GB2249600A

GB2249600A - Apparatus for installing a pipe joint

Info

Publication number: GB2249600A
Application number: GB9106601A
Authority: GB
Inventors: Goran Sundholm
Original assignee: Individual
Current assignee: Individual
Priority date: 1990-11-06
Filing date: 1991-03-28
Publication date: 1992-05-13
Anticipated expiration: 2011-03-28
Also published as: GB9106601D0; GB2249600B; FI905496A; JP3244511B2; DE4110414A1; JPH05312296A; FI905496A0

Abstract

In an apparatus for use in the installation of pipe joints comprising two support members 7, 13 displaceable towards each other under the influence of fluid pressure, and positioned internally of the pipe ends, a plurality of rolls 9, 15 with surface grooves or the like are positioned around each support member with spring means 20 positioned between the rolls around one support member and the rolls around the other support member. the spring means being arranged to cause the rolls to roll along respective flared end parts 8, 14 of the support members into engagement with the inner surface of the respective pipe end when the support members are displaced towards each other under the influence of said pressure, and thereafter to bring the pipe ends, through the engagement of the rolls, axially against each other with a predetermined force. An alternative arrangement employs the apparatus in securing a flange to a pipe end (Figure 6). <IMAGE>

Description

-12.4 c)']; J 1 Apparatus for installing a pipe joint The present

invention relates to an apparatus for use in the installation of a pipe joint.

On installing pipe joints, it is often necessary to press the pipe ends to be joined with great force against each other. Previously, this has been carried out with powerful means gripping the pipe from the outside. Such means are difficult to handle and take up plenty of space.

An aim of the present invention is to provide an apparatus for pressing together pipe ends on installing a pipe joint which is small in size and easy to handle.

The apparatus according to the invention comprises two support members displaceable towards each other under the influence of pressure, the support members being intended to be positioned internally on both sides of the joint to be formed and comprising end parts enlarging in a direction away from said joint; a plurality of rolls with surface grooves or the like, the rolls being positioned around the support members, respectively; the surface of the enlarging end part of each support member, along which the rolls are caused to roll, being provided with surface grooves for co-operation with surface grooves provided on the rolls, respectively; and a spring means positioned between the rolls around one support member and the rolls around the other support member, the spring means being arranged to cause the rolls to roll along the surf ace of the enlarging end part of the respective support member into engagement with the i nner surf ace of the 2 respective pipe end when the support members are displaced towards each other under the influence of said pressure, and thereafter allow further displacement of the support members towards each other when the pressure is increased, thus bringing the pipe ends, through the engagement of the rolls, axially against each other with a predetermined force.

The cooperation of the surface grooves of the enlarged, preferably conical end parts of the support members and the roll grooves, respectively, is essential in order to obtain a sufficiently firm grip between the rolls and the internal surface of the pipe ends to be joined. In pipe joints here contemplated, one should be able to apply an axial f orce in the range of 10 to 50 tons when urging the pipe ends together. When completed, the pipe joint should preferably be able to withstand axial forces of up to 165 tons.

In the following, the invention will be described with reference to exemplifying embodiments shown in the attached drawing.

Figure 1 is a partial longitudinal section of a preferred embodiment of the apparatus of the invention.

Figures 2, 3 and 4 illustrate the operation of the apparatus shown in Figure 1 when installing a welded pipe joint.

Figure 5 shows the pipe joint with completed welds.

Figure 6 shows an alternative embodiment of the apparatus, intended for use in the installation of a flange to a pipe end.

The apparatus shown in Figure 1 comprisesa body 1 preferably circular in cross-section. One end portion 2 of the body 1 (to the right in the drawing) 3 has a greater diameter than the middle portion of the body 1. A cylinder sleeve 3 is provided in close sliding contact around said end portion 2 and an adjacent part of the middle portion of the body 1, so that an annular chamber 4 is defined between the sleeve and the inner end surface of the end portion 2 of the body 1. The chamber 4 communicates by means of a conduit 5 with a pressure line 6.

An outer end part 7 of the cylinder sleeve 3 is arranged to enlarge, preferably conically, and the conical surface is provided with grooves 8 or the like for co-operation with similar surf ace grooves 9 provided on a plurality of wheels or rolls 10 positioned around the cylinder sleeve 3 ana inter- is connected by means of spiral springs 11, for example.

An end piece 13 is attached, by means of a threaded joint, for example, to the other end portion 12 of the body 1 (to the left in the figure). Similarly as the end part 7 of the cylinder sleeve 3, the end piece 13 enlarges conically towards its end and is provided with surf ace grooves 14 or the like for co-operation with similar surface grooves 15 provided on a plurality of wheels or rolls 16 positioned around the end piece 13 and interconnected with spiral springs 17, for example.

A first spiral spring 18 is arranged between the inner end surf aces of the cylinder sleeve 3 and the opposite end piece 13, in close contact with said surfaces; and a second spiral spring 20, preferably stronger than the first spiral spring 18, is arranged around the cylindrical sleeve 13 and an axially inwardly directed cylindrical support 19 in the end piece 13. A ring 21 and 22 with a smooth surf ace is arranged between the ends of the second spiral spring 20 and the wheels or rolls 10 and 16, respectively.

4 The wheels or rolls 10 and 16 as well as the rings 21 and 22 are preferably of metal. The reference numeral 23 designates a hook to which a rope can be attached for drawing the apparatus through the pipe to the joint in question if the stiffness of the pressure line 6 is not sufficient to push in the apparatus.

In the following, the operation of the apparatus will be described with reference to Figures 2, 3 and 4.

Two pipes to be joined are designated with 24 and 25, and a sleeve to be welded across the joint by means of end welds is designated with 26. A seal ring 27 is provided between the ends of the pipes 24 and 25. The seal ring 27 comprises an inner, substantially cylindrical part 28 and a guide part 29 extending between the end surfaces of the pipes. The guide part 29 is preferably provided with such side bends or the like as disclosed in US Patent 4,728,126. The pipe ends are provided with internal bevellings 30 and 31 so as to bring the cylindrical part 28 of the ring 27 in close elastic contact with the pipe ends when the pipes are pressed ax4J-aljl-y together, as is shown in Figures 3, 4 and 5.

In Figure 2, the apparatus according to the invention has been inserted into the joint to be formed and it is in inactivated state similarly as in Figure 1.

When pressure is applied to the chamber 4 through the conduit 5 f rom the line 6, the cylinder sleeve 3 is displaced to the lef t in the drawing so that it compresses the inner spring 18. The outer spring 20 causes, by means of the rings 21 and 22, the wheels 10 and 16 to roll upwards along the conical surfaces of the end pieces 7 and 13 into engagement with the inner surfaces of the pipes 24 and 2 5.

After a firm engagement has been achieved between the wheels 10 and 16 and the inner surface of the pipes 24 and 25, respectively, the pressure in the chamber 4 is further increased so that the pipes are brought axially together into the position shown in Figure 3 while the outer spring 20 is in compressed state. In Figure 3, the cylindrical part 28 of the seal ring 27 is in close elastic contact with the bevellings 30 and 31, and the end surfaces of the pipes 24 and 25 are positioned against the guide part 29 of the seal ring 27.

Thereafter the weld sleeve is positioned in place and it can be f ixed temporarily by means of spot welds 32, Figure 4. The pressure is decreased in the chamber 4, whereby the cylinder sleeve 3 is dis placed to the right in the drawing'and the wheels 10 and 16 are disengaged f rom the pipes 24 and 25. The apparatus is withdrawn, and the sleeve 26 is f ixed f inally by means of end welds 33. In principle, the end welds can be made immediately while the apparatus of the invention still keeps the pipes together; there is, however, a risk that the heat damages the seals.

In the embodiment of Figure 6, the pipe 25 and the sleeve 26 are replaced with a flange 34, and the wheels 10 with a retainer ring 35. In principle, the situation in Figure 6 is the same as in Figure 3; the flange 34 is temporarily fixed to the pipe 24 by means of spot welds 32.

An axial press force as high as about 10 ton can be readily achieved by means of the apparatus of the invention. No stationary powerful means are needed. The apparatus can be used to advantage also in connection with thin-walled pipes, whereby 6 deviations from circular shape frequently occurring in the production of such pipes will be automatically compensated for.

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Claims

Claims:

1. Apparatus for axially pressing together two pipe ends or the like on installing a pipe joint, comprising two support members displaceable towards each other under the influence of pressure, the support members being intended to be positioned internally on both sides of the joint to be f ormed and comprising end parts enlarging in a direction away from said joint; a plurality of rolls with surf ace grooves or the like, the rolls being positioned -around the support members, respectively; the surface of the enlarging end part of each support member, along which the rolls are caused to roll, being provided with surface grooves for co-operation with surface grooves provided on the rolls, respectively; and a spring means positioned between the rolls around one support member and the rolls around the other support member, the spring means being arranged to cause the rolls to roll along the surf ace of the enlarging end part of the respective support member into engagement with the inner surface of the respective pipe end when the support members are displaced towards each other under the influence of said pressure, and thereafter allow further displacement of the support members towards each other when the pressure is increased, thus bringing the pipe ends, through the engagement of the rolls, axially against each other with a predetermined force.

2. Apparatus according to claim 1, wherein the enlarging end part of each support member is conical and adjoins a cylindrical part in a direction towards the respective opposite support member.

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3. Apparatus according to claim 1, wherein said spring means is formed by a spiral spring, and that a ring having a smooth surface and preferably made of metal is provided between the end of the spiral spring and the respective rolls.

4. Apparatus according to claim 1, wherein the support members are mounted on a preferably cylindrical body, one end portion of the body having a greater diameter than an adjacent body portion, and one support member is formed by a cylindrical sleeve positioned in close sliding contact around said end portion of the body and the adjacent body portion so as to define a pressure chamber together with said end portion.

5. Apparatus according to claim 4, wherein the other support member is fixedly mounted on the body.

6. Apparatus according to claim 1, wherein a spring is provided between the two support members so as to drive them apart from each other.

7. Apparatus according to claim 6, wherein the spring between the support members is weaker than the spring between the rolls positioned around the support members.

8. Apparatus according to claim 1, wherein the rolls positioned around the support members are resiliently interconnected, preferably by means of spiral springs.

9. An apparatus for axially pressing together two pipe ends or the like on installing a pipe joint substantially as hereinbefore described with reference to Figures 1 to 5 or Figure 6.