Apparatus for repairing a pipeline and method for using same

Abstract: A pipe repair apparatus (10) includes an outer carrier tube (17), an inner bladder tube (48) within the carrier tube, and a repair sleeve (16) within the bladder tube. The bladder tube (48) and the carrier tube (17) are formed by one unitary tube which is folded back upon itself. A wick (70) extends from the repair sleeve (16) to the rear end of the bladder tube (48) and permits evacuation of gases from the bladder tube when the bladder tube is flattened by a vacuum during insertion of a curable resin into the bladder tube (48) at its forward end. The bladder tube (48) can be inverted out of the carrier tube (17) so as to place the repair sleeve (16) in contact with an area to be repaired within a sewer pipe. This method may also be used to repair the damaged joint between a lateral sewer line and a main sewer line.

Description: BACKGROUND OF THE INVENTION This invention relates to apparatus for repairing a pipeline and method for using same. One method of repairing damaged sewer pipe is to excavate the area surrounding the sewer pipe and replace the broken portion. This is a very expensive and labor intensive solution and is also an inconvenience to residents living in the area and utilizing roadways overlying the area. Another solution is in situ relining of sewer pipes. In situ methods typically utilize a resin coated liner which is inserted into the existing sewer pipeline and unrolled against the sewer pipe. The unrolled liner is held against the existing sewer pipe while the resin cures to form a new pipe lining within the existing pipe. One example of such a method is shown in U.S. Patent 4,366,012 dated December 28, 1982. In this patent is shown a process utilizing an elongated outer tube having an inner tube comprised of felt. Uncured resin is introduced into the tube and is used to impregnate the felt inner tube. The two concentric tubes are then inverted into the end of the sewer pipe to be repaired and the inversion process continues until the area of the sewer pipe needing repair has been reached by the inverting tubes. Upon inversion the impregnated felt liner is placed on the outside of the original outer liner, and is pressed against the interior surface of the sewer pipe. When the resin cures a new pipe liner is provided at the area to be repaired. Patent 4,366,012 shows a method for impregnating the inner felt tube with uncured resin. The impregnation is initiated by pouring the uncured resin in one end of the two concentric tubes. A slit is made in the outer tube approximately 30 cm (12 inches) from the other end of the outer tube. A vacuum cup is placed over the slit and a vacuum is drawn from the outer tube, thereby causing flattening of the outer tube and assisting the resin to spread through the fabric liner and impregnate it from one end to the other. Once the resin has impregnated the entire felt liner the vacuum is shut off and a patch is solvent welded over the slit. There are several disadvantages to this impregnation process. The slit makes the outer tube or bladder weaker. Furthermore the cutting of a slit and the patching of a slit are time consuming. If the removal of the vacuum source from the vacuum cup is not timed properly, the vacuum cup will suck up some of the resin, thereby rendering the vacuum equipment inoperable. Another disadvantage of the method of repairing a sewer pipe shown in Patent 4,366,012 is that the outer bladder and the inner felt tube must be inverted into the sewer pipe beginning at a manhole located nearest to the area to be repaired. The inverted tubes must then extend to the area to be repaired, thereby requiring a length of tube which will reach from the nearest manhole to the area to be repaired. For example, if a 90 m (300 foot) long liner is required, the method of Patent 4,366,012 requires pouring resin at one end of the tube, moving down the tube for approximately 15 m (50 feet), making a slit in the coating of the fabric liner, placing a suction cup over the slit, drawing the resin to that point, removing the vacuum, and placing a patch over the slit. Then it will be necessary to move another 15 m (50 feet) down the tube and repeat the process. This process will continue at approximately 15 m (50 foot) intervals until the desired location on the tube is reached. The foregoing 15 m (50 foot) intervals are necessary because it is only possible to draw a vacuum so far down the tube and still be effective. Another disadvantage of the method shown in Patent 4,366,012 is that the fabric liner is coated. In some applications, it would be desirable to utilize a liner that is not coated and instead use a liner that is separate from the bladder. Most of the sewer mainlines are usually located in roadways and are buried at a considerable depth. These mainlines have lateral pipes that branch off to houses, businesses and industries. Lateral lines are conduits for carrying waste from these houses, businesses and industries out to the mainline sewer. Mainline sewers are typically straight with access manholes at spaced apart positions along the length of the main sewer line. Mainline sewers are usually owned by municipalities or utility companies who utilize the services of civil or professional engineers for the design of sewer installations, inspections, and final work acceptances. Lateral sewers on the other hand are typically installed by local plumbers or home owners. It is common to find numerous bends or fittings in a lateral sewer as well as inappropriate materials used in the original construction. These lateral installations offer a greater challenge in repair than do the reconstruction of the straight and professionally designed mainline sewers. Therefore, a primary object of the present invention is the provision of an improved apparatus for repairing a pipeline and method for using same. It is another object of the present invention to provide an apparatus for the insertion and installation of a new liner into an existing pipe which is particularly suitable for the spot repair of damaged sections of a given pipeline, wherein the liner is introduced into the existing pipe by means of a carrier which encloses the liner and protects it from contact with the surrounding pipe walls until the liner is in its desired location within the existing pipe. It is a further object of the present invention to provide a method for relining pipes in which the pipe liner is secured to an inflation bladder, impregnated with resin and encapsulated within a positioning element, the positioning element then being inserted into an existing pipe and fluid being introduced under pressure into the positioning element to cause the inflation bladder and the liner secured thereto to invert outwardly from within the positioning element to a placement position near the compromised pipe section, the inflation bladder expanding radially in response to fluid pressure and urging the liner into contact against the pipe wall, and subsequently removing the inflation bladder and positioning the element from the pipe. A further object of the present invention is the provision of an improved method for impregnating a resin absorbent material with an uncured resin while the resin absorbent material is within an inflatable bladder tube. A further object of the present invention is the provision of an improved method for repairing lateral sewer pipe and particularly for repairing the juncture between the lateral sewer pipe and the mainline sewer pipe. A further object of the present invention is the provision of an improved carrier which is integral with the bladder tube, and which permits the positioning of the bladder tube within the sewer pipeline in the general area of the pipeline to be needing repair. A further object of the present invention is the provision of a method for repairing sewer pipeline wherein the outer carrier is disposable after use. A further object of the present invention is the provision of an improved method and apparatus for repairing pipeline which is economical in manufacture, durable in use, and efficient in operation. SUMMARY OF THE INVENTION The present invention provides an elongated bladder tube having a fill end for receiving a quantity of fluid resin, a vacuum end for connection to a vacuum source, and flexible tube walls forming a tube cavity therein. A layer of resin absorbent material is within the tube cavity and includes first and second material ends. The first material end is spaced a predetermined distance from the vacuum end of the bladder tube. An elongated wick includes an interior wick end positioned between the first and second material ends of the resin absorbent material. The wick extends from its interior wick end toward the vacuum end of the bladder tube and terminates in a vacuum wick end with at least a portion of the wick being located between the vacuum end of the bladder tube and the second material end of the resin absorbent material. One modified form of the above apparatus involves the use of an elongated carrier which is separate from the bladder tube and which contains the bladder tube and the tube of resin impregnated material so as to protect them during insertion into a sewer pipeline. When the carrier is located adjacent the area in the pipeline to be repaired, the bladder tube is inverted out of the carrier tube and this places the resin impregnated material in contact with the sewer pipe walls needing repair. Another modified form of the present invention utilizes a carrier which is integral with the bladder tube, and which is folded back on the bladder tube so as to create an outer carrier tube in protective relation over the bladder tube. The present invention also provides a method for impregnating a curable resin in a layer of resin absorbent material as claimed in claim 4. An embodiment of the method involves introducing a quantity of curable resin into the fill end of the bladder tube, the quantity of resin being sufficient to impregnant all of the resin absorbent material within the bladder tube. A vacuum source is then connected to the bladder tube at a point spaced downstream from the downstream end of the resin absorbent material whereby the wall of the bladder tube will collapse on the layer of resin absorbent material and the gas conduit will provide a path for evacuating gas through the collapsed tube walls. Gas is continuously evacuated from the bladder tube until the curable resin moves to the downstream end of the absorbent material and completely impregnates the absorbent material. A further method of ensuring complete impregnation of the sleeve is defined in claim 8. BRIEF DESCRIPTION OF THE FIGURES OF THE DRAWINGS Figure 1 is a perspective view of a carrier tube having a bladder tube and a repair sleeve mounted therein. Figure 2 is a perspective view of the bladder tube having the repair sleeve therein. Figure 3 is a perspective view of the bladder tube of Figure 2 showing the method for inserting the resin into the bladder tube. Figure 4 is a sectional view taken along line 4-4 of Figure 2. Figure 5 is a sectional view taken along line 5-5 of Figure 1. Figure 6 is a sectional view taken along line 6-6 of Figure 1. Figure 7 is a perspective view of a modified form of the present invention. Figure 8 is a view similar to Figure 7, but showing the method of applying the resin to the interior of the bladder tube. Figure 9 is a sectional view taken along line 9-9 of Figure 7. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings the numeral 10 generally designates a repair apparatus of the present invention. Apparatus 10 includes a carrier assembly 12, a bladder assembly 14, and a repair sleeve 16 within the bladder assembly 14. Carrier assembly 12 is comprised of a carrier tube 17 having a rear end 18 and a forward end 19. An end cap 20 is secured to the rear end 18 of carrier tube 17 by means of clamps 22. Extending through the end cap 20 are a bladder control line 24, a fluid injection line 26 and an air escape valve 28 (Fig. 6). At the forward end of carrier tube 17 is a rigid collar 30 (Fig. 5). A pair of end flaps 32, 34 have their rear ends engaging the collar 30 and clamped to the collar 30 by means of clamp 36. Clamp 36 also holds the forward end 19 of carrier tube 17 against the collar 30. Within the carrier tube is a carrier cavity 38. The attachment of the forward end 19 of the carrier tube 17 to the collar 30 is further facilitated by threads or serrations 40 on the outer surface of collar 30. The forward ends of end flaps 32, 34 include grommets 42. A pull line 44 is threaded through grommets 42 (Fig. 1) and includes a knot 46 which permits the line 44 to pull the carrier 12 to the left as viewed in Figure 1. However, when the pull line 44 is pulled to the right, it slips free from the grommets 42. Bladder assembly 14 is shown in Figure 2 and includes bladder tube 48 having a rear end 50 and a forward end 52. Fitted within the rear end 50 is a threaded receptacle 54 (Fig. 6) which is held in place in attachment to the rear end 50 by means of clamps 56. A pulling loop 57 is also held by clamps 56 and is attached to bladder control line 24 as shown in Figure 6. Referring to Figure 5, within the bladder tube 48 is repair sleeve 16 formed of felt or other resin absorbent material. The sleeve 16 is attached at its forward end to an inversion collar 62 by means of stitches 60. The forward end of inversion collar 62 is fixedly attached to the forward end 52 of bladder tube 48 by heat sealing, adhesive, or other suitable securing means. The stitches 60 are easily broken away so as to permit the forward end of the repair sleeve 58 to be separated from the rear end of inversion collar 62 by tension forces. A cuff 51 is folded back at forward end 52 of bladder tube 58 and is secured to collar 30 by means of a hose clamp 53. Referring to Figure 4, a vacuum coupler 64 includes a threaded end adapted to thread within the threaded receptacle 54 so as to connect a vacuum hose 66 and a vacuum source 68 to the bladder tube 48. A wick 70 includes a forward end 72 located forwardly of the rear end 76 of repair sleeve 58. The wick 70 extends rearwardly therefrom to a rear end 74 located adjacent the threads of threaded receptacle 54. The method of impregnating the repair sleeve 58 with resin involves pouring the resin into the forward end 52 of bladder tube 48 as illustrated in Figure 3. A quantity of resin sufficient to impregnate the entire repair sleeve 58 is poured into the bladder tube. A vacuum is applied to the vacuum tube 26 so as to cause the bladder tube 48 to collapse in a flattened state. The wick 70 provides an important function in this regard since it permits the gas within the bladder tube 48 to be withdrawn even though the bladder tube 48 is collapsed. The felt or other resin absorbent material of repair sleeve 58 permits gas to be withdrawn, but this sleeve does not permit gas to be withdrawn in the area between the rear end 76 of sleeve 58 and the rear end 50 of the bladder tube 48. The wick 70 however, permits the gases to be withdrawn through this particular area. As a result the flattening of the bladder tube 48 causes the resin to be pressed rearwardly from the forward end until it has completely impregnated the felt or other resin absorbent material of repair sleeve 58. Rollers (not shown) may also be applied to the flattened bladder tube 48 to facilitate the spread of resin to all portions of repair sleeve 58. The bladder tube 48 is preferably formed of a transparent or translucent material which permits visual observation of the progress of the resin as it is spread through the repair sleeve 58. By visual inspection it is possible to determine when the resin has spread completely to the rear end 76 of the repair sleeve 58. The vacuum coupler 64 is then withdrawn from the threaded receptacle 54 and a closure cap 38 is threaded in its place. During the removal of the vacuum coupler 64, the wick 70 is grasped and pulled out of the bladder tube 48. The wick 70 will have resin impregnated on its inner end, and can be placed inside the manhole where the repair is taking place as a gauge for determining how long it takes for the resin to cure. After impregnating the repair sleeve 58, the bladder assembly 14 having the repair sleeve 16 therein is placed inside the carrier tube 17 as shown in Figure 1. As shown in Figure 10, the repair apparatus 10 is then pulled through a sewer line 134 having a area 136 requiring repair. A television camera (not shown) may be placed within the sewer line 134 to show the proper location for the carrier 10 relative to the area 136 needing to be repaired. When the carrier tube 17 reaches the position shown in Figure 11, air pressure, water pressure or other fluid pressure is applied to the carrier cavity 38. This causes the bladder tube 48 to begin to invert out of the carrier tube 17 in the manner illustrated in Figure 12. The inversion of the bladder tube 48 continues until it reaches the position shown in Figure 13. In this position the repair sleeve 58 is on the outside of the bladder tube 48 and is in engagement with the area 136 of pipe 134 which requires repair. The fluid pressure is continued to be applied to the inverted bladder tube 48, thereby pressing the bladder tube 48 radially outwardly so as to hold the repair sleeve 58 tightly against the area 136. The resin is permitted to cure and harden. Then the air pressure is released from the carrier tube 17 as shown in Figure 14 and the bladder control line 24 is pulled to cause the bladder 48 to move to the right and resume its original uninverted configuration within the carrier tube 17. During the withdrawal of the bladder tube 48, the stitches 60 break away as to permit separation of inversion collar 62 from repair sleeve 58, thereby leaving the hardened repair sleeve 58 in place as shown in Figure 15. Referring to Figure 7 a modified form of the present invention is shown and is designated by the numeral 80. Apparatus 80 includes an outer carrier tube 82 having a rear end 84 which surrounds an end cap 86 and is clamped thereto by means of clamps 88. Extending through end cap 86 are a bladder control line 90, a fluid injection line 92, and an air escape valve 94. The outer carrier tube 82 includes a forward end 96 to which is attached by heat sealing or welding a pair of end flaps 98, 100. Flaps 98, 100 are held in place by a spot weld 102 (Fig. 9). A pull cable 104 extends through the grommets 106 in the end flaps 98, 100 and includes a loop 108 on its end. A release cable 109 has a spring pin 111 on its end. Spring pin 111 is detachably retentively retained in loop 108 so as to attach cable 104 to flaps 98,100. Pulling cable 104 is used to pull the apparatus 80 through the sewer line to the desired location. Then release cable 109 is pulled and spring pin 111 releases from loop 108, thereby permitting cable 104 to slip through grommets 106 and release its attachment from flaps 98,100. Integrally formed with the outer carrier tube 82 is an inner bladder tube 110 which has a forward end 112 and a rear end 114 adapted to receive a threaded receptacle 116, clamps 118, and a pulling loop 120. A vacuum line 121 is adapted to connected to the receptacle 116 in the same fashion shown and described for the modification in Figure 2. The juncture between the outer carrier tube 82 and the inner bladder tube 110 comprises a fold 122 where the carrier tube 82 has been folded back over the bladder tube 110. Initially the bladder tube 110 and the carrier tube 82 are one continuous tube, and the carrier tube 82 is formed by folding it back over the bladder tube 110. An inversion collar 128 is spot welded or otherwise attached to the forward end 112 of bladder tube 110 and extends rearwardly therefrom. At its rear end it is attached to a repair sleeve 124 by means of threads 126. The repair sleeve is formed of felt or other material which is capable of absorbing an uncured resin. Fiber glass, seamless polyester knit tube, or other materials could be used other than felt or in combination with felt. Several advantages are obtained by the use of the modified apparatus 80 shown in Figures 7-9 over the apparatus 10 shown in Figures 1-6. For example, the apparatus 10 utilizes a rigid collar or clamp 36 at the forward end of the carrier tube 12 in order to connect the bladder assembly 14. This rigid collar can in some situations get caught on offset sewer pipe joints during installation or in places where the pipe is partially collapsed, and in those situations the carrier sometimes becomes caught or is unable to pass through the pipe. The rigid collar 36 also adds considerable weight to the repair apparatus whereas the apparatus 80 shown in Figures 7-9 is light in weight, weighing about one fourth of what the apparatus 10 weighs. Another advantage of the apparatus 80 is that it eliminates the step of pulling the bladder assembly 14 into the carrier 12. The rigid collar 36 used in device 10 must be smaller in diameter than the host sewer pipe. This smaller opening makes it harder for the liner to pass through and requires more pressure than the apparatus 80 which is collapsible and which has a front opening of a size which can be the same as the host pipe. This makes it easier for the apparatus 80 to pass through during inversion and requires less pressure. The apparatus 10 requires different length and diameter carriers for the various liners installed. This means that the installer must keep an inventory of carriers that are expensive. The installer must also transport more equipment to the job site. The carrier 82 of apparatus 80 is disposable and is designed especially for the liner length and diameter matched to the pipe that is being repaired. Figure 8 shows the manner in which the device is filled with resin. The resin is poured into the forward end of bladder tube 110 while bladder tube 110 is located within the outer carrier tube 82. Carrier tube 82 and bladder tube 110 are integral with one another and are preferably formed of a transparent or translucent material which will permit observation of the resin as it is poured into the bladder tube 110. The rear end 84 of the carrier tube 82 is folded forwardly as shown in Figure 8 so as to expose the rear end of the bladder tube 110 and permit the attachment and detachment of vacuum tube 121. As the vacuum is applied, a roller (not shown) may be used to roll the bladder tube 110 and the carrier tube 82 flat and press the resin rearwardly toward the rearward end of the bladder tube 110. When the fabric liner or repair sleeve 124 of bladder tube 110 is fully impregnated, the vacuum tube 121 is removed and a plug similar to the plug 78 is inserted after removal of the wick 70. The carrier tube 82 is then unfolded at its rear end and it is attached to the end cap 86 in the manner shown in Figure 7. In the drawings and specification there has been set forth a preferred embodiment of the invention, and although specific terms are employed, these are used in a generic and descriptive sense only and not for purposes of limitation. Changes in the form and the proportion of parts as well as in the substitution of equivalents are contemplated as circumstances may suggest or render expedient without departing from the scope of the invention as defined in the following claims.

Claims: In combination: an elongated bladder tube (48) having a fill end (52) for receiving a quantity of fluid resin, a vacuum end (50) for connection to a vacuum source (68), and flexible tube walls forming a tube cavity therein; a layer of resin absorbent material (16) within said tube cavity and having a first material end spaced a predetermined distance from said vacuum end (50) of said bladder tube (48) and a second material end; characterized by an elongated wick (70) having an interior wick end (72) positioned between said first and second material ends of said resin absorbent material (16), said wick (70) extending from said interior wick end (72) toward said vacuum end (50) of said bladder tube (48) and terminating in a vacuum wick end (74), at least a portion of said wick being between said vacuum end (50) of said bladder tube (48) and said second material end of said resin absorbent material (16). The combination of claim 1 wherein said layer of resin absorbent material (16) is in the shape of a sleeve. The combination of claim 1 wherein a coupler (64) is connected to said vacuum end (50) of said bladder tube (48), said coupler (64) being adapted to be connected to a vacuum source (68), said coupler (64) being spaced from said second material end whereby an application of a vacuum to said coupler (64) will cause said bladder tube (48) to collapse around said wick (70) between said first material end of said resin absorbent material (16) and said vacuum end (50) of said bladder tube (48), said wick (70) providing a passageway for the evacuation of gases from said tube cavity between said first material end of said resin absorbent material (16) and said fill end (52) of said bladder tube (48). A method for impregnating a curable resin in a layer of resin absorbent material (16) having a first end and a second end, comprising: taking a flexible bladder tube (48) having a fill end (52) and a vacuum end (50) positioned downstream from the fill end (52); positioning the first end of the layer of resin absorbent material (16) within the bladder tube (48) downstream from the second end of the resin absorbent material (16), the first end of the layer of resin absorbent material (16) being upstream a first spaced distance from the vacuum end (50) of the bladder tube (48); characterized by taking an elongated wick (70) having first and second wick ends; positioning the wick (70) to span the first spaced distance so that the first wick end (72) is between the downstream and upstream ends of the layer of resin absorbent material (16) and the second wick (74) end protrudes outwardly beyond the vacuum end (50) of the bladder tube (48); connecting a vacuum tube (57) to the bladder tube (48) at a point spaced downstream from the first end of the layer of resin absorbent material (16); introducing a quantity of curable resin into the fill end (52) of the bladder tube (48), the quantity of the curable resin being sufficient to impregnate all of the layer of resin absorbent material (16) within the bladder tube (48); applying a vacuum to the vacuum tube (57) to cause the bladder tube (48) to collapse on the layer of resin absorbent material (16) and also along the first spaced distance between the downstream end of the layer of resin absorbent material (16) and the vacuum end (50) of the bladder tube (48), using the wick (70) to evacuate gas through the collapsed bladder tube (48) along the first spaced distance between the downstream end of the layer of resin absorbent material (16) and the vacuum end (50) of the bladder tube (48), and outwardly from the vacuum end (50) of the bladder tube (48); continuing to use the wick (70) to evacuate gas until the resin impregnates all of the layer of resin absorbent material (16) from the second end thereof to the first end thereof and also impregnates the first wick end (72). A method according to claim 1 and further comprising removing the wick (70) from the layer of resin absorbent material (16) and the bladder tube (48) after the resin has impregnated all the layer of resin absorbent material (16) and has impregnated the first wick end (72). A method according to claim 2 and further comprising using the curing time of the resin impregnating the first wick end (72) to measure the time necessary for the resin to cure within the layer of resin absorbent material (16). A method according to claim 1 and further comprising connecting said vacuum tube (57) to a coupling (64) located adjacent the vacuum end (50) of the bladder tube (48). A method for preparing a repair assembly for repairing an interior pipe surface of a pipe comprising: placing an elongated sleeve (16) of resin impregnable material within an elongated bladder tube (48); placing said bladder tube (48) with said sleeve (16) therein into a carrying cavity within a carrying tube (17); inserting a quantity of curable resin into one end of said bladder tube (48) while said bladder tube (48) is within said carrying tube (17), said carrying tube (17) and said bladder tube (48) being sufficiently transparent or translucent to permit viewing of said resin within said bladder tube (48); collapsing said bladder tube (48) to cause said resin to spread to and impregnate said sleeve (16) of resin impregnable material; viewing the spread of said resin to said sleeve (16) of resin impregnable material; stopping the collapsing of said bladder tube (48) when said resin has spread to and impregnated said entire sleeve of resin impregnable material.

Inventors: KIEST LARRY W JR, VANAMEYDE GARY, KIEST, LARRY W. JR., VANAMEYDE, GARY
Applicants: LMK ENTPR INC, LMK ENTERPRISES, INC.
Application year: 1997
Main classification: F16L55
IPC codes: F16L55, B29C63