Abstract:
A process for lining an existing pipeline or conduit with a flexible resin impregnated cured in place liner by pulling in the liner and inflating an eversion bladder with air and curing the liner with flow-through steam without loss of pressure is provided. The liner includes a resin absorbent material in tubular form with an impermeable membrane forming an outer layer. The absorbent material is saturated with a thermoset resin and pulled into the existing conduit. A flexible inflation bladder is passed through a gland mounted on an eversion apparatus and everted into the collapsed liner. The gland is pressurized to isolate the eversion bladder. As the bladder reaches the distal manhole, it enters a receiving canister where it is punctured while maintaining air pressure within the bladder. Steam is then introduced into the bladder to cure the resin and is exhausted through the receiving canister. The bladder is then removed and lateral service reinstated.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    This invention relates to a method for installation of a cured in place liner into an existing conduit by pulling in and inflating the liner and more particularly to a method of trenchless rehabilitation of an existing conduit by pulling into the existing conduit a resin impregnated liner, everting an inflation bladder into the liner with air and curing the resin with continuous flow-through steam without loss of pressure in the bladder and to the apparatuses for practicing the method.  
           [0002]    It is generally well known that conduits or pipelines, particularly underground pipes, such as sanitary sewer pipes, storm sewer pipes, water lines and gas lines that are employed for conducting fluids frequently require repair due to fluid leakage. The leakage may be inward from the environment into the interior or conducting portion of the pipelines. Alternatively, the leakage may be outward from the conducting portion of the pipeline into the surrounding environment. In either case, it is desirable to avoid this leakage.  
           [0003]    The leakage may be due to improper installation of the original pipe, or deterioration of the pipe itself due to normal aging or to the effects of conveying corrosive or abrasive material. Cracks at or near pipe joints may be due to environmental conditions such as earthquakes or the movement of large vehicles on the overhead surface or similar natural or man made vibrations, or other such causes. Regardless of the cause, such leakages are undesirable and may result in waste of the fluid being conveyed within the pipeline, or result in damage to the surrounding environment and possible creation of a dangerous public health hazard. If the leakage continues it can lead to structural failure of the existing conduit due to loss of soil and side support of the conduit.  
           [0004]    Because of ever increasing labor and machinery costs, it is increasingly more difficult and less economical to repair underground pipes or portions that may be leaking by digging up and replacing the pipes. As a result, various methods had been devised for the in place repair or rehabilitation of existing pipelines. These new methods avoid the expense and hazard associated with digging up and replacing the pipes or pipe sections, as well as the significant inconvenience to the public. One of the most successful pipeline repair or trenchless rehabilitation processes that is currently in wide use is called the Insituform® Process. This Process is described in U.S. Pat. Nos. 4,009,063, 4,064,211 and 4,135,958, the contents of all of which are incorporated herein by reference.  
           [0005]    In the standard practice of the Insituform Process an elongated flexible tubular liner of a felt fabric, foam or similar resin impregnable material with an outer impermeable coating that has been impregnated with a thermosetting curable resin is installed within the existing pipeline. Generally, the liner is installed utilizing an eversion process, as described in the later two identified Insituform patents. In the eversion process, radial pressure applied to the interior of an everted liner presses it against and into engagement with the inner surface of the pipeline. However, the Insituform Process is also practiced by pulling a resin impregnated liner into the conduit by a rope or cable and using a separate fluid impermeable inflation bladder or tube that is everted within the liner to cause the liner to cure against the inner wall of the existing pipeline. Such resin impregnated liners are generally referred to as “cured-in-place-pipes” or “CIPP liners” and the installation is referred to a CIPP installation.  
           [0006]    The CIPP flexible tubular liners have an outer smooth layer of relatively flexible, substantially impermeable polymer coating the outside of the liner in its initial state. When everted, this impermeable layer ends up on the inside of the liner after the liner is everted during installation. As the flexible liner is installed in place within the pipeline, the pipeline is pressurized from within, preferably utilizing an eversion fluid, such as water or air to force the liner radially outwardly to engage and conform to the interior surface of the existing pipeline. Cure is initiated by introduction of hot water into the everted liner through a recirculation hose attached to the end of the everting liner. The resin impregnated into the impregnable material is then cured to form a hard, tight fitting rigid pipe lining within the existing pipeline. The new liner effectively seals any cracks and repairs any pipe section or pipe joint deterioration in order to prevent further leakage either into or out of the existing pipeline. The cured resin also serves to strengthen the existing pipeline wall so as to provide added structural support for the surrounding environment.  
           [0007]    When tubular cured in place liners are installed by the pull in and inflate method, the liner is impregnated with resin in the same manner as the eversion process and positioned within the existing pipeline in a collapsed state. A downtube, inflation pipe or conduit having an elbow at the lower end typically is positioned within an existing manhole or access point and an everting bladder is passed through the downtube, opened up and cuffed back over the mouth of the horizontal portion of the elbow. The collapsed liner within the existing conduit is then positioned over and secured to the cuffed back end of the inflation bladder. An everting fluid, such as water, is then fed into the downtube and the water pressure causes the inflation bladder to push out of the horizontal portion of the elbow and cause the collapsed liner to expand against the interior surface of the existing conduit. The eversion of the inflation bladder continues until the bladder reaches and extends into the down stream manhole or second access point. At this time the liner pressed against the interior surface of the existing conduit is allow to cure. Cure is initiated by introduction of hot water into the inflation bladder which is circulated to cause the resin in the impregnated liner to cure.  
           [0008]    After the resin in the liner cures, the inflation bladder may be removed or left in place in the cured liner. If the inflation bladder is to be left in place, the bladder will generally be one that has a relatively thin resin impregnable layer on the inside of the impermeable outer layer. In this case, the impregnable layer after eversion will cause the bladder to adhere to the resin impregnated layer of the liner as is well known in the art. At this time, entry into the manhole or access point is required to open the liner to release the water used to inflate the bladder and to cut off the ends extending into the manholes. When the inflation bladder is to be removed, it may be removed by pulling at the evasion end on a holdback rope attached to the trailing end of the inflation bladder used to control the speed of the eversion. This is generally done after puncturing the bladder at the receiving end to release the water used to evert the bladder and initiate the resin cure. Finally, the downtube can then be removed and service can be reconnected through the lined pipeline. If intersecting service connections are present, they would be reopened prior to resumption of service through the lined pipeline.  
           [0009]    When a cured in place liner is installed using the pull in and inflate method, the outer impermeable layer of the liner remains pressed against the interior surface of the existing conduit. Certain advantages may be attained by this method of installation because the resin in the resin impregnable layer of the liner is trapped between two impermeable layers, namely the outer coating of the liner and the inflation bladder on the inside. Accordingly, there is little or no resin migration out of the liner. In a pull in and inflate installation, the liner coating need not be as strong as required in an installation by eversion, because the coating is not subjected to the pressure head required to evert the liner using the eversion process. Additionally, the coating does not come into contact with hot fluid circulating during the resin cure cycle. Thus, the liner may be of more uniform thickness in a pull in and inflate using an inflation bladder cured in place process compared to when the liner itself is everted.  
           [0010]    While the pull in and inflate method has these advantages, the installation process is somewhat more complex than an eversion. Pull in and inflate requires banding the inflation bladder to the downtube elbow and securing the collapsed liner already positioned in the existing pipeline to the downtube. This requires work within a restricted manhole space. Additionally, at the end of the installation, the inflation bladder may need to be removed after being cut at the distal end to release the water used as the inflation fluid.  
           [0011]    While the pull in and inflate method utilizing water does have the various advantages noted above, the shortcomings tend to increase labor costs which are a significant aspect of the installation process. Accordingly, it is desirable to provide a rehabilitation method using pull in and inflate, wherein the liner is inflated with air and the resin is cured by steam flow-through, to take advantage of the energy available in the steam to provide an installation method which is faster and more efficient economically than various rehabilitation methods currently practiced.  
         SUMMARY OF THE INVENTION  
         [0012]    Generally speaking, in accordance with the invention, a method of rehabilitation of an existing pipeline by pull in and inflate installation of cured in place liners using air to inflate an inflation bladder and curing with flow-through steam without loss of pressure in the liner is provided. A resin impregnated liner is pulled into the existing pipeline to be repaired and cut at the ends to extend into both manholes. An inflation bladder in a length somewhat longer than the pipeline to be lined is attached to an inflation elbow that is placed in the upstream or eversion manhole and the collapsed liner is secured to the outlet end of the bladder on the elbow. The elbow includes a gland at the inlet side through which the bladder passes and which can be pressurized to seal against the bladder during inflation. The bladder is everted using air causing the liner to expand progressively. When the bladder approaches the downstream access point, the bladder is restrained and clamped at the gland on the inlet side of the eversion elbow. The bladder is then allowed to evert further into a receiving canister in the downstream or receiving manhole and punctured. Air pressure is maintained in the bladder and exits the canister through an exhaust line attached to the distal end of the canister.  
           [0013]    While maintaining pressure in the bladder, steam is introduced into the elbow downstream of the gland and passes into the bladder to initiate the cure and exit through the canister exhaust. After the resin in the liner is cured, the steam is turned off and the air pressure is adjusted to maintain pressure in the bladder and maximize cooling. The inflation bladder is then withdrawn by de-everting using a power spool at the eversion end. Any condensate in the bladder is removed through a condensate trap in the elbow in the eversion manhole.  
           [0014]    In a preferred embodiment of the invention, an easement vehicle carries a spooled inflation bladder of appropriate length on a staging spool to the upstream access and includes valves and regulators for applying pressurized air for eversion of the bladder and steam for curing of the liner and removal of the bladder after cure. In a most preferred aspect of the invention, the inflation fluid is air which is introduced into the inflation bladder at an elbow having an inlet gland through which the liner passes. After the bladder inflates the liner, it enters a receiving canister having a puncturing element positioned in the downstream manhole. The bladder is sealed against the canister wall and is punctured to allow air to exit through an exhaust. Steam is introduced at the elbow downstream of the gland pressurized against the bladder. Steam flows through the bladder to cure the resin quickly and completely without loss of pressure in the bladder.  
           [0015]    Accordingly, it is the object of the invention to provide an improved method for rehabilitation of an existing pipeline by the installation of a cured in place liner by the pull in and inflate method utilizing air to evert an inflation bladder.  
           [0016]    Another object of the invention is to provide an improved method for pull in and inflate installation of a cured in place liner by utilizing flow-through steam to effect cure of the resin.  
           [0017]    A further object of the invention is to provide an improved method of installation of a cured in place liner by pull in and inflate wherein air is used to evert the bladder to inflate the liner and flow-through steam is used to cure the resin of the bladder which is automatically punctured when the bladder enters a receiving canister in the downstream manhole.  
           [0018]    Still another object of the invention is to provide a receiving canister to puncture automatically the inflation bladder and allow for regulation of air and steam flowing through the inflation bladder.  
           [0019]    Still another object of the invention is to provide an improved easement unit for use in the installation of cured in place liner by the pull in and inflate method including a staging reel for holding the length of inflation bladder to be used.  
           [0020]    Yet another object of the invention is to provide an installation elbow including a sealing gland to permit introduction of air into the inflation bladder for everting the installation bladder and expanding the liner and steam for curing.  
           [0021]    Still another object of the invention is to provide a manifold to regulate air and steam to be fed to an eversion elbow to effect air eversion of an inflation bladder and flow-through steam for curing.  
           [0022]    Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.  
           [0023]    The invention accordingly comprises the several steps and the relation of one or more of such steps with respect to the others, and the apparatuses possessing the features, properties and relation of elements which are exemplified in the detailed disclosure and the scope of the invention will be indicated in the claims. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0024]    For a fuller understanding of the invention, references had to the following description taken in connection with the accompanying drawings in which:  
         [0025]    [0025]FIG. 1 is a perspective view of a length of a typical resin impregnable cured in place liner suitable for use in lining an existing pipeline in accordance with the invention;  
         [0026]    [0026]FIG. 2 is a perspective view of the liner of FIG. 1 with the leading end folded with a cable secured to it for pulling the liner into the existing pipeline;  
         [0027]    [0027]FIG. 3 is a cross-sectional elevational schematic view showing pulling in of a resin impregnated cured in place liner of the type illustrated in FIGS. 1 and 2 from a downstream or receiving manhole to an upstream or eversion manhole at the start of the installation process to line an underground conduit;  
         [0028]    [0028]FIG. 4 is a cross-sectional elevational schematic view of the collapsed cured in place liner of FIG. 3 after it is positioned within the existing conduit at the start of the installation in accordance with the invention;  
         [0029]    [0029]FIG. 5 is an elevational view of an eversion apparatus constructed and arranged in accordance with the invention with the eversion bladder and starter sleeve installed;  
         [0030]    [0030]FIG. 6 is a cross-sectional elevational view showing the downtube and elbow assembly of FIG. 5 inserted into the liner at the start of the eversion in accordance with the invention;  
         [0031]    [0031]FIG. 7 is a detailed sketch of the air and steam piping and eversion apparatus in the eversion manhole during an installation;  
         [0032]    [0032]FIG. 8 is a detailed schematic view of the manifold for controlling air and steam temperature and volume in the process;  
         [0033]    [0033]FIG. 9 is a cross-sectional elevation view of the reviewing canister constructed and arranged in accordance with a preferred embodiment of the invention positioned in the receiving manhole before completion of eversion of the bladder; and  
         [0034]    [0034]FIG. 10 is a cross-sectional elevational view of a receiving canister in the receiving manhole as used in accordance with an alternative embodiment of the invention. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0035]    [0035]FIG. 1 illustrates a flexible cured in place liner  11  of the type generally well known in the art. Liner  11  is formed from at least one layer of a flexible resin impregnable material, such as a felt layer  12  having an outer impermeable polymer film layer  13 . Felt layer  12  and film layer  13  are stitched along a seam line  14  to form a tubular liner. A compatible thermoplastic film in a form of a tape or extruded material  16  is placed on or extruded over seam line  14  in order to ensure the impermeability of liner  11 . In the embodiment illustrated in FIG. 1 and used throughout this description, liner  11  includes an inner second felt layer  17  also stitched along a seam line  18  which is positioned at a point in the tube other than the location of seam line  14  in outer felt layer  12 . Liner  11  has a leading end  19  with a continuous length stored in a refrigeration unit  21  (FIG. 3) to suppress early cure of the resin. Liner  11  is cut to a desired length after being pulled into the existing pipeline.  
         [0036]    Liner  11  of the type illustrated in FIGS. 1 and 2 is impermeable to water and air. This will allow use in an air or water eversion as described above. However, in a pull in and inflate installation in accordance with the invention, the liner need only be sufficiently impermeable to allow for suitable wet out and retention of resin and to prevent damage to the liner as it is pulled into the existing pipeline.  
         [0037]    For larger liner diameters, several layers of felt material may be used. Felt layers  12  and  17  may be natural or synthetic flexible resin absorbable material, such as polyester or acrylic fibers. Impermeable film  13  in outer layer  12  may 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. In the initial step in all trenchless rehabilitation installations, the existing pipeline is prepared by cleaning and videotaping.  
         [0038]    Prior to commencing installation pursuant to the method in accordance with the invention, a curable thermosetting resin is impregnated into the felt of a liner  33  similar to liner  11  by a process referred to as “wet-out”. The wet-out process generally involves injecting resin into felt layer or layers  12  and  17  of liner  11  through the end or an opening formed in impermeable film layer  13 , drawing a vacuum and passing the impregnated liner through nip rollers as is well known in the lining art. One such procedure of this vacuum impregnation is described in Insituform U.S. Pat. No. 4,366,012, the contents of which are incorporated herein by reference. A wide variety of resins may be used, such as polyester, vinyl esters, epoxy resins and the like, which may be modified as desired. It is preferable to utilize a resin which is relatively stable at room temperature, but which cures readily when heated.  
         [0039]    [0039]FIG. 2 shows a leading end  32  of a liner  33  with a winch rope or cable  22  secured by a slip knot and three half hitches  23  for pulling liner  33  into the pipeline. Leading end  32  of liner  33  and cable  22  may be duct taped to prevent slip of cable  22  and to seal leading end  32 .  
         [0040]    Referring now to FIG. 3, an existing pipeline  24  located below a surface  25  with a section  26  in need of repair between an upstream opening  27  and a downstream opening  28 . Pipeline section  26  has a plurality of cracks  29  and a section of missing pipe material  31 . There is first upstream or access at an upstream manhole U and a second downstream access opening at manhole D. Of course, the installation and steps to be described can be done at either end of pipeline section  26  to be repaired. For convenience, the process in accordance with the invention will be described with the eversion proceeding from upstream manhole U to downstream manhole D.  
         [0041]    A conventional jetter is used to pull in winch cable  22  into pipeline section  26  from upstream manhole U to downstream manhole D. Cable  22  is then connected to leading end  32  of liner  33 . Liner  33  is of the type shown in FIG. 1, but may have a less robust impermeable film than used in eversion installations. Liner  33  is pulled from refrigeration unit  21  positioned at downstream manhole D into pipeline section  26  to be repaired by a winch  34  positioned on an easement unit  36  on surface  25  at upstream manhole U.  
         [0042]    Winch  34  may be a stand alone unit positioned on surface  25 , or be mounted on a vehicle, such as easement unit  36 . Easement unit  36  includes additional apparatuses such as a bladder staging reel  37  including a length of an inflation bladder  38  of a length a safe margin longer than the length of pipeline section  26  to be repaired. Typically, an excess of about 2 to 15 percent of bladder length is placed on staging reel  37  is provided, and preferably about 5 to 10 percent in excess.  
         [0043]    Referring now to FIG. 4, installation of resin impregnated liner  33  using an improved pull in and inflate method in accordance with the invention is illustrated. Resin impregnated liner  33  is pulled into the pipeline section  26  to be relined with about a foot of liner  39  extending into upstream manhole U. A length of excess of liner  41  of about eight to ten feet remains in downstream manhole D. Excess  41  may be held on surface  25  by a piece of tape or rope  42  secured to a sandbag  43 . Excess liner  41  is provided to accommodate movement of liner  33  as it is expanded.  
         [0044]    In the conventional pull in and inflate installation process utilizing a water eversion process, pressure within the bladder and liner is maintained due to the height of the water column within the downtube. Cure is initiated by exposing the impregnated liner to heat. This is usually accomplished by introducing heated water into the eversion pipe or by circulating hot water through a recirculation hose pulled into the everting bladder by a hold back rope connected to the trailing end of the everting bladder. Generally, cure takes between about 3 to 5 hours depending on the type of resin selected and the thickness of the liner. After cure, entry into the downstream manhole is necessary to release the heated water after cure prior to removal of the inflation bladder.  
         [0045]    [0045]FIG. 5 illustrates an eversion apparatus  44  including a downtube  45  and an eversion elbow  46  used in accordance with a preferred embodiment of the invention. Eversion apparatus  44  is mounted on easement unit  36  for convenience during the installation. An elevating platform  47  on easement unit  36  allows for easy adjustment of height depending on the depth of manhole U. Elbow  46  includes an inlet or vertical section  48  and an outlet or horizontal section  49 . A lower inlet gland or sphincter valve  51  with an air inlet  52  for pressurizing a flexible element within lower gland  51  is mounted to the inlet side of vertical section  48 . An upper gland  54  with an air inlet  56  is also mounted to the inlet of downtube  45 . Both upper gland  54  and lower gland  51  are constructed similarly. Each is a spincter valve formed from a flexible element secured within an outer cylindrical wall so that a chamber is formed behind the flexible wall to pressurize the flexible element against bladder  38 . Each gland  51  and  54  is constructed and operates similarly to the eversion apparatus described in U.S. Pat. No. 5,154,936, the contents of which are incorporated herein by reference.  
         [0046]    Inflation bladder  38  wound on staging reel  37  on easement unit  36  is fed through downtube  45 , upper gland  54 , lower gland  51  and elbow  46 . Bladder  38  is then cuffed back and banded to horizontal section  49  of elbow  46 . Upper gland  54  is pressurized against bladder  38  before the eversion begins in order to isolate bladder  38 . Air pressure is applied to air/steam inlet  61  and to bladder  38  sufficient to effect the eversion. Lubricant is applied to the surface of bladder  38  to facilitate movement through upper gland  54  during the eversion of bladder  38   
         [0047]    Horizontal section  49  of elbow  46  is fitted with a flexible starter sleeve  58 . Starter sleeve  58  is a length of about two feet of flexible robust tubular material banded over bladder  38  with at least one banding strap  59 . Starter sleeve  58  is sufficiently flexible so that when not supported it will generally lay flat. When attached to horizontal portion  49  of elbow  46 , distal end of starter sleeve  58  lies flat as illustrated in FIG. 6. Eversion apparatus  44  is lowered into upstream manhole U and the flattened end of starter sleeve  58  is inserted into the upstream end of liner  33  so that the liner overlaps starter sleeve  58  by at least about 3 to 6 inches. Care is taken to maintain starter sleeve  58  flat about the end of bladder  38  to avoid introduction of air into liner  33 . Alternatively, liner  33  can be simply secured about bladder  38  by banding or the like.  
         [0048]    Inflation bladder  38  is formed of a tube of thermoplastic film, such as a polyolefin or polyvinyl chloride. A wide variety of thermoplastic materials would be suitable, such as polypropylene or polyurethane so long as the material will withstand the temperatures reached during cure.  
         [0049]    Horizontal section  49  of elbow  46  is formed with an air/stream inlet port  61  for receiving air for eversion of bladder  38  and steam for cure. In the illustrated embodiment, elbow  46  also includes a condensate drain  62  for removing any condensate that forms in bladder  38  during cure and cool down. After inflation bladder  38  and starter sleeve  58  are installed, eversion assembly  44  is positioned in upstream manhole U as shown in FIG. 6.  
         [0050]    At this time, inflation of liner  33  is ready to begin. At the start, air at about 5 psi is introduced in to upper gland  54 . Once air pressure has stabilized, inflation bladder  38  is lubricated and permitted to proceed through eversion apparatus  44  while maintaining an eversion pressure of about 5 psi.  
         [0051]    Inflation bladder  38  is everted through starter sleeve  58  by introducing air into air/steam inlet port  61  of elbow  46 . In the preferred embodiment, air is introduced from an air inlet line  63  fed through a valve manifold  64  shown in FIG. 8. Air is then directed to air/steam inlet line  65 . As inflation bladder  38  passes through starter sleeve  58  and enters liner  33 , starter sleeve  58  will be locked in against the inlet of pipeline section  26  thereby locking eversion apparatus  44  and elbow  46  in place in upstream manhole U. Inflation bladder  38  continues to evert through liner  33  until it is brought to a few feet from downstream manhole D.  
         [0052]    The details of valve manifold  64  and the piping attached to eversion apparatus  44  is shown in FIG. 8. Air enters from air hose  63  through an air pressure regulator  81  and pressure is controlled by an air valve  82 . Steam entering from steam hose  77  is regulated by a steam pressure regulator  83  and controlled by a steam valve  84 . Air and steam are mixed in air/steam hose  65  after passing through air/steam temperature gauge  79  and air/steam pressure gauge  78 . Air/steam inlet hose  65  is coupled to manifold  64  and air/steam inlet in elbow  46  by a pair of cam lock fittings  86  or any other convenient hose coupling.  
         [0053]    When the eversion continues and bladder  38  approaches downstream manhole D, inflation bladder  38  is stopped at about 5 to 10 feet from downstream manhole D. The 5 psi air pressure is maintained when the eversion is stopped. At this time, the remaining excess of liner  33  in downstream manhole D is cut to about one foot from the back face of downstream manhole D. A sample mold  67  and two screw-type bands  66  are placed over the end of liner  33 . The distal end of liner  33  is then banded about a cylindrical receiving canister  68  positioned at the back of downstream manhole D. Liner  33  is then secured to canister  68  with bands  66 .  
         [0054]    Canister  68  is a cyclindrical section of rigid material having a closed backwall  69 . A bladder punch  71  is mounted to backwall  69 . Bladder punch  71  is a sharp tapered tubular member coupled to a condensate drain  72  through backwall  69 . An exhaust coupling  73  is fitted to condensate a drain  72  and an exhaust hose  74  is coupled thereto. The free end of exhaust hose  74  is positioned outside of downstream manhole D and securely positioned so that any steam-air discharge will not cause a safety hazard. At this time, thermocouples and pressure gauges at the steam-air discharge to read temperature and stream-air flow may be installed.  
         [0055]    Receiving canister  68  is positioned securely within downstream manhole D using sandbags or other convenient implements. At this time, eversion of bladder  38  is resumed at the  5  psi air pressure. Inflation bladder  38  is everted until the nose of bladder  38  reaches backwall  69  of receiving canister  68 . When bladder punch  71  punctures the everting face of bladder  38  allowing air to exhaust through exhaust hose  74 . Pressure in inflation bladder  38  can be controlled by an exhaust value  76  on exhaust hose  74 .  
         [0056]    At this time air pressure between about 20 to 30 psi is applied to lower gland  51  and steam is introduced into air/stream inlet port  61  to initiate cure of the resin in liner  33 . Steam is provided from a steam inlet hose  77  which is regulated by valve manifold  64  to provide an air/steam mixture to air/steam inlet line  65  for providing steam to eversion elbow  46 . The air/steam flow is adjusted to maintain a curing pressure of about 7-10 psi until the combined air/steam flow temperatures reach a desired temperature of about 220° F. measured at exhaust hose  74 . Depending upon the particular resin and tube thickness, once the cure is complete, steam flow is turned off while simultaneously adjusting the air flow to maintain cure pressured. Exhaust valve  76  is adjusted while cooling to about 150° F.  
         [0057]    Once the temperature has cooled to the desired level, air flow pressure is reduced to zero, exhaust valve  76  is fully opened and inflation bladder  38  is slowly de-everted. As bladder  38  de-everts, it will seal off the punctured end. Accordingly, it is desirable to monitor the air flow pressure to prevent pressure build up. Any condensate that may have accumulated in bladder  38  is removed by condensate drain  62  in elbow  46 .  
         [0058]    In the alternative embodiment illustrated in FIG. 10, a flexible receiving sleeve  87  is secured to canister  68  by a pair of bands  66 . Receiving sleeve  87  is of the same robust flexible material as starter sleeve  58  and operates in the same manner to seal expanding liner  33  positioned therein between everting bladder  38  and the insider of receiving sleeve  87 . As bladder  38  approaches backwall  69  and is punctured, pressure is maintained within bladder  38  in the same manner as described in connection with FIG. 9.  
         [0059]    After bladder  38  has been totally de-everted, it is safe to enter downstream manhole D and remove sample mold  67  and receiving canister  68 . Eversion apparatus  44  is then removed from upstream U and any cured liner extending into either manhole is trimmed. At this time, liner  33  is now ready for any lateral reinstatement.  
         [0060]    It can readily be seen that the process in accordance with the invention readily allows one to attain the advantage of curing a resin liner with flow through steam. By practicing the process, a tubular member can be easily everted through an existing pipeline. By clamping and then cutting an opening in the distal end of the everted tubular member, pressure can be maintained within the everting tubular member and steam can be introduced at the eversion access and flow through the curing liner to utilize the higher energy available in the steam to cure the resin significantly faster than one can cure utilizing circulating hot water.  
         [0061]    It will thus be seen that the objects set fort above, among those made apparent from the preceding description, are efficiently attained and, since certain changes may be made and carrying out the above method and in the construction set forth without departing from the spirit and scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.  
         [0062]    It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described and all statements of the scope of the invention which, as a matter of language, might be said to fall there between.