the pipe will ensure that the sealing compound spreads out and permeates into any interstices that remain, including the part of the groove 6 not occupied by the sealing ring. The device shown in section in Figure 3 is identical in operation. It differs in construction in that the inner and outer ring sections are made integral so that there is a single split ring 19. The adjusting screws, ball bearings and sealing rings are referenced similarly to Figure 2. These devices are largely re-usable, although the sealing rings themselves may need replacement. However, they are only a relatively small part to replace. WHAT WE CLAIM IS:

1. A sealing device for insertion between opposed end flanges of adjacent pipeline sections, comprising a split ring with an annular sealing member mounted therein to be exposed at one axially facing side, and cam means operable from the radially outward side for urging said sealing member outwardly. in the axial direction, from said ring.