MXPA06005050A - Resin impregnation tower for cured in place liner - Google Patents

Abstract

A non-pressurized resin impregnation tower (54) for continuously impregnating the resin impregnable layer of a tubular cured in place liner (55) is provided. The tower (54) is at a height to provide sufficient resin pressure head to impregnate the resin impregnable layer fully. The resin impregnated tube (55) is fed into the top of the tower (54), drawn down about a roller at the bottom, removed from the top of the tower (54) and then wrapped with an outer impermeable coating. The impregnated liner (55) is suitable for pull-in-and-inflate method of installation or may be everted. For liners formed with an inner impermeable layer, the Linner is suitable for curing with steam.

Description

TOWER PE IMPREGNATION OF RESIN FOR A CURED LINING IN ITS PLACE BACKGROUND OF THE INVENTION This invention relates to cured liners in place for the trenchless rehabilitation of existing products and pipes, and more particularly to an impregnation tower for the continuous impregnation of cured liners in place which may have an internal impermeable layer to be wrapped with an external waterproof layer for trenchless rehabilitation of existing ducts through traction and inflation. It is generally known that existing conduits and pipes, particularly underground pipes, such as sanitary sewer pipes, sewage pipes, water lines and gas lines that are used to conduct fluids, often require repair due to fluid leakage. .

The leak can be inward from the environment to the interior or conductive portion of the pipes. Alternatively, the leakage may be outwardly from the conductive portion of the pipe to the surrounding environment, in any case of infiltration or exfiltration, it is desirable to avoid this type of leakage. The leak in the existing conduit may be due to improper installation of the original pipe, or to deterioration of the pipe itself due to normal aging, or the effects of transporting corrosive or abrasive material. Cracks in, or near pipe joints may be due to environmental conditions such as tremors, or to large vehicle movement, on the surface above, or similar natural or man-made vibrations, or other cases. Regardless of the cause, such leaks are undesirable and can result in waste of fluid being transported within the pipeline, or damage to the surrounding environment and possible creation of bad public health hazards. If the leak continues, it can lead to structural failure of the existing conduit due to loss of soil and lateral support of the conduit. Due to the enormous work in increase and costs of machinery, it is enormously more difficult and less economical to repair pipes or underground portions that may have leaks by dragging the existing pipe and replacing the pipe with a new one. As a result, several methods have been advised for the repair or rehabilitation of existing pipes instead. These new methods prevent the expense and dangers associated with the dragging and replacement of pipe or pipe sections, as well as significant inconvenience to the public during construction. One of the most successful no-trench pipe repair or rehabilitation procedures currently in use is the so-called Insituform® procedure. The Insituform® Process is described in detail in the US patents. No. 4,009,063, No. 4,064,211 and No. 4,135,958, the contents of which are incorporated herein by reference. In the standard practice of the Insituform® Process, an elongated flexible tubular liner of a felt fabric, foam or similar resin waterproof material with an external waterproof coating that has been impregnated with a thermoset curable resin is installed within the existing piping. In the most widely practiced mode of that process, the liner is installed using an eversion process, as described in the Insituform® '211 and' 958 patents. In the eversion process, the radial pressure applied to the inside of an outwardly facing liner compresses it against and to a coupling with the inner surface of the pipe as the liner unfolds along the length of the pipe. The Insituform® Procedure is also practiced by pulling a lining impregnated with resin into the duct through a string or key and using an inflation bladder impermeable to the separated fluid or a tube that flips out into the liner to make the lining be cured against the internal wall of the existing pipe. Such resin impregnated liners are generally referred to as "cured pipes in place" or "CIPP liners" and the installation is referred to as a CIPP installation. Flexible tubular linings cured in their conventional place for CIPP installations of both eversion, fraction and inflation have an outer smooth layer of substantially impermeable polymer coating, relatively flexible, in its initial state. The outer coating allows a resin to be impregnated in the inner layer of the resin impregnable material, such as felt. When turned out, this waterproof layer ends on the inside of the lining with the layer impregnated with resin against the wall of the pipeline. As the flexible liner is installed in place within the pipe, the pipe is pressurized from the inside, preferably using an eversion fluid, such as water or air to force the liner radially outward to engage and conform to the surface inside the existing pipe. The curing of the resin is initiated through the introduction of hot curing fluid, such as water to the liner turned outwardly through a recirculation hose attached to the end of the eversion liner. The resin impregnated in the impregnable material is then cured to form a tight, hard-fitting adapter pipe liner within the existing pipe. The new liner effectively seals any crack and repairs any pipe section or pipe joint deterioration in order to prevent further leakage either in or out of the existing pipe. The cured resin also serves to reinforce the existing pipe wall in order to provide additional structural support for the surrounding environment. When cured tubular liners are installed through the inflation and traction method, the liner is impregnated with resin in the same manner as in the eversion process and is pulled into and placed within the existing pipeline in a collapsed state. In a typical installation, a down tube, inflation pipe or conduit having an elbow at the lower end, is placed inside an existing manhole or access point and an eversion bladder is passed through the down tube, opens and wraps over the mouth of the horizontal portion of the elbow and inserts into the collapsed liner. The collapsed liner within the existing duct is then placed over and secured to the bent end of the inflation bladder. An eversion fluid, such as water, is then fed into the down tube and the water pressure causes the inflation bladder to push the horizontal portion of the elbow and cause the collapsed liner to expand against the interior surface of the existing conduit. Eversion of the inflation bladder continues until the bladder arrives and extends to the downstream sewer manhole or second access point. At this time, the liner compressed against the inner surface of the existing duct is allowed to cure. Healing is initiated through the introduction of hot healing water introduced into the inflation bladder in the same way as the recirculation line attached to the end of the eversion bladder causes the resin in the impregnated layer to cure. After the resin in the liner is cured, the inflation bladder can be removed or left in place in the cured liner. Both the traction and inflation method and the eversion method typically require man's access to a restricted manhole space several times during the procedure. For example, man's access is required to secure the eversion lining or bladder to the end of the elbow and insert it into the collapsed liner. Regardless of how the liner is to be installed, a curable thermosetting resin is impregnated into the resin absorbent layers of a liner through a process termed "wetting". The wetting procedure generally involves injecting resin into the resin absorbent layers through an end or an aperture formed in the outer impermeable film, removing a vacuum and passing the impregnated liner through press rolls as is well known in the art. of linings. A wide variety of resins can be used, such as polyesters, vinyl esters, epoxy resins and the like, which can be modified as desired. It is preferred to use a resin that is relatively stable at room temperature, but which is easily cured when heated with air, steam or hot water, or subjected to appropriate radiation, such as ultraviolet light. One of these methods for wetting a liner through vacuum impregnation is described in the U.S. Patent. No.4, 336, 012 of Insituform. When the liner has inner and outer waterproof layers, the tubular liner can be supplied flat and grooves are formed on opposite sides of the flattened liner and the resin is injected on both sides, as described in the '063 patent. Another apparatus for moistening at the time of installation while removing a vacuum at the trailing end of the liner is shown in U.S. Pat. No. 4,182,262. The contents of each of these patents are incorporated herein by reference. Recent efforts have been made to modify the traction and inflation method to use air to flip a bladder out toward the liner pulled from a nearby access point. When the eversion bladder reaches the distant access point, steam is introduced into the nearby access point to initiate healing of the resin impregnated resin. This procedure offers the advantage of a faster healing due to the increased energy carried by the steam as the healing fluid. However, the procedure still requires the eversion of a bladder toward the impregnated liner pulled. Efforts to avoid this step of eversion of the bladder towards the pulled liner include performing an eversion step on the ground. For example, in the U.S. Patent. No. 6,270,289, the method includes everting a calibration hose to a liner hose lying flat above the floor before pulling the hose assembly toward the existing conduit. This procedure avoids low-grade eversion, but is severely limited to the length of the lining that can be laid above the ground before pulling. A further suggestion to avoid this eversion is to manufacture a liner having an inner liner and an outer liner, so that a healing fluid can be introduced directly into a pulled liner. The disadvantages here involve the difficulty encountered when trying to impregnate the impregnable resin material disposed between the internal and external waterproof coatings. The outer coating remains essential to handle the impregnated liner and to allow the liner to be pulled towards the existing duct and the inner lining is desired for all curing with the vapor. Despite the modifications of both the eversion and trenchless rehabilitation and inflation methods, both procedures are labor intensive, require an eversion step and suffer from the increased costs associated with this. Accordingly, it is desirable to provide a method and apparatus for continuously impregnating a cured liner in its place to be wrapped with an outer impermeable layer.

COMPENDIUM OF THE INVENTION Generally speaking, according to the invention, a non-pressurized resin impregnation tower is provided to impregnate a cured liner in its proper place for the rehabilitation by traction and inflation of existing pipes. The impregnation tower is constructed to have a sufficient resin head to impregnate the impregnable material of passing resin. A continuous section of the impregnable resin material in a tubular form is pulled directly onto a roller at the top of the tower and pulled down through the resin in the tower and below a roller at the base of the tower and then up through the tower toward the calibration roller on the top as it exits. The wet tube is then wrapped with an impermeable layer of external resin and sealed. The outer layer can simply be sealed with heat using a thermal bond or tape. This outer seal merely encapsulates the resin-impregnated material but must have sufficient strength to withstand handling and abrasion as the liner is transported and then pulled into the existing conduit. The impregnable resin material can be formed into a tube and sealed in a variety of ways. This includes bonding by heat and applying conventional tape, sewing and applying tape or sealing with an extruded material. In one embodiment, the liner may have an impermeable layer on the inside that may be attached to the impregnable material. This liner can be formed around a forming device with an impermeable layer on the outside, sealed in one of the conventional ways and then turned out continuously through the forming device. The outer layer is now the resin absorbent layer or layers which are impregnated and wrapped with an impermeable polymeric layer to contain the resin and allow the storage and traction of the impregnated liner towards the existing conduit. The inner layer must be one that is impervious to and resistant to the high temperatures of the healing fluid.

Accordingly, it is an object of the invention to provide an improved method for rehabilitation by curing existing pipes instead. Another object of the invention is to provide an improved apparatus for impregnating a liner for rehabilitation by curing an existing pipeline instead. A further object of the invention is to provide an apparatus for impregnating a flexible resin liner having an internal impermeable layer suitable for trenchless rehabilitation of existing pipelines. Yet another object of the invention is to provide an improved method for manufacturing an impregnated resin cured in place by having an outer impermeable coating or jacket in continuous sections without the use of vacuum. A further object of the invention is to provide a method for impregnating a cured liner in place for the installation of trenchless pipe by traction and inflation. A further object of the invention is to provide a method for the manufacture of a cured liner in its impregnated resin having an inner impermeable layer and an outer impermeable envelope. Still another object of the invention is to provide a method for the manufacture of a cured liner in its impregnated resin having an inner impermeable layer and an outer impermeable envelope.

Other objects and advantages of the invention will be partly obvious and partly evident from the specification. The invention, therefore, comprises the various steps and the relationship of one or more of said steps with respect to the steps among themselves, the apparatuses representing the construction aspects, combinations and arrangement of parts that are adapted to perform said steps, and the products having the characteristics, aspects, properties and the relation of components, which are illustrative in the following detailed description and the scope of the invention will be indicated in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS For a complete understanding of the invention, reference has been made to the following description taken in conjunction with the accompanying drawings, in which: Figure 1 is a perspective view of a section of a cured liner in its typical impregnable resin location, suitable for use in the application of a liner in an existing pipe of the type generally used in the current and well known in the art; Figure 2 is a cross-sectional view of a cured liner in place having internal and external waterproof layers constructed and arranged in accordance with the invention; Figure 3 is a schematic view of the apparatus used to prepare the inner portion of the liner having an outer felt layer with an integral internal high temperature polymeric layer used in relation to the preparation of the cured liner in place of Figure 2; Figure 4 is a cross-sectional view showing the structure of the inner tubular portion of the liner produced by the apparatus of Figure 3, before being impregnated according to the invention; Figure 5 is a schematic elevation view showing the resin impregnation tower and the tube sealing and wrapping apparatus for applying an outer impermeable layer constructed and arranged according to the intention; Figure 6 is a cross-sectional view of the edge sealant in the tube casing and sealing apparatus taken along line 6-6 of Figure 5; Figure 7 is a cross-sectional view of the impregnated liner prepared through the apparatus of Figure 5; and Figure 8 is a schematic elevational view, showing the envelope of the tubular member emerging from a resin impregnation apparatus with an external coating passing the wet liner through a tube filler having a tubular envelope stored therein.; and Figure 9 is a cross-sectional view of a liner prepared through the apparatus of Figure 8.

DESCRIPTION OF THE PREFERRED MODALITIES A cured liner in its place impregnated with resin prepared according to the invention has an internal and external impermeable lining, so that it can be installed through the traction and inflation method and inflated and cured with a hot fluid without the use of an inflation bladder. The lining has coatings or layers of internal and external polymer and is prepared in continuous sections. It is impregnated without the use of vacuum as it is assembled in view of the increased stress necessary to impregnate a flattened liner having a resin absorbent material between the inner impermeable layer and an external one using convention vacuum impregnation technology. This increased effort is evidenced through the procedure suggested in the patent of E.U.A. No. 6,270,289. Here, above the ground, a calibration hose is inverted to an extended flat impregnated liner hose, or an impregnated liner hose is inverted to a tubular film using compressed air. In this case, the length of the lining hose approximates the length of the underground conduit to be lined. The inversion of the tube within the other requires an unobstructed length equal to the length of the longest layer. If the two layers have not been previously impregnated, it may be necessary to inject the resin between the layers on both sides of the extended flat tubes to provide adequate impregnation. This is a difficulty and an inefficient way to impregnate liner tubes. In this way, not only the length is restricted, but also the impregnation is extremely difficult. Figure 1 illustrates a cured liner in its flexible place liner 11 of the type currently used and well known in the art. The liner 11 is formed from at least one layer of a flexible resin impregnable material, such as a felt layer the felt layer 12 having an outer impermeable polymer film layer the outer polymer layer 13. The felt layer 12 and the outer polymer layer 13 are sewn along a seam line 14 to form a tubular liner. A compatible thermoplastic film in the form of a tape or extruded material 16 is placed on or extruded through the seam line 14 in order to ensure the impermeability of the liner 11. In the embodiment illustrated in Figure 1, and used throughout this description, the liner 11 includes an inner tube of a second layer of felt 17 also along a seam line 18 placed at a point on a tube other than the location of the seam line 14. in the felt layer 12. The outer felt layer 12 with the polymer layer 13 is then formed around the inner tubular layer 17. After impregnation of the liner 11 in a continuous section it is stored in a cooling unit to suppress the premature curing of the resin. The liner 11 is then cut to a desired length after being pulled into the existing pipe, or its cutter being cut into the existing pipe. The liner 11 of the type illustrated in Figure 1 is impermeable to water and air. This will allow the use in an eversion in air or water as described above. However, in an inflation and traction installation according to the invention, the outer liner on the liner alone needs to be sufficiently waterproof to allow easy handling of wetting and resin retention and to avoid damage to the liner as it is pulled towards the existing pipeline. For larger liner diameters, several layers of felt or impregnable resin material may be used, the felt layers 12 and 17 may be of a natural or synthetic flexible resin absorbable material, such as polyester, acrylic polypropylene, or inorganic fibers such as glass and coal. Alternatively, the resin absorbent material may be a foam. The waterproof film 13 in the outer waterproof layer 12 can be a polyolefin, such as polyethylene or polypropylene, a vinyl polymer, such as polyvinyl chloride, or a polyurethane as is well known in the art. Any form of stitching, bonding with adhesive or bonding by flame, or any other convenient means may be used to join the material in the tubes. In the initial step in all trenchless rehabilitation facilities, the existing pipeline is prepared by cleaning and video recording. Referring now to Figure 2, a cured liner in place 21 prepared in accordance with the invention is shown in cross section. The liner 21 is constructed in a manner similar to the convention liner 11, but includes an internal tubular member with an inner waterproof layer 22 having a thin felt or impregnable resin layer 23 attached thereto. The inner felt layer 23 with the waterproof layer 22 has been stitched along a seam line 24 through a row of stitches 26 and is sealed with a tape 27 applied over the stitches 26. An outer felt layer 28 it is wrapped around the inner thin felt layer 23 and a tube is formed through the stitches 29. Finally, an outer layer or wrap 31 is disposed around the outer felt layer 28. By providing a liner having impermeable layers both internal and external, it is not necessary to flip the liner outward during installation or eversion of an inflation bladder after the liner has been pulled into the existing duct. In this way, a significant saving in labor costs is available at the time of installation. It also allows the use of a hot curing fluid such as steam to cure the resin. In such a case, all hot fluids are introduced into the liner below ground level to provide a safe working environment. The felt layers 23 and 28 can be impregnated in the usual way using vacuum. Alternatively, the felt layers 23 and 28 are first impregnated with resin and then an outer impermeable wrapper 31 is applied. This avoids the difficulty with impregnation of a finished liner having layers of felt between an internal and external impregnable layer. In the patent of E.U.A. No. 4,009,063, Eric Word proposed to inject resin into the felt layer using needles inserted on opposite sides of a flattened constructed liner. This operation requires cutting and patching needle holes in the outer coating. The vacuum impregnation process taught in the U.S.A. No. 4, 366.012 may not be suitable unless the vacuum is removed on both sides since the inner lining is a barrier to the flow of resin in an inner and outer lining. In order to overcome these impregnation difficulties, the liner 21 is manufactured from wad rolls of flat coated felt and flat felt and continuously impregnated before the application of the outer wrapper 31. When the felt layers 23 and 28 are formed in tubes by sewing and / or applying adhesive tape, any of the conventionally known methods for forming felt or other resin-impermeable material in the tubes is suitable. For example, tubes can be formed through the use of various adhesives or adhesives, as well as flame-bonding. The tape can be applied to the inner waterproof layer 22 on the inner felt layer 23, by applying an adhesive strip or extruding a layer of polymeric material in order to seal the butt edges of the felt material and the holes formed during an operation sewing.

Referring now to Figure 3, a method for continuously forming a length of a tube of resin impregnable material with a sealed inner layer of the impermeable material l is shown. A roll of coated felt 36 having an endless section of felt 37 with an impermeable layer 38 attached to a surface, is fed through a directional roller 39 in a flat shape with a roller 39 facing the coated side towards a device formed of tube 41. The tube forming device 41 includes a tubular support frame 42 and a sewing device 43 which can be a sewing and belt application machine, glue machine or flame joining apparatus. The felt 37 with the waterproof layer 38 facing the roller 39 is fed in the direction of an arrow A towards the end of the tube-forming device 41, where it is wrapped around the support frame 42 and stitched in a tube 44 to along a seam line 46, with the felt 37 on the inside of an impermeable layer 38 on the outside. The tube 44 then passes an adhesive tape applying device 47, wherein a tape 48 is placed on the seam line 46 to form a tube member 45 with impermeable coated adhesive tape. The tube member 45 with adhesive tape then continues the path along the tubular support frame 42 towards an inverting ring 49 at the distal end 42. The tube member 45 with adhesive tape is then turned out towards the tubular support frame. 42, so that the waterproof layer 38 is now on the inside of the tube 45 as it is removed from the near end of the support frame 42 along a line defined by the arrow B. At this point, the tube turned towards 45 outside has the structure illustrated in cross-section to Figure 4, with the impermeable layer 38 on the interior of tube 45 and the felt layer 37 on the outside. The tube 45 then continues the path in the direction of the arrow B for the addition of one or more layers of flat felt. The tube 45 is then stored for further use, wrapped with an outer impermeable coating, or can be passed directly to a resin impregnation and reinforcement step as shown in Figure 5 before the final wrap. Figure 5 illustrates a schematic view of the impregnation of a supply 51 of the tubular member 45. Here, the tube 45 is pulled through a pair of rubber-covered traction rollers 52 and 53 to a resin tower 54 with the open top, filled to a predetermined level with a curable thermosetting resin 57 to form an impregnated or wet tube 55. The tube 45 passes over the roll 53 and below the total height of the tower 54 towards a lower roll 59 which makes rotating the tube 45 in an upward direction towards a pair of compression rollers 61 and 62. The tower 54 has a height of approximately 1.82 to 4.26 meters, but it may be of sufficient height to provide a pressure head sufficient to wet and impregnate the impregnable layer of the tube 45. The height necessary to provide a pressure head sufficient to impregnate the impregnable material depends on the viscosity of the resin, the thickness of the material egnable and the speed through the tower. At this time, the impregnated tube 55 leaving the tower 54 is ready for the final wrap with an outer impermeable coating. At this time, the impregnated tuna 55 that leaves the tower 54 with the upper part open in the direction of an arrow D is fed to the inlet end 68a of the forming pipe 64 in the direction of an arrow D 'and is wrapped turning the film tube 72 outwardly. As the tube 72 is turned outwardly, the edge seal 73 is moved into the interior of the tube 72 so that the edge seal 73 is disposed between the impregnated tube 55 and the film tube 72. A wrapped wet tube 74 that includes wet tube 55 and tube flipped out 72, is pulled out of the outlet end 64b of the forming pipe 64 and is fed to a refrigerated truck for storage and shipping to an installation site. Referring to Figure 7, a cross-sectional view through the sealant 65 and forming pipe 64 is shown along the line 6-6 of Figure 5. The sealant 65 forms the edge seal 73 on the pipe. 72 film as the film tube 72 passes over the outside of the forming pipe 64. Once the tube 72 is turned over, the edge seal 73 is now inside the wet tube 74 as it is pulled from the end outlet 64b of forming pipe 68. External waterproof film 72 may be applied before or after wetting. In the case where it is wetted before, the tube 45 prepared as shown in Figure 3 is fed directly into the tube forming assembly 63 in Figure 5 and provides the liner 74 shown in cross section in Figure 7. In this case, the impregnable resin material 37 is not impregnated. Referring now to Figure 8 illustrates an alternative apparatus for wrapping an outer impermeable tube 81 around the impregnated tube 55 as shown generally at 82. Here the tube 55 may be impregnated in the same manner as described in relation to the tower dampening 54 in Figure 5 and then tube 55 is fed to a filling pipe 83 having an inlet end 83a and an outlet end 83b. The reference numbers, as used in Figure 5, apply to identical elements here. A supply of a flexible waterproof tube 81 is loaded onto the outer surface of the filling pipe 83 having an inlet end 83a and an outlet end 83b. The impregnated tube 55 exiting the resin tank 53 is fed to the inlet end 83a of the filling pipe 83. As the pipe 55 enters the inlet end 83a of the filling pipe 83, the waterproof pipe 81 is pulled from the outside of the filler pipe 83 and is turned around the inlet end 83a into the interior of the filler pipe 83 to wrap the impregnated tuna 55 as it exits the outlet end 83b. This forms a complete liner 86 having an inner waterproof layer 38 and an outer waterproof liner 81. The tube 86 with the outer skin 81 is removed from the outlet end 83b of the filling tube 83 through a pair of drive rollers 87 and 88. , or another traction device such as tractors, in a direction of an arrow F. When an extruded tube is used in this embodiment, there is no seam in the outer impermeable coating 81. The only limitation is to prepare the tube 86, of this This is the length of the impermeable tube 81 that can be placed on the filler tube 83. It has been found that approximately 304.8 meters of a waterproof tube can be compressed on a filler tube with a height of approximately 6,096 meters. Longer lengths can be stored in longer filler tubes. Figure 9 is a cross-sectional view of a liner 86 as it exits the filler tube 83. The liner 86 includes an inner tubular member of resin absorbent material 37 having an impermeable inner liner 38 sealed with a tape 48 as shown in FIG. described in relation to Figure 4. After it leaves the filler tube 83, the liner 86 includes the outer tubular sheath 81. In view of the fact that the tubular sheath 81 is a pre-extruded tube, the outer sheath 81 has no seam as in relation to Figures 6 and 8. Once in the installation site, the impregnated tube 74 or 86, having the inner impermeable layer 38 and the external impermeable wrapper 72, is already ready for installation through the method of traction and inflation. This method is fully described in the patent of E.U.A. No. 4, 009.063, the contents of which are incorporated herein by reference. In the case of installation through the method of traction and inflation of the impregnated liner 74, a separate eversion bladder is no longer necessary to inflate the liner, due to the presence of the internal impermeable layer 38. Through the appropriate selection of Materials for the inner waterproof layer 38, such as polypropylene, can be cured with steam introduced into the liner 74 or 86 once it is in place in the existing conduit. When the liner does not have the inner waterproof layer 38, and is wrapped with the outer waterproof wrapper 72, the installation can be carried out through the conventional eversion method as described in the U.S.A. No. 4,064,211. Alternatively, said liner can also be installed using an inflation bladder as described in the U.S. Patent. No. 6,539,979 B1 and Application Publication No. 2003/0015247 A1, the contents of which are incorporated herein by reference. The methods and apparatuses described herein provide a convenient means for preparing a cured liner in place having impermeable layers both internally and externally. An impregnation tower, as illustrated in Figure 5, readily provides a method for impregnating an impregnable resin tube having an internal impermeable layer before an external impermeable layer is applied. The tube prepared in the apparatus shown in Figure 5 avoids the need to impregnate with the use of vacuum or high pressure techniques, which are troublesome for use in view of the desire to impregnate in a continuous manner. In this way, it will be seen that the previously established objects, among others evident from the previous description, are efficiently obtained and, since certain changes can be made to carry out the above procedure, in the described product, and in the construction (is) established without departing from the spirit and scope of the invention, it is intended that the subject matter contained in the above description and shown in the accompanying drawings should be interpreted as illustrative and not as limiting. It should also be understood that the claims that you follow are intended to cover all the generic and specific aspects of the invention described here and all the declarations of the scope of the invention, which, as a matter of language, can be said to fall within it.

Claims (13)

1. - A method for preparing a cured liner in place, comprising: forming a first tubular member of a resin impregnable material; feeding the first tubular member to a Teresina impregnation tower of a suitable height to impregnate the resin impregnable material with resin; removing the impregnated tubular member from the tower; and placing a waterproof resin coating around the impregnated tubular member.

2. The method according to claim 1, wherein the step of placing an outer coating includes the step of wrapping a flat sheet around the impregnated tubular member and sealing the sheet to a tube.

3. The method according to claim 1, wherein the step of placing an outer coating around the impregnated tubular member includes flipping out a tube of impermeable material over the impregnated tubular material as it passes through the outer coating.

4. The method according to claim 1, wherein the first tubular member is fed to the upper portion of the tower, withdraws toward the lower portion and is removed from the upper portion.

5. - An impregnation tower for impregnating a tubular resin impregnable material, comprising a vertical column of sufficient height to impregnate the impregnable resin layer, the column having a roller in a lower portion for changing the direction of the tubular material as it is fed towards the upper portion of the column towards the lower portion and pulled out of the upper portion of the column after it passes through the resin in the tower.

6. The impregnation tower according to claim 5, wherein the column has a substantially rectangular cross section and the column has two opposite walls and two opposite edge walls.

7. The impregnation tower according to claim 5, wherein the column has a height of at least 1.52 meters. 8.- The impregnation tower according to the claim 5, wherein the tower has an open top and the tubular member is fed to the tower at the top. 9. A method for preparing a cured liner in place having an internal impermeable layer, comprising: forming a first tubular member of a resin impregnable material having an impermeable layer of internal resin; feeding the first tubular member to a resin impregnation tower of suitable height to impregnate the resin impregnable material with resin; removing the impregnated tubular member from the tower; and placing a waterproof resin coating around the impregnated tubular member. 10. The method according to claim 9, wherein the step of placing an outer coating includes the step of wrapping a flat sheet around the impregnated tubular member and sealing the sheet to a tube. 11. The method according to claim 9, wherein the step of placing an outer coating around the impregnated tubular member includes flipping out a tube of impermeable material in the impregnated tubular material as it passes through the outer coating. 12. The method according to claim 9, wherein the first tubular member of impregnable resin material has an integral internal impermeable layer. 13. The method according to claim 12, wherein the first tubular member is formed: providing a stretch of resin impregnable material having an impermeable layer attached to a surface; feeding the stretch of resin impregnable material in a first direction and forming the section of material to a tubular shape having the impermeable layer on the outside; joining the longitudinal edges of the stretch of resin impregnable material together to form a tubular member; sealing the joined longitudinal edges of the tubular member; turning the tubular member outwardly in a second opposite direction so that the outer layer is the resin impregnable material; and continuously removing the tubular member with the integral waterproof layer inside.