GB2192441A

GB2192441A - Lining a duct

Info

Publication number: GB2192441A
Application number: GB08616898A
Authority: GB
Inventors: Hunter Martin Franklin
Original assignee: Stanley Robert Moore; Stephen Tracey
Current assignee: Stanley Robert Moore; Stephen Tracey
Priority date: 1986-07-11
Filing date: 1986-07-11
Publication date: 1988-01-13
Also published as: GB8616898D0

Abstract

A pig or carrier 7 has a portion 9 which is rotatable about a longitudinal axis and carries a scissor linkage 10 having a tray 11. Detachably carried on the tray is a collapsed bag 15. By manoeuvring the carrier 7, portion 9 and extending the linkage 10 the bag 15 can be located in a port 4. Bag 15 is expanded by fluid under pressure through a non-return valve 16 to form a seal between a conduit 2 and port 4 to retain grouting in a space 5. Following its expansion in port 4, the bag 15 is detached from the platform 11 to isolate the bag from the carrier and the carrier can be used for the location of further expandible seals. The bag 15 when expanded may be tubular to maintain fluid communication between the conduit 2 and bore of a duct liner 3. The carrier 7 may be provided with a T.V. camera 13 and lights 14. <IMAGE>

Description

SPECIFICATION Amethodoflining afluidconduitandapparatusfor use in said method Technical field & background art The present invention relates to a method of lining a fluid conduit and apparatus for use in such a method. The invention was primarily developed for lining a wall of a main fluid conduit (such as a sewer, water, gas or other fluid pipe) having a branch conduit or pipe with atubularlinerhaving a port in its wall which co-operates with the branch conduit or pipe. Thetubularlinerwill usually be a plastics pipe which is pulled through the main fluid conduit and thereafter the port is cut th rough the wall of the liner, for example by use of a water jet cutter device which is the subject of our British Patent No. 2,098,300B.

With the liner located within the main fluid conduit, it frequently occurs that a space or air gap is formed between the exterior of the liner and the wall ofthe main conduit, particularly with rigid plastics liners and sewer pipes within which the liner is positioned.

Conventionallythis space or air gap is filled with grouting or other material such as foam plastics which sets to reinforce and firmly retain the liner within the main conduitand/orto alleviate the flow offluid between the branch conduit and the main conduit from entering the gap which may otherwise be formed between the exterior of the liner and the wall of the main conduit. With sewer pipes the grouting or other infill material is usually pumped under pressure into the appropriate space or gap to flow and fill that gap over a long distance (say 100 metres) of the plastics liner and within this length there may be one or several more ports and associated branch conduits.It will be appreciated that it is important to maintain clearthe communication between the branch conduit and main conduit byway of the associated port by ensuring that the grouting or infill material is contained within the gap or space intended and it is an object of the present invention to provide a relatively simple and economical method and apparatus by which the aforementioned requirements may be achieved.

Statements of invention & advantages According to the present invention there is provided a method of lining a wall of a main fluid conduit having a branch conduit which comprises providing within the main fluid conduit a tubular liner having a port in its wall which co-operates with the branch conduit; inserting into the port and branch conduit an expandable seal; expanding said seal within the port and branch conduit to be retained therein, and providing an infill material in a space formed between the wall of the main fluid conduit and the tubular liner and utilising the seal to restrain the infill material within said space from entering the branch conduit or the main fluid conduit by way of said port.

Further according to the present invention there is provided apparatus for use in the method as specified in the immediately preceding paragraph which comprises a carrier displaceable longitudinally along the main fluid conduit within the liner and carrying the expandable seal; extendible means for displacing the seal laterally relative to thecarrierfor locating the seal within the port and branch conduit, and means for expanding the seal to be retained within the port and branch conduit.

Still further according to the present invention there is provided a main fluid conduit when lined by the method specified in the preceding penultimate paragraph.

The present invention was primarily developed for use in the lining of sewer conduit or sewer pipes and, for convenience, will hereinafter be considered in this connection; however, as indicated above, it will be realised thatthe invention may be used in the lining of otherfjuid conduits such as gas orwater piping. It is well known to line an existing sewer pipe with a plastics sleeve, to cut ports in the linerwhich co-operate with branch pipes from the-main sewer that may lead to individual services, and thereafter to fill with grouting a gap which may be formed between the plastics liner and-the main sewer pipe.

Prior to this grouting however, and in accordance with the present invention, an expandable seal is located within the or each port and associated branch pipe to effectively bridge the space or gap at the periphery of the port between the wall of the liner and the branch pipe -thereby ensuring that the grouting is confined to the appropriate cavity between the opposing walls and does not flow into the bore ofthe liner by way of the portorintothe- branch pipe where it could set and form a blockage within those pipes.

The seal is preferably expandable to engage and be retained within the port and the branch pipe by the admission offluid under pressure into an expandable chamber thereof. The seal.may be generally tubularto maintain communication between the main and branch pipes when fitted, say of annularform with a toroidal expandable chamber, however it is preferably in the form of a plug when fitted, such as a flexible bag which is expandable to obturate the port and its associated branch pipe. The fluid which is admitted under pressure into the expandable chamber is preferably ai r but m ay be a liquid.The fluid will usually be admitted intothe expandable chamberbyway of a non-return valve from a hose. Typicallythe expandableseal will be manoeuvred within the liner of the main sewer pipe under remote control and by observation through a television camera and during this manoeuvring the seal may be mounted on the carrier by temporary retaining straps or bands which, upon expansion of the seal, automatically dis-engage the seal from the carrier so that the latter can be displaced along the linerwhilsttheseal remains isolated within the port and branch pipe.Where the seal includes a chamber which is expandable underfluid pressure, it is also preferred that the hose through which fluid is admitted to the chamber is automatically detachable from the seal when the seal is adequately expanded to be firmly retained in the port and branch pipe. This latter detachment is conveniently achieved by the hose "blowing-off" from a valve or nozzle on the seal through which its chamber is inflated when that chamber attains a predetermined pressure.Also for the purpose of manoeuvring the expandable seal for its location within the port, it is preferred that a portion of the carrier on which the expandable seal is carried can be rotated about the longitudinal axis along which the carrier will be displaceable within the main-sewer pipe so that by appropriate rotation and longitudinal displacement of the carrier, the expandable seal can be aligned to co-operate with a port positioned anywhere around the lining pipe. For the:purpose offacilitating the actual insertion ofthe expandable seal into the port and branch pipe,the carrier includes means which is extendible laterally -to movetheseal intothe hole.Theextendible means may be of any convenient form such as a scissors-type linkage or a lever system on which the expandable seal is temporarily mounted and this means is preferably rotatable through 360 as aforementioned to facilitate alignment between the seal and the port.

In the aforegoing-discussion it is implied that the expandable seal is inserted into the port and branch pipe in a direction from the main sewer pipe; it isto be realised however that the method ofthe present invention envisages the possibility of locating the expandable seal within the branch pipe and port in a direction from the branch pipe, for example where there may be a convenient access to the branch pipe from which the seal can be manoeuvred along the branch pipe and into the port.

When the seal has been expanded to be retained within the port and branch pipe, that seal may temporarily obturate the branch pipe and port during the grouting process or may betubularto maintain communication from the branch pipe to the main sewer pipe whilst bridging the gap between the main sewer pipe and its liner around the periphery ofthe branch pipe and port during the grouting process.

When the grouting has been completed and solidified the expandable seal is preferably removed from the port and branch pipe-especiallywherethe seal obturatesthe branch pipe. Where the seal -includes a chamberwhich is expandable underfluid pressure, the seal may be removed by bursting that chamberto collapse the seal, conveniently the seal is burst by cutting through the wall of the chamberwith water cutting jets from a device such as that which is the subject of our British Patent No.2,098,3008. The carrier is conveniently in the form of a sledge although itmay be mounted on otherforms of runners orwheelsto be pulled in controlled manner by-a hawserthrough the tubular lining.

Drawings One embodiment of-a method of lining a main sewer pipe and an apparatus to facilitate such lining will now be described, byway of example ~only; with reference to the accompanying illustrative drawing in which: - Figure 1 is a longitudinal section through a main sewer pipe with a branch pipe connection and having a tubular linerin a port of which an expandablesqal isto be fitted from a carrierwithin the tubular liner, and Figure2 is a similarviewto that shown in Figure 1 and illustrates the expandable seal fitted within the port and branch pipe and expanded to retain grouting within a space formed between the tubular liner and the main sewer pipe.

Detailed description of drawings Aconventional sewer pipe 1 has extending therefrom a branch pipe 2 and is provided with a plastics tubular liner or sleeve 3. The liner 3 has a port 4which coincides with the branch pipe 2 and through which fluid can flow from the branch pipe into the liner3 of the main sewer pipe. The port4is conveniently cut in the wall of the liner bythe apparatus and technique discussed in our British Patent No. 2,098,300B with particular reference to Figure 4thereof.Following location ofthe liner 3 within the main sewer 1 an air gap or space 5 may be formed between the wall ofthe liner3 and that ofthe main sewer 1; typically the airspace 5 is filled with grouting that will set to secure and reinforce the lining 3. ltisofcourseimportanttoensurethatthis grouting is retained within the gap 5 and does not flowto set and form a blockage in the branch pipe 2, port 4, liner 3 or in the communication between the branch pipe and the interior ofthe liner through the port4.

Located within the liner 3 and displaceable along the liner under control of forwardly and aftwardly extending hawsers 6 is a carrier 7 having sledge-type base runners 8. The carrier 7 has a portion 9 which extends forwardly of its main body and on which is mounted a scissors-type extendible linkage 10 carrying a platform 1. The linkage 10 is extendible and contractable by rotation of a screw rod 12 in the appropriate direction by an electric motor (not shown) within the body ofthe carrier. Extension and contraction ofthe linkage 10 displaces the platform 11 laterally relative to the portion 9 and to the longitudinal direction in which the carrier is displaceable as a whole.In addition the portion 9 can rotate (preferably through 300' to 360') about the longitudinal axis along which the carrier is displaceable so that by appropriate control of the hawsers 6 and rotation ofthe portion 9, the platform 11 can be manoeuvred into lateral alignmentorto coincide with the port 4. The aforementioned control will usually be achieved remotely in the manner discussed in our previously mentioned British Patent and under observation from a television camera 13 mounted with lights 14 on the carrier 7 (conveniently for rotation in unison with the portion 9).

Carried on the platform 11 and initially in a collapsed condition as shown in Figure 1 is a rubberised canvas bag 15 having a nozzle 16through which it can be inflated by air under pressure supplied through a hose 17 fittedto the nozzle. The bag 15 is temporarily retained on the platform 11 by elastomeric bands 18. The hose 17 is conveniently coupled to an appropriate air pressure source through the carrier7 while the nozzle 16 includes a simple form of non-return valve such as a conventional Schroder-type valve.

In use the platform 11 is manoeuvred as previously discussed to locate the collapsed bag 15 in line orto coincide with the port4following which the scissors linkage 10 is extended to move the bag 15 into the port 4 and possibly part-way into the branch pipe 2 which coincides with the port 4. The bag 15 is now inflated (by the admission of air under pressure from the hose 17) to expand within the port 4 and branch pipe 2 as shown in Figure 2. During expansion ofthe bag the bands 18 snap and release the bag from the platform 11. When the bag 15 has been sufficiently inflated it grips the side wall of the branch pipe 2 and the edge of the port 4 and forms an effective grouting seal between the port 4 and the branch pipe which bridges the gap 5 as shown in Figure 2.With the bag thus forming a plug or grouting seal, grouting 19 can be pumped into the gap 5 to fill that gap and solidify to reinforce and retain the liner 3.

When the bag 15 has been inflated to an appropriate pressure it is preferred that the hose 17 automatically blows-off to disengage from the nozzle 16. It is then merely necessary to contract the scissor linkage 10 to leave the bag 15 isolated within the port 4and branch pipe 2. In practice the main sewer pipe 1 will usually have a longitudinally spaced array of branch pipes 2 and corresponding ports 4 in its liner 3 and, prior to the 9 routing process, each of these branch pipes and ports will befitted with separate inflatable bags 15 in the manner discussed above (by repeatedly moving the carrier 7 along the liner 3to an appropriate location at which a collapsed bag 15 can be fitted to the platform 11 and thereafter again moving the carrier along the liner to manoeuvre and fit that bag within a port 4).

When the grouting 19 has set it is necessary to removethe bag or bags 1 5 from their respective branch pipes and ports 4. This is conveniently achieved by bursting each bag and allowing itto deflate and drop into the liner 3 from which it may be collected. The bags 15 may be punctured by cutting through the material of the bag with a water jet cutting through the material of the bag with a water jetcutting device such asthatdiscussed in our British Patent N o. 2,098,300 B which is drawn through the liner3; should the deflated bag fail to fall freely from the port 4 into the bore ofthe liner 3 it may simply be hooked, for example by a water nozzle, to be dragged from its port and branch pipe along the interior of the liner.

Claims

1. A method of lining a wall ofa mainfluid conduit having a branch conduit which comprises providing within the main fluid conduit a tubular liner having a port in its wall which co-operates with the branch conduit; manoeuvring a carrier within the liner and from said carrier inserting into the port an expandible seal; expanding said seal within the port and branch conduit to be retained therein; isolating the expanded seal from the carrier, and providing and infill material in a-space formed between the wall ofthemainfluidconduitandthetubularlinerand utilising the seal to restrain the infill material within said space from entering the branch conduit or the tubular liner by way of said port.

2. A method as claimed in claim 1 in which the seal has an expandible chamber and which comprises admitting fluid under pressure into said expandible chamberfrom a hose and byway of a non-return valve on the seal to retain the seal within the port and detaching the hose from the seal.

3. A method as claimed in claim 2 in which the hose automatically detaches from the seal when the expandiblechamberattainsa predetermined pressure.

4. A method as claimed in any one of the preceding claims in which the expandible seal is in the form of a bag and which comprises inserting the bag in a collapsed condition from the carrier into the port and expanding the bag by fluid under pressure forthe bag to be retained in the portand branch conduit.

5. A method as claimed in any one of the preceding claims in which the expanded seal is tubularto provide fluid flow communication therethrough between the branch conduit and the bore of the liner.

6. A method as claimed in any one of the preceding claims in which the expandible seal is detachably carried by the carrier and the expansion of the seal and securing of the seal in the port detaches the seal from the carrier.

7. A method as claimed in claim 6 in which the expandible seal is initially retained on the carrier by temporary retaining straps or bands which disengage or break on expansion of the seal.

8. A method as claimed in any one of the preceding claims which comprises locatin#g the expandible seal in a collapsed condition on a portion of the carrier; displacing the carrier longitudinally in the liner and rotating said portion ofthecarrierabout a longitudinal axis to maneouvrethe seal to coincide with the port and displacing the seal laterally on said portion of the carrier to insert the seal into the port.

9. A method as claimed in any one ofthe preceding claims which comprises contracting the seal following the infilling of the space between the liner and the main fluid conduit and removing the seal from the port within the liner.

10. Amethodasclaimed in claim 9when appendent to claim 2 which comprjses bursting the expandible chamberto contract the seal.

11. A method as claimed in claim 10 which comprises bursting the chamber bywater cutting

12. A method as claimed in any one ofthe preceding claims in which the main fluid conduit has an array of branch conduits and the liner has an array of ports which co-operate with the respective branch conduits and which comprises repeatedly manoeuvring the carrier within the liner to locate and isolate an expanded seal in each port and branch conduit with which that respective port communicates priorto infilling.

13. Apparatus for use in the method as claimed in claim 1 and comprising a carrier displacable longitudinally along the main fluid conduitwithin the liner and carrying the expandible seal; extendible means for displacing the seal laterally relative to the carrier for locating the seal within the port; means for expanding the seal to retain it within the port and branch conduit, and meansfor detaching the expanded seal from the carrier wherebythe seal is retained in the po#rt isolated from the carrier.

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14. Apparatus as claimed in claim 13 in which the seal has a chamberto be expandible bythe admission ofthefluid underpressurethereto byway dfa-non--rntumvalve on the seal.

15. Apparatus as claimed in-claim 14 in which a hose is provided which fluid under pressure is admitted to the valve, said hose automatically disengaging from the seal ata predetermined pressure therein.

16. - Apparatus as claimed in claim either claim 14 or claim 15 in which the expandible seal is in the form of a bag which is initially located on the carrier in a collapsed condition to be expanded by the admission offluid under pressu re thereta,

17. Apparatus as claimed in any one of claims 13to 16 in which the expandible seal is initially retained on the carrier in a collapsed condition by temporary retaining straps or bands which disengage or break on expansion of the seal to detach the seal from the carrier.

18. Apparatus as claimed in any one of claims 13 to 17 in which the expandible seal in an expanded condition is tubular for providing fluid flow co-rnrnunication between the branch conduit and the bore ofthe liner when retained in the port and branch conduit.

19. Apparatus as claimed in anyone of claims 13 to 18 in which the expandible seal is located on a portion ofthe carrier which portion is rotatable about a longitudinal axis and laterally extendable means is provided for displacing the expandible seal laterally on said portion.

20. Afluid conduit when lined bythe method as claimed in any one of claims 1 to 12.

21. A method of lining the wall of of a fluid conduit substantially as herein described.

22. A fluid conduit when lined by the method as claimed in claim 21.

23. Apparatus as claimed in claim 13 and substantially herein described with reference to the accompanying illustrative drawings.