AU660770B2 - Method and apparatus for in situ repair of pipelines while maintaining liquid flow therethrough - Google Patents

Description

PUlU/ll 28INGo Rogulallon 3.2(2)

AUSTRALIA

Patents Act 1990 %66O77

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT Application Number: Lodged: Invention Title: METHOD AND APPARATUS FOR IN SITU REPAIR OF PIPELINES WHILE MAINTAINING LIQUID FLOW THERETHROUGH r The following statement is a full description of this invention, including the best method of performing it known to :-US METHOD AND APPARATUS FOR IN SITU REPAIR OF PIPELINES WHILE MAINTAINING LIQUID FLOW THERETHROUGH BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a method and apparatus for the in situ repair of damaged conduits, pipelines and sewer pipes through application of a settable repair material to a repair zone on the inner wall of the conduit, pipeline or sewer pipe.

2. Descrition of Prior Art The repair of cracked, broken or eroded pipelines or sewer pipes through so called soft lining methods involving the application of a reinforced lining to their inner walls is well known in the art. Two principal methods have been used in practice in relation to application of such reinforced linings. The first has oooee comprised eversion of a tube of thermosetting resin impregnated reinforcement 15 fabric into a section of pipe or conduit to be relined from an external position by means of a head of water or pressurized gaseous medium. One example of such a method is disclosed in U.S. Patent No. 4581085. The second typical method has involved the application of a layer of repair material to the inner walls of a section to be relined by means of a form inflatable by air or water S: 20 pressure. An example of this type of device is disclosed in GB Patent No.

2136912 and Swiss Patent No. 635181.

A short coming of these known systems is that inflation of the inflatable forms which they employ or the repair process itself result in all flow in a pipeline being interrupted. Bypassing a section of conduit being refurbished or some other means of interrupting flow upstream of it is therefore a necessity,.

Inflatable forms which embody a coaxial duct capable of sustaining a flow through a section of pipeline or sewer pipe have also been used where a settable liquid or semi liquid repair material is pumped into a zone t*een two axially spaced inflated parts pressed against the inner wall of the pipeline.

These devices are used to fill cracks in or gaps between adjacent sections of conduit or pipeline. Moreover such devices cannot be used to repair medium to long lengths of pipelines.

Summary of the InventiQn The objective of the present invention is to provide apparatus and a method for the in situ repair of a length of pipeline or conduit while still permitting normal liquid flow through the pipeline or conduit thereby avoiding the need to either block the flow or bypass this flow around the repair zone. Accordingly the present invention provides a device for applying~a repair material sleeveAto a repair zone extending over a predetermined axial length of an inner wall of a conduit to be repaired, said device comprising a core member with opposed axial ends with a flow opening in each said axial end and a through-flow passage connecting each said flow opening whereby in use liquid in said conduit flows from one side of said device to the other through said flow openings and through-flow passage, a radially expandable member carried- on S said core member outwardly of said core member and extending axially along at least a portion of said core member and around the circumference of said core S et ew, .e, 15 member, said repair materiali in use, being carried by said device outwardly of said radially expandable member whereby upon said radially expandable -deve being expanded radially, said repair material sleeve is pressed against a complete inner circumferential zone of said conduit, at least at opposed axial end regions of said repair zone.

20 The present invention also provides a method for in situ, repair of a repair zone of an inner wall of a conduit, while permitting continued liquid flow in said conduit, said method comprising externally of said conduit applying a settable S repair material sleeve to a device comprising a core member with opposed axial ends with a flow opening in each said axial end and a through-flow passage connecting each said flow opening and a radially expandable member carried on said core member outwardly of said core member extending axially along at least a portion of said core member, and circumferentially around said core member, moving said device with said settable repair material sleeve carried thereby into said conduit and positioning said settable repair material sleeve adjacent said repair zone, expanding said radially expandable member to radially expand said settable repair material sleeve outwardly so that said sleeve is pressed against a complete circumferential zone of said conduit at -r4 J least on opposed axial end regions of said repair zone while liquid flow in said conduit continues passing through said flow openings and said through-flow passage, subsequently contracting said radially expandable member and withdrawing said device from said conduit leaving said repair material sleeve overlying said repair zone.

*S.

••o Brief Descriotion of the Drawings Various preferred aspects of the present invention will be more readily understood by reference to the following description of preferred embodiments given in relation to the accompanying drawings in which: Figure 1 is a longitudinal cross sectional view of one side of an inflatable form; Figure la is a partial cross sectional view showing an alternative embodiment of Figure 1; and Figure 2 is a longitudinal cross sectional view of part of the coaxial duct of a form.

With reference to Figure 1, an inflatable form 1 is made by partially everting a tube of a suitably elastic material and fastening by means of bands 22 and 23 its two ends 2 and 3 adjacent each other to a core member 4 in the form of a coaxial duct. The core member 4 has flow openings 30,31 at either axial 15 end and a through flow passage 32 inter-connecting the flow openings whereby oo..

water or sullage may flow through the device when in use so that this flow is not blocked during the repair process. The end 3 of the form 1 is positioned adjacent one end of said coaxial duct. Fixed to said coaxial duct by means of a band 24 between said ends 2 and 3 is one end 5 of a tubular director sleeve 6 20 which extends axially substantially throughout the length of said inflatable form and its other end being open. Said director sleeve may be made of impervious material or may be made wholly or partly foraminous. Inlet and outlet means 8,11 are provided on either side of the fixed end of the sleeve 6 to enable an inflating medium to be delivered and withdrawn from the form 1. Fastened 25 coaxially to end 3 of said tube by band 23 as shown in Figure 1 or to a point on said coaxial duct axially beyond the position of end 3 hy means of a band 25 as shown in Figure 1 a if the end of said coaxial duct is extended is one end of a flexible outer shroud 7, that the other end of which is free against the other end of said coaxial duct. It will of course be appreciated that the outer shroud 7 might be omitted from the embodiment illustrated and in which case the outer flexible wall 20 of the form 1 comprises the outer surface portion of the inflatable element. It is also possible, when using an outer shroud 7, that a simple inflatable element might be used with its axial ends connected to opposed ends of the core member 4. In operation, a tube or sleeve of thermosetting resinimpregnated reinforcement material 27 is placed over said inflatable form and the whole assembly is introduced into the section of a pipeline or sewer pipe required to be refurbished with end 3 of said tube foremost. Correct positioning may be verified through the use of closed circuit television. An inflation medium at a suitable temperature and pressure is then introduced through duct 8, causing said form to expand and force said resin-impregnated reinforcement material into intimate axial contact with the inner wall surfaces of the pipe at least on either axial side of the repair zone. The flow of the inflating medium passes through the annular spaces 9 and 10 between said tubular director sleeve and the opposing inner surfaces of said form to exit through duct 11, said circulation ensuring an even temperature distribution. The inflating medium circulates at a suitable pressure and temperature and is preferably continued 15 until full curing of the resin of said resin-impregnated reinforcement material is obtained. Temperature distribution may be adjusted as required by the S provision of a said tubular director sleeve provided with foramina of a number, size and positioning to allow a suitable short-circuiting of the heated flow.

Conveniently, the inflating medium might be water, air or some other suitable 20 gas or fluid.

Following full curing of the thermosetting resin with which said reinforcement material 27 is impregnated, water circulation is stopped and all water is drained or pumped from the internal spaces of said form. Said form is then slowly withdrawn from the pipeline or sewer pipe section with end 3 of said 25 tube rearmost. This action causes said flexible outer shroud 7 to evert and peel cleanly from said reinforcement material so that, as the form exits the section which has been refurbished, the outer shroud is more or less totally everted.

Said peeling action has been shown to be extremely efficient at overcoming any residual adhesion between said flexible outer shroud and the resin with which said reinforcement material is impregnated.

With reference to Figure 2, coaxial duct 4 of an inflatable form comprises a plurality of tubular elements 12 in a collinear arrangement. Each of said tubular elements is provided on one end face with a shaped, circumferential, axially extending ridge 16 and, at the other end, a complementary recess 17.

When the ends of adjacent said tubular elements are abutted, said ridges and recesses register to locate said tubular elements in collinearity. Provided through the length of each of said tubular elements is one or more cable ports 13 through which a tensioning cable 14 passes from one end of said coaxial duct to the other. Said tensioning cable is fixed at one end of said coaxial duct at 26 to a terminal member 27 and is provided at the other end with a screw mechanism 28 or other suitable means acting on a second terminal member 33 thereby enabling said tensioning cable to be tensioned. When said tensioning cable is tensioned, said tubular elements are held in rigid alignment with their adjacent said complementary circumferential ridges and recesses registering in a way which ensures their collinearity. Extending throughout the length of said coaxial duct is outer jacket 15 of some suitably flexible material which is :0 15 fastened by bands 29 and conveniently sealed to the terminal elements 12,27.

The jacket 15 serves to seal said tubular elements together. It will of course be Sappreciated that the jacket 15 is necessary when a simple inflatable member is used so that the inflating medium does not escape inwardly of the elements 12.

With the inflatable element as shown in Figure 1, the jacket 15 might be omitted.

i 20 In operation, prior to the positioning of an inflatable form and resinimpregnated reinforcement material in a pipeline or sewer pipe, said tensioning cable or cables are loosened allowing individual members of said tubular elements to move relative to one another, thus rendering both said coaxial duct and said inflatable form flexible. With said inflatable form and reinforcement 25 material in position in said pipeline or sewer pipe, said tensioning cable or cables are tensioned, rendering said coaxial duct and said inflatable form rigid in the manner aforesaid.

Claims (8)

1. A device for applying in-situ a repair material sleeve including a settable material to a repair zone extending over a predetermined axial length of an inner wall of a conduit to be repaired, said device comprising a core member with opposed axial ends with a flow opening in each said axial end and a through flow passage connecting each said flow opening whereby in use liquid in said conduit flows from one side of said device to the other through said flow openings and through flow passage, a radially expandable member carried on said core member outwardly of said core member and extending axially along at least a portion of said core member and around the circumference of said core member, said repair material sleeve, in use, being carried by said device outwardly of said radially expandable member whereby upon said radially expandable member being expanded radially, said repair material sleeve is pressed against a complete inner circumferential zone of said conduit at least at **.opposed axial end regions of said repair zone.

2. A device according to claim 1 wherein said radially expandable member includes a single inflatable zone, means being provided to introduce a pressure medium into said inflatable zone from a position external of the conduit to be repaired.

3. A device according to claim 2 characterized in that said pressure medium is a liquid. e

4. A device according to claim 3 characterized by means to heat said liquid.

A method for in-situ repair of a repair zone of an inner wall of a conduit, while permitting continued liquid flow in said conduit, said method comprising applying externally of said conduit a settable repair material sleeve to a device comprising a core member with opposed axial ends with a flow opening in each said axial end and a through-flow passage connecting each said flow opening -o~ and a radially expandable member carried on said core member outwardly of said core member extending axially along at least a portion of said core member, and circumferentially around a said core member, moving said device with said settable repair material sleeve carried thereby into said conduit and positioning said settable repair material sleeve adjacent said repair zone, expanding said radially expandable member to radially expand said settable repair material sleeve outwardly so that said sleeve is pressed against a complete circumferential zone of said conduit at least on opposed axial end regions of said repair zone while liquid flow in said conduit continues passing through said flow openings and said through-flow passage, subsequently contracting said radially expandable member and withdrawing said device from said conduit leaving said repair material sleeve overlying said repair zone.

6. A method according to claim 5 wherein said radially expandable member .:oo.i includes a single inflatable zone, expansion of said radially expandable zone •o occurring by introducing a pressure medium into said inflatable zone and 1 contraction of said radially expandable zone occurring by withdrawing said "pressure medium from said inflatable zone.

7. A method according to claim 6 wherein said pressure medium is a liquid.

8. A method according to claim 6 characterized in that said settable repair material sleeve comprises a thermosetting resin and said pressure medium comprises a heated liquid. o DATED this 9th day of November, 1994. go o BARRY BROS. SPECIALISED SERVICES PTY. LTD, WATERMARK PATENT TRADEMARK ATTORNEYS THE ATRIUM 290 BURWOOD ROAD HAWTHORN VICTORIA 3122 AUSTRALIA eA4 '73 'I A ABSTRACT A device for applying a repair material sleeve to a repair zone extending over a predetermined axial length of an inner wall of a conduit to be repaired, said device comprising a core member with opposed axial ends with a flow opening in each said axial end and a through flow passage connecting each said flow opening whereby in use liquid in said conduit flows from one side of said device to the other through said flow openings and through flow passage, a radially expandable member carried on said core member outwardly of said core member and extending axially along at least a portion of said core member and around the circumference of said core member, said repair material, in use, being carried by said device outwardly of said radially expandable member whereby upon said radially expandable device being expanded radially, said S• repair material sleeve is pressed against a complete inner circumferential zone of said conduit at least at opposed axial end regions of said repair zone. 6 6 6t *66