U.S. patent application number 11/842935 was filed with the patent office on 2008-09-04 for systems and methods for liner tensioning in pipeline rehabilitation.
Invention is credited to Corwin J. Bryant, John A. Cain, Dan Cohen, James D. Keigley.
Application Number | 20080213047 11/842935 |
Document ID | / |
Family ID | 39107612 |
Filed Date | 2008-09-04 |
United States Patent
Application |
20080213047 |
Kind Code |
A1 |
Bryant; Corwin J. ; et
al. |
September 4, 2008 |
SYSTEMS AND METHODS FOR LINER TENSIONING IN PIPELINE
REHABILITATION
Abstract
A system for liner tensioning according to embodiments of the
present invention includes a tubular liner inside a pipeline from a
front end of the pipeline to a back end of the pipeline, the
tubular liner having a front end and a back end, the tubular liner
coupled to the front end of the pipeline, the back end of the
tubular liner extending from the back end of the pipeline, as well
as a liner clamp coupled to the back end of the tubular liner, and
a tensioning element coupled to the liner clamp and the pipeline,
the tensioning element configured to apply a tensioning force
between the liner clamp and the pipeline. The tensioning element
may include one or more braces adjustable in length to accommodate
pipes of varying diameters or different lengths of liner extending
from the pipe.
Inventors: |
Bryant; Corwin J.; (Buena
Vista, CO) ; Cain; John A.; (Fairplay, CO) ;
Keigley; James D.; (Silt, CO) ; Cohen; Dan;
(Breckenridge, CO) |
Correspondence
Address: |
FAEGRE & BENSON LLP;PATENT DOCKETING
2200 WELLS FARGO CENTER, 90 SOUTH SEVENTH STREET
MINNEAPOLIS
MN
55402-3901
US
|
Family ID: |
39107612 |
Appl. No.: |
11/842935 |
Filed: |
August 21, 2007 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
60823085 |
Aug 21, 2006 |
|
|
|
Current U.S.
Class: |
405/184.2 ;
138/98; 242/410; 405/150.1 |
Current CPC
Class: |
F16L 55/16455 20130101;
F16L 2101/30 20130101 |
Class at
Publication: |
405/184.2 ;
242/410; 405/150.1; 138/98 |
International
Class: |
F16L 55/18 20060101
F16L055/18; B29C 63/34 20060101 B29C063/34 |
Claims
1. A system for liner tensioning in pipeline rehabilitation, the
system comprising: a tubular liner inside a pipeline from a front
end of the pipeline to a back end of the pipeline, the tubular
liner having a front end and a back end, the tubular liner coupled
to the front end of the pipeline, the back end of the tubular liner
extending from the back end of the pipeline; a liner clamp coupled
to the back end of the tubular liner; and a tensioning element
coupled to the liner clamp and the pipeline, the tensioning element
configured to apply a tensioning force between the liner clamp and
the pipeline.
2. The system of claim 1, wherein the tensioning element is coupled
to the pipeline by one or more supports configured to maintain a
fixed distance between the tensioning element and the pipeline, and
wherein the tensioning element is further configured to permit
axial displacement of the liner clamp with respect to the pipeline
as the tensioning force is applied.
3. The system of claim 2, wherein the one or more supports are
adjustable in length.
4. The system of claim 2, wherein each of the one or more supports
comprises a longitudinal portion maintaining a fixed distance
between the tensioning element and the pipeline, wherein each of
the one or more supports further comprises a radial portion
maintaining a fixed distance between the tensioning element and the
longitudinal portion, and wherein the radial portion is adjustable
in length.
5. The system of claim 2, wherein the tensioning element is a
pneumatic cylinder.
6. The system of claim 2, wherein the tensioning element is a
spring.
7. The system of claim 2, wherein the tensioning element is a
wingnut and threaded bolt combination.
8. The system of claim 2, wherein the tensioning element is coupled
to the liner clamp by one or more chains, and wherein the one or
more chains are adjustable in length.
9. A method for maintaining liner tension in pipeline
rehabilitation, the method comprising: deploying a tubular liner
along an inside of a pipeline; coupling the tubular liner with the
pipeline at a front end of the pipeline; coupling the tubular liner
with a liner clamp at a back end of the tubular liner; pulling the
liner clamp away from the pipeline to remove slack in the tubular
liner; and maintaining a tension force between the liner clamp and
the pipeline.
10. The method of claim 9, further comprising: coupling the
tensioning element to the pipeline by one or more supports
configured to maintain a fixed distance between the tensioning
element and the pipeline.
11. The method of claim 10, wherein the one or more supports are
adjustable in length.
12. The method of claim 10, wherein each of the one or more
supports comprises a longitudinal portion maintaining a fixed
distance between the tensioning element and the pipeline, wherein
each of the one or more supports further comprises a radial portion
maintaining a fixed distance between the tensioning element and the
longitudinal portion, and wherein the radial portion is adjustable
in length.
13. The method of claim 10, wherein maintaining a tension force
between the liner clamp and the pipeline comprises maintaining a
tension force between the liner clamp and the pipeline with a
pneumatic cylinder.
14. The method of claim 10, wherein maintaining a tension force
between the liner clamp and the pipeline comprises maintaining a
tension force between the liner clamp and the pipeline with a
spring.
15. The method of claim 10, wherein maintaining a tension force
between the liner clamp and the pipeline comprises maintaining a
tension force between the liner clamp and the pipeline with a
wingnut and threaded bolt combination.
16. A system for liner tensioning in pipeline rehabilitation, the
system comprising: a liner clamp configured to be coupled to a
tubular liner extending from within a pipeline; and a tensioning
element coupled to the liner clamp, the tensioning element
configured to apply a tensioning force between the tensioning
element and the liner clamp while permitting movement of the liner
clamp with respect to the tensioning element; and one or more
braces, the one or more braces coupled to the tensioning element,
and the one or more braces configured to be coupled to the
pipeline.
17. The system of claim 16, wherein the one or more braces are
adjustable in length.
18. The system of claim 16, wherein each of the one or more braces
comprises a longitudinal portion configured to maintain a fixed
distance between the tensioning element and the pipeline, wherein
each of the one or more braces further comprises a radial portion
maintaining a fixed distance between the tensioning element and the
longitudinal portion, and wherein the radial portion is adjustable
in length.
19. The system of claim 16, wherein the tensioning element is a
pneumatic cylinder.
20. The system of claim 16, wherein the tensioning element is a
wingnut and threaded bolt combination.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional
Patent Application Ser. No. 60/823,085, filed on Aug. 21, 2006, and
entitled, "Systems and Methods for Pipeline Rehabilitation," which
is incorporated herein by reference in its entirety for all
purposes.
TECHNICAL FIELD
[0002] Embodiments of the present invention relate generally to
rehabilitation of pipelines, and more specifically to maintaining
tension on a liner during pipeline rehabilitation.
BACKGROUND
[0003] After time, pipelines often suffer from corrosion of the
inner diameter and/or minor cracking and/or leakage. Such pipelines
must often be replaced or rehabilitated. Replacement often involves
the movement or destruction of above-ground structures, such as
roadways or sidewalks. Rehabilitation, on the other hand, may
permit a new inner diameter of the pipe to be created using the
existing pipeline as an outer shell, which may eliminate the need
to dig up large sections of existing pipeline and/or water mains,
and which may involve significant cost savings over
replacement.
[0004] One form of pipeline rehabilitation involves the
installation of a tubular liner inside of a host pipe with
hardenable cement mortar (formed from grout) between the tubular
liner and the host pipe. However, as a swab is advanced through the
liner or as grout is distributed between the liner and the
pipeline, the liner can be drawn into the pipe and twisted, pinned
or "bunched up," which may restrict further progress of the
installation or damage the liner.
SUMMARY
[0005] Embodiments of systems for liner tensioning in pipeline
rehabilitation include a tubular liner inside a pipeline from a
front end of the pipeline to a back end of the pipeline, the
tubular liner having a front end and a back end, the tubular liner
coupled to the front end of the pipeline, and the back end of the
tubular liner extending from the back end of the pipeline. Such
embodiments of systems may further include a liner clamp coupled to
the back end of the tubular liner, and a tensioning element coupled
to the liner clamp and the pipeline, the tensioning element
configured to apply a tensioning force between the liner clamp and
the pipeline. In some instances, the tensioning element is coupled
to the pipeline by one or more supports configured to maintain a
fixed distance between the tensioning element and the pipeline, and
the tensioning element may be further configured to permit axial
displacement of the liner clamp with respect to the pipeline as the
tensioning force is applied. In some cases, the one or more
supports are adjustable in length; for example, each of the one or
more supports may include a longitudinal portion maintaining a
fixed distance between the tensioning element and the pipeline and
a radial portion maintaining a fixed distance between the
tensioning element and the longitudinal portion, and the radial
portion may also be adjustable in length to accommodate pipes of
different diameters. According to some embodiments, the tensioning
element is a pneumatic cylinder, or a spring, or a wingnut and
threaded bolt combination, for example. The tensioning element may
also be coupled to the liner clamp by one or more chains which are
adjustable in length.
[0006] Embodiments of methods for maintaining liner tension in
pipeline rehabilitation include deploying a tubular liner along an
inside of a pipeline, coupling the tubular liner with the pipeline
at a front end of the pipeline, coupling the tubular liner with a
liner clamp at a back end of the tubular liner, pulling the liner
clamp away from the pipeline to remove slack in the tubular liner,
and maintaining a tension force between the liner clamp and the
pipeline. Embodiments of such methods may further include coupling
the tensioning element to the pipeline by one or more supports
configured to maintain a fixed distance between the tensioning
element and the pipeline, and the one or more supports may be
adjustable in length. For example, each of the one or more supports
may include a longitudinal portion maintaining a fixed distance
between the tensioning element and the pipeline and a radial
portion maintaining a fixed distance between the tensioning element
and the longitudinal portion, and either or both of the
longitudinal portion and the radial portion may be adjustable in
length. The tension force between the liner clamp and the pipeline
may be maintained with a pneumatic cylinder, a spring, and/or a
wingnut and threaded bolt combination, for example.
[0007] Embodiments of systems for liner tensioning in pipeline
rehabilitation include a liner clamp configured to be coupled to a
tubular liner extending from within a pipeline, a tensioning
element coupled to the liner clamp, the tensioning element
configured to apply a tensioning force between the tensioning
element and the liner clamp while permitting movement of the liner
clamp with respect to the tensioning element, and one or more
braces, the one or more braces coupled to the tensioning element
and configured to be coupled to the pipeline. The one or more
braces may include a longitudinal and/or radial portion, each of
which may be adjustable in length to accommodate pipes of varying
diameters and/or distance needed from the end of the pipe.
[0008] While multiple embodiments are disclosed, still other
embodiments of the present invention will become apparent to those
skilled in the art from the following detailed description, which
shows and describes illustrative embodiments of the invention.
Accordingly, the drawings and detailed description are to be
regarded as illustrative in nature and not restrictive.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 illustrates a side cross sectional view of a front
end system for pipe rehabilitation, according to embodiments of the
present invention.
[0010] FIG. 2 illustrates a side cross sectional view of a front
end system depicting a swab launcher according to embodiments of
the present invention.
[0011] FIG. 3 illustrates a front cross sectional view of a pipe
taken along line A-A of FIG. 1, depicting a pipe liner in a
deflated state for grout deployment, according to embodiments of
the present invention.
[0012] FIG. 4 illustrates a front cross sectional view of a pipe
taken along line A-A of FIG. 1, depicting a pipe liner in a
finished state after affixation of the liner to the pipe, according
to embodiments of the present invention.
[0013] FIG. 5 illustrates a side cross sectional view of a back end
system for pipe rehabilitation, according to embodiments of the
present invention.
[0014] FIG. 6 illustrates a side cross sectional view of a back end
system having a liner tensioning device according to embodiments of
the present invention.
[0015] FIG. 7 illustrates a front elevation view of the back end
system of FIG. 6, according to embodiments of the present
invention.
[0016] FIG. 8 illustrates a method for rehabilitating a pipeline,
such as a water main, according to embodiments of the present
invention.
[0017] FIG. 9 illustrates another method for rehabilitating a
pipeline, such as a water main, according to embodiments of the
present invention.
[0018] FIG. 10 illustrates a method for grout coverage inspection,
according to embodiments of the present invention.
[0019] FIG. 11 illustrates another method for grout coverage
inspection, according to embodiments of the present invention.
[0020] FIG. 12 illustrates a system for grout coverage inspection,
according to embodiments of the present invention.
[0021] FIG. 13 illustrates a camera frame for a system for grout
coverage inspection, according to embodiments of the present
invention.
[0022] FIG. 14 illustrates a linkage between a swab and a camera
frame for a system for grout coverage inspection, according to
embodiments of the present invention.
[0023] FIG. 15 illustrates a side cross sectional view of a front
end system depicting a swab launch box and swab launcher according
to embodiments of the present invention.
[0024] FIG. 16 illustrates a side cross sectional view of a
pipeline and liner with a rounding swab and a back pressure swab,
according to embodiments of the present invention.
[0025] FIG. 17 illustrates a grout injection manifold, swab
launcher, and end plate assembly according to embodiments of the
present invention.
[0026] FIG. 18 illustrates a swab with a plastic wrapper, according
to embodiments of the present invention.
[0027] FIG. 19 illustrates a swab, according to embodiments of the
present invention.
[0028] FIG. 20 illustrates a back pressure device, according to
embodiments of the present invention.
[0029] FIG. 21 illustrates an alternative back pressure device,
according to embodiments of the present invention.
[0030] FIG. 22 illustrates a liner folder, according to embodiments
of the present invention.
[0031] FIG. 23 illustrates an alternative liner folder, according
to embodiments of the present invention.
[0032] FIG. 24 illustrates a top perspective view of a back end
system including a tensioning device, according to embodiments of
the present invention.
[0033] FIG. 25 illustrates an exemplary image from an infrared
camera during grout coverage inspection, according to embodiments
of the present invention.
[0034] FIG. 26 illustrates a catcher bin according to embodiments
of the present invention.
[0035] While the invention is amenable to various modifications and
alternative forms, specific embodiments have been shown by way of
example in the drawings and are described in detail below. The
intention, however, is not to limit the invention to the particular
embodiments described. On the contrary, the invention is intended
to cover all modifications, equivalents, and alternatives falling
within the scope of the invention as defined by the appended
claims.
DETAILED DESCRIPTION
[0036] Embodiments of the present invention relate to improvements
in the rehabilitation of fluid-bearing pipelines such as, for
example, water mains. FIG. 1 illustrates a side cross sectional
view of a front end system for pipe rehabilitation, according to
embodiments of the present invention. According to embodiments of
the present invention, a pipe 100 may be rehabilitated by inserting
a liner 110 therethrough, and cementing the liner 100 to an inside
diameter 103 of pipe 100 with grout. Liner 110 may be, for example,
a liner with grout hooks as described in U.S. Pat. No. 6,167,913,
issued on Jan. 2, 2001, and entitled "Pipe Liner, a Liner Product
and Methods for Forming and Installing the Liner," which is
incorporated by reference herein for all purposes. Liner 110 may be
formed of an extruded medium-density polyethylene material or other
polymer or polymer-like material; for example, liner 110 may be
formed from a sheet of material created by Velcro.RTM. Europe S.A.
According to some embodiments of the present invention, liner 110
conforms to ASTM-D1248: Type 11, Class B, Category 5 standards, and
based upon ISO classifications, may be classified as PE-80 or
PE-100 material. According to some embodiments of the present
invention, liner 110 is substantially resistant to ultraviolet
radiation and is designed for potable water applications.
[0037] According to some embodiments of the present invention,
liner 110 has a tensile strength at breakage of approximately 30
Mpa, an elongation at breakage of approximately 1,100%, a flexural
modulus of approximately 700 Mpa, a hardness of approximately 60
Shore D, a Vicat softening point of approximately 126.degree.
Celsius, a density at twenty-three degrees Celsius of approximately
942 kilograms per cubic meter, a weight of approximately 450
kilograms per square meter (plus or minus fifty grams per square
meter), and a hook concentration of approximately twenty per square
centimeter (plus or minus ten percent).
[0038] As shown in FIG. 4, the sheet of material may then be formed
into a tube shape and welded to itself, to form a tube-shaped liner
110 with grout hooks 406 on an outer surface 404 and a smooth inner
surface 402. The seam (not shown) created by welding the sheet of
material into a tube shape may be located on the inner surface 402
or the outer surface 404; alternatively, the liner 110 may be
formed and/or welded such that a seam neither protrudes from inner
surface 402 nor from outer surface 404.
[0039] Pipe 100 has a front end 101 and a back end 502. Once liner
110 has been placed continuously through pipe 100 from front end
101 to back end 502, liner 110 may be attached to structures at
each end to prevent the liner 110 from slipping back into pipe 100,
and for stretching and/or tensioning liner 110 within pipe 100. For
example, a liner clamp 106 may be used at each end 101, 502 to
secure the liner 110. Liner clamp 106 may include a clamp base 105
having a tubular neck 107 over which liner 110 may be inserted,
according to embodiments of the present invention. Once liner 110
has been inserted over tubular neck 107, cuff 104 may be placed
over liner 110 and tubular neck 107 and bolted or otherwise
connected with clamp base 105 to form a pressure fit with clamp
base 105. Such a configuration squeezes liner 110 between base 105
and cuff 104; according to some embodiments of the present
invention, tubular neck 107 may include an angled portion 109
configured to mate with a similarly-angled portion of cuff 104 to
further emphasize the pressure fit between base 105 and cuff
104.
[0040] Various stages of liner 110 installation may involve the
insertion and removal of objects and/or fluids into liner 110;
liner clamp 106 may facilitate the insertion and/or removal of
objects and/or fluids (e.g. air) from within liner 110, while
minimizing the potential for tearing, crumpling, folding, or
otherwise damaging the ends of liner 110. This quality is further
enhanced by the presence of tubular neck 107 to ease insertion of
objects into liner 110 near front end 101. Similarly, a liner clamp
106 may be used near back end 502 (see FIG. 5, for example).
[0041] According to some embodiments of the present invention,
liner 110 may be folded flat and wound into a spool prior to
deployment through pipe 100. Liner 110 is preferably deployed
within pipe 100 in a fashion which minimizes twisting of liner 110
within pipe 100. One way in which twisting of liner 110 may be
minimized during deployment through pipe 100 constitutes imparting
a V-shape or bend longitudinally in liner 110 as it enters pipe
110. Such V-shape or longitudinal bend (see FIG. 3 for example)
also encourages effective grout coverage of the top portions of the
liner 110. Such a shape may be imparted to liner 110 as liner 110
is inserted into pipe 100 manually, by shaping the liner 110 with
one's hands, or via use of a specially designed frame as depicted
in FIGS. 22 and 23.
[0042] A swab 504 may be used for initial deployment and proper
placement of liner 110. One example of a swab 504 is depicted in
FIG. 5; other examples of swabs 1802, 1901 are depicted in FIGS. 18
and 19. According to embodiments of the present invention, swab 504
is a slightly deformable plug-type device which fills an inside
diameter 103 of pipe 100 and/or inside diameter 402 of liner 110,
thereby applying a radial force to such inside diameter 103 and/or
402. For example, swab 504 may be constructed with a stiff foam,
and may be sized so as to fit within pipe 100 and/or liner 110 only
upon contraction and/or compression of outer diameter 506 of swab
504. Swab 504 may be moved along pipe 100 and/or liner 110 by
applying a force to one side of swab 504; such force may be
applied, for example, by applying an air or water pressure to one
side of swab 504, where swab 504 forms a substantially hermetic
seal with inner diameter 103 and/or inner diameter 402.
[0043] Prior to initial deployment of liner 110 through pipe 100, a
swab 504 may be run through pipe 100 from front end 101 to back end
502. This may be achieved by pumping compressed air into pipe 100
behind swab 504. This may accomplish two results: first, swab 504
can be configured to clean inner diameter 103 in preparation for
the pipeline rehabilitation; second, swab 504 may be attached to a
string, rope, cord, or cable which, once it extends the length of
pipe 100, may be used to pull liner 110 from front end 101 to back
end 502. In addition, once liner 110 has been initially deployed
within length of pipe 100, swab 504 may be run through liner 110 in
order to remove any debris from inside 402 of liner 110 and to
straighten liner 110 within pipe and remove any twisting of liner
110 within pipe 100. A swab 504 may also be referred to as a "pig;"
alternatively, a swab 504 may be used for initial deployment of a
liner 110, while a pig 504 having a different configuration may be
used for the later step of smoothing the liner 110 against the
grout and against inside 103 of pipe 100.
[0044] Prior to attachment of liner 110 to liner clamp 106, a pipe
interface flange 112 may be coupled to front end 101 of pipe 100.
Pipe interface flange 112 may serve to protect front end 101 of
pipe 100 and permit additional hardware to be attached to pipe 100.
A grout injection manifold 102 may then be coupled to pipe 100 via
interface flange 112. Grout injection manifold 102 permits grout to
be injected through grout injection port 114 into the space between
liner 110 and pipe 100 prior to smoothing of the liner 110 against
pipe 100 by swab 504. Once grout injection manifold 102 has been
coupled with interface flange 112, liner 110 may then be clamped
between cuff 104 and base 105 of liner clamp 106, and liner clamp
106 may be coupled with grout injection manifold 102, as
illustrated in FIG. 1 according to embodiments of the present
invention.
[0045] As used herein, the term "coupled" is used in its broadest
sense to refer to elements which are connected, attached, and/or
engaged, either directly or integrally or indirectly via other
elements, and either permanently, temporarily, or removably. For
example, one way in which swab launcher 108 may be coupled to liner
clamp 106 would be to place bolts through corresponding holes in a
flange in swab launcher 108 and in liner clamp 106 and tighten the
bolts. According to some embodiments, the bolts may be tightened
until a hermetic or quasi-hermetic seal is formed. Such a hermetic
seal may also be formed by inserting an O-ring between swab
launcher 108 and liner clamp 106 prior to bolting them together.
Based on the disclosure provided herein, one of ordinary skill in
the art will recognize the various ways in which pipe-like elements
may be coupled together to achieve the pipeline rehabilitation
methods described herein.
[0046] FIG. 2 illustrates a swab launcher 108 according to
embodiments of the present invention. Swab launcher 108 may be
coupled with liner clamp 106. Swab launcher 108 includes a
narrowing portion 202 and a straight portion 204, the straight
portion enclosing a launch chamber 206. Swab launcher 108 is
configured to compress a swab 504 from an outer diameter 506
corresponding to inner diameter 220 of swab launcher 108, to an
outer diameter 506 corresponding to inner diameter 212 near the
back end of swab launcher 108. According to embodiments of the
present invention, swab 504 may be placed into launch chamber 206,
and an end plate 208 may be coupled with swab launcher 108.
Compressed air (or other fluid) may be fed into swab launcher 108
via inlet 210 in order to compress swab 504 into narrowing portion
202 and then "launch" the swab 504 through tubular neck portion 107
and into liner 110.
[0047] According to embodiments of the present invention, an air
pressure of approximately five to seven pounds per square inch sets
swab 504 in motion through swab launcher 108, and an air pressure
of approximately two to three pounds per square inch maintains a
steady motion of swab 504 through liner 110 from front end 101 to
back end 502 after swab 504 has cleared swab launcher 108.
According to some embodiments of the present invention, the air
pressure supplied through inlet 210 does not exceed ten pounds per
square inch. FIG. 17 illustrates a front perspective view of an
assembled grout injection manifold 102, swab launcher 108, and end
plate 208 with fitting 210, according to embodiments of the present
invention.
[0048] According to some embodiments of the present invention, the
length of straight portion 204/launch chamber 206 is twice the
length of narrowing portion 202. According to some embodiments of
the present invention, the inner diameter 220 of launch chamber 206
is substantially equal to the diameter of the pipeline 100 being
rehabilitated for pipelines 100 of approximately 100 mm in diameter
to 300 mm in diameter, while the inner diameter 212 near the front
end the swab launcher 108 is approximately twenty-five millimeters
less than the corresponding launch chamber 206 diameter 220.
According to some embodiments of the present invention, the length
of straight portion 204/launch chamber 206 is approximately equal
to two and one-half times the diameter of the pipe 100 being
rehabilitated.
[0049] FIG. 5 illustrates a back end system for halting the
progression of swab 504. According to some embodiments of the
present invention, swab 504 is permitted to simply exit liner 110
at back end 502; however, in such cases a greater chance of tearing
or damaging liner 110 at back end 502 has been observed, because
swab 504 may have a tendency to exit and/or expand rapidly upon
exiting back end 502 in a manner that may not easily be controlled.
However, according to some embodiments of the present invention, a
back pressure device 508 may be lodged within liner 110 near back
end 502 to halt the advancement of swab 504 within liner 110. Back
pressure device 508 may resemble a swab 504, for example, except
back pressure device 508 includes an inner tube 510 according to
embodiments of the present invention. Inner tube 510 permits air or
other fluid displaced by swab 504 to be pushed through inner tube
510 and out of outlet 522. End plate 524 may resemble end plate 208
of FIG. 2, for example.
[0050] According to some embodiments of the present invention, back
pressure device 508 serves to maintain back pressure between the
liner 110 and pipeline 100 to encourage full grout distribution,
especially at back end 502. Back pressure device may be made from a
soft, two pound density swab through the middle of which runs an
equivalent length of two-inch diameter PVC pipe (which may also be
referred to as a core hole), for example. FIG. 20 depicts a back
pressure device 2001 which includes a foam swab portion 2004, a
core hole pipe 2006, and a handle 2002 to facilitate insertion
and/or removal of back pressure device 2001 into and/or out of
liner clamp 106 at near back end 502, according to embodiments of
the present invention. FIG. 21 depicts a plastic sleeve 2102 which
may also be used as a back pressure device 2102 for insertion
through liner clamp 106 near back end 502, according to embodiments
of the present invention.
[0051] Once front 516 of swab 504 makes contact with back pressure
device 508, swab 504 is halted because the pressure supplied
through inlet 210 is no longer enough to overcome the additional
friction between an outer diameter of back pressure device 208 and
inner diameter 402 of liner 110. Alternatively, back pressure
device 508 may make contact with liner clamp 106, end plate 524, or
other stopping mechanism near back end 502 which may halt or
prevent progression of back pressure device 508 and thus swab 504
according to embodiments of the present invention. According to
some embodiments of the present invention, back pressure device 508
includes a handle 2002 which permits a person, upon removal of end
plate 524, to reach through liner clamp 106 and/or liner 110, and
pull back pressure device 508 out of liner 110. As an additional
alternative embodiment, a plastic cylinder 2102 may be used on the
inside 402 of liner 110 to halt swab 504. According to some
embodiments of the present invention, an outer area 518 of liner
110 between back end 502 and liner clamp 106 may be wrapped with a
felt, or a polyethylene-backed or polyester felt, to further
reinforce liner 110 at an area 518 which may be more susceptible to
tearing during the installation of liner 110. According to some
embodiments, such a felt-based liner interfaces well with grout
hooks 406 on outer surface 404 of liner 110 in a hook-and-loop type
fashion. FIG. 24 depicts a back end system and illustrates how an
anti-split sleeve 2402 (e.g. a felt liner) may be wrapped around
liner 110 to protect the unsupported liner 110 which extends from
back end 502 from damage when the swab 504 emerges from the liner
110, according to embodiments of the present invention.
[0052] An indicator stick 512 may also be employed to visually
indicate when swab 504 has reached its final position near back end
502, according to embodiments of the present invention. Indicator
stick 512 may initially extend through inner tube 510, protruding
from back pressure device 508 on one end 514 and resting within
outlet 522 on another end 520. As swab 504 nears its end position,
front 516 of swab 504 contacts end 514 of indicator stick 512,
pushing end 520 of indicator stick 512 out through outlet 522. Once
the end 520 of indicator stick 512 is seen protruding from outlet
522, it is known that swab 504 has reached its final position. At
such point in time, after swab 504 has traveled the length of pipe
100 and liner 110 has been smoothed against inside 103 of pipe with
the grout therebetween, it is desirable to permit the grout to cure
while liner 110 is in a pressurized state. In order to minimize
pressure loss after swab 504 has reached its final position,
indicator stick 512 may be removed and outlet 522 may be capped
while the grout cures. According to some embodiments of the present
invention, swab 504 and/or back pressure device 508 are left in
place during the grout curing phase. According to other embodiments
of the present invention, swab 504 includes a transmitter and/or
transceiver which permits tracking of the location of the swab 504
from above-ground or from outside of pipe 100 with a paired
receiver and/or transceiver. According to other embodiments of the
present invention, a foot meter may be used to measure the length
of deployment of swab 504 within pipe 100; for example, the cord on
the foot meter may be tied or otherwise attached to the swab 504,
and the foot meter may measure how far the swab 504 travels,
according to embodiments of the present invention.
[0053] FIGS. 6 and 7 depict a liner tensioning device 600 used at
back end 502 of pipe 100 in order to maintain a tension on liner
110 during grout deployment, and/or grout smoothing/installation.
Near front end 101, liner 110 is secured by liner clamp 106 (see
FIG. 1), which holds that end of liner clamp 106 in place on grout
injection manifold 102 while liner 110 near back end 502 is
permitted to move longitudinally with respect to pipe 100. Liner
110 near back end 502 is also secured by another liner clamp 106
(see FIG. 6). According to embodiments of the present invention,
liner tensioning device 600 includes a crossbar 608 coupled (via
chains 606, for example) with liner clamp 106 and coupled also (via
a chain 610, for example) with pneumatic cylinder 612. Pneumatic
cylinder 612 is configured to apply a force toward canister 614
upon application of pressurized air to canister 614, thereby
pulling crossbar 608, liner clamp 106, and thus liner 110 into
tension.
[0054] Liner tensioning device 600 not only holds liner 110 in
tension with respect to the pipe 100, but it also removes slack in
liner 110 which extends from the back end 502. Without such slack
removal and tension, liner 110 would be susceptible to being drawn
into the pipe 100 and pinned, and travel of the swab 504 would
cause the liner 110 to "bunch up" at this point, which may restrict
movement of the swab 504 and/or rip or otherwise damage liner 110.
Liner tensioning device 600 may also include an anti-twist
mechanism; for example, the coupling between chain 610 and crossbar
608 may include a rotating and/or swiveling connection to permit
liner 110 to untwist as it is held in tension, according to
embodiments of the present invention.
[0055] Canister 614 is held in place with respect to pipe 100 via a
coupling with plate 620, which is coupled with radial supports 618,
which are coupled with longitudinal support 602, which are coupled
with an interface flange 112 similar to interface flange 112 of
FIG. 1, which is in turn coupled with pipe 100, according to
embodiments of the present invention. According to embodiments of
the present invention, longitudinal supports 602 are adjustable in
length to accommodate different configurations and lengths of liner
110 and/or other hardware protruding from back end 502. According
to yet other embodiments of the present invention, radial supports
618 are adjustable in length to accommodate pipes 100 of different
diameters; for example, radial supports 618 may be adjustable at
joints 616 by sliding an inner bar into and out of an outer sheath
bar. According to alternative embodiments of the present invention,
devices other than the canister 614/pneumatic cylinder 612 may be
employed to provide the tensioning force; for example, a spring or
other spring-like device, or a screw tensioning device such as a
wingnut on a threaded bolt setup, may be used to maintain tension
on liner 110. FIG. 24 depicts a liner tensioning device having a
wingnut on a threaded bolt setup, according to embodiments of the
present invention. Based on the disclosure provided herein, one of
ordinary skill in the art will recognize the various hardware
configurations that may be used to create tension on liner 110 by
pulling liner clamp 106 in a direction away from pipe 100.
[0056] Once liner 110 has been extended through pipe 100 and
attached to liner clamps 106 at both ends, outlet 522 may be capped
and/or plugged, and a vacuum may be applied to inlet 210. This
vacuum serves to pull the fluid (such as air) out of liner 110,
deflating the liner 110. The liner pulls in on itself, forming a
V-shape or U-shape cross section within pipe 100. According to some
embodiments of the present invention, an air ejector may be
connected to inlet 210 of end plate 208 or inlet 522 of end plate
524, and may be used to draw a partial vacuum inside liner 110,
causing liner 110 to collapse onto itself to form the desired
gutter or trough configuration. The tension on the liner 110 may be
released and/or relieved to permit the collapse of liner 110 during
deflation, and then re-applied for grouting.
[0057] According to some embodiments of the present invention,
instead of a cap or plug, a vacuum gauge may be applied to outlet
522 to indicate when the vacuum has reached back end 502 and
deflated the full length of liner 110. This step of drawing a
vacuum on liner 110 during grout injection has been found to
improve grout coverage around the full circumference of liner 110,
particularly at the uppermost sections of liner 110. This is
because when grout is injected between liner 110 and pipe 100 when
liner 110 is not deflated, the grout may tend to fall to the sides
and bottom of pipe 100 upon injection, leaving a thinner layer of
grout or no grout for the top and uppermost portions of liner 110,
according to embodiments of the present invention.
[0058] However, when a vacuum is applied to liner 110 during grout
injection, the flattened liner 110 tends to assume and/or maintain
a V-shape or U-shape, especially when grout is injected over the
center of liner 110. Such a cross-sectional V-shape may further by
promoted by the way in which the liner 110 is initially deployed
into pipe 100; for example, the liner folders of FIGS. 22 and 23
impart a V-shape to liner 110 during deployment of liner 110 into
pipe 100. The liner 110 thus creates a trough through which grout
may flow into pipe 100, thereby promoting better grout coverage
between upper portions of liner 110 and pipe 100. Such a trough
further hinders the grout from falling to the sides and bottom of
pipe, until swab 504 passes through liner 110, thereby pushing
liner 110 against all sides of pipe 100 and evenly distributing the
grout. According to some embodiments of the present invention, a
vacuum may be applied to the area between liner 110 and pipe 100 to
further promote the flow of grout from front end 101 to back end
502. Such a vacuum may be applied, for example, near back end 502
via outlet 522; according to some embodiments of the present
invention, such a vacuum between liner 110 and pipe 100 may be
applied in addition to or instead of an applied vacuum within liner
110.
[0059] Various grouts and/or cementitious mixtures may be employed
to bond the liner 110 with the pipe 100, according to embodiments
of the present invention. According to some embodiments of the
present invention, a grout manufactured by BASF and produced for
Mainsaver/Water World Holdings may be used, such grout being a
specially formulated cement based grout whose properties include
but are not limited to: zero bleed, extended working time under a
wide range of temperature conditions, integral anodic corrosion
inhibitor, consistency of product formulation and mix, excellent
wetting ability and non-absorbency, good contact angle when
distributing grout, cohesiveness, non-shrink (there may be an
expansion of 0.10% on the dry product, in some cases for example),
optimum rheology and surface tension properties, and no surface
laitance produced, according to embodiments of the present
invention.
[0060] According to some embodiments of the present invention, this
cement grout is specially formulated for pumpability, working time,
corrosion protection, stable volume, absence of bleed, lack of
shrinkage, and consistent mix and cured properties. According to
some embodiments of the present invention, the grout mortar mix
includes one hundred parts cement and twenty-eight parts water.
Based on the disclosure provided herein, one of ordinary skill in
the art will appreciate the varying cement-to-water ratios that may
be used to produce optimum and/or adequate cement grout mixtures,
depending on the type of grout used and other factors. The amount
of grout to be injected may be approximated by determining the
volume between the outer surface 404 of a fully-expanded liner 110
and the inner surface 103 of pipe. Then the result may be
multiplied by a safety factor, such as 2.0 or 1.3, because adding
too much grout may be less expensive than not adding enough grout
and having to redo the installation, according to embodiments of
the present invention.
[0061] Once a vacuum has been applied to inside of liner 110, liner
110 retains a somewhat open configuration as it extends from around
tubular neck 107, then sections of liner 110 further from liner
clamp 106 taper down and into a V-shape configuration, as depicted
in FIG. 1. FIG. 3 depicts liner 110 in a V-shape or U-shape
configuration, as a cross section taken along line A-A of FIG. 1.
Injecting the grout too close to tubular neck 107 and/or liner
clamp 106 may result in the grout flowing around liner 110 and to
the sides and bottom of pipe 100. Therefore, a grout injection
manifold 102 may be used which is long enough to permit injection
of grout through grout injection port 114 over a section of liner
110 which is sufficiently trough-shaped to retain adequate coverage
of grout over the top of liner 110 as the grout is deployed into
pipe 100. In addition to an overhead grout injection port 114,
additional grout injection ports may be used. For example, an
additional grout injection port may be formed within grout
injection manifold 102 directly below grout injection port 114, in
order to inject grout beneath liner 110, according to embodiments
of the present invention. According to embodiments of the present
invention, approximately seventy percent of the grout is pumped
into the trough-shaped portion of liner 110, and approximately
thirty percent of the grout is pumped through a grout injection
manifold below the liner 110.
[0062] Once a sufficient amount of grout has been injected into
pipe 100, the vacuum may be removed from inlet 210, and a swab 504
may be placed into launch chamber 206. Next, air pressure may be
applied to inlet 210 to push swab 504 through swab launcher 108 and
along the length of liner 110 from front end 101 to back end 502,
as described above. This will cause liner 110 and the grout around
liner 110 to assume the configuration depicted in FIG. 4, a cross
section taken along line A-A of FIG. 1 after deployment of swab 504
through liner 110.
[0063] According to some embodiments of the present invention, swab
504 may be wrapped tightly by plastic, and the plastic may have
holes and/or slits formed therein. FIG. 18 depicts a swab 1802
wrapped in plastic 1806 with slits 1808 and a tail 1804, the tail
1804 formed by twisting the plastic 1806, folding the plastic 1806
back onto itself, and taping it in a loop, according to embodiments
of the present invention. Wrapping the swab 1802 in plastic 1806
and forming slits 1808 may permit the "puffing up" of the plastic
1806 surrounding the swab 504, 1802 when fluid pressure is applied
to one end of swab 504, 1802 which in turn may permit more
effective grout smoothing and/or distribution, and/or better
engagement of swab 504, 1802 outer diameter 506 with inside 402 of
liner 110.
[0064] FIG. 19 depicts a foam swab 1901. Swab 1901 may be flexible
and bi-directional, according to embodiments of the present
invention. Swab 1901 may be constructed with two pound polyurethane
foam (with or without nose), and one end of swab 1901 may be coated
with resin to form an impermeable seal, for more effective use of
compressed air to transport the swab 1901, according to embodiments
of the present invention. Swab has a length 1902 and a diameter
1904 which may vary depending on the diameter of the pipe 100 being
rehabilitated. For example, for a rehabilitated pipe of 100 mm
diameter, the length 1902 may be 300 mm and the diameter 1904 may
be 140 mm; for a rehabilitated pipe of 150 mm diameter, the length
1902 may be 400 mm and the diameter 1904 may be 190 mm; for a
rehabilitated pipe of 200 mm diameter, the length 1902 may be 500
mm and the diameter 1904 may be 240 mm; for a rehabilitated pipe of
225 mm diameter, the length 1902 may be 600 mm and the diameter
1904 may be 265 mm; for a rehabilitated pipe of 250 mm diameter,
the length 1902 may be 625 mm and the diameter 1904 may be 310 mm;
and for a rehabilitated pipe of 300 mm diameter, the length 1902
may be 750 mm and the diameter 1904 may be 325 mm, according to
embodiments of the present invention.
[0065] According to some embodiments of the present invention, the
swab 1802 (FIG. 18) may be formed by starting with an
appropriately-sized piece of foam as depicted in FIG. 19, then
piercing the foam axially through the center with a piece of rebar.
The rebar may be left in place, and a length of 0.5 mm to 1.0 mm
linear low density polyethylene ("LLDPE") tube is taped to the
rebar and then pulled through the center of swab 1802 with the
rebar. The LLDPE tube is then cuffed back to completely cover the
swab, and the excess plastic is twisted into a tail 1804, wrapped
in tape, and turned back onto itself to form an eyelet, according
to embodiments of the present invention. Tail 1804 and the eyelet
formed therein may be used for tying or otherwise attaching things
to swab 1802; for example, the foot meter line may be tied onto the
tail 1804 for monitoring the longitudinal position of swab 1802
within pipe 100.
[0066] According to some embodiments of the present invention,
multiple swabs 504 may be deployed through liner 110 after
deployment of grout through pipe 100. According to such
embodiments, the multiple swabs 504 serve to "massage" the grout
between the liner 110 and pipe 100, thereby promoting more
effective grout coverage and lining. According to some embodiments
of the present invention, successive swabs 504 are used with
successively increasing and/or decreasing diameters to interact
with liner 110 and the associated grout in customized ways.
[0067] FIGS. 15 and 26 depict additional hardware that may be used
to launch multiple successive swabs 504, or to launch the same swab
504 multiple times. For example, the catcher bin 2600 of FIG. 26
may be coupled with liner clamp 106 near back end 502 instead of
end plate 524, and may be configured to catch the swab 504 as it is
ejected from the end of liner 110 near back end 502. The back plate
2602 stops the swab 504 as it is ejected from the ejection hole
2604 in the front wall of the catcher bin 2600. The launch box 1502
of FIG. 15 may be coupled with swab launcher 108 in lieu of end
plate 208. Such a launch box 1502 may permit the swab 504 to be
inserted therein through a door 1504 which hinges about hinge point
1506, for example, which closes and/or is held shut by air pressure
(or vacuum pressure), such that the door closes easily while
maintaining the appropriate pressure inside of the launch box 1502
and thus the swab launcher 108. Such a launch box 1502 may permit
fast and easy successive launches of swab 504, for example.
Alternatively, the hinged (and optionally hermetically sealable)
door 1504 may permit easy insertion of swab 504 through an
insertion opening 1508 into the launch box 1502 and thus the swab
launcher 108, according to embodiments of the present invention.
The door 1504 may be biased in a direction indicated by arrow 1512,
such that door 1504 closes itself; for example, such biasing may be
achieved by a spring. Launch box 1502 may also include one or more
apertures 1510 for inserting compressed air and/or cords for
electrical/camera equipment, according to embodiments of the
present invention.
[0068] Embodiments of the present invention have successfully been
used with sections of pipe 100 up to approximately one hundred
meters long; however, it is contemplated that longer sections of
pipe 100 may be rehabilitated according to embodiments of the
present invention. According to such embodiments, an intermediate
grout port may be used at intervals along a pipe 100, to inject
grout at each interval, in order to help ensure adequate and
homogenous grout coverage. Based on the disclosure provided herein,
one of ordinary skill in the art will recognize that various
intermediate grout injection port intervals may be used depending
upon the type of grout used, the diameter and inner surface 103
structure of the pipe 100, the outer surface 104 structure of liner
110, and other factors which determine grout coverage between liner
110 and pipe 100.
[0069] One potential reason for the use of intermediate grout ports
may be the maintenance of adequate back pressure to ensure uniform
grout distribution and coverage, according to embodiments of the
present invention. According to alternative embodiments of the
present invention, longer sections of pipe 100 may be grouted and
lined by using a back pressure device which is pushed directly in
front of swab 504 as swab 504 advances from front end 101 to back
end 502. FIG. 16 illustrates an alternative back-pressure device
1606, according to embodiments of the present invention. Back
pressure device 1606 is a swab 1606 through which a core hole 1608
is formed. The liner 110 is fed through the core hole 1608. As swab
504 is advanced forward in the direction of arrow 1602 by the
application of compressed air into the space 1604 behind swab 504,
swab 504 pushes against liner 110 and thus against swab 1606.
According to some embodiments of the present invention, grout is
present between liner 110 and back pressure swab 1606, such that a
distance between back pressure swab 1606 and swab 504 as they
advance forward in the pipe 100 may depend on the amount of grout
between liner 110 and back pressure swab 1606. Use of back pressure
swab 1606 encourages more uniform distribution of grout by
maintaining a back pressure within the grout coverage area between
liner 110 and pipe 100, and also prevents or hinders the
introduction of air into the grout pocket between the liner 110 and
pipe 100, according to embodiments of the present invention.
[0070] Once the swab 504 has been run through liner 110, it may be
desirable to inspect the degree and adequacy of grout coverage
between liner 110 and pipe 100. According to some embodiments of
the present invention, liner 110 is not transparent, and so using a
traditional visual inspection camera would not be effective for
detecting unwanted air pockets and/or areas of insufficient grout
coverage or gaps between liner 110 and pipe 100. However, due to
the fact that undesired grout coverage gaps absorb heat at a
different rate than the areas between liner 110 and pipe 100 with
full grout coverage, a heat source may be applied to the inside of
liner 110, and an infrared camera may be used to detect differences
in absorbed heat along the liner 110. Detecting such differences in
absorbed heat and/or infrared emissions will identify which areas
of liner 110, if any, lack sufficient grout coverage between liner
110 and pipe 100.
[0071] According to some embodiments of the present invention, an
Aries PE4000 "ThermaView IR" multi-conductor, pan and tilt radial
view, color and IR sewer TV camera may be used for liner 110
inspection. According to embodiments of the present invention, the
infrared camera used is a thermal imaging system operable to form
an image using long wavelength infrared waves emitted by any object
with a temperature above absolute zero. Such a passive imaging
system requires no external light to form an image. Thermography or
remote thermal sensing according to embodiments of the present
invention is a non-contact and non-intrusive temperature
differential measurement technique; high resolution images
containing tens of thousands of different temperature measurements
may be rendered to detect even minute temperature differences and
thus detect unsatisfactory grout distribution. Although the color
visual spectrum camera may not be able to detect defects in grout
coverage, it may optionally be used to detect other
visually-observable defects, such as tears in the liner 110 or
non-conformance of the liner 110 to the inner diameter of pipe 100,
for example. In order to create the heat source within liner 110 to
permit the inspection with an infrared camera, various methods may
be used.
[0072] For example, according to some embodiments of the present
invention, ambient air may be pumped through liner 110, the ambient
air being warmer than liner 110 and pipe 100 and thus conveying
heat through liner 110. According to other embodiments of the
present invention, a space heater or similar device may be used to
heat ambient air at one end of pipe 100 before the air is blown
through liner 110. According to yet other embodiments, compressed
air may be blown through liner 110; due to its higher pressure,
compressed air may also serve to heat liner 110. According to yet
other embodiments of the present invention, a heating coil may be
deployed through liner 110 to heat liner 110; for example, such a
heating coil or heating element may be placed on or near to the
infrared camera, described above. According to yet other
embodiments of the present invention, a light bulb (another form of
heating element) may be used to heat liner 110. After heating of
liner 110, the infrared camera may be deployed through liner 110 to
detect, in 360 degrees according to some embodiments, any heat
differentials which indicate a defect in grout coverage, along with
the shape and location of any such defects.
[0073] According to some embodiments of the present invention, a
heat source may be used which is mounted on or near the infrared
camera itself. For example, according to some embodiments of the
present invention, a high-intensity light source may be coupled
with the back end of the infrared camera. The camera may then be
run within the length of pipe 100 to perform a visual inspection
using a traditional visual spectrum portion of the camera, while at
the same time heating the pipe using the back-mounted
high-intensity light source. Such a visual inspection may involve
the camera moving through pipe 100 at a speed of approximately one
half feet per second, for example. Then, once the camera has run
the length of pipe 100, the high-intensity light source may be
switched off, and the camera may be backed up through the length of
pipe 100, using the infrared portion of the camera to inspect for
defects in grout coverage. Performing the heating steps and the
infrared detection steps during different runs of the camera
through pipe 100 may minimize the chance that the infrared camera
picks up heat signals from the high-intensity light itself, rather
than from the grout and non-grout areas between liner 110 and pipe
100. Such a procedure also permits the full visual and infrared
inspection process to be conducted with a simple "there-and-back"
process.
[0074] According to some alternative embodiments of the present
invention, the camera may be run from one end of the pipe 100 to
another with the heat source turned off for an optional visual
inspection, then the heat source may be turned on and the infrared
camera, which is pointed away from, or in an opposite direction
from, the heat source (such as a high-intensity light source), may
be used to inspect for grout coverage during the return trip of the
camera. According to some embodiments of the present invention, the
infrared inspection occurs during the first trip of the camera
along the length of the pipe 100 and the visual inspection occurs
on the return trip. According to other embodiments of the present
invention, a visual inspection and/or an infrared inspection is
made during the entire there-and-back trip of the camera along pipe
100, and according to some embodiments, no visual inspection is
made with the camera but only an infrared inspection.
[0075] According to some embodiments of the present invention, such
an inspection of liner 110 may occur immediately after or within a
short time after deployment of swab 504 through liner 110, in order
to fix any grout defects before curing of the grout. Such a fix may
be accomplished by, for example, pumping more grout between liner
110 and pipe 100 and re-deploying swab 504 through liner 110 and/or
removing liner 110 and grout and restarting the installation
process. According to some embodiments of the present invention, a
grout may be used which exhibits exothermic or other heat-related
properties which would permit the immediate detection of
abnormalities or defects of grout coverage prior to the curing of
the grout, and without application of an external heat source.
According to other embodiments of the present invention, an
ultrasound-based camera may be employed instead of or in addition
to an infrared-based camera.
[0076] According to some embodiments of the present invention, a
heat transfer is created across liner 110 by cooling the inside of
liner 110 rather than heating it. This alternative may further take
advantage of the grout coverage inspection system of FIGS. 12-14,
by permitting the swab 1202 to be deployed from front end 101 to
back end 502 to distribute the grout while at the same time
propelling the swab 1202 with chilled compressed air to cool the
liner 110, while at the same time using the swab 1202 to tow a
camera frame 1212 including an infrared camera 1308 to inspect
grout coverage during swab 1202 deployment. Such a method of
concurrent swab 1202 deployment and grout inspection permits
immediate feedback even before the grout has hardened, and permits
the installation to be redone and/or repaired if necessary,
according to embodiments of the present invention.
[0077] FIGS. 12-14 illustrate a concurrent grout distribution/grout
coverage inspection system according to embodiments of the present
invention. A swab 1202 is wrapped in plastic and the tail 1204 is
attached to a harness 1210 by swivel clips 1206. The harness 1210
and swivel clips 1206 couple the camera frame 1212 (which has two
or more wheels) with the swab 1202. A coaxial cable, such as an
RG58U coaxial cable, connects to the input/output module 1310 on
the camera frame 1212 at coaxial cable connector 1314. A power
switch 1312 turns the unit on and off. Also mounted to the camera
frame 1212 are infrared camera 1308 having a protective lens cap
1304, as well as one or more protective roll bars 1306 to protect
the electronic components should the camera frame 1212 become
overturned. Infrared camera 1308 according to embodiments of the
present invention may be an infrared camera available from Flir
Systems, Inc., for example. Swivel clips 1206 permit the swab 1202
to twist slightly without overturning the camera frame 1212. A
power connector 1302 and battery pack (not shown) may also be
mounted on the camera frame 1212. A low-loss air fitting 1214 may
be affixed to the end plate 208 or other fitting through which the
coaxial cable 1208 enters the pressurized zone; low-loss air
fitting 1214 permits cable 1208, which connects the electronics of
the camera cart 1212 to external monitoring and/or closed-circuit
television equipment, to be advanced and retracted without causing
significant pressure loss for propulsion of swab 1202, according to
embodiments of the present invention. According to some embodiments
of the present invention, low-loss air fitting 1214 is a one-half
inch brass pipe plug which is through-drilled and chamfered and
threadably connected with end plate 208 or other air manifold.
According to some embodiments of the present invention, a footage
meter line is also attached to camera frame 1212 and/or swab
1202.
[0078] The infrared camera transport cart 1212 consists of a
rectangular aluminum frame with axles and wheels mounted to it;
axle length and wheel diameter can be changed to suit various size
pipe 100 diameters. A platform on the frame supports the camera
1308, power supply (e.g. batteries), input/output module 1310, and
cables, according to embodiments of the present invention. The tow
harness 1210 extends from the frame 1212 to the tail 1204 of the
swab 1202; the coaxial cable 1208 may be looped through the tail
1204 and routed back to the cable connection 1314 on the
input/output module 1310, according to embodiments of the present
invention.
[0079] According to some embodiments of the present invention,
compressed air is routed through a heat exchanger to drop the
temperature to twenty-five to thirty degrees below ambient
temperature. Chilled air may then be introduced into the liner 110
(e.g. via inlet manifold 210), forcing or otherwise advancing the
swab 1202 through the liner 110. As the swab 1202 travels from the
front end 101 to toward the back end 502 through the liner 110, it
pulls the transport cart 1212 and rear-facing infrared camera 1308.
The chilled air cools the thin liner 110 except where liner 110 is
in contact with the relatively warmer grout. Where the liner 110 is
not in contact with the grout, the infrared camera 1308 can detect
the temperature differential between the cool bare liner 110 and
the liner 110 which is in contact with the grout, thereby
indicating the presence of voids or gaps between the liner 110 and
host pipeline 100, according to embodiments of the present
invention. FIG. 25 illustrates an exemplary image produced by
infrared camera 1308, showing the front opening 2504, the inside
2502 of the liner 110, as well as a spot 2506 of inadequate grout
coverage, which shows up in a different shade or color, according
to embodiments of the present invention.
[0080] According to some embodiments of the present invention, the
camera cart 1212 may be releasably coupled with the swab 1202 at
the clips 1206 and/or the harness 1210. According to such
embodiments, an operator may observe the inside of liner 110 as
camera 1308 is transported from front end 101 to back end 502 with
swab 1202, then may send a release signal to cause the camera cart
1212 to be released from the swab 1202 to return through liner 110
to perform additional inspections, all without compromising the
internal pressurization of liner 110, according to embodiments of
the present invention.
[0081] According to yet other embodiments of the present invention,
a direct attachment of the camera 1308 to the swab 1202 may be
achieved by inserting the camera 1308 into the back of the swab
1202 by means of creating a pocket in the swab 1202 or creating an
attachable holder. Such a method would eliminate the use of a
wheeled cart or skid towed behind the swab 1202, according to
embodiments of the present invention. It may also minimize any
contact between the camera 1308 and soft grout, thereby deterring
formation of unwanted tracks or deformation in the grout prior to
cure.
[0082] FIG. 8 depicts a flow diagram 800 illustrating a method for
pipeline rehabilitation, according to embodiments of the present
invention. An inside of the pipe 100 may be swabbed to clean the
inside or remove debris, and a guide rope may be deployed within
the length of pipe 100 (block 802). Using the guide rope, the liner
110 may be deployed within the length of pipe by, for example,
tying the guide rope to one end of the liner 110 and pulling the
liner 110 through the pipe 100 (block 804). As liner 110 is
deployed within the pipe 100, liner 110 may be folded by a folding
device such as, for example, the folding devices depicted in FIGS.
22 and 23. The twisting of liner 110 should be avoided as it
travels through pipe 100, and liner 110 should be inspected near
back end 502 for any damage. The liner 110 may also be held closed
near back end 502 and inflated with compressed air to confirm tube
integrity, according to embodiments of the present invention. Liner
clamps 106 may be coupled to the liner 110, and a tensioning device
600 installed at the back end 502 (block 806).
[0083] A swab 504 may be deployed through the liner 110 by, for
example, injecting compressed air behind swab 504, to straighten
liner 110 and/or remove any twists (block 808). A vacuum or partial
vacuum may be applied to the liner 110 to restore and/or encourage
the liner 110 to assume a substantially trough-shaped cross section
(block 810). When the liner 110 has assumed a trough-shape, grout
may be injected between the liner 110 and the pipe 100 (block 812).
The swab 504 may again be deployed through liner 110 from front end
101 toward back end 502 to round the liner 110 and evenly
distribute the grout between liner 110 and pipe 100 (block 814).
Finally, grout coverage may be inspected for defects using an
infrared camera as described above, either before or after the
grout hardens (block 816). Air pressure may be maintained within
the liner 110 until the cement hydrates, which, according to some
embodiments of the present invention, occurs after approximately
sixteen hours. Once the cement mortar (e.g. grout) has hardened,
the liner 110 becomes self-supporting, according to embodiments of
the present invention.
[0084] FIG. 9 depicts a flow diagram 900 illustrating another
method for pipeline rehabilitation, according to embodiments of the
present invention. An inside of the pipe 100 may be swabbed to
clean the inside or remove debris, and a guide rope may be deployed
within the length of pipe 100 (block 9802). Using the guide rope,
the liner 110 may be deployed within the length of pipe by, for
example, tying the guide rope to one end of the liner 110 and
pulling the liner 110 through the pipe 100 (block 904). As liner
110 is deployed within the pipe 100, liner 110 may be folded by a
folding device such as, for example, the folding devices depicted
in FIGS. 22 and 23. Liner clamps 106 may be coupled to the liner
110, and a tensioning device 600 installed at the back end 502
(block 906).
[0085] A swab 504 may be deployed through the liner 110 by, for
example, injecting compressed air behind swab 504, to straighten
liner 110 and/or remove any twists (block 908). A back pressure
swab 1606 may be inserted into the front end 101 of the pipe 100
(block 910), and the liner 110 may be fed or otherwise placed
through hole 1608 in back pressure swab 1606 (block 912), according
to embodiments of the present invention. Optionally, a vacuum or
partial vacuum may be applied to the liner 110 to restore and/or
encourage the liner 110 to assume a substantially trough-shaped
cross section. Grout may be injected between the liner 110 and the
pipe 100 (block 914). The swab 504 may again be deployed through
liner 110 from front end 101 toward back end 502 to round the liner
110 and evenly distribute the grout between liner 110 and pipe 100,
and also to advance the back pressure swab 1606 ahead of swab 504
to maintain back pressure between liner 110 and pipe 100 to ensure
more even grout coverage (block 916). Finally, grout coverage may
be inspected for defects using an infrared camera as described
above, either before or after the grout hardens (block 918).
[0086] FIG. 10 depicts a flow chart 1000 illustrating a method for
pipeline installation grout coverage inspection, according to
embodiments of the present invention. A liner 110 is installed
within a pipeline 100 with grout between the liner 110 and pipeline
100 (block 1002). A heat transfer is created across the liner
(block 1004), which, as described above, may be accomplished by
heating or cooling the inside of the liner 110, according to
embodiments of the present invention. The liner 110 may be observed
from the inside with an infrared camera 1308 to detect grout
coverage by detecting a temperature differential between the areas
of liner 110 in contact with the grout and the areas of liner 110
not in contact with the grout (block 1006), because the heat
transfer across the liner 110 occurs differently for areas of liner
110 in contact with the grout and areas of liner 110 not in contact
with the grout, according to embodiments of the present
invention.
[0087] FIG. 11 depicts a flow chart 1100 illustrating a method for
simultaneous swab 1202 advancement/grout smoothing and grout
coverage inspection, according to embodiments of the present
invention. A liner 110 is installed within a pipeline 100 with
grout between the liner 110 and pipeline 100 (block 1102). An
infrared camera 1308 is mounted on a camera frame 1212 (block
1104), and the camera frame 1212 is coupled to a swab 1202 (block
1106). Compressed air is chilled and the chilled compressed air is
injected into liner 110 behind swab 1202 to simultaneously advance
the swab 1202 through liner 110 and cool the liner 110 (block
1108). As the swab 1202 pulls the infrared camera 1308 through
liner 110, camera 1308 observes liner 110 from the inside to detect
grout coverage by detecting a temperature differential between the
areas of liner 110 in contact with the grout and the areas of liner
110 not in contact with the grout (block 1110), according to
embodiments of the present invention. Based on the disclosure
provided herein, one of ordinary skill in the art will recognize
that various steps may be performed in different orders, and that
less than or more than all of the described steps may be used in a
particular method, according to embodiments of the present
invention.
[0088] Various modifications and additions can be made to the
exemplary embodiments discussed without departing from the scope of
the present invention. For example, while the embodiments described
above refer to particular features, the scope of this invention
also includes embodiments having different combinations of features
and embodiments that do not include all of the described features.
Accordingly, the scope of the present invention is intended to
embrace all such alternatives, modifications, and variations as
fall within the scope of the claims, together with all equivalents
thereof.
* * * * *