GB2450119A

GB2450119A - Pipe repair / reinforcing cover with inflatable liner

Info

Publication number: GB2450119A
Application number: GB0711380A
Authority: GB
Inventors: Paul Davidson
Original assignee: FLUID LEADER Ltd
Current assignee: FLUID LEADER Ltd
Priority date: 2007-06-12
Filing date: 2007-06-12
Publication date: 2008-12-17
Also published as: GB0711380D0; WO2008152369A1

Abstract

A reinforcing cover 6 for a pipe A or pipe joint comprises two semi cylindrical housing parts 8, 20 which can surround the conduit A so as to form a gap between the housing the external face of the conduit. The cover 6 also includes an expandable (inflatable) cushion 12 between the pipe and the housing parts 8, 20 which is wrapped around the pipe and expanded to fill and seal the gap. The cushion 12 is held in place by adhesive strips 18, or alternatively hook and loop (Velcro RTM) fasteners.

Description

REINFORCING SYSTEM

The present invention relates to a reinforcing system for reinforcing and maintaining tubular conduits, in particular for repairing and maintaining pipeline based fluid transport systems, for example where joints between pipe sections have failed or are suspected of future failure.

Fluid transport systems are known for conveying materials, such as liquids and gasses, with common examples including water and fuels such as gas and oil. The systems may vary from domestic plumbing systems installed in a building to convey water, to oil and gas pipelines for conveying fuel over thousands of miles. The tubular conduits used in fluid transport systems may be made of many different materials, including steel, iron, copper, aluminium and plastic.

Such fluid transport systems are generally formed from sections of pipe connected together. In addition, pipe sections comprising bends, t-junctions, valve section etc., are connected into such fluid transport systems, according to requirements. Many types of joints are known for smaller diameter pipes, for example in the plumbing and gas fitting trade, for connecting sections of pipe. When such joints fail it can be inconvenient to repair the failure and the repair will generally involve shutting off the fluid flow through the failed portion of pipeline and drainage of the failed portion of pipeline. The repair is generally done by replacing the joint between the pipes, which often involves

I

replacement of the ends of the pipe sections between which the failure has occurred.

For larger diameter pipes, such as those used in oil and gas pipelines, welded joints may be used. If a welded joint fails, skilled workers are required to make the repair. Before a welded joint can be repaired the affected section of the pipeline may have to be shut off and the section requiring repair may have to be drained. For example, construction of a gas conveying pipeline, made from 40 metre long lengths of steel pipe and with a 1 metre diameter, conventionally uses welded joints. Each failed joint can take a skilled team several days to repair, when taking into consideration, the deployment of equipment at the joint location, repair of the joint and inspection of the joint by X-ray equipment after repair. This makes such pipelines expensive and time consuming to maintain and repair.

Where plastic pipes are used, heat-fused joints may be used, in which the ends of pipes to be connected are heated up and then fused together. Push fit couplings, welded joints and fused joints are difficult to disconnect, for example for repair or maintenance, with such disconnection often causing damage to the pipes.

The present invention provides a reinforcing system for reinforcing tubular conduits, in particular for repairing and maintaining pipeline based fluid transport systems. The system comprises a housing connectable around such a tubular conduit so as to form a gap around such a tubular conduit between the housing and a portion of an external surface of such a conduit; an expandable cushion comprising a central portion mounted within a portion of the housing and two side portions; wherein when the cushion is in an unexpanded state the cushion is adapted to be wrapped around such a conduit with at least partially overlapping side portions and when the cushion is so wrapped and in an expanded state the cushion is adapted to fill the gap.

The present invention also provides a method of deploying the system on a tubular conduit, comprising the steps of: locating the portion of the housing to which the central portion of the cushion is mounted on the tubular conduit; wrapping the side portions of the cushion around the conduit with at least part of the side portions overlapping; fixing the housing around the conduit so as to form the gap within which the cushion is located; and expanding the cushion so as to seal the gap.

The present invention can be used for routinely reinforcing all joints, for example for reinforcing welded joints in oil and gas pipelines. This may be particularly useful, where subsequent failure of the joint might result in expensive and time consuming repair work. The invention may also be used to reinforce a joint, where the joint is tested and found to be susceptible to failure in the future. The invention is also valuable when a joint has failed as the reinforcing system can be deployed while the joint is leaking. This means that provided any leak from the pipe is not too violent and provided the fluid leaking from the pipe is not dangerous, a leaking joint can be repaired without disturbing the flow of fluid through the pipeline. In addition, a repair to a joint using the system according to the present invention does not require the joint to be dismantled and also avoids any risk of damaging the ends of the pipes which come together at the joint.

The housing may be made of a rigid material so as to provide a rigid boundary against which the cushion can expand in order to fill the gap around the joint and to seal the joint against leakage.

The housing may be a clamshell housing comprising at least an upper housing part and a lower housing part. The housing may comprises a first end and a second end remote from the first and each end may be formed with an inwardly extending lip and each lip may contoured to envelop the external surface of such a conduit. The cushion can be located between the lips so that the lips form.a part of a boundary against which the cushion can expand.

The housing, which preferably envelops the cushion also protects the cushion from damage.

The tubular conduit may be part of a cylindrical pipeline and in this case the gap is preferably an annular gap and the housing is preferably a cylindrical housing.

The housing may compnse a clamshell housing including a first housing part.

In this case the central portion of the cushion may mounted to the first housing part and for example may line an internal surface of the first housing part.

Also, in this case, the side portions of the cushion may extend from the first housing part. Then when the first housing portion is located on a tubular conduit, the side portions of the cushion extend free from the first housing portion and are available to be wrapped around the reminder of the tubular conduit.

Where the housing is a clamshell housing comprising at least an upper housing part on which the cushion is mounted, the locating step of the method of deploying the system may comprise the step of positioning the upper housing part on an upper portion of the tubular conduit.

The cushion may comprise a nozzle, via which it is expandable and the nozzle may extend from an internal to an external surface of the housing through a hole which may be formed in a portion of the housing to which the cushion is mounted. The nozzle may have a one way valve formed in it so as to allow fluid to enter the cushion but not leave the cushion. The cushion may have an enclosure made of a skin of expandable material. The expandable material may be a form of rubber, for example a synthetic rubber based on polychioroprene.

Where the cushion comprises a nozzle, via which it is expandable, the expanding step of the method of deploying the system may comprise introducing a fluid into the cushion via the nozzle.

It is preferred that at least one of the side portions of the cushion carries a fastening strip which may be adapted for securing the side portions in their overlapping position. The fastening strip may be a strip of adhesive, a strip of Velcro or a row of individual fastening elements. Where at least one of the side portions of the cushion canies a fastening, the wrapping step of the method of deploying the system may additionally include securing the overlapping cushion parts to each other using the fastening strip. In particular the side portions of the cushion may each carry a fastening strip for securing the side portions in their wrapped position. Where the side portions of the cushion each carry a fastening strip, the wrapping step of the method of deploying the system may additionally include securing a first of the side portions to the conduit and securing a second of the side portions to the first using the fastening strip. For convenience of deployment, where the fastening strip is an adhesive strip, the adhesive strip may be covered by a release liner until the adhesive is required for use.

The cushion in its expanded position may be filled with a fluid, for example a gas, liquid or a gel. In particular, the fluid may be a settable fluid which sets within the cushion.

The present invention also provides a method of reinforcing tubular conduits, comprising the steps of: providing at least two housing portions which co-operate to fit around a portion of a tubular conduit so as to form a gap between the housing portions and the tubular conduit, which gap extends around the tubular conduit; providing an expandable cushion, which cushion comprises a central portion mounted within a first of the housing portions, the cushion additionally comprising two side portions; locating the first of the housing portions with the central portion of the cushion located in the portion of the gap between the first of the housing portions and the tubular conduit; wrapping the side portions of the cushion around the tubular conduit so that the side portions at least partially overlap; fixing the further housing portion(s) over the wrapped side portions of the cushion; and then expanding the cushion so as to fill the gap.

The invention will now be described by way of example only and with reference to the accompanying schematic drawings, wherein: Figure 1 shows a transverse cross-section through a portion of a pipeline incorporating a pipe joint requiring reinforcement onto which an upper component of the joint reinforcement system according to the present invention has been located; Figure 2 shows a side on perspective view of the portion of pipeleine and upper component of Figure 1; Figure 3 shows a transverse cross-section through a portion of a pipeline and upper component similar to that of Figure 1 but with the side portions of the expandable cushion wrapped around the pipeline; Figure 4 shows a transverse cross-section through a portion of a pipeline and upper component similar to that of Figure 3 but with a lower component, a housing portion, of the joint reinforcing system fitted to a housing portion of the upper component and with the expandable cushion expanded; Figure 5 shows a longitudinal cross-section through the length of the upper component along line A-A in Figure 1 with the cushion not expanded; and Figure 6 shows a longitudinal cross-section through the length of the upper component along line A-A in Figure 1 with the cushion expanded.

Figures 1, 2 and 5 show a portion of a pipeline incorporating a failed joint (1) between two adjacent sections of pipe (2, 4). Alternatively, the joint may require routine reinforcement or may be suspected of future failure. Where the joint has failed, fluid under pressure may be leaking out of the joint.

Depending on the nature of the fluid and the force with which the fluid is leaking from the failed joint, it may be necessary to reduce the fluid pressure within the pipe. However, the pipeline need not to be shut off or drained for a repair to be made to the joint.

An upper component (6) of the reinforcing system comprises a first housing portion in the form of a rigid hood (8) fitted with an expandable sealing cushion (12). The hood (8) has a substantially semi-circular transverse cross-section and is dimensioned so that it can be fitted over substantially the upper half of a section of the pipeline (2, 4) surrounding the joint, so as to leave a small gap between a recessed radially inwardly facing face (9) of the hood (8) and a radially outwardly facing face (5) of the pipeline (2, 4). A central portion (12a) of the expandable sealing cushion (12) lines the internal surface of the hood (8) and fits within this gap. For example, the side of the central portion (12a) facing the hood (8) may be adhered to the recessed radially inwardly facing face (9). A radially outwardly extending lip (10) is located at each opposing straight side edge (28, 30) of the hood. A number of fixing holes are formed through the lip (10). The hood (8) may for example be made from metal.

The expandable sealing cushion (12) comprises two layers of expandable skin connected together around their edges so as to form a central space (38) therebetween, as shown in Figure 5. The skin may be made of a suitable resilient material, for example of a synthetic rubber, although many alternative materials will be apparent to a person skilled in the art.

In the present example, the expandable sealing cushion (12) is substantially rectangular, with a central portion (12a) of the rectangle covering the recessed internal surface (9) of the hood (8). For example, the central portion (12a) of the sealing cushion which covers the hood (8) may be attached to the hood, for example using an adhesive. A hole is formed in the centre of the hood (8), through which a nozzle (14) of the cushion (12) extends, which nozzle communicates with the central space (38) of the cushion (12). The nozzle may be formed with a one way valve which opens to allow fluid to enter the cushion but closes to prevent fluid from leaving the cushion The side portions of the sealing cushion (12a, 12b), extend one from either straight opposing edge (28, 30) of the hood (8). The edges of the sealing cushion (12) remote from the hood (8) have a strip of adhesive (16) located on their surface facing away from the hood. The strip of adhesive may be covered by a release liner (18) before the upper component (6) is deployed. Release liners (18) are well known in the art for protecting layers of adhesive and which can be peeled away from the adhesive layer when the adhesive layer is required.

The strip of adhesive (16) could be replaced by other fastening strips including Velcro or rows of individual fastening elements.

At each opposing semi-circular edge (24, 26) of the hood (8) is located a radially inwardly extending lip (22), with an internal diameter dimensioned to match the external diameter of the pipeline (2, 4).

The reinforcing system additionally comprises a lower component, which comprises a further housing portion (20), shaped substantially identically to the hood (8), but with no central hole, and generally made from the same material as the hood. The further housing portion (20) is shaped to fit over the lower half of the section of pipeline (2, 4). The further housing portion (20) is also formed with radially outwardly extending lips (32) at its opposing straight edges. A number of fixing holes are formed through each radially outwardly extending lip (32), which holes correspond to the position of the fixing holes in the lip (10) of the hood (8).

In use, the reinforcing system of Figures 1 to 5 is deployed so as to reinforce a joint in the section of pipeline (2, 4), as follows.

The upper component (6) is positioned over the section of pipeline (2, 4) centred on the position of the joint (I), as is shown in Figures 1, 2 and 5. The central portion (1.2a) of the expandable cushion (12) is located in the gap between the internal recessed surface (9) of the hood (8) and the external face (5) of the upper half of the pipeline (2, 4). The semi-circular side edges of this gap are closed by the radially inwardly extending lips (22) which protect and enclose the central portion (12a) of the cushion. The side portions of the cushion (12b, 12c) depend from respective straight edges (28, 30) of the hood (8) as is shown in Figure 1. It should be noted that the upper component (6) may be deployed on a section of pipeline (2, 4) while a failed joint (1) is leaking, providing the pressure at which the leaking fluid passes through the failure is not too high.

With the upper component (6) deployed, as is shown in Figure 1, the release liner (18) covering one of the adhesive strips (16) (in this example the left hand strip of cushion side portion (12b)) is peeled off so as to expose the adhesive strip (16). The left hand side portion (12b) of the cushion is then wrapped around the underside of the pipeline section (2, 4) and the edge of the cushion (12) fixed to the pipeline section along its edge by the strip of adhesive (16). Then the release liner (18) covering the other of the adhesive strips (16) (in this example the right hand strip of cushion side portion (12c)) is peeled off so as to expose the adhesive strip (16). The right hand side portion (12c) of the cushion is then wrapped around the underside of the pipeline section (2, 4) over the left hand portion (12b) of the cushion and the edge of the cushion (12) is fixed to the left hand cushion portion (12b) by the strip of adhesive (16). This is shown in Figure 3. It should be noted that leakage of fluid from the pipeline section (2, 4) need not prevent deployment of the upper component as shown in Figure 3.

It should also be noted that in the arrangement of Figure 3, the adhesive strip of the left hand portion (1 2b) of the cushion is not essential to secure the cushion (12) in its position in which it is wrapped around the pipeline section (2, 4) as shown in Figure 3.

The further housing portion (20) is then fitted over the overlapping side portions (12b, 12c) of the cushion and the underside of the pipeline section (2, 4) as is shown in Figure 4. A small gap is provided for the cushion (12) between the inwardly facing recessed face of the lower component (20) and the outwardly facing face of the pipeline section (2, 4). Again, there are radially inwardly extending lips at the curved edges of the lower component (equivalent to the lips (22) in the hood (8)), which lips protect and enclose the cushion (12). The further housing portion (20) and the hood (8) are fixed together along their contacting straight edges by a fixing arrangement between the radially outwardly extending lips (10, 32) of the hood (8) and the further housing portion (20). For example, a plurality of fixing elements (34), for example bolts, can be passed through the corresponding fixing holes through the lips (10, 32) so as to fix the hood (8) and the lower component (20) together. Again, the further housing portion (20) can be fitted to the upper component (6) in this way, while a leak is ongoing, provided the pressure of the leak is not too high.

The expandable cushion (12) is then expanded into an expanded position, shown in Figures 4 and 6 by injecting or pumping a fluid (36) into the central space (38) of the cushion (12) via the nozzle (14). In the expanded position of the cushion (12), the skin of the cushion takes the shape of the annular gap between the radially outer surface (5) of the pipeline (2, 4) over which the cushion extends and the recessed radially inner surface (9) of the hood (8) and further housing portion (20) so as to provide a seal therebetween. The fluid (36) injected or pumped into the cushion (12) might be a liquid or a gas which is pumped or injected into the cushion (12) until the cushion takes up a fully expanded position of Figure 4. Then the end of the nozzle (14) is closed off, or the one way nozzle may close off the nozzle, so as to maintain the cushion in its expanded position. Alternatively, the fluid (36) may be made of a composition which sets permanently after the cushion (12) is in its expanded position.

If the reinforcing system of Figures 1 to 4 is deployed, as is described above, while the pipeline (2, 4) is leaking, the expansion of the cushion (12) by the injection of fluid into the cushion will stop the leak. In this way the reinforcing system described in relation to Figures 1 to 4 is able to provide a permanent repair to the failed joint.

Claims

1. A reinforcing system for reinforcing tubular conduits, comprising: a housing connectable around such a tubular conduit so as to form a gap around such a tubular conduit between the housing and a portion of an external surface of such a conduit; an expandable cushion comprising a central portion mounted within a portion of the housing and two side portions: wherein when the cushion is in an unexpanded state the cushion is adapted to be wrapped around such a conduit with at least partially overlapping side portions and when the cushion is so wrapped and in an expanded state the cushion is adapted to fill the gap.

2. A system according to claim I wherein the housing is made of a rigid material.

3. A system according to claim 1 wherein the housing is a clamshell housing comprising at least an upper housing part and a lower housing part.

4. A system according to any one of claims I to 3 wherein the housing comprises a first end and a second end remote from the first and each end is formed with an inwardly extending lip and each lip is contoured to envelop the external surface of such a conduit.

5. A system according to any one of claims I to 4 wherein the gap is an annular gap.

6. A system according to any one of the preceding claims wherein the housing comprises a clamshell housing including a first housing part and the central portion of the cushion is mounted to the first housing part, with the side portions of the cushion extending therefrom.

7. A system according to any one of the preceding claims wherein the cushion comprises a nozzle, via which it is expandable and the nozzle extends from an internal to an external surface of the housing through a hole formed in a portion of the housing to which the cushion is mounted.

8. A system according to any one of the preceding claims wherein the cushion comprises an enclosure having a skin made of an expandable material.

9. A system according to any one of. the preceding claims wherein at least one of the side portions of the cushion carries a fastening strip adapted for securing the side portions in their overlapping position.

10. A system according to any one of the preceding claims wherein the side portions of the cushion each carry a fastening strip for securing the side portions in their wrapped position.

11. A system according to claim 9 or claim 10 wherein the fastening strip comprises an adhesive strip is covered by a release liner.

12. A system according to any one of the preceding claims wherein the cushion in its expanded position is filled with a fluid.

13. A method of deploying a system according to any one of claims I to 12 on a tubular conduit, comprising the steps of: locating the portion of the housing to which the central portion of the cushion is mounted on the tubular conduit; wrapping the side portions of the cushion around the conduit with at least part of the side portions overlapping; connecting the housing around the conduit so as to form the gap within which the cushion is located; and expanding the cushion so as to seal the gap.

14. A method according to claim 13 wherein the housing is a clamshell housing comprising at least an upper housing part on which the cushion is mounted and a lower housing part, and the locating step comprises the step of positioning the upper housing part on an upper portion of the tubular conduit.

15. A method according to any one of claim 13 or 14 wherein the cushion comprises a nozzle, via which it is expandable and the step of expanding comprises introducing a fluid into the cushion via the nozzle.

16. A method according to any one of claims wherein 13 to 15 wherein at least one of the side portions of the cushion carries a fastening and the step of wrapping additionally includes securing the overlapping cushion parts to each other using the fastening strip.

17. A method according to any one of claims 13 to 16 wherein the side portions of the cushion each carry a fastening strip and the step of wrapping additionally includes securing a first of the side portions to conduit and securing a second of the side portions to the first using the fastening strip.

18. A method of for reinforcing tubular conduits, comprising the steps of: providing at least two housing portions which co-operate to fit around a portion of a tubular conduit so as to form a gap between the housing portions and the tubular conduit, which gap extends around the tubular conduit; providing an expandable cushion, which cushion comprises a central portion mounted within a first of the housing portions, the cushion additionally comprising two side portions; locating the first of the housing portions with the central portion of the cushion located in the portion of the gap between the first of the housing portions and the tubular conduit; wrapping the side portions of the cushion around the tubular conduit so that the side portions at least partially overlap; fixing the further housing portion(s) over the wrapped side portions of the cushion; and then expanding the cushion so as to fill the gap.

19. A method according to claim 18 wherein the housing is a clamshell housing comprising at least an upper housing part on which the cushion is mounted and a lower housing part, and the locating step comprises the step of positioning the upper housing part on an upper portion of the tubular conduit.

20. A method according to any one of claim 18 or 19 wherein the cushion comprises a nozzle, via which it is expandable and the step of expanding comprises introducing a fluid into the cushion via the nozzle.

21. A method according to any one of claims wherein 18 to 20 wherein at least one of the side portions of the cushion carries a fastening and the step of wrapping additionally includes securing the overlapping cushion parts to each other using the fastening strip.

22. A method according to any one of claims 18 to 20 wherein the side portions of the cushion each carry a fastening strip and the step of wrapping additionally includes securing a first of the side portions to conduit and securing a second of the side portions to the first using the fastening strip.