GB2514903A

GB2514903A - Repair of pipes and pipelines

Info

Publication number: GB2514903A
Application number: GB1406214.5A
Authority: GB
Inventors: Mark Thomas William Potter
Original assignee: SOURCE ONE ENVIRONMENTAL Ltd
Current assignee: SOURCE ONE ENVIRONMENTAL Ltd
Priority date: 2012-06-20
Filing date: 2012-06-20
Publication date: 2014-12-10
Anticipated expiration: 2032-06-20
Also published as: WO2013190283A3; GB201210926D0; WO2013190283A2; AU2013279090B2; GB2514903B; AU2013279090A1; GB2503248B; GB2503248A; EP2867137A2; GB201406214D0

Abstract

A protective sheath 40 suitable for use when inserting and positioning apparatus for pipe repair of the type comprising an absorbent patch 10 impregnated with a curable resin fitted around a substantially cylindrical inflatable bladder 20. The sheath comprises a tube provided with a series of eyelets around each open end, the eyelets at the first end 41 being reinforced, the eyelets at the second end 42 not being reinforced. The eyelets as the first end may be reinforced by bonding an additional layer of material to the sheath around the eyelets. The additional layer may be the same material as the remainder of the sheath. The additional layer may be a different material as the rest of the sheath. The sheath may be transparent. The sheath may be formed of a plastic material. The sheath may be formed of a soluble material such as Polyvinyl alcohol (PVOH). A tie may be threaded through the eyelets of the second end of the sheath and tightened to secure the sheath to the bladder.

Description

Repair of Pipes and Pipelines The present invention relates to improvements in and in relation to the repair of pipes and pipelines.

As pipes, in particular sewer or waste water pipes, age they can develop cracks or fractures. This can he 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 positioned on an inflatable bladder. The bladder and patch can then he 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 he readily sealed.

Commonly, the bladder and patch is inserted into the pipe at a convenient entry point some distance from the repair location. hi order to reach the repair location, the bladder and patch is pushed along the pipe by a wheeled crawler robot.

The robot may also he provided with a flexible cord carrying control cables and/or an air/water supply for inflating the bladder. In order to confirm the colTect 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 UPS or similar.

Whilst these techniques are well known and well understood, there are still some known difficulties. For instance, crawler robots axe very expensive and the method of locating the robot by monitoring distance is not completely accurate, 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 he thst 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 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.

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 inipregnated material at the repair site or 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.

It is thus an object of the present invention to provide apparatus and methods that at least partially overcomes or alleviates the above problems.

According to a first aspect of the present invention there is provided a resin container suitable for holding separately two components, which when mixed provide a curable resin suitable for use in repairing a pipe, the container comprising: a single hag separated into two container sections by a removable sealing clip, the separate container sections each being provided with a temperature sensing means operable to respond to variations in the temperature of the resin components. container or container sections and an indicator means provided on the exterior of the container section operahlc to output an indication thereof.

In this manner, a user can determine the curing timescale of the resin and thus whether the resin needs to he heated or cooled in order to effect the repair.

Beneficially, such a container removes the need for separate component containers, measuring means or mixing means.

According to a second aspect of the present invention there is provided a method of repairing a pipe, the method comprising the steps of: mixing a curable resin from two or more separate components; impregnating an absorbent patch with a curable resin; fitting the patch to a substantially cylindrical bladder; securing the patch to thc main body of the bladder; inserting the impregnated patch and bladdcr into a pipe to be repaired; locating the impregnated patch and bladder at the desired repair site; and inflating the bladder so as to press the tube portion of the patch against the walls of the pipe, wherein the method includes the further steps of determining the temperatures of the resin components before mixing; and thereby determining the curing timescale br (lie resin and thus whether (lie resin needs to he heated or cooled in order to effect the repair.

The method may include the further step of determining the ambient temperature and using the determined ambient temperature to determine the curing timescale for the resin and thus whether the resin needs to be heated or cooled in order to effect the repair.

The method may he carried out using a resin supplied in a container according to the first aspect of the present invention. The method may include the step of removing the dip and kneading the hag to mix the resin.

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 niay 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 he provided with indications of the likely product lifespan or curing time. These indications may he in the form of a table. 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.

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 protective sheath suitable for use when inserting and positioning apparatus br pipe repair of the type comprising an absorbent patch impregnated with a curable resin fitted around a substantially cylindrical inflatable bladder, the sheath comprising a tube provided with a series of eydets around each open end, the eyelets at a first end being reinforced the eyelets at a second end not being reinforced.

According to a fourth aspect of the present invention there is provided a method of repairing a pipe, the method comprising the steps of: mixing a curable resin from two separate components; impregnating an absorbent patch with a curable resin; fitting the patch to a substantially cylindrical bladder; securing the patch to the main body of the bladder; placing a protective sheath around the patch and bladder, the sheath comprising a tube provided with a series of eyelets around each open end, the eyelets at a first end being reinforced and the eyelets at a second end not being itinfomed; insetting the sheath, impregnated patch and bladder into a pipe to be repaired; locating the impregnated patch and bladder at the desired repair site; removing the sheath from the impregnated patch and bladder; and inflating the bladder so as to press the tube portion of the patch against the walls of the pipe.

A sheath of this type can ho readily placed over a patch and bladder for insertion into a pipe and readily removed from said patch and bladder when the patch is positioned at the repair site. The sheath can provide protection from contamination of the pipe and/or the resin during the insertion of the bladder and patch into the pipe.

The sheath and method of the third and fouilh aspects of the present invention may include any or all features of the first and second aspects of the present invention, as desired or as appropriate.

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.

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.

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 hladder. The tie may he 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 he attached to a connector device which is itseff 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 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 the dissipation of heat from within the sheath thus maintaining the prc-dctcrmincd The remova' step may he achieved by pulling on the elongate flexilie 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 puffing on the elongate flexible member allowing the sheath to he released.

According to a fifth aspect of the present invention there is provided a method of repairing a pipe, the method comprising the steps of: mixing a curable resin from two or more separate components; impregnating an absorbent patch with a curable resin; fitting the patch to a substantially cylindrical bladder; securing the patch to the main body of the bladder; inserting the impregnated patch and bladder into a pipe to he repaired; connecting the bladder to one or more flexible insertion rods; locating the impregnated patch and bladder at the desired repair site by pushing and/or pulling the Madder athng the pipe using the one or more flexiffle insertion rods; and inflating the bladder so as to press the tube portion of the patch against the walls of the pipe.

Using flexible insertion rods in this manner is siniper and more reliable than

the prior art technique of using crawler robots.

The method of the firth aspect of the present invention may incorporate any or all aspects of the first, second, third and fourth aspects of the present invention, as desired or as appropriate.

The flexible insertion rods may he connected together end to end. The flexible insertion rods may he formed from steel or other suitable metal. 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 be provided between the end rod and the bladder. This facilitates insertion into a pipe from a manhole of restricted size.

The bladder may be adapted to be connected to the rods by way of a T-bar fitting or crank winding handle. This maintains a fixed orientation between the Madder and the rods. 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.

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: Figure 1 is a schematic view of a pipe for repair; Figure 2 is an iflustration of an apparatus for repairing the pipe of figure 1 according to the present invention; Figure 3 is an iflustration of the apparatus of figure 2 in use to repair the pipe of figure 1; Figures 4 shows a resin container according to the present invention Figure Sa is a schematic view of a sheath for use in the present invention; and Figure Sb shows the sheath of figure 5a in use in the present invention.

Turning now to figure 1, a pipe I having a fracture 3 for repair is shown. 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 a fibreglass and felt.

combination. The curable resin may typically be a watcr-glass based polysilicate.

The patch 10 is then positioned on an inflatable bladder 20. The bladder 20 and patch 10 can then he positioned at the fracture zone 3 where the repair is required.

Inflation of the bladder 20 (figure 3) then holds the impregnated patch against the walls of the fracture zone 3 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 pipe 1.

In the present invention, as is shown in figure 2, the patch 10 is a tube or sheet wrapped to form a tube. The tube portion 12 is adapted to fit the pipe 1 in the vicinity of the fracture 3.

The bladder 20 comprises an inflatable body 21. The inflatable body 21 is substantially cylindrical and adapted to be inflated from a first circumference being significantly narrower than the corresponding pipe I to a second circumference at least equal to the circumference of the corresponding pipe I such that the patch 10 can be pressed against the fracture zone 3.

The patch 10 and bladder 20 are inserted into the primary pipe I and thcated adjacent to thc lateral pipc 2. In the prcscnt invcntion, thc bladdcr 20 can bc pushed along pipe I by means of one or more flexihk insertion rods (not shown) formed from steel or other suitable metal connected together end to end. The bladder 20 is connected to the rods by way of a T-bar fitting or crank winding handle (not shown).

In addition to flexible insertion rods one or more spring coils (not shown) may he provided connected between two rods or between the end rod and the bladder. Tn 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.

Wheels 23 allow the bladder 20 to movc along pipc 1 with minimal resistance.

Once the patch 10 is positioned adjacent to the fracture 3 the bladder 20 is inflated.

The inflation presses the patch 10 against the intersection 3. One or more elongate flexible members may be attached to the bladder 20 to facilitate removal after deflation.

In order to prevent unwanted contamination ci the pipe I or resin by the patch rubbing against the inside of the pipe I 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 unreinforced eyelets 42 provided at a second end. A cable 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 Sb. -10-

A karahiner 44 maybe threaded through the reinforced eyelets 41. A cord 45 can be connected to the karabiner 44. Once the patch 10 is positioned and aligned correcfly relative to the intersection 3, the sheath 40 can he removed by pulling on cord 45. Exerting sufficient force on the cord causes the eyelets 42 to tear and thus allows the sheath to he removed.

Turning now to figure 4. a resin container 50 in the form of a bag is shown.

The 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 he mixed by kneading the hag 50.

The bag is additionally provided with temperatures sensing means 60. The temperature sensing means 60 may comprise an indicator means 62. operable to 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 he provide with a probe 61 which passes through the hag into the resin component to provide a measure of the temperature of the component. The indicator means 62 is retained on the bag 50 by a suitable adhesive.

Typically the indicator means 62 comprise one or more areas of thermochromatic 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.

The user of the resin can thus check the temperature of the resin components using the temperature sensing means 50 and can separately cheek the ambient temperature. This will provide the user with an indication of the curing tirnescale for the resin and/or the overall life time of the resin. In some embodiments, a table of -11-curing timescales for specified component and/or ambient temperatures can he provided on a label (not shown) placed on the bag.

It is of course to he understood that the invention is not to he restricted to the details of the above embodiments which are described by way of example only.

Claims

Claims 1 A protective sheath suitable for use when inserting and positioning apparatus for pipe repair of the type comprising an absorbent patch impregnated with a curable resin fitted around a substantiafly cylindrical inflatable bladder, the sheath comprising a tube provided with a series of eyelets around each open end, the eyelets at a first end being reinforced the eye'ets at a second end not being reinforced.
2. A sheath as claimed in claim t wherein the eyelets at the first end are reinforced by bonding an additional layer of material to the sheath around the eyelets.
3. A sheath as claimed in claim 2 wherein the additional layer is comprised of the same material as the rest of the sheath.
4, A sheath as claimed in claim 2 wherein the additional layer is comprised of a different material to the rest of the sheath.
5. A sheath as claimed in any preceding claim wherein the sheath is transparent or substantially transparent.
6. A sheath as claimed in any preceding daim wherein the sheath is formed from a plastic material.
7. A sheath as claimed in any preceding claim wherein the sheath is formed from a soluble material such as PVOI-1
8. A sheath as claimed in any preceding claim wherein a tie is threaded through the eyelets of the second end of the sheath and tightened to secure the sheath to the bladder.
9, A sheath as claimed in claim 8 wherein the cable tie is a conventional cable tie.
10. A sheath as daimed in claim 8 wherein the tie is a soluble tie.-13 -
11. A sheath as claimed in any preceding claim wherein an elongate flexible member is attached to the reinforced eyelets of the first end of the sheath.U. A sheath as claimed in claim 11 wherein the elongate flexible member is directly passed through the reinforced eyelets.H. A sheath as claimed in claim 11 wherein the elongate flexible member is attached to a connector device which is itself passed through the reinforced eyelets.14. A sheath as claimed in any one of claims t t to t3 wherein the elongate flexible member is a string, rope or cord.5. A sheath as claimed in claim 14 wherein the connector device is a hook, loop orkarabiner.16, A sheath as claimed in any preceding claim wherein the second end of the sheath is secured over the end of the bladder that will be inserted into the pipe first.17. A sheath as claimed in any preceding claim wherein the protective sheath is provided with a number of ventilation apertures along its length 18. A method of repairing a pipe, the method comprising the steps of mixing a curable resin from two separate components; impregnating an absorbent patch with a curable resin; fitting the patch to a substantially cylindrical bladder; securing the patch to the main body of the bladder; placing a protective sheath around the patch and bladder, the sheath comprising a tube provided with a series of eyelets around each open end, the eyelets at a first end being reinforced and the eyelets at a second end not being reinforced; inserting the sheath, impregnated patch and bladder into a pipe to be repaired; locating the impregnated patch and bladder at the desired repair site; removing the sheath from the impregnated patch and bladder; and inflating the bladder so as to press the tube portion of the patch against the walls of the pipe.19. A method as claimed in claim 18 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 the bladder.20. A method as claimed in claim 18 or claim 19 wherein this step fhrther includes attaching an elongate flexible member to the reinforced eyelets of the first end of the sheath.21. A method as claimed in any one of claims t 8 to 20 wherein the removal step is achieved by pulling on the elongate flexible member attached to the eyelets of the first end of the sheath.22. A method as claimed in any one of claims 18 to 21 wherein locating the impregnated patch and bladder at the desired repair site is achieved by pushing and/or pulling the bladder along the pipe using one or more flexible insertion rods; and inflating the bladder so as to press the tube portion of the patch against the walls of the pipe.23. A method as claimed in claim 22 wherein the flexible insertion rods are connected together end to end.24. A method as claimed in claim 22 or claim 23 wherein the flexible insertion rods are formed from steel.25. A method as claimed in any one of claims 22 to 24 wherein in addition to flexible insertion rods one or more spring coils are provided.26. A method as claimed in claim 25 wherein the spring coils are connected between two rods.27. A method as claimed in claim 25 or claim 26 wherein a spring coil is provided between the end rod and the bladder. -15-28. A method as claimed in any one of claims 22 to 27 wherein the bladder is adapted to be connected to the rods by way of a T-bar fitting or crank handle winding device.29. A method as claimed in any one of claims 22 to 28 wherein the method S includes the steps of connecting one or more such rods together.