GB2429505A

GB2429505A - A method of lining a conduit and apparatus for lining a conduit

Info

Publication number: GB2429505A
Application number: GB0517203A
Authority: GB
Inventors: Olaleke Osibamowo
Original assignee: Project Building Co Ltd
Current assignee: Project Building Co Ltd
Priority date: 2005-08-23
Filing date: 2005-08-23
Publication date: 2007-02-28
Also published as: GB0517203D0

Abstract

A method of lining an interior of a conduit 42 comprising the steps of: inserting a liner positioner 16 and a liner 14 into the interior of the conduit, wherein a portion of the liner positioner is frangibly connected to the liner; and removing the liner positioner from the conduit. The length of the liner positioner 16 may in some embodiments be selected in dependence on the location of a defect. Removing the liner positioner 16 may in some embodiments disconnect the frangibly connected portion of the liner positioner from the liner 14 by peeling. The liner positioner 16 may in some embodiments be fastened 52 exterior to the conduit and removal of the liner positioner may include pulling the liner positioner. The liner positioner 16 may in some embodiments be used as a guide for inserting a bladder 18 into the conduit. The liner 14 may in some embodiments comprise a flange (20, figure 1) or may be formed from sliver knitted material. The liner 14 is preferably turned inside out, and inserted into the conduit by eversion.

Description

TITLE

A method of lining a conduit and apparatus for lining a conduit.

FIELD OF THE INVENTION

Embodiments of the invention relate to lining of a conduit. In particular, they relate to the remote lining of conduits.

BACKGROUND TO THE INVENTION

Over time, defects may occur in underground pipes. For instance, ground movement may cause a pipe to crack, which can result in the leakage of fluid carried by the pipe into the surrounding environment. If the pipe is carrying waste water or sewage, the surrounding environment may be polluted.

Furthermore, ground water may enter a pipe carrying sewage and mix with the sewage. This results in the ground water being treated at a Sewage Treatment Works, which is uneconomic.

If an underground pipe does develop a defect, it is often impractical to replace the pipe, as significant excavation work would be required. Instead, pipes are repaired in situ.

A main sewer pipe may have a series of lateral pipes connected to it. These lateral pipes may, for instance, run to households in the region. Lateral connections carrying waste water terminate with a clean-out at a household.

The lateral pipe may be accessible via the clean-out or a manhole adjacent the pipe.

At present, there are two main ways of lining a defective underground pipe.

The first method involves sending an assembly into the pipe which has a bladder fixed to its outer surface. A resin impregnated liner for lining the pipe covers the outer surface of the bladder. The assembly is pulled along the

I

pipe using a rope. When the liner is in place adjacent the defect, the bladder is inflated, pushing the liner against the inner circumference of the pipe. The liner is then cured, which hardens the liner and fixes it in place. Once the liner has been cured, the bladder is deflated and the assembly is removed from the pipe. This method is described in US 20040161301 Al, assigned to Project Building Co. Limited.

This method is advantageous in that the liner can be positioned close to the defect and may be made small (i.e. large amounts of the pipe that are not close to the defect need not be lined). However, pulling an assembly along a pipe may, in some circumstances, be problematic. For example, the pipes may be old with misaligned joints, and may contain scale and debris. Pulling the assembly along such pipes is very difficult. Consequently, this method of lining may not always be appropriate.

A second method involves shooting and everting a bladder and a liner into an adjacent pipe using driving apparatus, which may be internal or external to the pipe to be lined. The bladder is often tubular in shape and a tubular liner is placed within the bladder, along the whole length of the bladder. As the bladder is shot and everted, its interior surface becomes an exterior surface surrounded by the liner.

This method is advantageous in that a defect in an adjacent pipe can be lined without having to pull an assembly along the pipe. However, sometimes a pipe may have a relatively small defect at a point that is remote from the position of the driving apparatus. Using this method, the entire pipe between the driving apparatus and the defect is lined, rather than just the portion of the pipe around the defect. A lot more lining is therefore used than need be used to repair only the defect.

BRIEF DESCRIPTION OF THE INVENTION

According to one embodiment of the invention, there is provided a method of lining an interior of a conduit having a defect, comprising the steps of selecting a length of a liner positioner from a first fastened portion to a second portion for frangible connection to a liner in dependence on the location of the defect; inserting a bladder, the liner positioner and a liner into the interior of the conduit; and removing the bladder and the liner positioner from the conduit. The bladder and the liner positioner and liner combination may be inserted together or separately. The bladder and the liner positioner may be removed together or separately.

As the liner positioner is connected to the liner, once the bladder, liner positioner and liner have been inserted into the conduit, the length of the liner positioner determines which part of the adjacent conduit will be lined.

Advantageously, it is therefore possible to line a posterior part of the conduit without lining an anterior part.

According to a second embodiment of the invention, there is provided a method of lining an interior of a conduit, comprising the steps of: inserting a bladder, a liner positioner and a liner into the interior of the conduit, wherein the liner positioner has a first portion fastened exterior to the conduit and a second portion frangibly connected to the liner; and removing the bladder and the liner positioner from the conduit, the removal including pulling the first portion of the liner positioner to disconnect the second portion of the liner positioner from the liner. The bladder and the liner positioner & liner combination may be inserted together or separately. The bladder and the liner positioner may be removed together or separately.

As a first portion of the liner positioner is exterior to the conduit and that first portion is pulled to remove the liner positioner, there is no need to enter the conduit to remove the liner positioner. The liner positioner may therefore be removed quickly and easily. Furthermore, the length of the bladder plays no part in determining which part of the conduit will be lined, and therefore, advantageously, a generic bladder that is not specifically sized for a particular job may be used.

According to a third embodiment of the invention, there is provided a method S of lining an interior of a conduit, comprising the steps of: inserting a liner positioner and a liner into the interior of the conduit, wherein a portion of the liner positioner is frangibly connected to the liner; and removing the liner positioner from the conduit, wherein removing the liner positioner disconnects the frangibly connected portion of the liner positioner from the liner by peeling.

The liner positioner is easily removed from the liner by peeling. If the liner were not as easily removable from the lining positioner, debris may be left in the conduit which may contribute to a future blockage.

According to a fourth embodiment of the invention, there is provided a method of lining an interior of a conduit having a defect, comprising the steps of: selecting a length of a liner positioner from a first portion to a second portion for frangible connection to a liner in dependence on the location of the defect; inserting the liner and the liner positioner into the interior of the conduit; and subsequently inserting a bladder into the conduit by using the liner positiorer as a guide.

According to a fifth embodiment of the invention, a method of lining a conduit, comprising the steps of: rolling a sheet of material and adhering two opposing ends of a side of the sheet to form a liner having a substantially tubular portion and a flange extending from the substantially tubular portion, wherein the flange is formed by the two opposing ends; inverting the liner so that the flange is on the interior of the liner; and everting the inverted liner into a conduit.

According to a sixth embodiment of the invention, there is provided an elongate liner for lining a conduit, comprising: a substantially elongate tubular b portion having a length; and a protruding flange, extending along the length of the substantially tubular portion.

The liner advantageously allows for easier eversion, as the presence of the flange reduces the frictional forces between the liner and any adjacent objects during eversion.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the present invention reference will now be made by way of example only to the accompanying drawings in which: Fig. 1 illustrates a perspective view of a first liner for use in lining a pipe; Fig. 2A illustrates a cross section of the first liner; Fig. 2B illustrates a cross section of the first liner in an inverted state; Fig. 3 illustrates a cross section of a second liner in an inverted state; Fig. 4 illustrates a cross section of a third liner in an inverted state; Fig. 5A illustrates a cross section of a fourth liner; Fig. 5B illustrates a cross section of the fourth liner in an inverted state; Fig. 6 illustrates a liner being impregnated with resin; Fig. 7 is a schematic diagram of a liner arrangement in its inverted state; Fig. 8 is a schematic diagram of the liner arrangement in its everted state; Fig. 9 illustrates driving apparatus for driving a portion of the liner arrangement into an adjacent pipe; Fig. 10 illustrates the driving apparatus loaded with the liner arrangement; Fig. 11 illustrates a first liner arrangement after a portion of it has been everted into an adjacent pipe; Fig. 12 illustrates a pipe after it has been lined in accordance with embodiments of the invention; Fig. 13 illustrates a second liner arrangement after a portion of it has been everted into an adjacent pipe.

Fig. 14 illustrates a liner and a liner positioner for eve rsion into a pipe; Fig. 15 illustrates a liner and a liner positioner in their everted states; Fig. 16 illustrates a pipe having two separate defects being lined in accordance with embodiments of the invention; Fig. 17 illustrates a pipe having two defects after it has been lined in accordance with embodiments of the invention; and Fig. 18 illustrates a pipe having a defect being lined using a packer.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

The Figures illustrate a method of lining an interior of a conduit 42 having a defect, comprising the steps of selecting a length of a liner positioner 16 from a first fastened portion 17 to a second portion 58/59 for frangible connection to a liner 14 in dependence on the location of the defect; inserting, together or separately, a bladder 18, the liner positioner 16 and a liner 14 into the interior of the conduit 42; and removing, together or separately, the bladder 18 and the liner positioner 16 from the conduit 42.

Fig. 1 illustrates a perspective view of a first liner 14 for lining a portion of a pipe. Fig. 2A illustrates a cross section of the liner 14. The liner 14 is made using a rectangular, flat, flexible sheet of material with a first side 27 having a pile fabric 21, and a second side 29 that does not have a pile fabric.

The liner 14 is typically made from a sliver knitted material. The sliver knitting process involves locking individual fibres directly into a backing, allowing each fibre to stand upright from the backing, creating a pile fabric 21 on the first side 27 of the liner 14. The fibres may be knit into various pile heights and densities depending on the required specification. The fibres are aligned through carding and combing processes. In these processes, the fibres get pulled in the same direction and aligned parallel to one another creating a rope, commonly called "roving" or "sliver". Alternatively, the liner 14 may be made from a fleece material.

The backing is on the second side 29 of the liner 14, and has a transfer coating applied to it. The transfer coating allows the liner 14 to stretch more easily. The transfer coating is, for example, a polymer film that is transferred to the backing from a carrier using a transfer process.

The liner 14 is formed by folding the sheet of rectangular material so that the two opposing end portions 23, 25 of the second side 29 are brought together and adhered to create a substantially tubular portion 15 and a flange joint 20.

The opposing end portions 23, 25 may be connected to each other using an adhesive, a solvent, or by welding methods involving heat, ultrasonic, microwave or thermoplastic treatments known in the art. The flange joint 20 formed by the opposing end portions 23, 25 is substantially flat, and extends along the length of the substantially tubular portion 15 of the liner 14.

Once the flange joint 20 has been formed, the liner 14 is turned insideout, so that the second side 29 is on the exterior of the liner 14 and the first side 27, the flange part 20 and the pile fabric 21 are on the interior of the liner 14. A cross section of the inside-out liner 14 is shown in Fig. 2B. The outer surface 29 of the inside-out liner 14 contains a recessed portion 9 at a point corresponding to where the flange 20 extends inwardly from the inner surface 27 of the substantially tubular portion 15.

When the liner 14 is installed into the interior of a conduit, it will be everted so that the first side 27 is again on the exterior of the liner 14. The eversion of the liner 14 will be described in further detail later. As the outer surface 29 of the inverted liner 14 in Fig. 2B has a recessed portion 9, the frictional forces between the outer surface 29 of the liner 14 and an adjacent bladder during eversion will be lower than they would be without the recessed portion 9. The liner 14 therefore advantageously allows for easier evérsion.

Fig. 3 illustrates a cross section of a second liner 114 for lining a portion of a pipe. The second liner 114 is made from a rectangular sheet of material which takes the same form as that used to make the first liner 14. The second liner 114 is made by bringing an end portion 123 of a side 127 having a pile fabric together with an end portion 125 of a side 129 not having a pile fabric. The two end portions 123, 125 are overlapped and adhered together to create an overlap joint 120. Once adhered, the liner 114 is tubular in shape. The methods used to adhere the two end portions 123, 125 are the same as those used in respect of the first liner 14. As an alternative or in addition to these methods, the two end portions 123, 125 may be sealed using sealing tape 140.

Fig. 4 illustrates a cross section of a third liner 214 for lining a portion of a pipe. The third liner 214 is made from a rectangular sheet of material which takes the same form as that used to make the first and second liners 14 and 114. In this embodiment, however, the two end portions 223, 225 are brought towards each other but are not adhered together directly. Sealing tape 140 is used to connect the first end portion 223 to the second end portion 225, creating a tube. The sealing tape is adhered to the first end portion 223 and the second end portion 225 on the side 229 not having a pile fabric to create a connection between the two end portions 223, 225. A "fillet piece" 241 is inserted into the inner side 227 of the tube, which has a pile fabric. The side 242 of the fillet piece 241 not having a pile fabric is adhered to the side 227 of the liner 214 having a pile fabric. The fillet piece acts to substantially fill in the gap 250 between the two end portions 223, 225.

When the liners 114 and 214 are installed into the interior of a conduit, they will be everted such that the sides 127, 227 having a pile fabric will be on the exterior of the liners 114 and 214.

Figs 5A and 5B illustrate a cross section of a fourth liner 314 for lining a portion of a pipe. Two rectangular sheets of material 301 and 302 having a pile fabric on one side but not the other are used to make the liner 314. The two opposing ends of the first sheet of material 301 are adhered to the equivalent opposing ends on the second sheet of material 302. The sheets are adhered on the side not having a pile fabric, forming two flange joints 320 and 321.

Once the two flange joints 320 and 321 have been formed, the liner 314 is turned inside-out so that the flange parts 320 and 321 and the sides 303 and 305 having a pile fabric are on the interior of the liner 314. The inside- out liner 314 has two recessed portions 309 and 310 at the points corresponding to whether the flanges 309 and 310 extend inwardly.

When the liner 314 is installed into the conduit, it will be everted so that the sides 303 and 305 having a pile fabric are again on the exterior of the liner 314. The recessed portions 309 and 310 provide a similar advantage to that expressed in relation to the recessed portion 9 of the first liner 14.

Finally, before it is installed in a conduit, a liner 14, 114, 214 or 314 is impregnated with resin. To impregnate a liner 14, 114, 214, 314 with resin, firstly resin is poured inside the tubular liner 14, 114, 214, 314 and then the liner 14, 114, 214, 314 is passed through rollers 24 as illustrated in Fig. 6.

The following description of a method of lining a pipe according to embodiments of the invention refers to the use of the first liner 14. It will be appreciated by those skilled in the art that the method could be performed using any of the aforementioned liners 14, 114, 214, 314 or indeed other types of liner.

Fig. 7 is a schematic of a liner arrangement 40 in its inverted state. The liner arrangement 40 comprises the liner 14 and a liner positioner 16. The liner positioner 16 is cut on-site to a length that depends upon the location of a defect in a pipe and connected to the liner 14. The liner 14 and the liner positioner 16 may be connected using an adhesive such as cyanoacrylate.

Two alternative embodiments of the liner positioner 16 are illustrated by Fig. 7. In the first embodiment, the liner positioner 16 is substantially tubular. In this first embodiment, an end portion 58 of the tubular liner positioner 1 6 is folded in towards the centre of the tube and back onto itself to create a double cuff. In effect, once the end portion 58 has been folded inwards, the lining positioner 16 becomes twice as thick at its new end. The exterior side 29 of an end portion 61 of the liner 14 is then adhered to the side 70 of the folded back end portion 58 that is on the interior of the tubular liner positioner 16.

The end portion 61 of the liner 14 is therefore positioned inside the liner positioner 16. The liner positioner 16 in this embodiment is connected to the liner 14 across the whole of the circumference of the liner 14.

In the second embodiment, the liner positioner 16 comprises two elongate strips. An end portion 59 of each of the elongate strips is folded back upon itself so that it becomes twice as thick at its new end. The exterior side 71 of the folded back end portions 59 are adhered to the exterior side 29 of an end portion 61 of the liner 14 so that the liner 14 is positioned inside the liner positioner 16. The two folded back end portions 59 may be connected to opposing points of the circumference of the end portion 61 of the liner 14.

In the liner arrangement 40 illustrated in Fig. 7, the interconnected liner 14 and liner positioner 16 are positioned inside a bladder 18. The bladder 18 is made from a plastics material or rubber, and is generally tubular with a closed end 36 and an open end 38. In one embodiment of the invention, the liner positioner 16 is attached to the bladder 18. In another embodiment, the liner positioner 16 is unattached to the bladder 18.

The liner 14 is the innermost layer of the liner arrangement 40 when it's in its inverted state, and the bladder 18 is the outermost layer. The liner positioner 16 is positioned in between the liner 14 and the bladder 18. A pull such as a rope 28 is connected to the closed end 36 of the bladder 18.

Fig. 9 illustrates a inserting apparatus 12. The inserting apparatus 12 has a cylindrical or tubular shaped body and an internal cavity 13. The inserting apparatus 12 comprises a rotatable shaft 26, a first aperture 30 to the internal cavity 13 and a second aperture 34 to the internal cavity 13. A collar 32 is positioned around the edge of the first aperture 30.

A portion of the liner arrangement 40 may be inserted into the inserting apparatus 12 in the direction 48 indicated in Figs. 7 and 9. To insert the liner arrangement 40, an end of the rope 28 is connected to the shaft 26. The shaft 26 is rotated so that the rope 28 winds around the shaft 26 which, in turn, causes the liner arrangement 40 to pass through the first aperture 30 of the inserting apparatus 12 and into its internal cavity 1 3. The liner arrangement is subsequently wound around the shaft 26.

At a point where almost all of the liner arrangement 40 has been wound around the shaft 26, the open end 38 of the bladder 18 and an end portion 17 of the liner positioner 16 are positioned around the outside edge of the collar 32. The open end 38 of the bladder 18 and the end portion 17 of the liner positioner 16 are fixed in position using a clamp 52.

Fig. 10 illustrates the liner arrangement 40 wound around the shaft 26, where the open end 38 of the bladder 18 has been clamped to the collar 32 of the inserting apparatus 12. As the liner arrangement 40 may be coiled around the shaft 26 inside the inserting apparatus 12, an adjacent underground pipe may be lined using a limited amount of space on the ground above. The detail of the liner arrangement 40 in Fig. 10 has been omitted for reasons of clarity, but takes the same form as shown in Fig. 7.

Once the liner arrangement 40 has been inserted into the inserting apparatus 12 using the method indicated above, it is ready to be driven into an adjacent pipe 42. The liner arrangement 40 may be "shot" in a direction 50 by introducing fluid under pressure into the cavity 13 of the inserting apparatus 12 through the second aperture 34. The introduction of fluid increases the pressure within the inserting apparatus 12, causing the liner arrangement 40 to unravel from the shaft 26 and evert through the first aperture 30. As the open end 38 of the bladder 18 is fixed to the inserting apparatus 12, when the liner arrangement 40 unravels from the shaft 26 it is everted such that the liner 14 and the liner positioner 16 are exterior to the evened bladder 18.

A cross section of the everted liner arrangement 40 is shown in Fig. 8 and Fig 11. During the eversion of the liner arrangement 40, the liner positioner 16 begins to leave the inserting apparatus 12 before the liner 14. Eversion continues until none of the liner 14, liner positioner 16 and bladder 1 8 remain inside the inserting apparatus 12. When the liner apparatus 40 is evened, the bladder's interior surface 72, the liner positioner's interior surface 76 and the liner's interior surface 27 all become exterior surfaces. After the eversion of the liner arrangement 40, the liner 14 is the outermost layer of the arrangement 40, and the bladder 18 is the innermost layer. The liner positioner 18 is positioned in between the liner 14 and the bladder 18. As can be seen in Fig. 11, the length of the liner positioner 16 determines the distance of the liner 14 from the collar 32.

Following eversion, the rope 28 remains connected to the shaft 26, and the open end 38 of the bladder and the end portion 17 of the liner positioner 16 remains fixed to the inserting apparatus 12 by the clamp 52. The open end 38 of the bladder 18 and the end portion 17 of the liner positioner 16 are therefore retained by the inserting apparatus 12, which is on a surface above the pipe 42 being lined, exterior to the pipe 42.

Fig. 11 illustrates the inserting apparatus 12 and the liner arrangement 40 after the liner arrangement 40 has been shot and everted into an adjacent pipe 42 from a clean out 56. The pipe 42 in this example is a lateral pipe which extends from a main sewer pipe 54. However, the lining arrangement may also be used to line a main sewer pipe. The point X indicates the position of a defect in the lateral pipe 42, and the liner 14 covers the defect at X because a liner positioner 16 of the correct length has been used.

Once the impregnated liner 14 is in the correct position, it is cured. Hot air or water may be introduced into the inserting apparatus 12 through the second aperture 34 and sent into the bladder 18 to speed up the curing process.

Since the liner positioner 16 has not been impregnated with resin, it does not cure. This allows the second portion 46 of the pipe 42 to be lined without lining the first portion 44.

As can be seen in Fig. 11, the length of the liner positioner 16 from the inserting apparatus 12 to the liner 14 in this embodiment of the invention determines the position of the liner 14 within the pipe 42. The further away from the inserting apparatus 12 the defect X is, the longer the liner positioner 16 needs to be. As the length of the bladder 18 does not determine the ultimate position of the liner 14 within the pipe 42, a generic bladder 18 may be used.

Once the liner 14 has been cured, much of the fluid introduced into the inserting apparatus 12 and the bladder 18 is removed and the bladder 18 is deflated. After deflation, the bladder 18 becomes flaccid and winding the rope 28 around the shaft 26 pulls the bladder 18 out of the adjacent pipe 42 and towards the inserting apparatus 12. The bladder 18 is subsequently wound around the shaft 26 and removed from the pipe 42.

The liner positioner 16 may be removed from the pipe 42 by pulling the retained end portion 17 of the liner positioner 16 from the surface above the pipe 42. When the liner positioner 16 is pulled, the liner positioner 16 peels away from the liner 14 because there is a frangible, fold-back connection between the liner positioner 16 and the liner 14. The adhesive used to bond the liner positioner 16 and the liner 14 should not be very strong to allow the peeling action to take place. As indicated earlier, an adhesive such as cyanoacrylate is suitable.

Given that the bond between the liner 14 and the liner positioner 16 is not very strong, it is important that the liner arrangement 40 can be driven into the pipe 42 by applying a relatively low pressure to the inserting apparatus 12.

The flexible nature of the liner 14 allows it to be everted by applying a relatively low pressure (of the order of 7 x Pa) to the inserting apparatus 12. For reasons explained earlier, the flange joint 20 of the liner 14 allows for easier eversion.

Fig. 12 shows the liner 14 after it has been shot into place and cured. The liner positioner 16 and the bladder 18 have been removed from the pipe 42.

Fig. 13 shows an alternative embodiment of the invention. In this embodiment, the liner positioner 16 is securely attached to the bladder 18 at the opposite end 19 of the liner positioner 16 to the end portion 58/59 that is frangibly connected to the liner 14. The liner positioner 16 may therefore be made smaller than in the previous embodiment. The open end 38 of the bladder 18 is retained at the inserting apparatus 12, but an end portion of the liner positioner 16 is not retained at the inserting apparatus 12 in this embodiment.

The liner arrangement 40 is everted into an adjacent pipe 42 and the liner 14 is cured in the same way in the embodiment of Fig. 13 as was described in relation to the previous embodiment, illustrated in Fig. 11.

However, in this embodiment, the liner positioner 16 is not directly pulled at the surface above the pipe 42 to remove it from the pipe 42. Once the bladder 18 has been deflated following the curing of the liner 14, the rope 28 is wound around the shaft 26 to remove the bladder 18. As the bladder 18 is physically attached to the liner positioner 16, when the bladder 18 is pulled out of the pipe 42, the liner positioner 16 is also pulled out of the pipe 42.

When the liner positioner 16 is pulled, the liner positioner 16 peels away from the liner 14 because there is a frangible, fold-back connection between the liner positioner 16 and the liner 14. Once the liner positioner 16 and the bladder 18 have been removed, a remote portion 46 of the pipe 42 is lined, as illustrated in Fig. 12.

Using the methods described above, a remote part 46 of a pipe 42 having a defect X has been lined, without requiring the liner 14 to be installed from within the pipe 42, or without requiring the lining of the first part 44 of the pipe 42.

Figs 14 to 17 illustrate a further embodiment of the invention. Fig. 14 shows a liner 14 that is frangibly attached to a liner positioner 16. The liner 1 4 and the liner positioner 16 are in an inverted state in Fig. 14,and are the same as those described above in reference to the previous embodiments. In this particular embodiment, however, the end portion 58/59 of the liner positioner 16 is not folded inwards to create a double cuff, Instead, to create a liner 14 and liner positioner 16 combination in an inverted state, the end portion 58/59 of the liner positioner 16 is made to overlap the liner 14 without being folded back. A small portion 7 of the interior side 76 of the overlapped region 58/59 of the liner positioner 16 is then adhered to the exterior side 76 of the liner 14 at an end 55 of the liner 14. The small portion 7 of the liner positioner 16 is not at the very end of the liner positioner 1 6. This results in an unconnected part of the end portion 58/59 between the very end of that end portion and the adhered small portion 7. The unconnected part is tethered by the adhered small portion 7 but is otherwise unconnected. As will be described subsequently the unconnected portion may be used to peel the liner positioner 16 from the liner 14 after curing. The adhesion between the liner 14 and the liner positioner 16 is relatively weak, so that the application of a pulling force to the liner positioner 16 may detach the liner positioner 16 from the liner 14.

A low temperature melt film 57 is optionally applied to an area 77a at the end of the exterior side 77 of the liner positioner 16 in its inverted state. After eversion, the side 77 will be on the interior of the liner positioner 16 as illustrated in Fig. 15. When the film 57 is initially applied, it does not cause the liner positioner 16 to adhere to other bodies. However, when heat is applied to the film, it melts and acts as an adhesive.

Liner positioners and liners such as those illustrated in Figs 14 and 15 may be used to repair one or more a defects in a pipe 42. The pipe 42 illustrated in Fig. 16 has two separate defects at point X and point Y. Initially, a first liner positioner 16 is selected that is the correct length for repairing the defect at point X and is adhered to a first liner 14, forming the combination shown in Fig. 14.

The first liner 14 and the first liner positioner 16 are then evened from the inserting apparatus 12, according to the method described above in relation to Figs. 7 to 12 except that a bladder is not used to evert. As in that method, one end 17 of the liner positioner 16 is fixed to the inserting apparatus 12 by a clamp 52 before eversion.

In this embodiment, a bladder 18 is not used to evert the first liner 14 and the first liner positioner 16 as in the previous embodiments. Instead an unconstrained fluid flow is used for eversion. This works because the end 53 of the liner 14 is effectively closed when the liner positioner 16 and the liner 14 are ravelled around the shaft 26 of the inserting apparatus 12. Thus, the liner 14 operates as its own bladder until it is fully evened and the effective closure at the end 53 of the liner 14 is opened by the fluid flow first.

The introduction of fluid into the inserting apparatus 12 causes the liner positioner 16 and the liner 14 to unravel from the shaft 26 and evert. The end 53 of the liner 14 remains closed during the eversion process. Once the liner positioner 16 and the liner 14 have been everted and are situated in the area of the pipe 46 that is to be lined, an opening at the end 53 of the liner 14 will form (as the liner 14 and the liner positioner 16 have been completely unravelled) and the fluid being introduced into the inserting apparatus 12 will flow directly through the lining positioner 16 and the liner 14, causing them to collapse inside the pipe 42.

Once the first liner 14 and the first liner positioner 16 have been everted into the pipe 42, a second liner positioner 16' is selected that is the correct length for repairing the defect at point Y. The second defect is further away from the inserting apparatus 12 and the clean out 56 than the first defect X. The second liner positioner 16' is therefore longer than the first liner positioner 1 6.

The second liner positioner 16' is frangibly attached to a second liner 14' forming a combination similar to that shown in Fig 14. A low temperature melt film 57 is also applied to an area 77'a of a side 77' of the second liner positioner 16'. The side 77' corresponds to the inner side of the liner positioner 16' when it is its everted state.

The second liner 14' and the second liner positioner 1 6' are then everted from the inserting apparatus 12, such that they pass through the interior of the first lining positioner 16 and the liner 14. Once fully everted, the second liner 14 is situated further into the pipe 42 than the first liner 14, and part of the second liner positioner 16' is positioned inside the first liner positioner 16.

The second liner 14' and the second liner positioner 16' may or may not be evened at the same time as a bladder 18. If the second liner 14' and the second liner positioner 16' are not everted with a bladder 18, the bladder 18 is driven into the pipe 42 at a later point in time, by eversion or by another method to effect curing of the liner 14. In this instance, the second liner positioner 16' may act as a guide for the bladder 18 being inserted into the pipe 42. During the eversion process, the end 17' of the second liner positioner 16' and an open end 38 of the bladder 18 are fixed in position to the inserting apparatus 12 using a clamp 52.

Fig. 16 illustrates a point in time where the first liner 14 and liner positioner 16 and the second liner 14' and liner positioner 16' have been everted into the pipe 42, and a bladder 18 has been driven into the pipe 42. At this point, hot air or water is introduced into the bladder 18. This causes the bladder 18 to inflate and the impregnated liners 14 and 14' to cure. While the liners 14 and 14' are being cured, the heat from the curing process causes the low temperature film 57 that was applied to the inner surfaces 77 and 77' of the liner positioners 16 and 16' to melt. This causes the first, outer liner positioner 16 to adhere to the second, inner liner positioner 16' and the second liner positioner 16' to adhere to the bladder 18. The unconnected part of the end portion 58/59 of the first liner positioner 16 at the very end adheres to the bladder 18 or the second liner positioner 16'. The unconnected part of the end portion 58/59 of the second liner positioner 16' adheres to the bladder 18. If low temperature melt film 57 is used then it may facilitate this adhesion. The unconnected parts enable the liner positioner to be separated from its respective liner by a peeling action.

At this point, any one of the bladder 18, the first liner positioner 16 or the second liner positioner 16' may be pulled at the exterior of the pipe 42 to remove the bladder 18, the first liner positioner 16 and the second liner positioner 1 6' in one step.

For instance, if the shaft 26 is rotated, the rope 28 winds around the shaft, causing the bladder 18 to return to the inserting apparatus 12. As the rope 28 is attached to the closed end 36 of the bladder 18, the closed end 36 begins to return to the inserting apparatus 12 first. The second liner positioner 16' is attached to the bladder 18 at a portion 77a of its inner surface 77, SO the pulling of the rope 28 and therefore the bladder 18 causes the second liner positioner 16' to peel away from the second liner 14'. This process repeats in the case of the first liner positioner 16, where the first liner positioner 16 is attached to the second liner positioner 16' at the portion 77a, so the pulling of the attached bladder 18 and second liner positioner 16' causes the first liner positioner 16 to peel away from the first liner 14.

In summary, when the bladder 18, the first liner positioner 16 or the second liner positioner 16' are pulled, either directly or indirectly, the liner positioners 16 and 16' are detached from the liners 14 and 14', leaving them in position at defects X and Y. Fig. 17 illustrates the pipe 42 after it has been lined at points X and V and the bladder 18 and the two liner positioners 16 and 16' have been removed.

Using this method, two remote parts 46, 47 of a pipe 42 having two separate defects X and Y have been lined, without requiring the liner 14 to be installed from within the pipe 42, without requiring the first part 44 of the pipe 42 to be lined, and without requiring a second part 45 of the pipe 42 in between the first defect X and the second defect Y to be lined. The technique of lining a pipe 42 described in relation to Fig. 16 could be used to line the pipe at any number of points along the pipe.

Although this embodiment has not been described in relation to a "fold back" connection between the first liner 14 and the first liner positioner 16', such a fold back connection could be used. Furthermore, a low temperature melt film 57 need not be used in some circumstances. Depending on the materials used for the lining positioners 16 and 16' and the bladder 18, the heat from the curing of the liner 14 and the pressure applied to the liner positioners 16 and 16' from inflating the bladder 18 may cause the liner positioners 16 and 16' to become attached to the bladder 18 while they are in the pipe 42, without requiring a separate adhesive to be used.

The preceding embodiments relate to the in-situ curing of a liner. The curing is typically effected using a bladder, that forces the liner against the walls of the pipe, and may provide a heat source. The eversion of a bladder 18, liner and liner positioner has been described in detail in the preceding embodiments.

However, it will be appreciated by those skilled in the art that the positioning of the liner may be effected using eversion or by pushing or pulling it into position. If eversion is used, this may be achieved without using a bladder or by using the bladder that is also used for curing.

A further embodiment of the invention is illustrated in Fig. 18. In this embodiment, a packer 500 is pulled or pushed into a pipe 42 to repair a defect in the pipe 42 at point X. The packer 500 has a rigid outer body 501 that is covered across its whole circumference by a bladder 18. A liner positioner 1 6 is placed around the bladder 18, but not along the whole length 502 of the packer 500. A portion 90 of the inner surface 77 of the liner positioner 16 is attached to the bladder 18 towards the rear end 504 of the packer 500. A liner 14 surrounds part of the liner positioner 16, and is adhered to the end portion 58/59 of the liner positioner 16 that is opposite to the end attached to the bladder 18.

Once the packer 500 has been positioned in the pipe 42 near to the defect at point X, a fluid is introduced into the bladder 18 to inflate it. The inflation of the bladder 18 causes the liner 14 to be pushed against the pipe 42 so that it covers the defect at X. The introduction of the fluid into the bladder 18 also causes the liner 14 to cure.

When the liner 14 has been cured, the packer 500 is removed by pulling the rope 28 in the direction 100. As the rope 28 is pulled, the packer 500 moves in the direction 100, causing the liner positioner 16 to peel away from the liner 14, leaving the liner 14 in position at the defect X. Although embodiments of the present invention have been described in the preceding paragraphs with reference to various examples, it should be appreciated that modifications to the examples given can be made without departing from the scope of the invention as claimed. For example, the inserting apparatus 12 may not be tubular or cylindrical. The pipe being lined may not be an underground pipe. The liners 14, 114, 214 and 314 have described in their inside-out configuration in reference to Figs 1, 2A, 2B, 3, 4, 5A and 5B, such that they ready for eversion according to the method described above, It should be appreciated that the liners 14, 114, 214 and 314 could be made in the form that they will eventually take in the pipe (i.e. the configuration after eversion). If the liners 14, 114, 214, 314 are made in this way, they would then be pulled or pushed into the pipe rather than everted.

Whilst endeavoring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the Applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in the drawings whether or not particular emphasis has been placed thereon.

Claims

I/we claim: CLAIMS

1. A method of lining an interior of a conduit having a defect, comprising the steps of: selecting a length of a liner positioner from a first fastened portion to a second portion for frangible connection to a liner in dependence on the location of the defect; inserting, together or separately, a bladder, the liner positioner and a liner into the interior of the conduit; and removing, together or separately, the bladder and the liner positioner from the conduit.

2. A method of lining the interior of a conduit as claimed in claim 1, wherein the removal of the liner positioner from the conduit includes pulling directly or indirectly the liner positioner to disconnect the second portion of the liner positioner.

3. A method of lining an interior of a conduit as claimed in claim 1, wherein the length of the liner positioner determines the position of the liner after the liner has been inserted into the conduit.

4. A method of lining an interior of a conduit as claimed in claim 1, wherein the second portion of the liner positioner is backwardly folded and frangibly connected to the liner, and removing the liner positioner disconnects the backwardly folded portion by peeling.

5. A method of lining an interior of a conduit as claimed in claim 1, wherein the liner positioner comprises a third portion adjacent a first end of the liner positioner that overlaps the liner, wherein part of the third portion between the second portion and the first end is unconnected to the liner.

6. A method of lining an interior of a conduit as claimed in claim 1, wherein the liner positioner has a substantially tubular portion.

7. A method of lining an interior of a conduit as claimed in claim 6, wherein the second frangibly connected portion of the liner positioner is inwardly folded upon an adjacent portion of the liner positioner, forming a double cuff portion.

8. A method of lining an interior of a conduit as claimed in claim 6, wherein the second frangibly connected portion of the liner positioner is connected to a portion of the liner, at points around the circumference of the liner.

9. A method of lining an interior of a conduit as claimed in claim 1, wherein the liner positioner comprises a plurality of elongate strips of material.

10. A method of lining an interior of a conduit as claimed in claim 1, wherein the liner positioner comprises at least two elongate strips of material connected to an end portion of the liner, at opposite ends of the circumference of the liner.

11. A method of lining an interior of a conduit as claimed in claim 1, wherein the liner positioner and the liner are frangibly connected using an adhesive.

12. A method of lining an interior of a conduit as claimed in claim 1, wherein a portion of the bladder is retained exterior to the conduit.

13. A method of lining an interior of a conduit as claimed in claim 12, wherein the bladder is removed by applying a pulling force to the bladder.

14. A method of lining an interior of a conduit as claimed in claim 1, wherein the liner is a resin impregnated liner and the conduit is an underground pipe.

1 5. A method of lining an interior of a conduit as claimed in claim 1, wherein the liner positioner and the liner are everted into the conduit or pulled or pushed into the conduit.

16. A method of lining an interior of a conduit as claimed in claim 15, wherein the bladder is separately pulled, pushed or everted into the conduit.

17. A method of lining an interior of a conduit as claimed in claim 1, wherein the bladder is inflated with an inflator positioned on a surface above the conduit to insert the bladder into the interior of the conduit.

1 8. A method of lining an interior of a conduit as claimed in claim 1, wherein the liner positioner is made from a plastics material.

19. A method of lining an interior of a conduit as claimed in claim 1, wherein the bladder and liner positioner are unattached.

20. A liner positioner for use in the method as claimed in claim 1.

21. A method for lining an interior of a conduit as claimed in claim 1, wherein the bladder and the liner positioner are removed from the conduit together in one step.

22. A method for lining an interior of a conduit as claimed in claim 1, wherein the bladder and the liner positioner are unattached when inserted into the conduit, but become attached when positioned in the interior of the conduit.

23. A method for lining an interior of a conduit as claimed in claim 22, wherein the liner is cured in the conduit and liner positioner and the bladder become attached during the curing process.

24. A method for lining an interior of a conduit as claimed in claim 1, wherein the conduit has a second defect, the method further comprising the steps of: selecting a length of a second liner positioner from a first fastened portion to a second portion for frangible connection to a second liner in dependence on the location of the second defect; inserting the second liner positioner and the second liner into the interior of the conduit through the first liner and first liner positioner; and removing the second liner positioner from the conduit.

25. A method for lining an interior of a conduit as claimed in claim 24, wherein the first liner positioner, the second liner positioner and the bladder are removed from the conduit together in one step.

26. A method for lining an interior of a conduit as claimed in claim 24, wherein the first liner positioner, the second liner positioner and the bladder are unattached when inserted into the conduit, but become attached when positioned in the conduit.

27.A method for lining an interior of a conduit as claimed in claim 26, wherein the first and second liners are cured in the conduit and the first liner positioner, second liner positioner and the bladder are attached in the conduit during the curing process.

28. A method of lining an interior of a conduit, comprising the steps of: inserting, together or separately, a bladder, a liner positioner and a liner into the interior of the conduit, wherein the liner positioner has a first portion fastened exterior to the conduit and a second portion frangibly connected to the liner; and removing, together or separately, the bladder and the liner positioner from the conduit, the removal including pulling the first portion of the liner positioner to disconnect the second portion of the liner positioner from the liner.

29. A method of lining an interior of a conduit, comprising the steps of: inserting a liner positioner and a liner into the interior of the conduit, wherein a portion of the liner positioner is frangibly connected to the liner; and removing the liner positioner from the conduit, wherein removing the liner positioner disconnects the frangibly connected portion of the liner positioner from the liner by peeling.

30. A method as claimed in claim 29, wherein a backwardly folded portion of the liner position is frangibly connected to the liner, or, alternatively, a portion of the liner positioner adjacent an end of the liner positioner, overlapping the liner, and located between the frangibly connected portion and the end of the liner positioner is unconnected to the liner and participates in peeling the liner positioner from the liner.

31. A method of lining an interior of a conduit having a defect, comprising the steps of: selecting a length of a liner positioner from a first portion to a second portion for frangible connection to a liner in dependence on the location of the defect; inserting the liner and the liner positioner into the interior of the conduit; and subsequently inserting a bladder into the conduit by using the liner positioner as a guide.

32. A method of lining a conduit, comprising the steps of: folding a sheet of material and adhering two opposing ends of a side of the sheet to form a liner having a substantially tubular portion and a flange extending from the substantially tubular portion, wherein the flange is formed by the two opposing ends.

33. A method of lining a conduit as claimed in claim 32, further comprising the steps of: inverting the liner so that the flange is on the interior of the liner; and everting the inverted liner into a conduit. *

34. A liner for lining a conduit, comprising: a substantially elongate tubular portion having a length; and a protruding flange, extending along the length of the substantially tubular portion.

35.A liner for lining a conduit made from a sliver knitted material.