Abstract:
Installation of a flexible cured in place liner by inverting the liner utilizing an inversion sleeve assembly with an installation apparatus having at least one selectively operable rigid gland. The sleeve assembly includes a sleeve portion of an absorbable material secured in an apparatus with an inversion boot fitted at the distal end with an inlet port for inversion and/or curing fluid. The sleeve assembly and apparatus are particularly well suited for inverting with air and curing the liner with steam introduced through a perforated lay flat hose using an apparatus with two glands. The installation sleeve is the same dimension as the liner to be installed and is reusable thereby substantially reducing the set up time to install using the dual gland apparatus. Preferably, the flexible sleeve is a length of dry cured in place liner inverted on to itself to expose two impregnable surfaces. The sleeve may have a built in fluid inlet port for use with a dual gland apparatus.

Description:
CROSS REFERENCE TO RELATED APPLICATION  
       [0001]     This application is based on and claims the benefit of co-pending provisional application Ser. No. 60/840,818, filed Aug. 29, 2006, the contents of which is incorporated herein by reference in its entirety. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     This invention relates to a reusable inversion sleeve assembly for installing a cured in place liner with an apparatus having at least one rigid gland. The methods and apparatus reduce the time needed to set up a wet out cured in place liner for installations using air for inversion and steam for curing and use of a dual gland apparatus allowing use of a hold back strap and a lay flat hose for introduction of steam.  
         [0003]     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 or deterioration. 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.  
         [0004]     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 leakage is 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.  
         [0005]     Because of ever increasing labor, energy 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, all the contents of which are incorporated herein by reference.  
         [0006]     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 liner 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.  
         [0007]     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.  
         [0008]     Typically, an eversion tower is erected at the installation site to provide the needed pressure head to evert the liner or a bladder. Alternately, an eversion unit as shown and described in U.S. Pat. No. 5,154,936, No. 5,167,901 (RE 35,944) and No. 5,597,353, the contents of which are incorporated herein by reference. Cure may be initiated by introduction of hot water into the everted liner through a recirculation hose attached to the end of the everting liner. Inversion water is recirculated through a heat source such as a boiler or heat exchanger and returned to the inverted liner until cure of the liner is complete. 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.  
         [0009]     The eversion tower, which was time consuming to construct, caused workers to be 30 feet above the ground often near trees and electrical wires. This method was improved by an apparatus, which allowed Insituform to create a hydraulic head by the use of a sphincter valve. The liner was fed into the top of the apparatus and pulled through the sphincter valve by pressurized water below the valve. The pressurized water applied a force on the nose of the liner causing it to invert into the pipe being rehabilitated. These apparatuses for the rehabilitation of small diameter pipe have been in use for about fifteen years.  
         [0010]     The major disadvantage to the use of these apparatuses with water is the quantity and availability of the inverting water. Water must be heated typically from 55° F. to 180° F. in order to affect the cure, and then cooled by the addition of more water to 100° F. before being released to an acceptable disposal system.  
         [0011]     This disadvantage may be overcome by using air in lieu of water to create the inverting force. Once the impregnated liner is fully inverted, it then can be cured with steam. Although water is necessary to produce steam, the quantity of water in the form of steam is only 5-10% of that required for water inversion, cure and cool down. This means that steam can be used for curing even if water is not readily available on site. This drastic reduction in the quantity of water is the result of the higher energy available from one pound of water in the form of steam versus one pound of heated water. One pound of steam condensing to one pound of water gives off approximately 1000 BTUs while one pound of water gives off only one BTU for each degree in temperature drop. This reduced water requirement plus virtual elimination of the heat up cycle greatly reduces cure cycle and installation time.  
         [0012]     With this apparent advantage in using air inversion and steam cure why has the industry been slow to abandon water inversion and hot water cure? 
         [0013]     When water is used to invert the resin-impregnated liner, the uninverted portion of the liner from the inverting nose to the inverting apparatus is buoyed up by a force equal to the quantity of water displaced by the liner. In the case of CIPP liners, this mean the effective weight of the liner is substantially reduced, as is the force necessary to pull the uninverted liner forward to the inverting nose. When air is used to create the inverting force, the uninverted liner lies on the bottom of the pipe and the air pressure acting on the inverting nose of the liner must pull the full weight of the liner forward.  
         [0014]     Three forces must be over come to invert a CIPP liner no matter what is used to create the inverting energy. These forces are: 
        1. Force required to invert the liner (turn liner inside out). This force varies by liner thickness, material type and relation of liner thickness to diameter.     2. The force necessary to pull the liner from the inverting apparatus to the inversion nose.     3. The force necessary to pull the liner through the inverting apparatus.        
 
         [0018]     Force number one (1) above is generally the same for both air and water inversions.  
         [0019]     Force number two (2) varies greatly between air and water and can limit the length of air inversions. There is limit on how much pressure can be used to invert a liner without adversely affecting the quality of the installed CIPP liner and/or damaging to the existing conduit. Lubricant can be used for both water and air inversion to reduce the required pulling force.  
         [0020]     Force number three (3) can vary based on the apparatus design. In most apparatus presently in use, the force required to pull the liner through the apparatus will increase when either or both forces one and two increase. This is caused by the fact that in order to increase available inversion energy, typical apparatus in use today restrict loss of pressurized fluid from the pressure chamber below the liner entry point into the apparatus and the cuff and banded end of the liner being inverted. This restriction is typically accomplished by increasing the air pressure in a pneumatic sphincter gland, or by using a gland that is energized by the inverting fluid. The movement inward in typical cases is restricted by the gland material and compression of the inverting CIPP liner. This in turn causes an increase on the friction between the inverting CIPP liner and gland.  
         [0021]     In view of these apparent benefits of steam cure compared to hot water cure, the use of steam has been proposed in view of the energy it carries. Air invert an inflation bladder and flow-through steam to cure has been disclosed in Insituform U.S. Pat. No. 6,708,728 and No. 6,679,293, the contents of which are incorporated herein by reference. The processes disclosed in these recently issued patents utilize pull in and inflate technology and are currently in use for small diameter liners. They provide advantages over water eversion for small diameters. However, the process described does not provide for use of a lay flat hose for introduction of steam. Moreover, use of a puncturing canister disclosed in these patents is not suitable for medium and large diameter liners. Generally, medium size liners are considered to be those between about 18 and 36 inches in diameter. Large diameters are those in excess of about 42 inches and larger in diameter.  
         [0022]     Accordingly, it is desirable to provide improvements to reduce the efforts needed to prepare a CIPP liner for installation using an apparatus having at least one selectively operable rigid gland for introduction of air for inversion without having to deflate the liner prior to injecting steam for curing.  
       SUMMARY OF THE INVENTION  
       [0023]     Generally speaking, in accordance with the invention, an inversion sleeve assembly for installation of a cured in place liner with a rigid gland apparatus is provided. The inversion sleeve assembly includes a tubular flexible sleeve and a cylindrical banding boot having an inlet port for introducing inversion and/or curing fluid at the distal end of the sleeve. The sleeve and the inversion boot are of the same dimension as the cured in place pipe liner to be inverted. The assembly is used with an installation apparatus having a frame with at least one selectively operable rigid gland upstream of the banding boot. The sleeve passes between a rigid gland used to form a fluid seal. The flexible inversion sleeve may have an installed curing fluid inlet for use with an apparatus having two rigid glands. In this case, the inlet on the sleeve is located between the two glands with the banding boot downstream of the lower gland. In a preferred embodiment the flexible sleeve is a length of dry cured in place liners of the same dimension as the liner being installed. The sleeve has at least one layer of impregnated material and an outer impermeable layer. The impregnable material holds lubricant to aid in the installation and the sleeve assembly is reusable.  
         [0024]     A resin impregnated liner is fed through the flexible inversion sleeve and banding boot, turned back and banded about the banding boot prior to being inverted into the existing conduit. Selective opening and closing of the glands in a dual gland apparatus allows passage of a hold-back cable or strap to control the speed during the second half of the inversion and passage of a lay flat hose and steam fitting for introduction of heated air or steam during cure. Use of a perforated lay flat hose for steam cure allows for introduction of steam along the entire length of the inverted liner to avoid the consequences of accumulation of condensate that often leads to poorly cured sections of liner in steam cure processes. The dual glands allow for the lay flat hose with steam attachment to pass through the frame and into the inverted liner without deflating the liner prior to introduction of curing fluid. Preferably, the lay flat hose has alternating holes formed along its length near the edge. Typically, this is ¼ to 1½ inches from the edge of the lay flat hose. This is to insure distribution of steam at the bottom along the full length of the liner regardless of the orientation of the hose. Once the inversion is stopped, a porting drill or forming device may be used to form an exhaust port with an adjustable exhaust hose. Steam is introduced into the liner through the lay flat hose to cure the resin without allowing the inverted liner to deflate.  
         [0025]     Accordingly it is an object of the invention to provide an improved reueable sleeve assembly for use with a rigid gland apparatus for installing a CIPP liner.  
         [0026]     It is another object of the invention to provide an inversion sleeve with installed fluid(s) inlet for use with a rigid gland apparatus for inverting a CIPP liner with air and curing with steam.  
         [0027]     It is another object of the invention to provide an improved method for air inversion and steam cure of a CIPP liner with an apparatus having rigid dual glands.  
         [0028]     It is a further object of the invention to provide an improved method wherein a cured in place pipe liner is inverted with air and cured with steam without deflating the liner after being positioned within the existing conduit.  
         [0029]     Yet another object of the invention is to provide a method and apparatus suitable for air inversion and steam cure wherein the liner is inverted through a segment of liner formed with at least one port for introduction of air and/or steam.  
         [0030]     Still another object of the invention to provide an improved method of air inversion of a CIPP liner with a holdback strap and lay flat hose for introduction of steam to cure the liner.  
         [0031]     Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.  
         [0032]     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  
       [0033]     For a fuller understanding of the invention, reference is had to the following description taken in connection with the accompanying drawings in which:  
         [0034]      FIG. 1  is a schematic perspective view of an apparatus with a rigid glands for air inversion and steam cure of a cured in place pipe liner constructed and arranged in accordance with the invention;  
         [0035]      FIG. 1A  is a schematic elevational view of an apparatus with dual rigid glands for air inversion and steam cure of a cured in place pipe liner constructed and arranged for use in accordance with the invention;  
         [0036]      FIGS. 2, 2A  and  2 B are a cross-sectional views of the inversion sleeve assembly constructed in accordance with the invention;  
         [0037]      FIG. 3  is a schematic view of the elements of an inversion sleeve assembly constructed and arranged in accordance for use with the invention suitable for use with an apparatus of the type shown in  FIGS. 1 and 1 A;  
         [0038]      FIG. 4  is a schematic view in cross-section showing the inversion sleeve assembly and position of the gland of a single gland apparatus of  FIG. 1  during inversion;  
         [0039]      FIG. 5  is a schematic view in cross-section showing an inversion sleeve assembled with a fluid inlet in the flexible tubular section and showing the position of the glands of a dual gland apparatus of  FIG. 2  with air/steam supply hose attached in preparation for introduction of steam for curing; and  
         [0040]     FIGS.  6 ( a ) and  6 ( b ) illustrate an exhaust porting technique. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0041]     An improved method and apparatus for air inverting and steam curing a CIPP liner in compliance with ASTM F1216 Standard Practice for Rehabilitation of Existing Pipelines and Conduits by the Inversion and Curing of a Resin-Impregnated Tube is described. The method and apparatus described herein are well suited for the installation of medium diameter CIPP liners working from the surface through structures, such as manholes to rehabilitate existing buried pipelines and conduits.  
         [0042]     An inverting apparatus  11  having a single rigid lower gland  21  constructed and arranged in accordance with the invention is shown in  FIG. 1 . In  FIG. 1A , a similar apparatus  11   a  having an upper gland  16  and lowe gland  21  is shown. In view of the similarity of elements, the same reference numeral are used in  FIGS. 1 and 1 A to describe identical elements.  
         [0043]     Apparatuses  11  and  11   a  are rigid frames dimensioned to be positioned over the inverting access to the conduit to be lined. Apparatuses  11  and  111  are fabricated from metal bars or tubes to form a frame  12  having a sufficient width “w” to receive a flattened cured in place pipe liner to be installed. Frame  12  is substantially rectangular in the illustrated embodiment and has a rectangular entry opening  13  with a plurality of hooks  14  to secure a flexible inversion sleeve  207  as shown in  FIG. 2 . Opening  13  has a thickness “t” selected to allow the inversion sleeve assembly to be secured on hooks  14  and pass through entry opening  13 .  
         [0044]     Frame  12  has a height “h” sufficient to support sleeve  207  and a banding boot  211  secures to the bottom of sleeve  207 . In the dual gland unit of  FIG. 1A , a first or upstream gland  16  formed of a fixed gland member  17  and an opposed cooperating displaceable gland member  18  is positioned adjacent to entry  13 . A pair of air cylinders  19  are attached to the ends of frame  12  and connected to displaceable member  18  for displacing member  18  towards fixed member  17 . Cylinders are pneumatic air cylinders with linear guide bearings. Cylinders  19  may be any mechanical closing mechanism or motor of any type, such as hydraulic or electrical, or a mechanical clamping mechanism.  
         [0045]     In  FIG. 1A , a second or downstream gland  21  formed in the same manner as upper gland  16  has a rigid gland member  22  fixed to frame  12  and a moveable gland member  23  on a pair of linear guide bearings  20   b  with an attached air cylinder  24 . Height “h” of frame  12  is selected to provide sufficient room between upper gland  16  and lower gland  21  to utilize a fluid inlet port installed in flexible sleeve  207  for introduction of air and/or steam into a liner  200 . An inverting fluid inlet port is installed in the inversion boot of the inverted liner and positioned downstream of lower gland  21  and before the manhole access. A complete description of the liner and installation ports will be set forth in more detail below.  
         [0046]     In the illustrated embodiment of  FIG. 1 , only lower glad  21  is mounted on frame  12 . In both  FIGS. 1 and 1 A, frame  12  has a base  25  formed of two side tubes  26  and  27  welded to a rectangular front frame  28  formed of a bottom tube  29 , two vertical side tubes  31  and  32  and a top tube  33 . Vertical tubes  31  and  32  are welded to base side tubes  26  and  27 , respectively. A matching rectangular back frame  34  formed of a bottom tube  36 , two side tubes  37  and  38  and a top tube  39  is welded to base side beams  26  and  27  in the same manner as front frame  28 . A pair of upper horizontal gland support tubes  41  and  42  is secured between front side tubes  31  and  32  of front frame  28  and side tubes  37  and  38  of back frame  34 . Similarly, a pair of support beams  43  and  44  is secured between front frame  28  and back frame  34  to support lower gland  21 . Four angled support tubes  46 ,  47 ,  48  and  49  are welded between the front and back of side tubes  26  and  27  to provide stability to frame  12 . While angled support tubes are shown, it is contemplated that rectangular support members forming a step may be used to provide a working platform at or about the height of lower gland  21 .  
         [0047]     Air cylinders  24  and shown mounted above lower gland  21 . Each cylinder is connected to a coupling so that runs on a pair of linear guide bearings.  
         [0048]     In  FIG. 1A  fixed gland member  17  and displaceable gland member  18  of upper gland  16  has a compressible high temperature resistant blanket  54  and  56  mounted on the opposed mating faces. This compressible material  54  and  56  will conform to and tightly engage an inverting liner with a holdback strap and lay flat hose as they pass through upper gland  16  during the second half of the inversion. In addition, compressible material  54  and  56  will form a suitable conforming seal when upper gland  16  is closed during steam cure.  
         [0049]     The rigid cooperating opposed faces of members  22  and  23  of lower gland  21  may be flat. Curvature may be added to the mating surfaces by welding a small diameter pipe to beams  22  and  23  or by using tubes or pipes for member  22  and  23 . This curved surface provides a smoother surface for engaging the inverted liner.  
         [0050]     Lower gland  21  forms the air seal during air inversion in both apparatus  11  and  11   a . During the start and first half of the inversion, lower gland  21  is closed to a distance apart of about four times the thickness of the liner by use of a gap setting device. This device may be appropriately sized spacers placed on guide hearings  20   a  and  20   b . Once the holdback strap and lay flat hose pass through lower gland during the second half of the inversion, the gap of lower gland  21  is reduced to about twice the liner wall thickness.  
         [0051]     By utilizing this construction, an increase in inverting air pressure will cause the liner to invert without requiring an increase in pressure on the liner at lower gland  21  by members  22  and  23 . Air pressure to cylinders  24  may be increased to prevent gland  21  from opening to a gap more than twice the liner thickness. The gap adjustment device, such as spacers placed on guide bearings or threaded bolts prevent a reduction of the gap beyond that desired.  
         [0052]      FIG. 2  illustrates a section of a cured in place liner suitable for forming flexible sleeve  207  inverted to a fold line  206 . A port  209  is formed through both layers of flexible material. End  208  is folded over to form hanging sleeve  207  on apparatus  11  or  11   a . A banding boot  211  having a properly dimensioned cylindrical wall  212  with a pair of banding ribs  214  and  216  and a fluid inlet port is also shown.  
         [0053]      FIGS. 3, 3A  and  3 B illustrate the elements of an inversion tube assembly  201  constructed and arranged in accordance with the invention. In this embodiment, assembly  201  includes a sleeve portion  207  formed from a dry section of a cured in place liner  202  having a resin impregnable layer  223  with an impermeable coating  224  of approximately twice the desired length. Liner  202  is inverted on itself along a fold line  206 . This positions impermeable layers  224  facing each other with resin impregnable material  223  on the outer surfaces of an inverted sleeve  207  as shown in  FIG. 2  detail B. A short segment of sleeve  207  is folded back at the edges to form a hanging section  208  as shown in  FIG. 3 .  
         [0054]     A fluid inlet port  209  for introduction of air and/or steam is formed at an appropriate location along the length of the sleeve  207 . Port  209  provides access to the interior of sleeve  207  wherein resin impregnable layers  223  face each other. A banding boot  211  formed of a substantially rigid cylindrical wall  212  is formed with a fluid inlet port  213 . Ribs  214  and  216  are formed at each end of cylindrical sidewall  212 . This allows banding folded end  206  of sleeve  207  to ribs  214  to complete construction of an inversion sleeve  201  assembly as illustrated in  FIG. 2 . Upon inserting a cured in place liner through sleeve  207  and boot  211 , the end of a liner  200  to be inverted is banded to ribs  216 .  
         [0055]      FIG. 3  illustrates in cross-section the various layers of a liner  200  and an inversion sleeve secured to hooks  14 . As shown, hanging section  208  of sleeve  207  is secured on hooks  14  with a layer of resin impregnable material  223  on the outside of hooks  14  with an impermeable layer  224  facing an impermeable layer  224  on the inside. Banding boot  211  is attached to folded end  206  of sleeve  207  and secured at ribs  214 . Sleeve section of liner  207  is selected to be the same dimension as liner  200  to be installed. This provides the efficient sealing when a rigid gland is closed.  
         [0056]     By utilizing a double thickness of a section of cured in place pipe liner  202  as inversion sleeve  207 , this provides increased dimensional stability. In additional to utilizing a standard coated resin impregnable section of liner, reinforcement in the weft and/or warp direction of an impregnable material may be included. Alternatively, helical reinforcement elements may be utilized or a reinforced coating such as a reinforced coated scrim providing increased strength in both the warp and weft direction may be used to provide additional dimensional stability to sleeve  202  during the inversion and cure.  
         [0057]     Folded edge  208  is retained so as to provide additional stability after banding at ribs  214 . By utilizing this construction, lubricant can be added to interior impregnable layer  223  of inversion sleeve  207 . This allows inversion sleeve  207  to be utilized for several installation.  
         [0058]     The seal around liner  200  to be installed is created by sleeve  207  of the identical profile and dimension. Thus, it is not necessary to be concerned about forming a seal at the edges of the flattened liner. The length of the edge perimeter of the flattened liner is minimal compared to the long sides of the flattened liner so that stress on the edges are minimal and no addition closure or support at the edges is needed. This allows use of straight rigid tubes or beams to form the gland and seal. The process and apparatus disclosed provide an advantage over prior art inversion devices. In these latter devices forming a seal at the edges is difficult because the inversion commences downstream of the seal or gland. Here, there is an advantage due to the fact that the inversion of the liner has commenced before the liner passes through a gland for forming an inversion and curing seal.  
         [0059]     The first half of an inversion with apparatus  11   a  is shown in schematic in  FIG. 4 . The same would be true for apparatus  11  of  FIG. 1  if a lay flat hose was not to be used in the installation. Gland  21  is closed to a fixed gap to accommodate the thickness of sleeve  207  and flattened liner  200  using gap setting devices. Inversion air is fed into inlet port  213  from an air inlet hose  107  to cause liner  200  to invert into the conduit being lined.  
         [0060]      FIG. 5  illustrates installation using apparatus  11   a  of  FIG. 1A  with dual rigid glands  16  and  21 . At the halfway point of the inversion upper gland  16  is closed to engage a holdback strap  111  and a lay flat hose  112 . Lay flat hose  112  has a closed end  112   a . Then, during the second half of the inversion, lower gland  21  is opened and inversion air is fed into air inversion inlet port  213  to complete the inversion. At this time lower gland  21  is closed and upper gland  16  is opened.  
         [0061]     When upper gland  16  is open, lay flat hose  112  is cut above upper gland  16  and a steam hose is attached to the cut end through port  209  with a flexible layflat adapter attached to layflat hose  112  and inserted into air/steam port  209  to facilitate the addition of steam to inverted liner  200 . The layflat adapter may be a thin tubular rigid bendable metal sleeve with a flared profile which prevents it from being pulled into the air/steam port. The tubular portion of the sleeve is inserted into the cut end of the lay flat and inserted into the inlet port. The lay flat hose is then engaged between the flared region of the sleeve and the port. The slack in lay flat hose  112  will drop into the invert when upper gland  16  is closed and lower gland  21  opened at the start of the steam cycle as shown in  FIG. 5 .  
         [0062]     Referring now to  FIG. 5 , steam is introduced into attached perforated lay flat hose  112  to initiate cure of the resin in inverted liner  200  with gland  16  closed and gland  21  open. In an exemplary embodiment of the invention, lay flat hose  112  is a high temperature thermoplastic tube about 4 inches in diameter with one-eighth to one-quarter inch orifices depending on the size of the CIPP liner. The size and spacing may vary depending on the boiler and liner size and length. The orifices are created at one foot intervals at almost one-half inch from the folded edges at alternating edges. The distance from the edges may vary depending on size and length. This pattern is selected to insure that steam will be injected into any ponded condensate in the conduit invert. This heats the condensate to temperature that will affect cure of the CIPP liner section directly under the ponded condensate.  
         [0063]     The orifice pattern described provides more steam at the proximal end of liner  200  and ensures good mixing even if hose  112  becomes twisted. This also insures that steam is injected into any condensate that forms in the pipe invert to cure that portion of the resin in the liner covered by the condensate pool. Steam is provided from a steam inlet hose  109  that is regulated by a valve manifold. The steam flow is adjusted to maintain a curing pressure of about 3-6 psi until cure cycle is complete.  
         [0064]     Knowing the physical properties of the CIPP liner (diameter, length, thickness, resin and catalyst system) and available boiler output in BTUs per hour permits the adjustment of orifice size to match boiler output in pounds of steam per hour with recommended cure cycle time.  
         [0065]     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 inverted through an existing pipeline. Providing an apparatus having two rigid glands allows an inverting liner to be installed with a hold back strap and lay flat hose. Use of gap setting devices to maintain the gap at the lower gland allows for increasing eversion pressure to be applied to the complete profile of the liner without increasing the gland pressure on the inverting liner. Steam is then passed into the inverted liner to utilize the higher energy available in the steam that significantly shortens the cure cycle when compared to hot water cure.  
         [0066]     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.  
         [0067]     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.