Apparatus and method for repairing a pipeline

An apparatus for repairing a pipeline includes an elongated flexible tube with one end inverted upon itself to create an outer inverted portion and an inner non-inverted portion connected at an inversion end. An elongated sleeve-shaped liner impregnated with rosin is fitted within the non-inverted portion of the tube member in contact with the interior surface thereof. A plurality of attachment strips are frangible connected at one end to the liner, and permanently affixed to the tube inner surface, such that inversion of the tube member will cause the attachment strips to invert to the exterior of the inverted portion, and thereby also invert the liner to the exterior surface of the inverted portion of the tube.

TECHNICAL FIELD 
The present invention relates generally to resin impregnated liners for 
repair of pipelines, and more particularly to an improved method and 
apparatus for installing the liner at a desired location within a 
pipeline. 
BACKGROUND OF THE INVENTION 
One method of repairing damaged sewer pipe is to excavate the area 
surrounding the sewer pipe and replace the broken portion. This is a very 
expensive and a labor intensive solution and is also an inconvenience to 
residents living in the area and utilizing roadways overlying the area. 
Another solution is In situ relining of sewer pipes. In situ methods 
typically utilize a resin coated liner which is inserted into the existing 
sewer pipeline and unrolled against the sewer pipe. The unrolled liner is 
held against the existing sewer pipe while the resin cures to form a new 
pipe lining within the existing pipe. 
One example of such a method is shown in U.S. Pat. No. 4,366,012. In this 
patent, a process for installing a liner in a sewer pipe is disclosed 
which utilizes an elongated tube of felt coated on the exterior with 
urethene to form an "outer" tube. Because the felt tube is coated with 
this material, the two tubes act as a single integral laminated tube--with 
a urethane outer layer and a felt inner layer. Uncured resin is introduced 
into the tube and is used to impregnate the felt layer of the tube. The 
tube is then inverted into the end of a sewer pipe so that the impregnated 
felt layer is inverted to the outside and the urethane layer is located on 
the interior. The inversion process continues until the area of the sewer 
pipe needing repair has been contacted by the impregnated felt layer of 
the tube. When the resin cures, a pipe liner is formed by the inverted 
tube. 
The applicant's co-pending patent application shows a method for 
impregnating a curable resin in a layer of resin absorbent material 
located within an elongated flexible bladder tube having a fill end and a 
vacuum end positioned down stream from the fill end. The bladder tube 
includes two walls forming a tube cavity therein. The layer of resin 
absorbent material has a down stream end positioned a predetermined 
distance from the vacuum end of the bladder tube, and an upstream end. An 
elongated gas conduit having first and second conduit ends is placed 
within the tube cavity with the first conduit end positioned up stream 
from the down stream of the resin absorbent material and with the second 
conduit end positioned down stream from the down stream end of the resin 
absorbent material. 
A quantity of curable resin is then introduced into the fill end of the 
bladder tube, the quantity of resin being sufficient to impregnate all of 
the resin absorbent material within the bladder tube. A vacuum source is 
then connected to the bladder tube at a point spaced down stream from the 
down stream end of the resin absorbent material whereby the wall of the 
bladder tube will collapse on the layer of resin absorbent material and 
the gas conduit will provide a path for evaluating gas through the 
collapsed two walls. Gas is continuously evacuated from the bladder tube 
until the curable resin moves to the down stream end of the absorbent 
material and completely impregnates the absorbent material. 
As described in detail in the co-pending '817 application, the repair 
sleeve is attached at its forward end to an inversion collar by means of 
stitches. The forward end of the inversion collar is then affixed to the 
forward end of the bladder tube by heat sealing, adhesive, or other 
suitable securement. In this way, as the bladder tube is inverted, the 
inversion collar will also be inverted so as to be positioned on the 
outside of the bladder after the inversion. Similarly, the stitches 
connecting the inversion collar to the repair sleeve will also cause the 
repair sleeve to invert, so as to be positioned on the outside of the 
bladder tube in contact with the portion of the pipeline to be repaired. 
While the inversion collar described in the co-pending '817 application 
serves its purposes, it has been found that there are several drawbacks to 
a continuous collar connecting the bladder tube to the repair sleeve. 
First, the use of a continuous collar adds an additional layer of material 
to the bladder tube. This additional layer resists expansion when the 
bladder tube is pressurized to radially expand and maintain the repair 
sleeve in position during curing of the resin. 
A second problem with the use of a continuous collar to invert the felt 
liner is that the collar encapsulates a portion of the liner between the 
collar and bladder thereby making it difficult to impregnate that portion 
with resin. 
Obviously, the cost of material is greater with a continuous collar than 
with the attachment strips described herein. The strips of the present 
invention may be made from scrap from the manufacture of the bladder, 
resulting in a lower overall cost. 
Another deficiency in the prior art method for inverting the repair sleeve 
resides in the pressures required to invert a continuous sleeve in 
addition to the pressure required to invert the bladder tube and repair 
sleeve. High pressures during the inversion process can squeeze the resin 
out of the repair sleeve liner, thereby decreasing the strength and 
durability of the repair. It is therefore desirable to decrease the amount 
of pressure required to complete the inversion process, as much as 
possible. 
Another problem with prior art methods for repairing pipelines is present 
in pipelines of small diameter such as in laterals, wyes, and in pipelines 
which change diameter along their lengths. Previously, it was necessary to 
begin a liner at the entrance to the pipeline to be repaired, and continue 
the repair sleeve liner a distance to reach the repair site. If the repair 
site is located a great distance from the pipeline entrance, there is a 
great quantity of wasted material, as well as increased labor costs. 
SUMMARY OF THE INVENTION 
It is therefore a general object of the present invention to provide an 
improved apparatus for inverting a repair sleeve liner within a pipeline 
to repair the pipeline. 
Another object is to provide an apparatus for installing a repair sleeve 
liner within a pipeline which reduces the necessary pressure for inverting 
the liner and carrier tube within the pipeline, as compared to prior art 
apparatus. 
Still another object of the present invention is to provide an improved 
apparatus and method for installing a repair sleeve liner through a clean 
out, and begin the liner after a tee or wye fitting. 
A further object of the present invention is to provide a method and 
apparatus for installing a repair sleeve liner in a lateral through a 
small diameter pipe which changes to a larger diameter pipe, while 
beginning the liner at the beginning of the large diameter pipe. 
These and other objects of the present invention will be apparent to those 
skilled in the art. 
The apparatus for repairing a pipeline of the present invention includes an 
elongated flexible tube with one end inverted upon itself to create an 
outer inverted portion and an inner non-inverted portion connected at an 
inversion end. An elongated sleeve-shaped liner impregnated with rosin is 
fitted within the non-inverted portion of the tube member in contact with 
the interior surface thereof. A plurality of attachment strips are 
frangibly connected at one end to the liner, and permanently affixed to 
the tube inner surface, such that inversion of the tube member will cause 
the attachment strips to invert to the exterior of the inverted portion, 
and thereby also invert the liner to the exterior surface of the inverted 
portion of the tube.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring now to the drawings, in which similar or corresponding parts are 
identified with the same reference numeral and more particularly to FIG. 
1, the liner/bladder assembly of the present invention is designed 
generally at 10 and includes a bladder tube 12 having a rearward end 14 
and a forward end 16. Fitted within the rearward end 14 of bladder tube 12 
is a threaded receptacle 18 which is held in place by means of clamps 20. 
A pulling loop 22 is also held by clamps 20 and is attached to control 
line 24. Within bladder tube 12 is a repair sleeve liner 26, formed of 
felt or other resin-absorbent material. As shown in FIG. 1, bladder tube 
12 has the forward end 16 reversed and inverted upon itself to form an 
inverted portion 12a with a cavity 28, within which the non-inverted 
portion 12b is located. 
Referring now to FIGS. 2 and 3, liner 26 has a plurality of attachment 
strips 30 secured to its leading end 26a by stitches 32. The forward ends 
of attachment strips 30 are affixed to the interior surface of bladder 
tube 12 (shown on the exterior of inverted portion 12a in FIG. 3) by heat 
sealing, adhesive, or other permanent attachment means. Stitches 32 are 
easily broken away so as to permit the leading end 26a of liner 26 to be 
separated from the rearward end of attachment strips 30 and the bladder 
tube 12, by use of a dynamic tension force. 
The method of impregnating the repair sleeve liner 26 with resin is set 
forth in detail in the applicant's co-pending '817 application, and the 
contents of that application are incorporated herein by reference thereto. 
As shown in FIGS. 2-3, attachment strips 30 are generally parallel to one 
another and uniformly spaced apart, such that inversion of bladder tube 12 
will cause attachment strips 30 to invert from the interior of assembly 10 
to the exterior thereof, thereby pulling the forward end 26a of liner 26 
to an inverted position on the exterior of the inverted portion 12a of 
bladder tube 12. The use of spaced apart strips 32 reduces the force 
required to invert the strips, as compared to the forces required to 
invert a continuous sleeve, as was used in co-pending '817 application. 
Referring now to FIG. 4, the method of use of the present invention is 
shown in more detail. The initial step in installing repair sleeve liner 
26 within a lateral 34, or other similar pipe, includes providing a 
liner/bladder assembly 10 with liner 26 fully impregnated with resin, as 
described in detail in the co-pending '817 application. As shown in FIG. 
4, a small diameter clean out 36 communicates with lateral 34 through a 
wye fitting 38. With this type of arrangement, it is not possible to begin 
the repair liner at the entrance 36a of clean out 36, since this would 
effectively block lateral 34 upstream of the wye fitting 38. With the 
liner/bladder assembly 10 of the present invention, it can be seen that 
the liner 26 may be positioned to begin after the wye fitting 38, and 
extend a predetermined distance along the lateral 34 to repair the pipe. 
As shown in FIG. 1, attachment strips 30 are mounted to bladder tube 12 a 
predetermined distance from the end cap 40 at the forward end 16 of 
bladder tube 12, so as to position the leading end 26a of liner 26 at the 
appropriate position within the lateral pipe 34. For ease of description, 
the portion of bladder tube which is inverting will be identified as 
inversion end 12c, which continuously moves along the length of bladder 
tube 12 as the tube is inverted and reverted. 
The initial step in repairing a lateral pipe 34 includes forming the 
liner/bladder assembly 10 with liner 26 attached via attachment strips 30 
at a predetermined position spaced from end cap 40. The inverted end 12c 
of assembly 10 is then inserted within the entrance 36a of clean out 36, 
as shown in FIG. 4, and then air pressure, water pressure or other fluid 
pressure is applied within cavity 28. This causes bladder tube 12 to 
continue to invert until attachment strips 30 are inverted, which then 
causes liner 26 to invert, as shown in FIGS. 3 and 4. In this position, 
repair sleeve liner 26 is inverted to the outside of the bladder tube 12 
in engagement with lateral pipe 34. The fluid pressure is continued, so as 
to continue the inversion of bladder tube 12, until the liner 26 
completely contacts the portion of lateral pipe 34 which is to be 
repaired. Continuation of fluid pressure within bladder tube 12 then 
presses bladder tube 12 radially outwardly, so as to hold the liner 26 
tightly against the interior surface of lateral 34. 
Once the resin has cured and hardened, the fluid pressure is released from 
bladder tube 12, and control line 24 (shown in FIG. 1) is pulled to cause 
bladder 12 to resume its original uninverted configuration, thereby 
continuously "peeling" the bladder from liner 26 affixed in lateral 
pipeline 34. Once bladder tube 12 has been reverted back to the location 
of attachment strips 30, the stitches 32 forming the frangible connection 
of the strips to the liner are broken with a sharp tug on the bladder tube 
12. 
Referring now to FIG. 5, a second use of the liner/bladder assembly 10 of 
the present invention permits installation of liner 26 within a pipe 42 
which changes from a smaller diameter pipe 42a to a larger diameter pipe 
42b. Rather than requiring a transition in the liner 26 from a smaller 
diameter to a larger diameter, attachment strips 30 are attached to 
bladder tube 12 at a predetermined location, and have a predetermined 
length so as to begin the leading end 26a of liner 26 at the beginning of 
the larger diameter pipe 42b. 
FIGS. 6 and 7 disclose yet another use for liner/bladder assembly 10 with 
attachment strips 30 of selected length. FIG. 6 shows use of short length 
attachment strips 30, while FIG. 7 shows attachment strips 30' of a longer 
length, thereby shifting the location of the liner 26 within the lateral 
34 off a main sewer line 44. In this embodiment of the invention, the 
forward end of the liner/bladder assembly 10 is journaled through a guide 
tube 46, which has an end cap for introducing a fluid at one end, and is 
attached to a 90.degree. elbow 48 at the other end. A hose clamp 50 or 
other similar clamp may be used to attach guide tube 46 to elbow 48, to 
provide an airtight seal. Liner/bladder assembly 10 is then journaled 
through guide tube 46 and elbow 48 so as to project out the distal end 48a 
of elbow 48. Bladder tube 12 is then inverted or rolled inside out and 
affixed to the distal end 48a of elbow 48 with a clamp 52 to form an 
airtight seal. 
Elbow 48 and guide tube 46 are then moved into the main sewer liner 44 in a 
conventional fashion, until elbow 48 is positioned adjacent the lateral 34 
to be repaired. A mechanical robot of conventional construction is used to 
rotate elbow 48 to align distal end 48a with lateral 34. Fluid pressure is 
then introduced within guide tube 46, thence through elbow 48 so as to 
pressurize cavity 28 and invert bladder tube 12. As bladder tube 12 
inverts, attachment strips 30 will cause liner 26 to invert and contact 
the interior surface of lateral 34. Once bladder tube 12 is fully 
inverted, pressure is maintained until the resin impregnated within liner 
26 has cured and hardened. Control line 24 is then pulled to revert the 
bladder tube and peal it from the installed liner 26. The frangible 
stitches connecting attachment strips 30 to liner 26 are easily broken, to 
leave liner 26 firmly in place lining lateral 34, and permit removal of 
guide tube 46 and elbow 48 from main sewer line 44. 
The length of adjustment straps 30 may be adjusted to more specifically 
locate the liner 26 within lateral 34. FIG. 7 shows attachment strips 30' 
of a greater length than shown in FIG. 6, such that liner 26 is positioned 
further into lateral 34, as desired. 
The first embodiment of the invention, described above and shown in FIGS. 
1-7 may be described as a "launcherless" style of liner/bladder assembly 
as opposed to the "launcher" style assembly described in the applicant's 
prior patent application Ser. No. 08/293,697, which is incorporated herein 
by reference thereto. The launcher style assembly includes a tubular outer 
cover which may be pulled through a main line sewer pipe so as to locate 
the liner/bladder assembly immediately adjacent the portion of the pipe to 
be repaired. The launcherless style described above is intended to be 
immediately inverted at the end of the pipe to be repaired and has a 
length to extend over the portion of the pipe to be repaired. No 
additional outer covering or "launcher" is needed because the inversion 
and lining process proceeds immediately from the location of the pipe 
entrance. 
Large diameter pipe lines require a repair liner with a significant weight, 
and therefore the internal pressure required to invert the bladder is also 
much greater than for a smaller diameter laterals and the like. The 
applicant's current method for impregnating the repair liner with resin 
preferably includes the use of a transluscent bladder so that the process 
of impregnating the liner within the bladder with resin may be observed to 
verify that the liner is thoroughly "wet out". 
In the situation of large diameter pipe lines, the exterior bladder must be 
reinforced with other materials, such as fibers or the like, thereby 
significantly reducing the transluscent properties of the bladder, 
preventing observation of the impregnation process. The second embodiment 
of the invention, shown in FIGS. 8-10, overcomes these problems. 
Referring now to FIG. 8, the second embodiment of the liner/bladder 
assembly is designated generally at 110, and includes a bladder tube 112 
having a rearward end 114 and forward end 116, similar to the first 
embodiment of the invention. Bladder 112, however, is a larger diameter 
bladder with additional reinforcing material, and is therefore 
substantially opague, although much stronger than the first embodiment of 
the bladder 12. Bladder tube 112 is shown with the forward end 116 
reversed and inverted over itself to form an inverted portion 112a with a 
cavity 128 within which the non-inverted portion 112b of bladder tube 112 
is located. 
A plurality of attachment strips 130 of the same material as bladder tube 
112, with forward ends affixed to the interior surface of bladder tube 112 
(shown on the exterior of inverted portion 112a in FIG. 8) by heat 
sealing, adhesive, or other permanent attachment means. The opposing ends 
of attachment strips 130 will be frangibly connected to the repair liner 
126 and/or auxiliary bladder 160, as described in more detail hereinbelow. 
In the second embodiment of the liner/bladder assembly 110, the repair 
sleeve liner 126, formed of felt or other resin absorbent material, is 
pulled within the interior of auxiliary bladder 160. Auxiliary bladder 160 
is formed of a transluscent flexible rubber like material, and includes a 
forward end 162 and a rearward end 164, with an overall length greater 
than the length of liner 126. The method of impregnating liner 126 with 
resin is set forth in detail in the applicant's co-pending '817 
application, referred to above. An end cap 166 is fastened to the forward 
end 162 of auxiliary bladder 160 and includes a pair of apertures 168 
therein through which a cord 170 is threaded and doubled back upon itself. 
Once liner 126 has been impregnated with resin, cord 170 is used to pull 
the auxiliary bladder 160 (with liner 126 therein) within the non-inverted 
portion 112b of bladder tuber 112. 
The two ends of cord 170 are threaded through the rearward end of bladder 
tube 112, and thence through the forward end 116 to permit the auxiliary 
bladder 160 to be pulled within the non-inverted portion 112b of bladder 
tube 112. One end of cord 170 is then released, and the other end pulled, 
to remove the cord from end cap 166 and auxiliary bladder 160. Once 
auxiliary bladder 160 is positioned within non-inverted portion 112b, a 
threaded receptacle 118 is fitted to the rearward end 114 of bladder tube 
12, and held in place by clamps 120. A pulling loop 122 is also held by 
clamps 120 and is attached to control line 124. Steel end cap 140 is 
banded to the forward end 116 of bladder tube 112 to form an airtight fit. 
Apertures in the end cap permit control line 124 to be journaled 
therethrough, as well as an air supply line 172. 
As shown in FIG. 9, the rearward end 164 of auxiliary bladder 160 and the 
leading end 126a of liner 126 are positioned proximal the bladder tube 
inversion end 112c. The free ends of attachment strips 130 are frangibly 
connected to either or both of liner 126 and auxililary bladder 160 using 
thin plastic tie strips, snaps, hook and loop fastener, or any other 
convenient connector which permits the connection to be broken with a 
sharp dynamic force. In FIG. 9, a plurality of plastic ties 174 are 
journaled through apertures in attachment strips 130 and apertures in the 
liner 126 and auxiliary bladder 160 and then looped and fastened in a 
conventional manner. 
Once the liner/bladder assembly 110 has been assembled, and attachment 
strips 130 connected to the liner 126 and auxiliary bladder 160, the liner 
bladder assembly 110 is positioned at the entrance, or within, the large 
diameter pipe line to be repaired as shown in FIG. 10. Fluid pressure is 
applied within cavity 128 through supply line 172 in end cap 166 to cause 
bladder tube 112 to invert within the pipe line 176. Attachment strips 130 
will cause liner 126 and auxiliary bladder 160 to invert to the outer 
surface of the inverted portion of bladder tube 112 into contact with the 
interior surface of pipe line 176. The fluid pressure is continued until 
liner 126 completely contacts the portion of pipe 176 which is to be 
repaired. Continuation of fluid pressure within bladder tube 112 then 
presses bladder tube 112 radially outwardly, so as to hold liner 126 
tightly against the interior surface of pipe line 176. 
Whereas the invention has been shown and described in connection with the 
preferred embodiment thereof, many modifications, substitutions and 
additions may be made which are within the intended broad scope of the 
appended claims.