Abstract:
A flexible liner resin impregnable for lining a lateral pipe which leads into a main pipe having at one end a flexible collar for installation at the location where the lateral liner meets the main, wherein after installation the collar extends along the interior of the main seating against the opening of the lateral. The flexible liner is installed by everting the liner through the opening in the collar by means of fluid under pressure supplied to a launching device which is held in position by an inflatable bladder and seals the collar at the lateral main pipe junction.

Description:
This is a divisional of application Ser. No. 08/599,045 filed Feb. 9, 1996 now U.S. Pat. No. 5,975,878, issued Nov. 2, 1998 which is a divisional of Ser. No. 08/394,622, filed Feb. 27, 1995, now U.S. Pat. No. 5,624,629 issued on Apr. 29, 1997, which is a continuation of Ser. No. 07/934,678, filed Sep. 10, 1992, now U.S. Pat. No. 5,393,481 issued on Feb. 28, 1995. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention relates to the lining of pipelines or passageways, using flexible tubular materials which are impregnated with curable synthetic resin and which, when placed in position lining the pipeline or passageway are held by fluid pressure against the pipeline or passageway surface until the resin cures to a hard condition leaving a hard lining pipe lying on the pipeline or passageway surface. 
     The most widely practised method using such resin impregnated linings is disclosed in British Patent No. 1449455 from which it will be seen that the impregnated lining is applied to the pipeline or passageway surface by eversion of same into the pipeline or passageway, using fluid pressure. 
     The present invention is concerned with lining pipelines which are called “laterals” insofar as they enter sidewise a main pipeline or passageway, such as a main sewer. Of any particular main line, there may be a plurality of laterals entering the main line, and it frequently arises that the laterals have to be lined by means of a resin impregnated tube. Using existing methods for lining laterals, it is not possible to perform any lining operation of a second or subsequent lateral whilst the lining in one lateral is being cured. As the cure time may take up to 5 or 6 hours, if a section of main line having say 5 laterals to be lined is involved, the minimum total time to line all laterals will be in the order of 25 to 30 hours. As these lining operations are required to be carried out during the night for purposes of convenience, it is often the case that the completion of the work has to take place over several evenings and therefore the work crew must depart the site and return at a later date to complete the work. 
     The present invention is concerned with providing an arrangement wherein the completion of a plurality of lateral lining operations may be effected in a much shorter period. 
     SUMMARY OF THE INVENTION 
     In accordance with the present invention, a plurality of laterals meeting a common main line are lined by inserting resin impregnated linings into said laterals and to hold same in position by fluid pressure whilst curing of the resin takes place, and after insertion of each lining, a seal arrangement at the location where the lateral meets the main line enables the second and subsequent laterals to be lined whilst the first or previously inserted lining is held in position and is being cured. 
     The seal arrangement may comprise a flexible bag which is pressurised with the medium which urges the lining against the lateral surface so as to prevent escape of the pressurising medium, but such bag allowing pressure fluid supplying pipes to pass to the inside or outside of the bag and to other lateral connections downstream of the bag in the main pipe whereby such other laterals may be lined by the eversion there into of a resin impregnated lining tube, the holding of the lining tube to the lateral surface being affected by fluid pressure, and a sealing bag retaining the lining in position and forming a seal between the lateral and the main line. 
     It will be seen that by using the method, the linings for the laterals can be inserted sequentially, and held in installed position under pressure, and cured simultaneously. A plurality of laterals can be lined and cured in a total time equal to the time it takes to line one lateral multiplied by the number of laterals plus the curing time for one of the lateral linings which total time in the case of 5 laterals may be in the order of 8 hours, which is a considerable reduction from the 25-30 hours which are required for the lining of 5 laterals by the conventional method. For example therefore the lateral lining on any particular contract may be capable of being completed in one evening as opposed to being completed in stages over two or three evenings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Embodiments of the invention will now be described, by way of example, with reference to the accompanying diagrammatic drawings, wherein: 
     FIG. 1 is a diagrammatic side elevation showing the method by which a lateral is lined in accordance with the method of the invention; 
     FIG. 2 is a sectional elevation taken on the line II—II; 
     FIG. 3 is an enlarged sectional view of the detail ringed III in FIG. 1; 
     FIG. 4 is an enlarged sectional view of the detail ringed IV in FIG. 1; 
     FIG. 5 is a sectional side view of an alternative form of apparatus for carrying out the method of the invention. 
     FIG. 6 is an end view of the arrangement shown in FIG. 5; and 
     FIG. 7 is a perspective view of the lining tube used in the method of FIGS.  5  and  6 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to the drawings, in FIG. 1 a main line  10  is intersected by a lateral  12  which is to be lined in accordance with a first method of the invention. 
     For the lining operation, a resin impregnated flexible lining tube  14  has a beaded end  16  which is reinforced, and forms a ring which seats against the opening of the lateral  12 . The tube  14  is loaded inside a carrier tube  18 . Carrier tube  18  has one end  20  anchored to an elbow pipe  22 , and to the other end of the elbow  22  is connected a containment tube  24 . A disc  26  seals the other end of the containment tube, but extending through the disc is a pressure hose  28  and a bleed hose  30 . 
     The pressure hose  28  and bleed hose  30  can slide through the disc  26  as insertion of the lining tube  14  takes place as will be explained. 
     If reference is made now to FIG. 4, as shown, the tail end of the carrier tube  18  is closed around the bleed hose  30 , and the pressure hose  28  is connected to the closed end of the carrier tube  18 . The end of the lining tube  14  stops short of the end of the carrier tube so that the lining tube can be left in position lining the lateral  12 . 
     The method of insertion comprises the introduction of pressurising fluid, water or gas, through the pressure hose  28  into the space between the containment tube  24  and the carrier tube  18  with the result that the carrier tube  18  and the lining tube  14  are everted as shown at  32  in FIG. 1 into the lateral  12 , the lining tube  14  being presented to the lateral surface. The assembly of tubes  14  and  18  therefore everts into the lateral  12  and the pressure hose  28  and the bleed hose  30  are pulled through the containment tube, through the elbow  22  and up to the top end of the lateral. The portion  30 A of the bleed hose projects out of the end of the eversion face so that if any water collects above the lining, it can bleed through end  30 A, which is provided with apertures  34  for this purpose, out of the tube  30  and back to drain so that there will be no undesirable collection of liquid in the lateral whilst lining is taking place. 
     The pressure fluid which is supplied by the hose  28  leaks through an aperture  36  in the elbow  22  and pressurises a bag or bladder  38  surrounding the elbow as shown. The bladder is therefore inflated so as to seal against the main line  10  and to seal the end  16  of the lining. The aperture is provided with or acts as a pressure reduction means so that whilst the everting pressure may be of the order of 20 p.s.i., the pressure in the bag or bladder  38  is much lower e.g. in the order of 5 p.s.i. The bladder  38  remains pressurised as long as the pressure is maintained inside the everted lining and carrier tube. As soon as this position has been reached, a towing assembly  40  which is used for positioning the elbow  22  by being connected thereto through a link  42  fast with elbow  22 , is released from that link insofar as, as shown in FIG. 3, the link  42  has a socket  44  in which engages a centralising pin  46 . The wall of the socket  44  has aligned apertures  48 ,  50  in which pegs  52  and  54  engage, these pegs being carried by pivotable jaws  56  and  58 . The jaws  56  and  58  are connected to the clamping device  60  having swingable arms  62  and  64  on the ends of which are provided guide rollers  66  and  68 . As the bladder  38  inflates, the rollers  66  which are held inwardly by spring action are caused to pivot to the position shown in FIG. 1 which has the effect of moving the jaws  56  and  58  apart to remove the pegs  52  and  54  from the apertures  48  and  50  and the positioning device  40  and the device  60  with the rollers and jaws can be detached from the bladder and the connecting tube  42  so that it can be pulled along the line  10  away from the inflated bladder. 
     A series of additional pressure pipes and corresponding bleed pipes  70 ,  72  (four in all) extend to the outside of the bladder  38  and are removably attached to the positioning device  40 . Device  40  is moved to the other end of the main line  10  and a second assembly comprising elbow  22 , bladder  38 , containment tube  24 , sealing disc  26  and the carrier tube and lining  18  and  14  with bladder  38  is connected to the positioning device (and one of the additional pressure/bleed pipe pair) which is again moved back into the main line  10  until the next lateral to be lined is reached when the device is placed in register therewith so that by appropriate pressurising of the assembly as described in relation to FIG. 1, the lining tube can be inserted into position in the lateral. When this process has been completed, the procedure is again repeated so that all five laterals can have lining tubes placed therein and the lining tubes can be cured simultaneously. 
     To effect the curing, it may be necessary to circulate hot water, steam or hot air through the pressurising hoses  28 ,  70  and  72  if the resin is of the heat cure type. 
     When curing has been completed, it is simply a matter of releasing the pressure in each of the bladders  38  which will then collapse, and each can be removed from the main line  10  by pulling on the pressure hose  28 ,  70  or  72  as the case may be. The restriction of such hose retracts the carrier tube  18  from inside the lateral, leaving the rigid lining tube  14  in position. 
     In the alternative arrangement shown in FIGS. 5,  6 , and  7 , the method of operation is the same as that described in relation to FIGS. 1-4, and only the structure of the bladder is varied in order to make it easier for the additional pressure/bleed pipes to pass the bladder assembly whilst it is inflated. 
     Thus, the bladder is in the form of diametrically opposite inflatable pillows  80 ,  82  which are carried on inner diametrically opposite plates,  84 ,  86  connected to the elbow  22  by being bolted thereto by bolts  88 . Plate  86  is carried by the elbow  22  on a radial leg  90  which is adjustable in length so that the arrangement can be adjusted to suit pipes of different diameters. Pillow  80  has a hole,  92  therein through which the elbow pipe  22  passes the pipe  94  which extends from the elbow  22  forms passage for the everting medium and also carries the coupling  42 . Pipes  96 ,  98  connect the interior of the pipe  94  and the pillows  80 ,  82 . The aperture  36  is also shown in FIG.  5 . The operation of the arrangement of FIGS. 5,  6  and  7  will be understood from the previous description of the embodiment of FIGS. 1-4. The lining  14  and the carrier tube  18  are inverted by pressurising the interior of elbow  22  and at the same time by passage of the pressurising medium through hole  36 , pipe  94 , and pipes  96 ,  98  inflation of the pillows  80 ,  82  to seal the lateral aperture whilst eversion takes place. The additional pressure/bleed pipes  70 ,  72  can pass between the pillows easily as shown in FIG. 6 in dotted lines. Whilst pillow  80  seals the lateral, pillow  82  forms a reaction means. 
     The lining tube  14  in the FIG. 7 arrangement as shown has a collar  100  which is preferably a sealed envelope containing a resin absorbent material which is impregnated with curable synthetic resin similar to the tube itself. As the lining tube  14  cures so the collar will also cure and the collar remains in place around the lateral aperture. 
     The present invention provides a system whereby a plurality of lateral linings may be cured simultaneously thereby reducing the overall cure time in a contract where a number of laterals have to be lined.