GB2503248A

GB2503248A - A method and apparatus for repairing a pipe.

Info

Publication number: GB2503248A
Application number: GB1210926.0A
Authority: GB
Inventors: Mark Thomas William Potter
Original assignee: FERNCO ENVIRONMENTAL Ltd
Current assignee: FERNCO ENVIRONMENTAL Ltd
Priority date: 2012-06-20
Filing date: 2012-06-20
Publication date: 2013-12-25
Anticipated expiration: 2032-06-20
Also published as: GB2514903B; GB2503248B; WO2013190283A2; WO2013190283A3; EP2867137A2; GB201210926D0; AU2013279090B2; GB2514903A; GB201406214D0; AU2013279090A1

Abstract

A first aspect relates to a resin container 50 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 bag separated into two container sections 51, 52 by a removable sealing clip 53. Each container section is provided with a temperature sensor and a temperature indicator 62. A second aspect relates to a protective sheath 40 suitable for use when inserting and positioning apparatus for pipe repair of the type comprising an absorbent patch (10, fig 5b) impregnated with a curable resin fitted around a substantially cylindrical inflatable bladder (20). The sheath comprises a tube provided with a series of eyelets 41, 42 around each open end, the eyelets at a first end being reinforced, the eyelets at a second end not being reinforced. A third aspect relates to a method of repairing a pipe (1, fig. 1) using one or more flexible insertion rods to locate an impregnated patch mounted to an inflatable bladder at a desired repair site (3).

Description

Renair of Pines and Pinelines 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 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 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 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 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 UPS or similar.

Whilst these techniques are well known and well understood, there are still some known difficulties. For Stance, crawler robots are very expensive and the p) 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 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 ifiture 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 impregnated 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.

Tt 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 bag 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 operable 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 be 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 the main body of the bladder; inserting the impregnated patch and bladder 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 thither steps of determining the temperatures of the resin components before mixing; and thereby determining 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 include the flirther 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 be 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 clip and kneading the bag to mix the resin.

The indicator means may comprise one or more areas of thermochromatie material printed or otherwise disposed on to the substrate. The thermochromatie material may be a thermoehromatic ink and may be of the liquid crystal or leueo 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. 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 for 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 eyelets 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 fir st 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.

A sheath of this type can be 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 fourth 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 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 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 preferaNy secured over the end of the bladder that will be inserted into the pipe fir st. 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 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.

According to a titIh 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 be 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 bladder along the pipe using the one or more flexible insertion rods; and inflating the bladder so as to press the tube portion of the patch against the walls ofthe pipe.

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

the prior art technique of using crawler robots.

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

The flexible insertion rods may be connected together end to end. The flexible insertion rods may be lbrmed 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 flx,m 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 bladder 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 illustration of an apparatus for repairing the pipe of figure 1 according to the present invention; Figure 3 is an illustration 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 5a 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 water-glass based polysilicate.

The patch 10 is then positioned on an inflatable bladder 20. The bladder 20 and patch 10 can then be 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 I 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 1 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 1 and located adjacent to the lateral pipe 2. In the present invention, the bladder 20 can be pushed along pipe I by means ofone or more flexible insertion rods (not shown) formed from steel or other suitable metal connected together cnd 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 be provided connected between two rods or between the end 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.

Wheels 23 allow the bladder 20 to move along pipe 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 of the pipe 1 or resin by the patch rubbing against the inside of the pipe 1 during insertion and travel, a sheath 40 may be provided. The sheath, as shown in figure Sa, 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.

A karabiner 44 may be threaded through the reinforced eyelets 41. A cord 45 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 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 be mixed by kneading the bag 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 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 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 timeseale 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 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.