AU2013279089A1

AU2013279089A1 - Repair of pipes and pipelines

Info

Publication number: AU2013279089A1
Application number: AU2013279089A
Authority: AU
Inventors: Mark Potter
Original assignee: SOURCE ONE ENVIRONMENTAL Ltd
Current assignee: SOURCE ONE ENVIRONMENTAL Ltd
Priority date: 2012-06-20
Filing date: 2013-06-18
Publication date: 2015-02-05
Also published as: WO2013190282A3; GB201210928D0; GB2503249A; EP2864689A2; GB201310857D0; GB2503353B; GB2503249B; WO2013190282A2; GB2503353A

Abstract

In order to repair fractures on a T joint between a primary pipe (1) and a lateral pipe (2), a top hat patch (10) of absorbent material is impregnated with curable resin and positioned on an inflatable bladder (20). The bladder (20) and patch (10) are positioned at the intersection (3) and inflation of the bladder (20) holds the impregnated patch against the intersection (2). Once the resin has cured, the resin and patch (10) form a rigid watertight layer. During the repair, the patch (10) is secured to the bladder (20) by use of soluble ties (31) provided around the brim portion (11) on either side of the tube portion (12). Once water is reintroduced to the pipe (1), the ties (31) dissolve and thus leave no permanent snagging hazard behind. Alternatively, absorbent strips (32) made from the same material as the patch (10) are wrapped around the brim portion (11) at either side of the tube portion (12) and impregnated with resin. Once the strips (32) are in place, elastic retaining bands (33) are placed around the strips (32). Once the resin has cured, the strips (32) overlie the bands (33) and thus the bands (33) cannot present an enduring snagging hazard.

Description

WO 2013/190282 PCT/GB2013/051583 Repair of Pipes and Pipelines The present invention relates to improvements in and in relation to the repair of pipes and pipelines and in particular to the repair of junctions between a main pipeline and a lateral pipeline. 5 As pipes, in particular sewer or waste water pipes, age they can develop cracks or fractures. This can be due to the deterioration of the pipe material, wear from the load flowing within the pipe or movement of the ground within which the pipe runs. A common technique for pipe repair involves impregnating a patch in the form of a tube of resin absorbent material with a curable synthetic resin. The patch is then 10 positioned on an inflatable bladder. The bladder and patch can then be positioned within the pipe at the location where the repair is required. Inflation of the bladder then holds the impregnated patch against the walls of the pipe whilst the resin cures. Once the resin has cured, the resin and absorbent material forms a rigid watertight layer bonded to the interior of the pipe. In this way cracks or fractures of the pipe can 15 be readily sealed. Commonly, the bladder and patch is inserted into the pipe at a convenient entry point some distance from the repair location. In order to reach the repair location, the bladder and patch is pushed along the pipe by a wheeled crawler robot. The robot may also be provided with a flexible cord carrying control cables and/or an 20 air/water supply for inflating the bladder. In order to confirm the correct location has been reached before inflating the bladder, the distance travelled by the robot along the pipes is monitored, typically on the basis of wheel rotations or alternatively by use of other location tracking systems such as GPS or similar.

WO 2013/190282 PCT/GB2013/051583 -2 A particularly common location for fractures in pipes is at the joint between a primary pipe and a branch pipe, the branch pipe being typically known as a lateral pipe. If the basic technique above is used in such an area, the lateral pipe can be blocked off at the end of the repair and will need to be reopened. Additionally, this 5 will not necessarily fix any fracture in the lateral pipe as it joins the primary pipe. As such, these repairs are typically carried out using a T or Y shaped patch positioned on a corresponding T or Y shaped bladder, the leg of the T or Y being held down or inverted during transport along the pipe, the technique otherwise substantially as described above. As most fractures at lateral joints occur at the point 10 where the lateral pipe connects to the main pipe, it is often sufficient (and would be more efficient in terms of materials) merely to repair the junction area rather than the full circumference of the primary pipe. This can be achieved by use of a 'top hat' patch comprising a tube portion and a brim portion attached around one end of the tube portion. In use, the tube portion can be inserted into the lateral pipe and the brim 15 portion can be held against the walls of the primary pipe around the joint with the lateral pipe. Whilst these techniques are well known and well understood, there are still some known difficulties. For instance, crawler robots are very expensive and the method of locating the robot by monitoring distance is not completely accurate, 20 particularly where a pipe is curved and/or if the robot's wheels slip or slide along part of the pipe. Another issue is that during the passage along the pipe resin can be lost from the impregnated patch if the patch rubs along the pipe. This lost resin may contribute to a build up of material along the pipe and present a snagging hazard. Deposits of resin on the inside of the pipe may also hinder future pipe interior WO 2013/190282 PCT/GB2013/051583 -3 surveillance. Conversely, rubbing during travel can additionally or alternatively result in the resin picking up contamination or debris from within the pipe. This can have an impact on the bond achieved between the resin and the pipe as the resin cures. Potentially, sufficient contamination could compromise the integrity of the repair. 5 The time taken to move the impregnated material to the repair location can also vary from job to job. The resin is typically comprised of two or more components that begin to cure on being mixed. The time from initial mixing to full cure depends upon the temperature of the material. As such, the amount of time available to correctly locate the bladder and impregnated material at the repair site or 10 the time required for holding the inflated bladder in position may vary both due to the initial temperature of the resin components and the ambient temperature of the site. In addition the general problems mentioned above, there are more specific issues relating to the lateral pipe repair methods. For instance, in order to maintain the top hat patch in position on the bladder during transit elastic bands are wrapped 15 around the bladder and opposite edges of the brim. Once the resin cures, the portion of the bands overlapping the brim are incorporated into the repair but the remainder of the bands remain free in the pipe. As such they constitute a significant snagging hazard and need to be removed. This additional step renders this method impractical and expensive. 20 An additional problem with lateral repairs is ensuring that the T, Y or top hat patch is correctly orientated with respect to the lateral pipe before inflating the bladder. Even in a relatively straight section of pipe it can be difficult to ensure that the crawler robot does not crab slightly around the pipe during transit. Accordingly, it is common to insert a camera along the lateral pipe so that the orientation of the T, Y WO 2013/190282 PCT/GB2013/051583 -4 or top hat patch can be ascertained and if necessary adjusted before inflation. Even with this step, identifying and adjusting the orientation can be difficult. It is thus an object of the present invention to provide apparatus and methods that at least partially overcomes or alleviates the above problems. 5 According to a first aspect of the present invention there is provided apparatus for repairing a junction between a primary pipe and a lateral pipe, the apparatus comprising: a patch having a tube portion and a brim portion attached around one end of the tube portion; an inflatable bladder having a main body and a side leg; wherein the tube portion of the patch is adapted to fit around the side leg of the bladder and 10 wherein the brim portion of the patch is secured to the main body of the bladder by one or more soluble ties. According to a second aspect of the present invention there is provided a method of repairing a junction between a primary pipe and a lateral pipe, using an apparatus according to the first aspect of the present invention, the method comprising 15 the steps of: impregnating the patch with a curable resin; fitting the patch to the bladder such that the tube portion of the patch fits around the side leg of the bladder; securing the patch to the main body of the bladder by one or more soluble ties; inserting the impregnated patch and bladder into a pipe to be repaired; locating the impregnated patch and bladder at the junction to be repaired; aligning the side arm of 20 the bladder with the lateral pipe; and inflating the bladder so as to press the tube portion of the patch against the walls of the lateral pipe and the brim portion of the patch against the walls of the primary pipe around the joint with the lateral pipe. The use of soluble ties enables a top hat type patch to be used to repair a lateral pipe junction without leaving an enduring snagging hazard.

WO 2013/190282 PCT/GB2013/051583 -5 Preferably, the ties may be cold water or warm water soluble as required or desired. Most preferably, the ties are water soluble on a timescale of the same order of the curing timescale of the resin when at a substantially similar temperature to the resin. Preferably, the ties are stretchable. In this manner they can continue to secure 5 the brim to the main body of the bladder during the inflation stage. This helps ensure that the brim is pressed evenly against the wall of the pipe. The soluble ties may be formed from any suitable material. In particular, the soluble ties may be formed from polyvinyl alcohol (PVOH) biodegradable polymer or compostable polymers. Beneficially, PVOH is substantially stretchable and typically 10 dissolves on a timescale of a few hours. The ties may comprise a flexible strap and a locking head whereby the flexible strap can be inserted through an aperture in the locking head to form a loop or noose about an item or items to be secured, the loop or noose being capable of being pulled tight about the said item(s) and then locked in place by the locking head. The strap 15 may be provided with an array of projections and recesses which cooperate with a pawl disposed in the aperture of the locking head to form a ratchet mechanism. The array of projections and recesses may take the form of an array of saw-toothed ribs. The strap may be provided with a region of weakness to facilitate more rapid disintegration. The region of weakness may take the form of a portion having 20 reduced thickness or may take the form of one or more notches set into a surface of the tie. Preferably, a pair of soluble ties is used to secure the patch to the bladder, one tie being provided on either side of the tube portion. In alternative embodiments other arrangements of tie may be used.

WO 2013/190282 PCT/GB2013/051583 -6 In addition to or alongside each said soluble tie a wire tie and/or an absorbent strip may be provided to secure the patch relative to the bladder. The wire tie may be adapted to snap once inflation of the bladder commences. The resin may comprise a water-glass based polysilicate. Typically such a 5 polysilicate may comprise a blend of silicate resin and polyurethane resin. The patch may be formed from an absorbent felt material. The felt may be formed from glass fibre or any other suitable fibre. The tube potion of the patch may be orientated substantially perpendicular to the brim portion. Alternatively, the tube potion of the patch may be orientated at a 10 substantially oblique angle to the brim portion. Accordingly, the patch may be adapted to a T or Y type lateral junction. The tube portion of the patch may be provided with a marker indication on its outer surface. Preferably, the marker indication is aligned with the axis of the tube portion. The marker indication can help with alignment of the tube portion relative to 15 the lateral pipe. The marker indication may be prominently coloured or shaded line on the tube portion. The marker indication may be provided by a dyed, inked or painted area of the tube portion. Additionally or alternatively, the marker indication may be provided by stitching on the tube portion. In embodiments wherein the patch has a marker indication, the method may involve the additional steps of: aligning the 20 marker indication with the axis of the main body of the bladder before securing the patch to the main body of the bladder. The apparatus may be provided with a protective sheath for use when inserting and positioning the apparatus within the pipe. The sheath may comprise a tube provided with a series of eyelets around each open end, the eyelets at a first end being WO 2013/190282 PCT/GB2013/051583 -7 reinforced the eyelets at a second end not being reinforced. The eyelets at the first end may be reinforced by bonding an additional layer of material to the sheath around the eyelets. The additional layer may be comprised of the same material as the rest of the sheath or of a different material. 5 The sheath may be transparent or substantially transparent. Typically, the sheath is formed from a plastic material such as polythene (polyethylene) or the like. In some embodiments, the sheath may be formed from a soluble material such as PVOH. In such embodiments, the method may include the step of placing the sheath 10 over the impregnated patch and bladder before inserting the impregnated patch and bladder into the pipe. The step of placing the sheath over the impregnated patch and bladder may include threading a tie through the eyelets of the second end of the sheath; and tightening said tie to secure the sheath to the bladder. The tie may be a conventional cable tie but is preferably a soluble tie. This step may further include 15 attaching an elongate flexible member to the reinforced eyelets of the first end of the sheath. The elongate flexible member may be directly passed through the reinforced eyelets or may be attached to a connector device which is itself passed through the reinforced eyelets. A suitable elongate flexible member may be formed from string, rope, cord or the like. A suitable connector device may comprise a hook, loop or 20 karabiner. Preferably, the second end of the sheath is secured to the bladder beyond the patch. The second end of the sheath is preferably secured over the end of the bladder that will be inserted into the pipe first. The protective sheath may be provided with a number of ventilation apertures along its length. The ventilation apertures can enable WO 2013/190282 PCT/GB2013/051583 -8 the dissipation of heat from within the sheath thus maintaining the pre-determined working life and curing time. In such embodiments, the method may include the step of removing the sheath from the impregnated patch and bladder. This step may take place either immediately 5 before or immediately after the step of aligning the side anm of the bladder with the lateral pipe. The removal step may be achieved by pulling on the elongate flexible member attached to the eyelets of the first end of the sheath. Since the eyelets at the second end of the sheath are not reinforced, they will tear when sufficient force is applied by pulling on the elongate flexible member allowing the sheath to be released. 10 The flexible insertion rods may be connected together end to end. The flexible insertion rods may be formed from steel or other suitable metal or material. In addition to flexible insertion rods one or more spring coils may be provided. The spring coils may be connected between two rods. In this manner, particularly sharp bends in the pipeline may be negotiated more easily. In particular, a spring coil may 15 be provided between the end rod and the bladder. This facilitates insertion into a pipe from a manhole of restricted size. In such embodiments, the method may include the steps of connecting one or more such rods together. The method may then involve the further step of pushing the impregnated patch and bladder to the repair location using the rods. The step of 20 aligning the side arm of the bladder with the lateral pipe, may involve rotating the rod or rods. This will then result in corresponding rotation of the impregnated patch and bladder. This is much simpler, more cost effective and more intuitive, than manoeuvring a crawler robot with a pipe to correct the orientation.

WO 2013/190282 PCT/GB2013/051583 -9 The resin may comprise two or more components, which when mixed provide a curable resin. The components may be supplied in separate containers or in separate sections of a single container. Preferably, the components are supplied in a single bag separated into two sections by sealing clip. This allows for the removal of the clip to 5 facilitate kneading of the bag to mix the resin. Beneficially, such a container removes the need for separate component containers, measuring means or mixing means. The separate containers or the separate container sections may be provided with a temperature sensing means. The temperature sensing means may be operable to respond to variations in the temperature of the resin components, container or 10 container sections and may be provided with indicator means operable to output an indication thereof. By monitoring the temperature of the resin components and the ambient temperature, a user can determine the average working time, 'pot-life' or likely curing timescale of the resin. Preferably, the indicator means may comprise one or more areas of thermochromatic material printed or otherwise disposed on to 15 the substrate. The thermochromatic material may be a thermochromatic ink and may be of the liquid crystal or leuco dye type. The thermochromatic areas may be shaped or otherwise adapted to indicate their transition temperature. The indicator means may further be provided with indications of the likely product lifespan or curing time. These indications may be in the form of a table. Preferably, the indicator means are 20 provided on the exterior of the container or container section. The indicator means may be affixed to the container or container section by a suitable adhesive. In some embodiments, the temperature sensing means may comprise a probe projecting into the resin component and connected to the indicator means provided on the exterior of the container or container section.

WO 2013/190282 PCT/GB2013/051583 - 10 In an alternative embodiment, the indicator means may comprise an alphanumeric display. According to a third aspect of the present invention there is provided a kit of parts for implementing the method of the second aspect of the present invention the 5 kit comprising: a patch having a tube portion and a brim portion attached around one end of the tube portion; an inflatable bladder having a main body and a side leg; and one or more soluble ties. The kit of the third aspect of the present invention may incorporate any or all features of the first or second aspects of the present invention, as desired or as 10 appropriate. The kit may additionally incorporate any one or more of: one or more protective gloves; one or more ground sheets or trays for use in applying the resin to the patch; a resin spreader; a protective sheath; one or more conventional cable ties; an elongate flexible member; one or more flexible insertion rods; an inflation hose for 15 connection to inflate the bladder; a compressor for use with an inflation hose to inflate the bladder; an ambient temperature sensor; a twin air supply control system; one or more pre-measured resin bags; one or more wire ties; one or more strips of absorbent material; one or more protective polythene (polyethylene) or PVOH tubes; one or more rubber bands; polythene (polyethylene) or PVOH stretch wrap; an outer box or 20 an outer box with a waxed interior; one or more anti-bacterial wipes or gel packs; or information leaflet. According to a fourth aspect of the present invention there is provided apparatus for repairing a junction between a primary pipe and a lateral pipe, the apparatus comprising: a patch .having a tube portion and a brim portion attached WO 2013/190282 PCT/GB2013/051583 - 11 around one end of the tube portion; an inflatable bladder having a main body and a side leg; wherein the tube portion of the patch is adapted to fit around the side leg of the bladder and wherein one or more absorbent strips are provided around the brim portion of the patch and the main body of the bladder the brim portion of the patch 5 being secured to the main body of the bladder by one or more retaining bands provided over the or each absorbent strip. According to a fifth aspect of the present invention there is provided a method of repairing a junction between a primary pipe and a lateral pipe, using an apparatus according to the fourth aspect of the present invention, the method comprising the 10 steps of: impregnating the patch with a curable resin; fitting the patch to the bladder such that the tube portion of the patch fits around the side leg of the bladder; impregnating one or more absorbent strips with curable resin; providing said one or more absorbent strips around the brim portion of the patch and the main body of the bladder; securing the patch to the main body of the bladder by one or more retaining 15 bands provided over the or each absorbent strip; inserting the impregnated patch and bladder into a pipe to be repaired; locating the impregnated patch and bladder at the junction to be repaired; aligning the side arm of the bladder with the lateral pipe; and inflating the bladder so as to press the tube portion of the patch against the walls of the lateral pipe and the brim portion of the patch against the walls of the primary pipe 20 around the joint with the lateral pipe. The use of retaining bands provided over absorbent strips ensures that the retaining bands are incorporated into the patch once the resin cures. As such, the retaining bands are not free to provide an enduring snagging hazard.

WO 2013/190282 PCT/GB2013/051583 -12 Preferably, one absorbent strip is provided for each retaining band. Most preferably, a pair of absorbent strips and a pair of retaining bands are used to secure the patch to the bladder, one absorbent strip and one retaining band being provided on either side of the tube portion. In alternative embodiments other arrangements of one 5 absorbent strips and retaining bands may be used. In addition to or alongside each said absorbent strip and retaining band a wire tie may be provided to further secure the patch relative to the bladder. The wire tie may be adapted to snap once inflation of the bladder commences. The absorbent strip is preferably formed from the same material as the patch. 10 The retaining band may be an elastic band. The resin may comprise a water-glass based polysilicate. Typically such a polysilicate may comprise a blend of silicate resin and polyurethane resin. The patch may be formed from an absorbent felt material. The felt may be formed from glass fibre or any other suitable fibre.. 15 The tube potion of the patch may be orientated substantially perpendicular to the brim portion. Alternatively, the tube potion of the patch may be orientated at a substantially oblique angle to the brim portion. Accordingly, the patch may be adapted to a T or Y type lateral junction. The tube portion of the patch may be provided with a marker indication on its 20 outer surface. Preferably, the marker indication is aligned with the axis of the tube portion. The marker indication can help with alignment of the tube portion relative to the lateral pipe. The marker indication may be prominently coloured or shaded line on the tube portion. The marker indication may be provided by a dyed, inked or painted area of the tube portion. Additionally or alternatively, the marker indication WO 2013/190282 PCT/GB2013/051583 - 13 may be provided by stitching on the tube portion. In embodiments wherein the patch has a marker indication, the method may involve the additional steps of: aligning the marker indication with the axis of the main body of the bladder before securing the patch to the main body of the bladder. 5 The apparatus may be provided with a protective sheath for use when inserting and positioning the apparatus within the pipe. The sheath may comprise a tube provided with a series of eyelets around each open end, the eyelets at a first end being reinforced the eyelets at a second end not being reinforced. The eyelets at the first end may be reinforced by bonding an additional layer of material to the sheath around 10 the eyelets. The additional layer may be comprised of the same material as the rest of the sheath or of a different material. The sheath may be transparent or substantially transparent. Typically, the sheath is formed from a plastic material such as polythene (polyethylene) or the like. In some embodiments, the sheath may be formed from a soluble material such as 15 PVOH. In such embodiments, the method may include the step of placing the sheath over the impregnated patch and bladder before inserting the impregnated patch and bladder into the pipe. The step of placing the sheath over the impregnated patch and bladder may include threading a tie through the eyelets of the second end of the 20 sheath; and tightening said tie to secure the sheath to the bladder. The tie may be a conventional cable tie but is preferably a soluble tie. This step may further include attaching an elongate flexible member to the reinforced eyelets of the first end of the sheath. The elongate flexible member may be directly passed through the reinforced eyelets or may be attached to a connector device which is itself passed through the WO 2013/190282 PCT/GB2013/051583 -14 reinforced eyelets. A suitable elongate flexible member may be formed from string, rope, cord or the like. A suitable connector device may comprise a hook, loop or karabiner. Preferably, the second end of the sheath is secured to the bladder beyond the 5 patch. The second end of the sheath is preferably secured over the end of the bladder that will be inserted into the pipe first. The protective sheath may be provided with a number of ventilation apertures along its length. The ventilation apertures can enable the dissipation of heat from within the sheath thus maintaining the pre-determined working life and curing time. 10 In such embodiments, the method may include the step of removing the sheath from the impregnated patch and bladder. This step may take place either immediately before or immediately after the step of aligning the side arm of the bladder with the lateral pipe. The removal step may be achieved by pulling on the elongate flexible member attached to the eyelets of the first end of the sheath. Since the eyelets at the 15 second end of the sheath are not reinforced, they will tear when sufficient force is applied by pulling on the elongate flexible member allowing the sheath to be released. The flexible insertion rods may be connected together end to end. The flexible insertion rods may be formed from steel or other suitable metal. In addition to flexible insertion rods one or more spring coils may be provided. The spring coils 20 may be connected between two rods. In this manner, particularly sharp bends in the pipeline may be negotiated more easily. In particular, a spring coil may be provided between the end rod and the bladder. This facilitates insertion into a pipe from a manhole of restricted size.

WO 2013/190282 PCT/GB2013/051583 - 15 In such embodiments, the method may include the steps of connecting one or more such rods together. The method may then involve the further step of pushing the impregnated patch and bladder to the repair location using the rods. The step of aligning the side aim of the bladder with the lateral pipe, may involve rotating the rod 5 or rods. This will then result in corresponding rotation of the impregnated patch and bladder. This is much simpler, more cost effective, and more intuitive, than manoeuvring a crawler robot within a pipe to correct the orientation. The resin may comprise two components, which when mixed provide a curable resin. The components may be supplied in separate containers or in separate 10 sections of a single container. Preferably, the components are supplied in a single bag separated into two sections by a sealing clip. This allows for the removal of the clip to facilitate kneading of the bag to mix the resin. Beneficially, such a container removes the need for separate component containers, measuring means or mixing means. 15 The separate containers or the separate container sections may be provided with a temperature sensing means. The temperature sensing means may be operable to respond to variations in the temperature of the resin components, container or container sections and may be provided with indicator means operable to output an indication thereof. By monitoring the temperature of the resin components and the 20 ambient temperature, a user can determine the average working time, 'pot-life' or likely curing timescale of the resin. Preferably, the indicator means may comprise one or more areas of thermochromatic material printed or otherwise disposed on to the substrate. The thermochromatic material may be a thermochromatic ink and may be of the liquid crystal or leuco dye type. The thermochromatic areas may be shaped WO 2013/190282 PCT/GB2013/051583 - 16 or otherwise adapted to indicate their transition temperature. The indicator means may further be provided with indications of the likely product lifespan or curing time. These indications may be in the form of a table. Preferably, the indicator means are provided on the exterior of the container or container section. The indicator means 5 may be affixed to the container or container section by a suitable adhesive. In some embodiments, the temperature sensing means may comprise a probe projecting into the resin component and connected to the indicator means provided on the exterior of the container or container section. In an alternative embodiment, the indicator means may comprise an 10 alphanumeric display. According to a sixth aspect of the present invention there is provided a kit of parts for implementing the method of the second aspect of the present invention the kit comprising: a patch having a tube portion and a brim portion attached around one end of the tube portion; an inflatable bladder having a main body and a side leg; one 15 or more absorbent strips; and one or more retaining bands. The kit of the third aspect of the present invention may incorporate any or all features of the first or second aspects of the present invention, as desired or as appropriate. The kit may additionally incorporate any one or more of: one or more 20 protective gloves; one or more ground sheets or trays for use in applying the resin to the patch; a resin spreader; a protective sheath; one or more conventional cable ties; an elongate flexible member; one or more flexible insertion rods; an inflation hose for connection to inflate the bladder; a compressor for use with an inflation hose to inflate the bladder; an ambient temperature sensor; a twin air supply control system; one or WO 2013/190282 PCT/GB2013/051583 - 17 more pre-measured resin bags; one or more wire ties; one or more strips of absorbent material; one or more protective polythene (polyethylene) or PVOH tubes; one or more rubber bands; polythene (polyethylene) or PVOH stretch wrap; an outer box or an outer box with a waxed interior; one or more anti-bacterial wipes or gel packs; or 5 information leaflet. According to a seventh aspect of the present invention there is provided a patch for use in repairing a junction between a primary pipe and a lateral pipe, the patch comprising: a tube portion and a base portion attached around one end of the tube portion wherein the tube portion is provided with a marker indication on the 10 outer surface of the tube portion, the marker indication being aligned with the axis of the tube portion. The provision of the marker indication can help with alignment of the tube portion relative to the lateral pipe. In particular, a user may align the marker indication with the axis of the main body of the bladder before securing the patch to 15 the main body of the bladder. The marker indication may be prominently coloured or shaded line on the tube portion. The marker indication may be provided by a dyed, inked or painted area of the tube portion. Additionally or alternatively, the marker indication may be provided by stitching on the tube portion. 20 The base portion may comprise a base tube so as to provide a T or Y tube patch. Alternatively, the base portion may comprise a brim so as to provide a top hat type patch. In order that the invention is more clearly understood it is described further below by way of example only and with reference to the accompanying drawings: WO 2013/190282 PCT/GB2013/051583 - 18 Figure 1 is a schematic view of a T joint between a lateral pipe and a primary pipe; Figures 2a-2b are illustrations of a patches according to the present invention for use in repairing pipe joints of the type shown in figure 1. 5 Figures 3a-3d are illustrations of a first implementation of the present invention; Figures 4a-4e are illustrations of a second implementation of the present invention; Figure 5a is a schematic view of a sheath for use in the present invention; 10 Figures 5b-5c show the sheath in use in the first and second implementations of the present invention; and Figure 6 shows a resin container according to the present invention. Turning now to figure 1, a T joint between a primary pipe 1 and a lateral pipe 2 is shown. The majority of fractures of such joints occur at the intersection 3 15 (shaded) of the lateral pipe 2 and the primary pipe 1. In order to repair fractures of this type, a patch 10 of absorbent material is impregnated with curable resin. The patch 10 may typically be comprised of fibreglass felt. The curable resin may typically be a water-glass based polysilicate. The patch 10 is then positioned on an inflatable bladder 20. The bladder 20 20 and patch 10 can then be positioned at the intersection 3 where the repair is required. Inflation of the bladder 20 then holds the impregnated patch against the walls of the intersection 2 whilst the resin cures. Once the resin has cured, the resin and patch 10 form a rigid watertight layer bonded to the interior of the intersection 3, in particular covering or penetrating into the cavities and displaced/broken joint.

WO 2013/190282 PCT/GB2013/051583 -19 In the present invention, as is shown in figure 2a, the patch 10 is of a top hat type comprising a tube portion 12 and a brim portion 11. The tube portion 12 is adapted to fit the lateral pipe 2 and the brim portion 11 is adapted to be held against the interior of the primary pipe 1 in the vicinity of the intersection 3. The patch is 5 further provided with a marker indication 13 in the form of a line running parallel to the axis of the tube portion 12. The marker indication 13 can be used to help align the tube portion 12 with the lateral pipe 2. It is also possible to provide a marker indication 13 on an alternative form or patch 1Ob (shown in figure 2b) comprising a base tube portion 11 b and a tube portion 10 12b. Such a patch 1Ob can be used in the present invention or with known methods of pipe repair utilising a T or Y type patch. The bladder 20, as is shown in figure 3, comprises a main body 21 and a side leg 22. The main body 21 and side leg 22 are each substantially cylindrical and adapted to be inflated from a first circumference being significantly narrower than the 15 corresponding pipe 1, 2 to a second circumference at least equal to the circumference of the corresponding pipe 1, 2 such that the patch 10 can be pressed against the intersection 3. In order to effect a pipe repair, the patch 10 is impregnated with a liquid resin. The patch 10 is subsequently positioned on the bladder 20 such that the side arm 22 20 projects through the tube portion 12 (figure 3a). The patch 10 is then secured to the bladder 20 by use of soluble ties 31 (figure 3b). The ties 31 are provided around the brim portion 11 on either side of the tube portion 12. The patch 10 and bladder 20 can then be inserted into the primary pipe 1 and located adjacent to the lateral pipe 2. In the present invention, the bladder 20 can be WO 2013/190282 PCT/GB2013/051583 - 20 pushed along pipe 1 by means of one or more flexible insertion rods (not shown) formed fiom steel or other suitable metal. The bladder 20 is connected to the rods by way of a T-bar fitting (not shown). Wheels 23 allow the bladder 20 to move along pipe 1 with minimal resistance. In order to facilitate the travel along pipe 1, the side 5 leg 22 and tube portion 12 may be bent over as is shown in figure 3d. Upon reaching the intersection 3, the alignment of the patch 10 is checked by use of a camera inserted along pipe 2. In this context, the marker indication 13 provides considerable assistance in quickly and accurately ascertaining the alignment of the patch. If the patch 10 is misaligned, the flexible insertion rods may be rotated, 10 as necessary, so as to rotate the bladder 20 and, in turn, the patch 10. Once the patch 10 is positioned and aligned correctly relative to the intersection, the bladder 20 is inflated. The inflation presses the patch 10 against the intersection 3. As the bladder 20 inflates, the ties 31 hold the patch 10 against the bladder 20. Subsequently, the resin cures enabling the combination of the patch 20 15 and the resin to form a watertight repair to the intersection 3. The bladder 20 may then be deflated and removed. One or more elongate flexible members may be attached to the bladder to facilitate such removal. The soluble ties 31 may be formed from polyvinyl alcohol (PVOH). Ties 31 of this type are described in more detail in GB2411205. As such, once water is 20 reintroduced to the pipe 1, the ties 31 dissolve and thus leave no permanent snagging hazard behind. Turning now to figure 4, an alternative embodiment of the present invention is shown. In this embodiment, the soluble ties 31 are omitted. In place of the ties 31 are provided absorbent strips 32 made from the same material as the patch 10. The strips WO 2013/190282 PCT/GB2013/051583 -21 32 are wrapped around the brim portion 12 at either side of the tube portion 12 (figure 4b). Similarly to the patch 10, the strips 32 are impregnated with resin. Once the strips 32 are in place, elastic retaining bands 33 are placed around the strips 32 (figure 4d). Optionally, wire ties 34 may also be provided around the strips 32 (figure 4c). In 5 order to facilitate the travel along pipe 1, the side leg 22 and tube portion 12 may be bent over as is shown in figure 4e. As in the previous embodiment, the patch 10 and bladder 20 can then be inserted into the primary pipe 1 and located adjacent to the lateral pipe 2 by means of one or more flexible insertion rods (not shown) connected together end to end. Upon 10 reaching the intersection 3, the alignment of the patch 10 is checked by use of a camera inserted along pipe 2 and marker indication 13. If the patch 10 is misaligned, the flexible insertion rods may be rotated, as necessary, so as to rotate the bladder 20 and, in turn, the patch 10. In addition to flexible insertion rods one or more spring coils (not shown) may be provided connected between two rods or between the end 15 rod and the bladder. In this manner, particularly sharp bends in the pipeline may be negotiated more easily and may facilitate insertion into a pipe from a manhole of restricted size. Once the patch 10 is positioned and aligned correctly relative to the intersection, the bladder 20 is inflated. The inflation presses the patch 10 against the 20 intersection 3. As the bladder 20 inflates, the bands 33 hold the patch 10 against the bladder 20. Subsequently, the resin cures enabling the combination of the patch 20 and the resin to form a watertight repair to the intersection 3. The bladder 20 may then be deflated and removed. One or more elongate flexible members may be attached to the bladder to facilitate such removal.

WO 2013/190282 PCT/GB2013/051583 - 22 Once the resin has cured, the strips 32 overlie the bands 33. As such the bands 33 cannot present an enduring snagging hazard. If wire ties 34 are provided they typically snap as bladder 20 inflates. The wire ties 34 will then either be covered by the strips 32 or, if they break free, will be swept away once water is reintroduced.to 5 the pipe 1, thereby not presenting an enduring snagging hazard. In order to prevent unwanted contamination of the pipe 1 or resin by the patch 10 rubbing against the inside of the pipe 1 during insertion and travel, a sheath 40 may be provided. The sheath, as shown in figure 5a, comprises a substantially transparent plastic tube having reinforced eyelets 41 provided at a first end and 10 unreinforced eyelets 42 provided at a second end. A tie 43 (soluble or conventional) may be threaded through the eyelets 42 and then secured around an end 24 of the bladder 20 as is shown in figure 5b for the first implementation of the invention and figure 5c for the second implementation of the invention. A karabiner 44 may be threaded through the reinforced eyelets 41. A cord 45 15 can be connected to the karabiner 44. Once the patch 10 is positioned and aligned correctly relative to the intersection 3, the sheath 40 can be removed by pulling on cord 45. Exerting sufficient force on the cord causes the eyelets 42 to tear and thus allows the sheath to be removed. Turning now to figure 6, a resin container 50 in the form of a bag is shown the 20 bag has two sections 51, 52 separated by a sealing clip 53. Each section 51, 52 contains a separate component of the resin. Once the clip 53 is removed, the two components can be mixed by kneading the bag 50. The bag is additionally provide with temperatures sensing means 60. The temperature sensing means 60 may comprise an indicator means 62 operable to WO 2013/190282 PCT/GB2013/051583 -23 respond to the temperature of the bag 50 and/or its contents. The indicator means 62 may be directly reactive to the temperature of the bag 50. Alternatively, the indicator means 62 may be provide with a probe 61 which passes through the bag into the resin component to provide a measure of the temperature of the component. The indicator 5 means 62 is retained on the bag 50 by a suitable adhesive. Typically the indicator means 62 comprise one or more areas of thernochromatic material printed or otherwise disposed on a substrate. The thermochromatic areas may be shaped or otherwise adapted to indicate their transition temperature and hence the temperature of the resin components. 10 The user of the resin can thus check the temperature of the resin components using the temperature sensing means 50 and can separately check the ambient temperature. This will provide the user with an indication of the curing timescale for the resin and/or the overall life time of the resin. In some embodiments, a table of curing timescales for specified component and/or ambient temperatures can be 15 provided on a label (not shown) placed on the bag. It is of course to be understood that the invention is not to be restricted to the details of the above embodiments which are described by way of example only.

Claims

1. An apparatus for repairing a junction between a primary pipe and a lateral pipe, the apparatus comprising: a patch having a tube portion and a brim portion attached around one end of the tube portion; an inflatable bladder 5 having a main body and a side leg; wherein the tube portion of the patch is adapted to fit around the side leg of the bladder and wherein the brim portion of the patch is secured to the main body of the bladder by one or more soluble ties.

2. An apparatus as claimed in claim 1 wherein the ties are cold water soluble on 10 a timescale of the same order of the curing timescale of the resin when at a substantially similar temperature to the resin.

3. An apparatus as claimed in any preceding claim wherein the ties are stretchable.

4. An apparatus as claimed in any preceding claim wherein the soluble ties are 15 formed from polyvinyl alcohol (PVOH).

5. An apparatus as claimed in any preceding claim wherein a pair of soluble ties is used to secure the patch to the bladder, one tie being provided on either side of the tube portion.

6. An apparatus as claimed in any preceding claim wherein a wire tie and/or an 20 absorbent strip is provided to further secure the patch relative to the bladder.

7. An apparatus as claimed in any preceding claim wherein tube potion of the patch is orientated substantially perpendicular to the brim portion or is orientated at a substantially oblique angle to the brim portion. WO 2013/190282 PCT/GB2013/051583 - 25

8. An apparatus as claimed in any preceding claim wherein the tube portion of the patch is provided with a marker indication on its outer surface.

9. An apparatus as claimed in claim 8 wherein the marker indication is aligned with the axis of the tube portion. 5

10. An apparatus as claimed in claim 8 or claim 9 wherein the marker indication is prominently coloured or shaded line on the tube portion.

11. An apparatus as claimed in any preceding claim wherein the apparatus is provided with a protective sheath for use when inserting and positioning the apparatus within the pipe, the sheath comprising a tube provided with a series 10 of eyelets around each open end, the eyelets at a first end being reinforced the eyelets at a second end not being reinforced.

12. An apparatus as claimed in claim 11 wherein the second end of the sheath is secured to the bladder beyond the patch.

13. An apparatus as claimed in claim 11 or claim 12 wherein the protective sheath 15 is provided with a number of ventilation apertures along its length.

14. An apparatus as claimed in any preceding claim wherein the apparatus includes one or more flexible insertion rods.

15. An apparatus as claimed in claim 14 wherein the apparatus includes one or more spring coils. 20

16. An apparatus as claimed in claim 14 or claim 16 wherein the bladder is adapted to be connected to the rods by way of a T-bar fitting or crank winding handle.

17. A method of repairing a junction between a primary pipe and a lateral pipe, using an apparatus according to any one of claims 1 to 16, the method WO 2013/190282 PCT/GB2013/051583 - 26 comprising the steps of impregnating the patch with a curable resin; fitting the patch to the bladder such that the tube portion of the patch fits around the side leg of the bladder; securing the patch to the main body of the bladder by one or more soluble cable ties; inserting the impregnated patch and bladder into a 5 pipe to be repaired; locating the impregnated patch and bladder at the junction to be repaired; aligning the side arm of the bladder with the lateral pipe; and inflating the bladder so as to press the tube portion of the patch against the walls of the lateral pipe and the brim portion of the patch against the walls of the primary pipe around the joint with the lateral pipe. 10

18. A method as claimed in claim 17 wherein if the patch has a marker indication, the method involves the additional steps of. aligning the marker indication with the axis of the main body of the bladder before securing the patch to the main body of the bladder.

19. A method as claimed in claim 17 or claim 18 wherein the method includes the 15 step of placing a sheath over the impregnated patch and bladder before inserting the impregnated patch and bladder into the pipe.

20. A method as claimed in claim 19 wherein the step of placing the sheath over the impregnated patch and bladder includes threading a tie through the eyelets of the second end of the sheath; and tightening said tie to secure the sheath to 20 the bladder.

21. A method as claimed in claim 19 or claim 20 wherein the method includes the step of removing the sheath from the impregnated patch and bladder either immediately before or immediately after the step of aligning the side arm of the bladder with the lateral pipe. WO 2013/190282 PCT/GB2013/051583 - 27

22. A method as claimed in claim 21 wherein the removal step is achieved by pulling on the elongate flexible member attached to the eyelets of the first end of the sheath.

23. A method as claimed in any one of claims 17 to 22 wherein the method 5 includes the steps of connecting one or more flexible insertion rods together pushing the impregnated patch and bladder to the repair location using the rods.

24. A method as claimed in any one of claims 17 to 23 wherein a spring coil is connected between two rods or between the end rod and the bladder. 10

25. A method as claimed in claim 24 wherein the step of aligning the side arm of the bladder with the lateral pipe, involves rotating the rods.

26. A kit of parts for implementing the method of any one of claims 17 to 25, the kit comprising: a patch having a tube portion and a brim portion attached around one end of the tube portion; an inflatable bladder having a main body 15 and a side leg; and one or more soluble ties.

27. The kit of claim 26 additionally incorporating any one or more of one or more protective gloves; one or more ground sheets or trays for use in applying the resin to the patch; a resin spreader; a protective sheath; one or more conventional cable ties; an elongate flexible member; one or more flexible 20 insertion rods; an inflation hose for connection to inflate the bladder; a compressor for use with an inflation hose to inflate the bladder; an ambient temperature sensor a twin air supply control system; one or more pre measured resin bags; one or more wire ties; one or more strips of absorbent material; one or more protective polythene (polyethylene) or PVOH tubes; one WO 2013/190282 PCT/GB2013/051583 - 28 or more rubber bands; polythene (polyethylene) or PVOH stretch wrap; an outer box or an outer box with a waxed interior; one or more anti-bacterial wipes or gel packs; or information leaflet..

28. An apparatus for repairing a junction between a primary pipe and a lateral 5 pipe, the apparatus comprising: a patch having a tube portion and a brim portion attached around one end of the tube portion; an inflatable bladder having a main body and a side leg; wherein the tube portion of the patch is adapted to fit around the side leg of the bladder and wherein one or more absorbent strips are provided around the brim portion of the patch and the 10 main body of the bladder, the brim portion of the patch being secured to the main body of the bladder by one or more retaining bands provided over the or each absorbent strip.

29. An apparatus as claimed in claim 28 wherein one absorbent strip is provided for each retaining band. 15

30. An apparatus as claimed in claim 28 or claim 29 wherein a pair of absorbent strips and a pair of retaining bands are used to secure the patch to the bladder, one absorbent strip and one retaining band being provided on either side of the tube portion.

31. An apparatus as claimed in any one of claims 28 to 30 wherein a retaining 20 band a wire tie may be provided to further secure the patch relative to the bladder.

32. An apparatus as claimed in claim 31 wherein the wire tie is adapted to snap once inflation of the bladder commences. WO 2013/190282 PCT/GB2013/051583 - 29

33. An apparatus as claimed in any one of claims 28 to 32 wherein the absorbent strip is formed from the same material as the patch.

34. An apparatus as claimed in any one of claims 28 to 33 wherein the retaining band is an elastic band. 5

35. An apparatus as claimed in any one of claims 28 to 34 wherein tube potion of the patch is orientated substantially perpendicular to the brim portion or is orientated at a substantially oblique angle to the brim portion.

36. An apparatus as claimed in any one of claims 28 to 35 wherein the tube portion of the patch is provided with a marker indication on its outer surface. 10

37. An apparatus as claimed in claim 36 wherein the marker indication is aligned with the axis of the tube portion.

38. An apparatus as claimed in claim 36 or claim 37 wherein the marker indication is prominently coloured or shaded line on the tube portion.

39. An apparatus as claimed in any one of claims 28 to 38 wherein the apparatus 15 is provided with a protective sheath for use when inserting and positioning the apparatus within the pipe, the sheath comprising a tube provided with a series of eyelets around each open end, the eyelets at a first end being reinforced the eyelets at a second end not being reinforced.

40. An apparatus as claimed in claim 39 wherein the second end of the sheath is 20 secured to the bladder beyond the patch.

41. An apparatus as claimed in claim 39 or claim 40 wherein the protective sheath is provided with a number of ventilation apertures along its length.

42. An apparatus as claimed in any one of claims 28 to 41 wherein the apparatus includes one or more flexible insertion rods. WO 2013/190282 PCT/GB2013/051583 - 30

43. An apparatus as claimed in claim 42 wherein the apparatus includes one or more spring coils

44. An apparatus as claimed in claim 43 wherein the bladder is adapted to be connected to the rods by way of a T-bar fitting or a crank winding handle. 5

45. A method of repairing a junction between a primary pipe and a lateral pipe, using an apparatus according to any one of claims 28 to 44, the method comprising the steps of. impregnating the patch with a curable resin; fitting the patch to the bladder such that the tube portion of the patch fits around the side leg of the bladder; impregnating one or more absorbent strips with curable 10 resin; providing said one or more absorbent strips around the brim portion of the patch and the main body of the bladder; securing the patch to the main body of the bladder by one or more retaining bands provided over the or each absorbent strip; inserting the impregnated patch and bladder into a pipe to be repaired; locating the impregnated patch and bladder at the junction to be 15 repaired; aligning the side arm of the bladder with the lateral pipe; and inflating the bladder so as to press the tube portion of the patch against the walls of the lateral pipe and the brim portion of the patch against the walls of the primary pipe around the joint with the lateral pipe.

46. A method as claimed in claim 45 wherein if the patch has a marker indication, 20 the method involves the additional steps of. aligning the marker indication with the axis of the main body of the bladder before securing the patch to the main body of the bladder. WO 2013/190282 PCT/GB2013/051583 -31

47. A method as claimed in claim 45 or claim 46 wherein the method includes the step of placing a sheath over the impregnated patch and bladder before inserting the impregnated patch and bladder into the pipe.

48. A method as claimed in claim 47 wherein the step of placing the sheath over 5 the impregnated patch and bladder includes threading a tie through the eyelets of the second end of the sheath; and tightening said tie to secure the sheath to the bladder.

49. A method as claimed in claim 47 or claim 48 wherein the method includes the step of removing the sheath from the impregnated patch and bladder either 10 immediately before or immediately after the step of aligning the side arm of the bladder with the lateral pipe.

50. A method as claimed in claim 49 wherein the removal step is achieved by pulling on the elongate flexible member attached to the eyelets of the first end of the sheath. 15

51. A method as claimed in any one of claims 45 to 50 wherein the method includes the steps of connecting one or more flexible insertion rods together pushing the impregnated patch and bladder to the repair location using the rods.

52. A method as claimed in any one of claims 45 to 51 wherein a spring coil is 20 connected between two rods or between the end rod and the bladder.

53. A method as claimed in claim 52 wherein the step of aligning the side arm of the bladder with the lateral pipe, involves rotating the rods.

54. A kit of parts for implementing the method of any one of claims 45 to 53, the kit comprising: a patch having a tube portion and a brim portion attached WO 2013/190282 PCT/GB2013/051583 - 32 around one end of the tube portion; an inflatable bladder having a main body and a side leg; one or more absorbent strips; and one or more retaining bands.

55. The kit of claim 54 additionally incorporating any one or more of. one or more protective gloves; one or more ground sheets or trays for use in applying the 5 resin to the patch; a resin spreader; a protective sheath; one or more conventional ties; an elongate flexible member; one or more flexible insertion rods; an inflation hose for connection to inflate the bladder; a compressor for use with an inflation hose to inflate the bladder; an ambient temperature sensor a twin air supply control system; one or more pre-measured resin bags; one or 10 more wire ties; one or more strips of absorbent material; one or more protective polythene (polyethylene) or PVOH tubes; one or more rubber bands; polythene (polyethylene) or PVOH stretch wrap; an outer box or an outer box with a waxed interior; one or more anti-bacterial wipes or gel packs; or information leaflet. 15

56. A patch for use in repairing a junction between a primary pipe and a lateral pipe, the patch comprising: a tube portion and a base portion attached around one end of the tube portion wherein the tube portion is provided with a marker indication on the outer surface of the tube portion, the marker indication being aligned with the axis of the tube portion. 20

57. A patch as claimed in claim 56 wherein the marker indication is a prominently coloured or shaded line on the tube portion.

58. A patch as claimed in claim 56 or claim 57 wherein the marker indication is provided by a dyed, inked or painted area of the tube portion. WO 2013/190282 PCT/GB2013/051583 - 33

59. A patch as claimed in any one of claims 56 to 58 wherein the marker indication is provided by stitching on the tube portion.

60. A patch as claimed in any one of claims 56 to 59 wherein the base portion comprises a base tube so as to provide a T or Y tube patch. 5

61. A patch as claimed in any one of claims 56 to 60 wherein the base portion comprises a brim so as to provide a top hat type patch.