HK1115560B - Exhaust and/or condensate port for cured in place liners and installation methods and apparatus - Google Patents

Description

Venting and/or condensation port for cured in place liner, method and apparatus for installation

Cross Reference to Related Applications

This application is based on and claims priority from copending provisional application No.60/651,698 filed on 9.2.2005, the contents of which are incorporated herein by reference.

Technical Field

The present invention relates to installation of cured in place liners, and more particularly to a curing method for installing a vent port in an inflated cured in place liner to allow continuous flow of steam therethrough without loss of pressure, and an apparatus and installation method for practicing the method.

Background

It is generally known that pipes or pipelines for conducting fluids, especially underground pipes such as sanitary sewer pipes, storm sewer pipes, water pipes and gas pipes, often require repair due to leakage or degradation of the fluid. Such leakage may be from the surroundings inwards into the interior or conducting part of the pipeline. Alternatively, the leakage may be outward from the lead portion of the pipeline into the surrounding environment. Such leakage, whether inward or outward, is desirably avoided.

Such leakage may be due to improper installation of the original pipe, or to degradation caused by normal aging of the pipe itself, or due to the effects of corrosive or abrasive materials being delivered. Cracks at or near the pipe joints may be due to environmental factors such as earthquakes, or movement of large vehicles over the surface of the pipe, or similar natural or man-made vibrations, or for other similar reasons. Such leakage is undesirable for whatever reason, and may result in waste of the fluid being transported in the pipeline or damage to the surrounding environment, as well as potentially causing a dangerous public health disaster. If the leak persists, it can lead to structural failure of the existing pipe due to loss of soil and side support of the pipe.

Due to the ever-increasing labor, energy and machinery costs, it is becoming increasingly difficult and uneconomical to dig out and replace pipes to repair underground pipes or sections of pipes that may be leaking. Accordingly, various methods of in-situ repair or rehabilitation of existing pipelines have been devised. The resin is impregnated and the liner is placed in the existing pipeline in a flattened (collapsed) state. Typically, a down tube (downtube), an inflation tube or conduit with an elbow (elbow) at the bottom end, is provided in an existing manhole or access point, and the everted bladder is passed through the down tube, expanded, and cuff backwards after exiting the opening in the horizontal portion of the elbow. The collapsed liner in the existing conduit is then placed over and secured to the end of the back cuff of the inflation bladder. An everting fluid, such as water, is then fed into the downward conduit, and the water pressure pushes the bladder out of the horizontal portion of the elbow and spreads the collapsed liner against the inner surface of the existing conduit. This eversion of the bladder will continue until the bladder reaches and extends into the downstream manhole or second access point. At this point, the liner pressed against the inner surface of the existing pipe may be cured. Curing is initiated by introducing circulating hot water into the bladder to cause the resin in the impregnable liner to cure.

After the resin in the liner is cured, the inflation bladder may be removed or left in place to cure the liner. If the inflatable bladder is left in place, the bladder is typically a bladder having a relatively thin resin impregnated layer on the inside of an impermeable outer layer. In such a case, the everted impregnable layer will attach the bladder to the impregnating resin layer of the liner, as is well known in the art. At the same time, access to 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 end extending into the manhole. When the inflation bladder is removed, it may be removed by pulling in a buffer cord at the escape end that is attached to the tail of the inflation bladder that is used to control the eversion rate. This is typically done after the receiving end of the bladder is pierced to release the water for inverting the bladder and begin the curing of the resin. Finally, the down pipe may then be removed and service (service) may be reconnected through the liner line. If there are service connections that cross, these service connections are reopened before service is restored through the liner pipeline.

In the existing water inversion method using the Insituform method, the liner is inverted using cold water. After the liner is fully inverted in the existing conduit, hot water is circulated through the lay-flat tubes connected to the inversion face of the liner. Hot water is circulated during the curing cycle. In medium and large diameter pipelines, the volume of water required for inversion increases dramatically as the liner diameter increases. All of the water used to inflate the liner, whether everted or pulled-in inflated, must be heated during the heating and curing cycle. In addition, once curing is complete, the curing water must be cooled by the addition of cold water or continuous circulation until, after the liner is cut at the end of the pipe, the curing water is at a temperature that can be released into the downstream pipe.

The main drawback of using these devices using water is the quantity and availability of the overturning water. The water must typically be heated from 55 ° F to 180 ° F to achieve solidification, and then cooled to 100 ° F by adding more water before being released into an acceptable processing system.

These new methods avoid excavating and replacing pipes or tubesThe expense and danger associated with the segments and also the great inconvenience to the public. One of the most successful pipeline repair or trenchless rehabilitation methods currently in widespread use is called the trenchless rehabilitation methodA method. This process is described in U.S. Pat. Nos. 4,009,063, 4,064,211, and 4,135,958, the contents of which are all incorporated herein by reference in their entirety.

In standard operation of the Insituform process, an elongated flexible tubular liner made of felt fabric (felt fabric), foam, or similar resin impregnated material and having an outer impermeable coating impregnated with a thermosetting curing resin is installed in an existing pipeline. Typically, the liner is installed using an inversion process, as described in the latter two Instualform patents. In the eversion process, radial pressure applied to the interior of the everted liner presses the liner against and into engagement with the inner surface of the pipeline. However, the Insituform method also pulls a resin impregnated liner into the pipe by a rope or cable and cures the liner against the inner wall of the existing pipeline using a separate fluid impermeable inflation bladder or tube everted in the liner. Such resin impregnated liners are generally referred to as "cured in place pipe" or "CIPP liners" and the installation is referred to as a CIPP installation.

The CIPP flexible tubular liner has, in an initial state, a smooth outer layer on the outside of the liner made of a relatively soft, substantially impermeable polymer coating. When inverted, this impermeable layer terminates on the interior of the liner after the liner is inverted during installation. When the flexible liner is installed in place in the pipeline, the pipeline is pressurized from within, preferably with an eversion fluid such as water or air, to urge the liner radially outwardly into engagement and conformity with the inner surface of the existing pipeline.

Typically, the inverting tower is erected at the installation site to provide the pressure head required to invert the liner or bladder. Alternatively, the flipping unit is as shown and described in U.S. patent nos. 5,154,936, 5,167,901(RE 35,944), and 5,597,353, the contents of which are incorporated herein by reference in their entirety. Curing may be initiated by introducing hot water into the inverted liner through a recirculation hose connected to the end of the inverted liner. The inversion water is recirculated through a heat source such as a boiler or heat exchanger and returned to the inversion tubes until curing of the tubes is complete. The resin impregnated in the impregnable material is then cured to form a hard, tight fitting rigid pipe lining in the existing pipeline. This new liner effectively seals any cracks and repairs any degradation of the pipe segment or pipe joint section, thereby preventing further leakage into or out of the existing pipeline. The cured resin also serves to strengthen the existing pipeline wall, thereby providing additional structural support to the surrounding environment.

When installing tubular cured in place liners by the pull-in-and-inflate method, the liner is used in the same manner as the eversion method

This disadvantage can be overcome by using air instead of water to create the turning force. Once the impregnated liner is fully inverted, the liner may then be cured with steam. While water is necessary to generate the steam, the amount of water in the form of steam is only 5-10% of the amount of water required for water tumbling, solidification and cooling. This means that steam can be used for curing even if water is not readily available on site. This dramatic reduction in water volume is due to the higher energy available from 1 pound of water in the form of steam than from 1 pound of hot water. Condensation of 1 pound of steam into 1 pound of water releases about 1000BTU, while 1 pound of water releases only about 1BTU per degree of drop in temperature. The reduced water requirement plus the virtually eliminated heating cycle greatly reduces the curing cycle and installation time.

Why the industry has progressed so slowly over the abandonment of water inversion and hot water curing, since the use of air inversion and steam curing has such significant advantages?

When water is used to invert the resin impregnated liner, the liner floats from the inverting front end to the non-inverting portion of the inverting apparatus by a force equal to the amount of water displaced by the liner. In the case of CIPP liners, this means that the effective weight of the liner is significantly reduced, as is the force required to pull the everted liner forward to the everting nose. When air is used to generate the inversion force, the non-inverted liner is placed on the bottom of the tube and air pressure acting on the inverted front end of the liner must pull forward into the total weight of the liner.

Whatever is used to generate the inversion energy, three forces must be overcome to invert the CIPP liner. These forces are:

1. the force required to invert the liner (turn the interior of the liner out). This force varies with the thickness of the liner, the type of material, and the thickness of the liner versus diameter.

2. The force required to pull the liner from the inversion apparatus to the inversion front end.

3. The force required to pull the liner through the inversion apparatus.

The first force described above is generally the same for air and water rollover.

The second force varies greatly between air and water and can limit the length of air turnover. There is a limit to how much pressure can be used to invert the liner without adversely affecting the quality of the installed CIPP liner and/or damaging the existing pipe. For both water and air tumbling, a lubricant may be used to reduce the required pulling force.

The third force may vary based on the design of the device. In most currently used devices, as one or both of the first force and the second force is increased, the force required to pull the liner through the device will increase. This is due to the fact that, in order to increase the available inversion energy, the usual devices currently used limit the loss of pressurised fluid from the pressure chamber below the liner entry point to the device and the cuff and the banded end of the liner being inverted. This restriction is typically achieved by increasing the air pressure in a pneumatic bungee device gland (gland) or by using a gland that is energized by a tumbling fluid. Inward movement is typically limited by compression of the capping material and inverting the CIPP liner. This in turn causes an increase in friction between the inverting CIPP liner and the gland.

In view of the obvious advantages of steam compared to hot water, it has been proposed to use steam in view of its energy carrying capacity. The use of air to inflate the inflatable bladder and flow steam through has been disclosed in the Insituform patents No.6,708,728 and No.6,679,293, the contents of which are incorporated herein by reference. The methods disclosed in these currently issued patents use pull-in inflation technology and are currently used for small diameter liners. For these sizes of liners, they offer advantages over water inversion. Moreover, the use of the containment metal cans (cans) disclosed in these patents is not always suitable for medium and large diameter liners. Medium sized liners are those having a diameter of between about 21 and 45 inches. Large diameter liners are those having a diameter in excess of about 45 inches.

While the existing methods of curing using hot water have the various advantages mentioned above, they have the disadvantages of a tendency to increase energy and labor costs, and involve the use of large amounts of water that may have styrene transport (entrained) due to the type of resin typically used. It is therefore desirable to provide a repair method in which a resin impregnated liner fitted with a bulkhead fitting (bulkhead fitting) is inflated at the pull-in end with air using a resin impregnated inflation bladder. After the bladder is inverted, a port is formed through the isolation fitting and an integral air/steam exhaust tube is connected to the isolation port, the resin being cured by the steam flowing through. Alternatively, an isolation fitting may be installed over the sleeve placed in the receiving passage to install the port over the inverted CIPP liner. This provides a faster and more efficient and economical installation method than various repair methods currently practiced.

Disclosure of Invention

The present invention provides a method of introducing the downstream end of an inflated cured in place liner without deflating the liner. The spacer fitting is attached to the downstream end of the pull-in liner prior to pulling in or by securing the fitting at the end of the pull-in or everting liner. An introducer vent sleeve and valve assembly are attached to the bulkhead fitting and a hole is cut in the liner and the inflation bladder with the liner pulled in. The cutting device is removed without shrinking the liner. The valve assembly is closed to allow the exhaust hose to be connected to the exhaust sleeve assembly.

According to one aspect of the present invention, there is provided a method of introducing a downstream end of an inflated cured in place liner without deflating the liner, the method comprising: connecting an isolation fitting to an end of the downstream end of the liner; connecting an intake vent sleeve and valve assembly to the bulkhead fitting; forming a hole through the inflated liner layer without shrinking the liner; isolating the inflated liner; and connecting an exhaust hose to the porting exhaust sleeve and valve assembly, wherein the bulkhead fitting is disposed on an porting sleeve and the bulkhead fitting is connected to the downstream end of the liner by pulling or everting the liner through the porting sleeve.

In the case of a cured in place liner installed by inversion, the bulkhead fitting may be installed after the liner has been completely inverted. An insulation fitting having a lower air/vapor barrier wall is installed by piercing the wall of the inverted liner using a tension ratchet strap. Alternatively, an inverted cured in place liner may be inverted into a hole in the liner by a flexible or rigid capture sleeve previously fitted with an isolation fitting.

In the case of pulling-in an inflated cured in place liner, the bulkhead fitting is installed distally prior to pulling-in. The liner may also be pulled through a capture sleeve previously fitted with an isolation fitting. In another embodiment, the pull-in liner and inflation bladder may be introduced simultaneously by puncturing the cured in place layer with a barrier fitting having an air/vapor barrier wall and ratchet strap.

In each case, once the liner is inflated and the insulation fitting is in place, the inversion air remains insulated in the liner and/or the inflation bladder. The closing valve is connected to the isolating fitting by means of a closing fitting or an external thread for connecting the cutting device. The valve opens to allow the cutting device to pierce the cured in situ layer and then removes to allow the valve to close and the cutting device to exit from the isolating fitting assembly. Finally, an exhaust hose is connected and a valve is opened to allow exhaust control to be conveniently done remotely. Curing with steam flow without shrinking the liner is an important aspect of the present invention. This avoids the potential that loose sections of existing pipe will be removed and randomly fixed in place between the liner and host pipe upon re-expansion.

In another embodiment of the invention, the resin impregnated pull-in liner is provided with a second bulkhead fitting at the pull-in end for forming a port for the condensate drain.

It is therefore an object of the present invention to provide an improved method of repairing an existing pipeline by installing a cured in place liner with at least one spacer fitting at the distal end of the liner.

It is another object of the present invention to provide an improved inflation bladder for installation of a cured in place liner through at least one bulkhead fitting for entry into the inflation bladder or inversion liner to permit flow through a vent hose mounted on the bulkhead fitting.

It is a further object of the present invention to provide an improved method for pull-in and inflate installation of cured in place liners by the use of inflow steam to cure the resin.

It is a further object of the present invention to provide an improved method for installing a cured in place liner by inverting and providing an inflow steam to cure the insulation fitting.

It is another object of the present invention to provide an improved method of installing a cured in place liner wherein air is used to inflate the liner and steam is used to cure the resin.

It is another object of the present invention to mount the vent isolation fitting on the inflated liner by tightening a strap around the liner to puncture the inner liner and allow for inflow without shrinking the liner.

Other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.

Accordingly, the invention includes several steps and the relation of one or more of such steps with respect to each other, as well as apparatus having features, capabilities, and relations between elements; these are exemplified in the following detailed description, and the scope of the invention will be set forth in the claims.

Drawings

For a more complete understanding of the present invention, reference is now made to the following descriptions taken in conjunction with the accompanying drawing, in which:

FIG. 1 is a cross-sectional front schematic view showing the drawing of a resin impregnated cured in place liner in a typical interstate highway pipe from the upstream or everted end of the pipe to the downstream or distal end of the pipe at the beginning of the installation process of the alignment leader;

FIG. 2 is a cross-sectional view of the bulkhead fitting with the cap installed at the pull-in end of the pull-in cured in place liner;

FIG. 3 is a plan view of the pull-in end of the liner of the drawings with two installed bulkhead fittings;

FIG. 4 is a cross-sectional view of the liner of FIG. 3;

FIG. 5 is a schematic cross-sectional view of a pressurized inversion unit for inverting an inflation bladder with air into a pulled-in liner according to one aspect of the present invention;

FIG. 6 is a schematic cross-sectional view of an inversion face of an expansion bladder with an isolation fitting at the distal end of a pulled-in liner during installation in accordance with the present invention;

FIGS. 7(a) -7 (g) are cross-sectional schematic views of a process of forming a vent at a distal end of a cured in place liner;

fig. 8(a) and 8(b) are cross-sectional views illustrating a step of installing a condensation drain pipe at a distal end of an expansion bladder after performing the steps illustrated in fig. 7(a) -7 (g);

FIG. 9(a) is a schematic front view showing the curing step of installing a resin impregnated liner through an exhaust hose coupled to the lead-in bulkhead fitting of FIG. 7(g) in accordance with the present invention;

FIG. 9(b) is a cross-sectional view of the receiving end of the liner of FIG. 9 (a);

FIGS. 10(a) and 10(b) are schematic plan and cross-sectional views of an introducer sheath for use with an inversion liner tube;

FIG. 11 is a schematic cross-sectional view of the inlet sleeve of FIG. 10 with the everted end of the liner tube fully everted;

FIGS. 12(a) -12 (d) are cross-sectional illustrations of the steps of installing an insulation fitting in an air-everted cured in place liner using a fitting including an air/vapor barrier wall having ratchet straps;

FIGS. 13(a) -13 (d) are cross-sectional illustrations of a step of forming a deflated stent in a pull-in tube expanded by an inflated balloon using a ratchet strap consistent with FIGS. 12(a) -12 (d); and

fig. 14(a) -14 (g) show the same steps for introducing an inverted cured in place liner using an inlet cannula consistent with fig. 7(a) -7 (g).

Detailed Description

Fig. 1 shows the upper end 11 of a typical highway culvert crossing (culverts crossing)12, which passes beneath the roadway and has a lower end 13. The resin impregnated liner 16 is pulled in from the upper end by a winch at the lower end. The liner 16 stored within the refrigerated vehicle 17 is wrapped with a polypropylene sleeve 18 to prevent damage and control radial expansion during pull-in from the upper end 11 to the lower end 13 by a rope 19 pulled by a winch 21 located at the lower end 13.

The liner 16 is a flexible cured in place liner of a type generally known in the art. The liner 16 is made of at least one layer of flexible resin impregnable material 22, such as a felt layer having an outer impermeable polymer film layer 23. Felt layer 22 and film layer 23 are stitched along a seam line to form a tubular liner. To ensure impermeability of the inner liner, a suitable tape-like thermoplastic film is provided on the seam line or an extruded material is extruded onto the seam line.

For larger diameter liners, multiple layers of felt material 22 may be used as shown in FIG. 2. Felt layer 22 may be a natural or synthetic flexible resin absorbent material, such as polyester or acrylic fibers. The impermeable membrane layer 23 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 steps of all trenchless rehabilitation installations, the existing pipeline or conduit 12 is prepared for cleaning and imaging.

The bulkhead fitting 31 shown in fig. 2 is installed at the pull-in end of the resin impregnated liner 16 (as shown in cross-section in fig. 2) and is in a flat condition as shown in fig. 4. The spacer fitting 31 is a rigid sleeve 32 having a sleeve 33, the sleeve 33 passing through a hole or opening 34 in the liner 16, and an inner flange 36 located on the inside of the felt layer 22. The exterior of the sleeve 33 has an external closure fitting, such as an external thread 37, for receiving a cap 38 having a corresponding internal thread 39. Alternatively, a Chicago (Chicago) fitting may be used to connect the valve assembly. A lock washer or compression nut 41 having internal threads 42 is placed on the sleeve 33 to securely fasten the bulkhead fitting 31 in place on the liner 16.

The isolator fittings 31 are made of steel, polypropylene or other rigid plastic material with sufficient strength and temperature characteristics to be able to withstand the temperatures of steam during curing.

As shown in fig. 3 and 4, a plurality of pull-in/restriction plates 43 are fixed to the pull-in end 16a of the liner 16. The plates 43, which are steel or other rigid plastic material, are placed on the top and bottom of the lay-flat liner 16 and secured through the lay-flat liner 16 by a plurality of bolts 44. An insulated fitting 31 is shown in figure 4 mounted on top of the liner 16. Two spacer fittings 31 are mounted in the liner 16 as shown in fig. 3 for coupling the steam vent pipe and the condensate drain pipe.

Before installation begins in accordance with the method of the present invention, a curable thermosetting resin is impregnated into the felt layer 22 of the innerliner 16 by a process known as "wet-out". As is well known in the art of lining technology, this method of soaking typically comprises: injecting resin into the felt layer through an end or an opening formed in the non-permeable membrane layer; vacuumizing; and passing the impregnated liner through nip rollers. One such process of vacuum impregnation is described in U.S. Pat. No.4,366,012 to Insituform, the contents of which are incorporated herein by reference. A wide variety of resins may be used, such as polyester resins, vinyl ester resins, epoxy resins, and the like, and may be modified as desired. It is preferred to use a resin that is relatively stable at room temperature, but readily cures upon heating.

Impregnated liner 16 is positioned about 20 feet from the inlet of the host pipe to the everted end 11. A rope is threaded from the upper end 11 to the lower end 13. The rope is then connected to a pull-in winch cable 19 which is pulled to the upper end.

The sleeve 18 is polypropylene or other suitable plastic film and, when entering the host pipe 12, the sleeve 18 is placed under the pull-in liner 16 and wrapped around the pull-in liner 16. The sleeve 18 may be folded over the liner 16 and lashed or strapped to protect the liner 16 as it is winched into the parent pipe 12. Pulling in continues until the trailing end of the liner 16 is at the desired distance from the lower end 13 of the parent pipe 12. Depending on the field conditions.

An inversion unit 46 having a cincher valve 47 of the type shown in U.S. patent No.5,154,936 is provided at the trailing end of the pull-in liner 16. The inversion unit includes an inlet end 48 and an outlet end 49 having an inversion boot 51 of a diameter to fit the liner 16. Air is used to operate the cinch valve 47 and the inversion boot 51 is adapted to contain air for inverting the inflation bladder 56. Steam for curing is supplied from a boiler 92 through a stainless hose 91 into a perforated lay-flat hose 93 that is pulled in with the inflation bladder 56.

The inflation bladder 56 is a resin impregnated tube of at least one layer of resin impregnable material as used in the liner 16 and has an outer impermeable layer. After the layer 16 is installed in the pipe 12, the inflation bladder is folded and pulled into the inversion unit 46 until it passes completely through the surface of a strap sleeve (wrapping boot) 51. The bladder is then folded over the sleeve and securely strapped. The pulled-in liner 16 is then strapped to the strap sleeve 51 over the strapped expansion bladder 56. An inversion air hose for operating the bladder of the inversion unit and the inversion inflation bladder is connected to the inversion unit 46.

According to another embodiment of the present invention, liner 116 is installed in an existing conduit by the inversion method described in U.S. Pat. No.4,064,211. To provide a flow through port at the everted end of liner 116, a porting sleeve 117 for everting the liner is provided as shown in fig. 10(a) and 10 (b). The sleeve 117 may be rigid or preferably flexible to fit within the receiving manhole.

The bushing 117 includes an exhaust isolator fitting 118 and a condensate drain isolator 119. Spacer fitting 118 and spacer 119 are the same as the spacer fitting provided on pull-in liner 16 shown in fig. 2 and described in detail above. Figure 2 shows a cross-sectional view of a fitting.

A sleeve 117 is provided at the receiving end of the existing conduit and liner 116 is inverted and restrained by sleeve 117. At this time, the ports 118 and 119 are formed using the processes outlined in conjunction with fig. 7(a) -7 (g) and 8(a) -8 (b).

Fig. 12(a) -12 (d) and 13(a) -13 (d) show the connection of the bulkhead fitting 201 to the cured in place liner. The partition fitting 201 has: a tubular portion 204 having external threads 204a and a slotted flange 202; and a tapered air/steam wall 203 projecting downward into the inflated cured in place liner. The liner may be a pull-in inflated liner 206 as shown in fig. 12(a) -12 (d), or an everted liner 207 as shown in fig. 13(a) -13 (d). In both cases, the insulation fitting 201 is mounted into the inflated liner using straps (strapping) or straps (strap)208, which straps or straps 208 pass under the liner and are joined to the insulation fitting 201 by ratchet straps 209 on each side of the fitting 201.

In particular, returning to fig. 12(a) -12 (d), there is shown in cross-section a pull-in inflated cured in place liner 206 with a spacer fitting 201 disposed on top. Liner 206 includes inner and outer resin impregnated layers 206a and 206b and a non-permeable inner layer 206 c. A protective sheet 211 is wound around the inner liner 206 to cover the exposed resin in the resin-impregnated layer 206. The strap 208 is positioned below the fully inverted and inflated liner 206. The ends of the strap 208 are inserted into a pair of ratchets 211. A pair of ratchet straps 206 having ratchet strap hooks 212 are inserted into slotted flanges 202 on the bulkhead fitting 201.

The isolator fitting 201 includes an externally threaded end 204 for receiving the threaded cap 38 as shown in fig. 2. With the threaded cap 38 in place, the ratchet 211 is tightened to create a recess 213 in the liner 201. A hole saw or assembly 212 similar to that used in connection with fig. 7(a) -7 (g) is inserted into place in the bulkhead fitting 201. A bore 217 is formed in the liner 206 and the air/vapor barrier wall 203 enters the interior of the liner 206. At this point, the ratchet strap 209 is fully tightened to position the bulkhead fitting 201, ready to contain steam in line with the process as described in connection with fig. 7(a) -7 (g). This is shown in the steps detailed in fig. 14(a) -14 (g).

Reference is now made to fig. 13(a) -13 (d), which show in cross-section an inverted cured in place liner 207 with an isolation fitting 201 on top and a fully inverted inflation tube 251. Liner 207 includes inner and outer resin impregnated layers 207a and 207b and a non-permeable outer coating 207 c. The strap 208 is disposed under the fully inverted and inflated liner 212. The ends of the strap 208 are inserted into a pair of ratchets 211. A pair of ratchet straps 209, each having a ratchet strap hook 212, are inserted into slotted flanges 202 on the bulkhead fitting 201.

The isolator fitting 201 includes an externally threaded end 204 for receiving the threaded cap 38 as shown in fig. 2. When the threaded cap 38 is in place, the ratchet 211 is tightened to create a recess 213 in the liner 207. A hole saw or assembly 212 similar to that used in connection with fig. 7(a) -7 (g) is inserted into place in the bulkhead fitting 201. A bore 217 is formed in the liner 207 and the air/vapor barrier wall 203 enters the interior of the liner 207. At this point, the ratchet strap 209 is fully tightened to position the bulkhead fitting 201, ready to contain steam consistent with the method as described in connection with fig. 7(a) -7 (g).

In conventional pull-in-and-inflate installation methods that use a water inversion method, pressure within the bladder and liner is maintained due to the height of the column of water within the down tube. Curing is initiated by exposing the impregnated liner to heat. This is typically accomplished by introducing hot water into the everting tube or by circulating the hot water through a recirculation hose that is pulled into the everting bag by a length of cord attached to the tail end of the everting bag. Typically, curing takes about 3 to 5 hours, depending on the type of resin selected and the thickness of the liner. After curing, access to a downstream manhole is required to release the cured hot water before the inflation bladder is removed.

This creates a serious problem for medium and large diameter liners, especially when replacing the liner for a typical highway pipeline having a significant incline as shown in fig. 1. Not only is the volume of water required large, but the additional pressure from the vertical drop will rupture the inflatable bladder. To avoid this problem, it is desirable to inflate with air and cure with steam. In addition, the energy obtained by the steam will cure the liner faster and at a lower energy cost.

For example, table 1 below shows a comparison of water and energy required for steam cure and water for curing a cured in place liner having a 9.5 foot down pipe and a length of 114 feet and a diameter of 42 inches downstream of 3.5 feet.

TABLE 1

FIG. 3 shows the location of the bulkhead fitting and limiting plate for attaching a pull-in cord to pull-in the liner.

A typical flipping apparatus of the type disclosed in us patent No.5,154,536, the contents of which are incorporated by reference into this specification, is used in a preferred embodiment according to the present invention. The turn-over device may be mounted horizontally at the upstream end of the main pipe. After tying, the inflation bladder 56 and liner 16 are tied at the everted end 51. The valve 47 is pressurized and the bladder 56 is inverted into the liner 16. Sufficient air pressure is applied to the air inlet to effect inversion. As lubricant is supplied, it is applied to the surface of the bladder 56 to facilitate movement through a gland (gland) on the valve 47 during inversion of the bladder 56.

The inflation bladder 56 may include air release vents formed about 2 to 4 feet from the end of the bladder. In this way, as the bladder is inverted, air within the bladder may be vented before passing through a valve in the inversion apparatus. As shown, the vent holes are formed by cutting 1/2 inch holes in the top layer of the pouch and covering it with two opposing patches.

The tumbling air supply and bladder pressure are adjusted to maintain a uniform tumbling speed. The suggested pressures are:

as eversion continues and the inflation bladder 56 approaches the lower opening 13, the everted end is stopped by the pull-in/restriction plate shown in fig. 3 and 4. This is illustrated in fig. 6. When the inversion is stopped, the air pressure within the inflation bladder 56 remains constant. Meanwhile, the port 30 is formed in the expansion bladder 56 after the steps shown in fig. 7(a) -7 (g) as follows to mount the valve exhaust pipe 61 shown in fig. 7 (g). The impregnated resin pull-in liner 16 is provided with a second bulkhead fitting 31 at the pull-in end 16a to form a second port 63 for a condensate drain 64, as shown in fig. 8(a) and 8 (b).

After the expansion tube 56 is fully inverted, the cap 38 is removed and the ball valve 71 is installed on the adapter sleeve 39. The ball valve 71 is closed. The nozzle 72 is mounted on the ball valve 71. A hole saw 73 with a drill rod (drill stem)74 is inserted into the nozzle 72 and a hole saw rod guide (hole saw stem guide)76 is secured to the end of the nozzle 72. The drill 73 is connected to a drill pipe (stem) 74.

Ball valve 71 opens at hole 30 or 63 and reamer 77 is activated to cut hole 30 or 63 while maintaining air pressure within bladder 56. When the port 30 or 63 is fully cut, the ball valve 71 is closed and the reamer 77 and hole saw 73 are removed from the fitting 31. Then, an exhaust pipe (exhaust hoe)61 was connected to the nozzle 72.

Referring now to fig. 8(a) and 8(b), the condensation port 63 is formed in the same step as shown in fig. 7(a) to 7 (f). After removing the reamer 77, a condenser gland 81 is placed on the nozzle 72, and a condensate drain hose 82 is placed on the gland 81 to reach the bottom of the bladder 56. The gland 81 is tightened to prevent the hose 82 from moving.

Referring now to fig. 9(a) and 9(b), steam is introduced into the attached, perforated lay-flat hose 86 to begin the curing of the resin drawn into the liner 16 and the inflation bladder 56. In an exemplary embodiment of the invention, lay-flat hose 86 is a 4-inch diameter high temperature thermoplastic pipe. Such as 1/8 inch holes (orifice). The size and spacing may vary depending on the boiler and liner size and length, with 1/2 inch holes drilled on the folded edges at one foot intervals at opposite edges. The orifice pattern provides more steam at the proximal end of the liner 16 and ensures good mixing even if the hose 86 is twisted. This also ensures that steam is injected into any condensate that forms within the eversion of the tube to solidify a portion of the resin in the liner covered by the condensation pool (condenstock). Steam is supplied to the inlet line (inletline) from a steam inlet hose regulated by a valve conduit to provide an air/steam mixture to provide steam. The air/steam flow is adjusted to maintain a cure pressure of about 3-6psi until the temperature of the mixed air/steam flow reaches the desired temperature of about 170F and 220F as measured at the exhaust.

The suggested heating and curing pressures (in psig) are as follows:

once curing is complete, the steam flow is turned off while the air flow is adjusted to maintain the curing pressure, depending on the specific resin and tube thickness. The vent valve is adjusted while cooling to about 130 ° F at the 6 o' clock position for at least the joint between the liner 16 and the existing pipe 12.

Once the temperature is cooled to the desired level, the air flow pressure is reduced to zero; the exhaust valve is fully open. Any condensate that may have accumulated in the bladder is removed through a condensate drain on the exhaust assembly.

It can be readily seen that the method according to the present invention readily allows one to obtain the advantages of an air-inflated and cured resin liner with a flow-through steam suitable for pulling in and inverting the liner. By implementing this method, the tubular member can be easily inverted through an existing pipeline. By providing an embedded barrier fitting for forming a selectively openable vent valve, pressure within the everted liner or bladder may be maintained and inflated pull-in liner and steam may be introduced into the everted access end and flowed through the cured liner without deflating the inflated liner. This uses the higher energy available from steam to cure the resin at a significantly faster rate than can be achieved with circulating hot water.

It will thus be seen that the objects set forth above, among others, are efficiently attained and some of the objects have been attained by the means set forth in the preceding description; also, since certain changes may be made and the above methods and described constructions may be practiced 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.

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 therebetween.

Claims (2)

1. A method of introducing a downstream end of an inflated cured in place liner without deflating the liner, comprising:

connecting an isolation fitting to an end of the downstream end of the liner;

connecting an intake vent sleeve and valve assembly to the bulkhead fitting;

forming a hole through the inflated liner layer without shrinking the liner;

isolating the inflated liner; and

a vent hose is connected to the introducer vent sleeve and valve assembly,

wherein the bulkhead fitting is disposed on a porting sleeve and the bulkhead fitting is connected to the downstream end of the liner by pulling or everting the liner through the porting sleeve.

2. The method of claim 1, wherein the hole through the inflated liner layer is formed using a hole saw.