U.S. patent application number 16/246392 was filed with the patent office on 2019-05-23 for nondestructive pipe refurbishment using liner pipe sections.
The applicant listed for this patent is Titan CMP Solutions LLC. Invention is credited to Roger W. Thompson.
Application Number | 20190154184 16/246392 |
Document ID | / |
Family ID | 63519091 |
Filed Date | 2019-05-23 |
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United States Patent
Application |
20190154184 |
Kind Code |
A1 |
Thompson; Roger W. |
May 23, 2019 |
NONDESTRUCTIVE PIPE REFURBISHMENT USING LINER PIPE SECTIONS
Abstract
Techniques for refurbishing an existing host pipe, useful in
deployments in confined spaces or providing limited access to the
host pipe. In currently preferred embodiments, a plurality of
cartridges each include (1) a liner pipe section, (2) at least one
rod and (3) at least one centering ball, wherein each rod and
centering ball is received inside its corresponding liner pipe
section such that each rod is stabilized within its corresponding
liner pipe section via contact between at least one centering ball
and the liner pipe section. Once the first cartridge is inserted
into the host pipe, a second cartridge is concatenated to the first
by connection of their respective rods and liner pipe sections. The
second cartridge is inserted into the host pipe, and so on. Upon
completion, the rods and centering balls may be withdrawn from the
concatenated string of liner pipe sections.
Inventors: |
Thompson; Roger W.; (Boise,
ID) |
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Applicant: |
Name |
City |
State |
Country |
Type |
Titan CMP Solutions LLC |
Boise |
ID |
US |
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Family ID: |
63519091 |
Appl. No.: |
16/246392 |
Filed: |
January 11, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15922407 |
Mar 15, 2018 |
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16246392 |
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62471389 |
Mar 15, 2017 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F16L 55/1658 20130101;
F16L 55/1657 20130101; F16L 55/18 20130101; F16L 2101/12 20130101;
F16L 55/163 20130101; E03F 2003/065 20130101; F16L 55/44
20130101 |
International
Class: |
F16L 55/18 20060101
F16L055/18; F16L 55/165 20060101 F16L055/165; F16L 55/44 20060101
F16L055/44; F16L 55/163 20060101 F16L055/163 |
Claims
1. A method for refurbishing an existing pipe, the method
comprising the steps of: (a) providing an existing host pipe; (b)
inserting a concatenated string of liner pipe sections inside the
host pipe, step (b) further including: (b1) providing a plurality
of cartridges, at least one cartridge including (1) a liner pipe
section, (2) at least one rod and (3) at least one centering ball,
wherein each rod and centering ball is received inside the liner
pipe section such that each rod is stabilized within the liner pipe
section via contact between at least one centering ball and the
liner pipe section; (b2) inserting a first cartridge into the host
pipe; (b3) concatenating at least one rod in the first cartridge to
at least one rod in the second cartridge; (b4) concatenating the
liner pipe section on the first cartridge to the liner pipe section
on the second cartridge; and (b5) inserting the second cartridge
into the host pipe; and (c) withdrawing the rods and centering
balls from within the concatenated string of liner pipe
sections.
2. The method of claim 1, in which concatenating the liner pipe
section on the first cartridge to the liner pipe section on the
second cartridge is accomplished by making a threaded connection
therebetween.
3. The method of claim 1, further comprising, prior to step (b),
the steps of: (aa) providing an expander, the expander having a
longitudinal expander axis, the expander adapted to generate
outward radial force perpendicular to the longitudinal expander
axis when the expander is actuated to expand; (ab) moving the
expander along a path inside the host pipe, the path having
stations at which the expander stops; (ac) expanding the host pipe
during step (ab), step (ac) further including, at each station:
(ac1) stopping the expander; (ac2) responsive to outward radial
force from the expander, increasing an interior diameter of the
host pipe; and (ac3) moving the expander to the next station.
4. The method of claim 3, in which step (ab) further comprises
concatenating a plurality of capsules into a string thereof,
wherein the string of capsules is inserted into the host pipe to
follow the expander as it moves along said path inside the host
pipe.
5. The method of claim 1, further comprising, prior to step (b),
the steps of: (aa) providing an expander, the expander having a
longitudinal expander axis, the expander adapted to generate
outward radial force perpendicular to the longitudinal expander
axis when the expander is actuated to expand; (ab) moving the
expander along a path inside the host pipe, the path having
stations at which the expander stops; (ac) expanding the host pipe
during step (ab), step (ac) further including, at each station:
(ac1) stopping the expander; (ac2) responsive to outward radial
force from the expander, increasing an interior diameter of the
host pipe; (ac3) rotating the expander about the longitudinal
expander axis; (ac4) repeating step (ac2); and (ac5) moving the
expander to the next station.
6. The method of claim 1, further comprising, prior to step (b),
the step of making a longitudinal cut in the host pipe.
7. The method of claim 6, further comprising inserting at least one
capsule into the host pipe as the longitudinal cut is made.
8. The method of claim 1, in which the first cartridge has a
leading end and a trailing end when inserted into the host pipe,
and in which a steel head is connected to the leading end of the
first cartridge via connection of at least one rod in the first
cartridge to the steel head.
9. The method of claim 8, in which the liner pipe section on the
first cartridge is also connected to the steel head.
10. The method of claim 8, in which the steel head includes a
vibrator, and in which step (b) further includes vibrating the
steel head during insertion.
11. The method of claim 8, in which the steel head includes an
impact hammer, and in which step (b) further includes jolting the
steel head during insertion.
12. A method for refurbishing an existing pipe, the method
comprising the steps of: (a) providing an existing host pipe; (b)
making a longitudinal cut in the host pipe; (c) providing an
expander, the expander having a longitudinal expander axis, the
expander adapted to generate outward radial force perpendicular to
the longitudinal expander axis when the expander is actuated to
expand; (d) moving the expander along a path inside the host pipe,
the path having stations at which the expander stops; (e) expanding
the host pipe during step (d), step (e) further including, at each
station: (e1) stopping the expander; (e2) responsive to outward
radial force from the expander, increasing an interior diameter of
the host pipe; and (e3) moving the expander to the next station;
(f) inserting a concatenated string of liner pipe sections inside
the host pipe, step (f) further including: (f1) providing a
plurality of cartridges, at least one cartridge including (1) a
liner pipe section, (2) at least one rod and (3) at least one
centering ball, wherein each rod and centering ball is received
inside the liner pipe section such that each rod is stabilized
within the liner pipe section via contact between at least one
centering ball and the liner pipe section; (f2) inserting a first
cartridge into the host pipe, wherein the first cartridge has a
leading end and a trailing end when inserted into the host pipe,
and in which a steel head is connected to the leading end of the
first cartridge via connection of at least one rod in the first
cartridge and the liner pipe section on the first cartridge to the
steel head; (f3) concatenating at least one rod in the first
cartridge to at least one rod in the second cartridge; (f4)
concatenating the liner pipe section on the first cartridge to the
liner pipe section on the second cartridge; and (f5) inserting the
second cartridge into the host pipe; and (g) withdrawing the rods
and centering balls from within the concatenated string of liner
pipe sections.
13. The method of claim 12, in which step (d) further comprises
concatenating a plurality of capsules into a string thereof,
wherein the string of capsules is inserted into the host pipe to
follow the expander as it moves along said path inside the host
pipe.
14. A method for refurbishing an existing pipe, the method
comprising the steps of: (a) providing an existing host pipe; (b)
inserting a concatenated string of liner pipe sections inside the
host pipe, step (b) further including: (b1) providing a plurality
of cartridges including at least first and second cartridges,
wherein at least the first and second cartridges each include (1) a
liner pipe section, (2) at least one rod and (3) at least one
centering ball, wherein each rod and centering ball is received
inside its corresponding liner pipe section such that each rod is
stabilized within its corresponding liner pipe section via contact
between at least one centering ball and the liner pipe section;
(b2) connecting a steel head to at least one rod within the first
cartridge at a leading end of the first cartridge; (b3) connecting
the steel head to the liner pipe section on the first cartridge;
(b4) inserting the steel head as attached to the first cartridge
into the host pipe; (b5) concatenating at least one rod in the
first cartridge at a trailing end of the first cartridge to at
least one rod in the second cartridge; (b6) concatenating the liner
pipe section on the first cartridge to the liner pipe section on
the second cartridge; and (b7) inserting the second cartridge into
the host pipe; (b8) separating the steel head from first cartridge;
and (c) withdrawing the rods and centering balls from within the
concatenated string of liner pipe sections.
15. The method of claim 14, in which the steel head includes a
vibrator, and in which step (b) further includes vibrating the
steel head during insertion.
16. The method of claim 14, in which the steel head includes an
impact hammer, and in which step (b) further includes jolting the
steel head during insertion.
17. The method of claim 14, further comprising, prior to step (b),
the step of making a longitudinal cut in the host pipe.
18. The method of claim 17, further comprising inserting at least
one capsule into the host pipe as the longitudinal cut is made.
19. The method of claim 14, further comprising, prior to step (b),
the steps of: (aa) providing an expander, the expander having a
longitudinal expander axis, the expander adapted to generate
outward radial force perpendicular to the longitudinal expander
axis when the expander is actuated to expand; (ab) moving the
expander along a path inside the host pipe, the path having
stations at which the expander stops; (ac) expanding the host pipe
during step (ab), step (ac) further including, at each station:
(ac1) stopping the expander; (ac2) responsive to outward radial
force from the expander, increasing an interior diameter of the
host pipe; and (ac3) moving the expander to the next station.
20. The method of claim 19, in which step (ab) further comprises
concatenating a plurality of capsules into a string thereof,
wherein the string of capsules is inserted into the host pipe to
follow the expander as it moves along said path inside the host
pipe.
Description
PRIORITY CLAIM AND RELATED APPLICATIONS
[0001] This application is a continuation of co-pending,
commonly-invented, commonly-assigned U.S. nonprovisional patent
application Ser. No. 15/922,407, filed Mar. 15, 2018, which in turn
claims priority to and the benefit of now-expired,
commonly-invented, commonly-assigned U.S. provisional patent
application Ser. No. 62/471,389 filed Mar. 15, 2017. This
application claims priority to, and the benefit of, Ser. No.
15,922,407 and Ser. No. 62/471,389, and incorporates the entire
disclosures of Ser. Nos. 15,922,407 and 62/471,389 herein by
reference. This application is further related to commonly-invented
and commonly-assigned U.S. patent application Ser. No. 14/732,565
filed Jun. 5, 2015 (hereafter, the "Prior Application"), now U.S.
Pat. No. 9,175,798 issued Nov. 3, 2015. The entire disclosure of
the Prior Application is also incorporated herein by reference as
if fully set forth herein.
FIELD OF THE DISCLOSURE
[0002] This disclosure is directed generally to a method for
refurbishing buried expandable pipes without open cut replacement
(i.e., without digging the pipe out of the ground), where such
pipes are located in confined spaces, such as under roads in
mountain passes with steep inclines on one side and open waterways
nearby on the other side.
BACKGROUND
[0003] The term "expandable" is used as a defined term of art
throughout this disclosure. By "expandable", this disclosure refers
to culverts and pipes that, when cut longitudinally in situ
underground, may then be radially expanded, preferably
nondestructively, by separation and widening of the longitudinal
cut, so that the expanded pipe (or expanded "host" pipe as
sometimes referred to herein) may then receive a new inner liner
pipe whose internal diameter is at least the same as, if not larger
than, the internal diameter of the original unrefurbished host
pipe. It is expected that many culverts or pipes falling within
this definition will be metal, and will be corrugated or
"accordion" in profile. However, the term is not limited to
corrugated or accordion profiles on metal pipes or culverts.
[0004] The Prior Application, incorporated herein by reference,
discloses a trenchless technology, now patented, for
nondestructively refurbishing underground pipes. Generally
speaking, the Prior Application describes embodiments in which a
longitudinal cut is initially made in the host pipe. In some
embodiments disclosed in the Prior Application, the host pipe is
then radially expanded, preferably nondestructively, by separation
and widening of the longitudinal cut. A new liner pipe is then
inserted into the expanded host pipe. Preferably, the internal
diameter of the liner pipe is at least the same as, if not larger
than, the internal diameter of the original unrefurbished host
pipe. Grout may then be injected into the annular space between the
liner pipe and the host pipe.
[0005] The Prior Application further describes some of the problems
that its disclosed technology solves, and some of the technical
advantages enabled in solving such problems. While embodiments of
the Prior Application have been shown to be highly serviceable, and
indeed highly advantageous, improvements have been identified in
deployments where the host pipe is located, for example, under
roads in mountain passes with steep inclines on one side and open
waterways nearby on the other side. Such locations may often
present additional access challenges in deploying the embodiments
of the Prior Application. As is shown on FIG. 1, host pipe H is
buried beneath road R with steep incline SI on one side and
waterway W on the other side. In the exemplary environment
illustrated on FIG. 1, access to host pipe H on the waterway W side
is from above only. Access to host pipe H on the other side is very
limited by steep incline SI. It will be appreciated that, for
example, the location of host pipe H presents challenges to
installing a new liner pipe inside host pipe H if the liner pipe is
approximately the same length as host pipe H. There is not enough
room on the steep incline SI side to insert a full-length liner
into the host pipe H from the incline side, and waterway W prevents
practical insertion of a full-length liner into host pipe H from
the water side.
[0006] Conventional prior art solutions to the above-described
access challenges present additional problems. For example, a
"cured in place" or "CIPP" method is known, in which a collapsible
liner, or "sock" is unrolled into host pipe H and then expanded
with steam and cured onto the inside of host pipe H. Such CIPP
solutions lack the structural integrity of a rigid liner pipe
solution, and their robustness against cracking and leaking in
service is not as good as a rigid liner pipe solution.
SUMMARY OF DISCLOSED TECHNOLOGY AND TECHNICAL ADVANTAGES
[0007] This disclosure describes enhanced embodiments of the
trenchless underground pipe refurbishment technology described in
the Prior Application. Embodiments of methods and apparatus
described in this disclosure solve the problem of inserting a liner
pipe into the host pipe in deployments where physical space
limitations make insertion of a full-length liner pipe impractical,
if not impossible. According to the embodiments described in this
disclosure, a confined space insertion tool (hereafter, a "pusher
box") enables the new inner liner pipe to be inserted into the host
pipe in concatenated sections.
[0008] Functionally, the pusher box manipulates rods of
pre-determined length into and out of the host pipe once the pusher
box has been positioned, leveled and stabilized at one end of the
host pipe. Functions performed by the pusher box on the rods
include inserting and retracting the rods from the host pipe,
rotating a rod string, and raising/lowering a rod string with
respect to the host pipe. With particular reference to inserting
and retracting, the pusher box inserts rods in a concatenated
string. Once the pusher box has inserted one rod into the pipe, the
next rod is concatenated to the trailing end of the
previously-inserted rod before being pushed in, and so on.
Retraction of the concatenated rod string is the reverse operation.
The pusher box pulls the rod string out so that the rods can be
removed from the string one at a time. A rod is disconnected from
the retracted string as it emerges, allowing the next rod in the
string to be retracted.
[0009] The rods may preferably be used first in the host pipe
cutting phase, in which a longitudinal cut is made in the host pipe
to facilitate nondestructive expansion of the host pipe via
separation of the cut. Some embodiments may use a self-propelled
cutting tool such as described in the Prior Application. Other
embodiments may use a cutting tool that is pushed into and
retracted from the host pipe using rods and the pusher box as
described below. In some embodiments, the cutting tool may be
"pushed while cutting" by inserting rods into a concatenated rod
string. In other embodiments (such as illustrated in this
disclosure), the cutting tool may be "pulled while cutting" by
retracting and removing rods from the string once the cutting tool
has been positioned at the far end of the host pipe by rod
insertion. However, this disclosure is not limited to any
particular design of cutting tool or direction in which the cut is
made using the rods in a rod string.
[0010] After the host pipe is cut, the rods may then preferably be
used again, this time in conjunction with a pipe expansion tool in
the host pipe expansion phase. Preferred embodiments include a host
pipe expansion phase, although the scope of the disclosed
technology is not limited in this regard. Preferred embodiments may
use a pipe expansion tool such as is described in the Prior
Application, or a lighter, smaller expansion tool as described in
this disclosure. However, this disclosure is not limited to any
particular design of expansion tool. As will be described in
greater detail below, the pusher box may insert and retract a rod
string connected to the pipe expansion tool, which allows the
operators to stop the expansion tool at desired stations along the
length of the host pipe interior in order to expand the host pipe
at those stations. Additionally, the pusher box may rotate the rod
string while the pipe expansion tool is attached at a remote end.
As a result, the pipe expansion tool may also be rotated in a
controlled way at each host pipe expansion station, allowing for
uniform radial expansion of the host pipe at each station. Also, as
with the disclosure regarding the cutting tool immediately above,
embodiments may use a "push and expand" technique on the pipe
expansion tool (in which rods are inserted into the concatenated
rod string), while alternative embodiments may use a "pull and
expand" technique (in which the rods are retracted and removed from
the rod string once the pipe expansion tool has been positioned at
the far end of the host pipe via rod insertion). This disclosure is
not limited to any particular design of pipe expansion tool or
direction in which host pipe is expanded using the rods in a rod
string.
[0011] Note also that not all embodiments of an expansion phase
require a cutting phase. The scope of this disclosure includes some
embodiments (not described herein in detail) in which expansion is
sufficient to "smooth out" the wavy profile of a corrugated host
pipe. Embodiments for expanding a host pipe in this fashion are
described in the Prior Application, incorporated by reference
herein. Once expansion of a host pipe is complete in these
"non-cut" embodiments, a liner pipe may be inserted into the host
pipe in sections, consistent with the liner pipe insertion phase
described below in this disclosure.
[0012] Once the expansion phase is complete, the pusher box, in
conjunction with the rods, then enables the liner pipe to be
inserted into the expanded host pipe in sections. Preferably, each
liner pipe section is approximately the same length as one of the
rods. Away from the pusher box, a rod is inserted into a liner pipe
section, and is centered and frictionally stabilized within the
liner pipe section with wireframe centering balls that are attached
to the rod along the rod's length. The wireframe centering balls
are sized and shaped to frictionally engage the internal surface of
the liner pipe so that the liner pipe section may be inserted into
the host pipe along with the rod. Advantageously, the liner pipe
sections arrive at the pusher box in "cartridge" form, with a
length of liner pipe already made up with the rods and wireframe
centering balls pre-deployed inside. The cartridges may be of any
length suitable for the application, but are preferably selected
from within a range from about 3 feet to about 7 feet in
length.
[0013] Currently preferred embodiments of the liner pipe itself are
a rigid liner pipe. More preferably, the liner pipe comprises
galvanized corrugated metal pipe ("CMP"), although the scope of
this disclosure is not limited in this regard. Examples of other
suitable rigid liner pipe constructions include, without
limitation, galvanized metal, aluminized steel, or asphalt coated
steel pipe (corrugated or plain), or plastic, ceramic or a fiber
reinforced resin compound pipe (corrugated or plain).
[0014] The pusher box inserts the liner pipe sections one by one
into the host pipe. As noted, the liner pipe sections are inserted
by the rods. As with the host pipe expansion phase, the pusher box
inserts rods (this time with liner pipe sections attached) in a
concatenated string. Once the pusher box has completed insertion of
one rod into the pipe, the next rod is concatenated to the trailing
end of the previously-inserted rod before being pushed in. Each
successive liner pipe section is also concatenated to the trailing
end of the previously-inserted liner pipe section before insertion
by its corresponding rod.
[0015] The leading ends of the first rod and the first liner pipe
section in the string are preferably attached to a conically-shaped
steel head, such that the steel head leads the entire string of
rods into the host pipe with concatenated liner pipe sections
attached to the steel head. The steel head, with its dead weight
and conical shape, assists the pusher box with smooth insertion of
the entire concatenated string of rods/liner pipe sections into the
host pipe. In particular, the steel head protects the leading edge
of the first liner pipe section from snagging against corrugations
and minor peripheral obstructions in the interior of the host pipe.
Embodiments herein of the steel head also advantageously provide a
vibrator that vibrates the steel head and the first rods/liner pipe
sections in the string against the host pipe interior as they are
inserted into the host pipe. Alternatively, steel head embodiments
may provide an impact hammer on board to generate a jolting force.
This vibration or jolting further assists the pusher box with
smooth insertion of the entire concatenated string of rods/liner
pipe sections into the host pipe. It will thus be appreciated that
in preferred embodiments deploying an attached steel head, the
pusher box is effectively pushing the steel head into the host pipe
via the rods, and the liner pipe sections are being "dragged along
for the ride". That is, compressive force from the pusher box
pushes the steel head further into the host pipe via thrust through
successive concatenated rods. As the steel head moves further into
the pipe, the steel head drags the attached concatenated liner pipe
sections behind it, even though the liner pipe sections are also
disposed about the rods via friction connection through the
wireframe centering balls. The concatenated liner pipe sections are
thus subjected to a tensile force as they are dragged into the host
pipe, rather than to a compressive force from a "push" into the
host pipe via the rods. In this way, the liner pipe sections are in
lower jeopardy of buckling or collapsing compressively in response
to the "push" force on the rods from the pusher box.
[0016] Once all of the liner pipe sections have been inserted into
the host pipe by the pusher box, and the steel head has emerged
from the host pipe at the far end, the steel head may be
disconnected from the rod string and the concatenated liner pipe
sections, and then removed from the host pipe at the far end. The
pusher box then retracts the rod string, with the wireframe
centering balls attached. The pusher box pulls the rod string out
so that the rods can be removed from the string one at a time. A
rod is disconnected from the retracted string as it emerges,
allowing the next rod in the string to be retracted, and so on. In
some embodiments, a combination of the dead weight of the entire
liner pipe as now deployed in the host pipe, plus the frictional
resistance of the entire length of liner pipe against the host pipe
interior, is sufficient to hold the liner pipe in place while the
rod string is retracted from the liner pipe with wireframe
centering balls attached. In other embodiments, it may be
preferable to initially disconnect only the rod string from the
steel head, and leave the liner pipe temporarily connected to the
steel head. In such embodiments, the dead weight and frictional
resistance of the liner pipe as attached to the steel head at the
far end of the host pipe will enable the rod string, with wireframe
centering balls attached, to be retracted from the liner pipe
without dislodging the liner pipe from within the host pipe. Once
the rods and wireframe centering balls are completely retracted,
the liner pipe may then be disconnected from the steel head at the
far end of the host pipe. The steel head may be taken away, leaving
the liner pipe in place in the host pipe.
[0017] Once the rod string is removed entirely from the host pipe,
the annular space between the host pipe and liner pipe may be
injected with grout. Alternatively, grouting may be done before the
rod string is removed to provide yet further immobilization of the
liner pipe during retraction of the rods and wireframe centering
balls.
[0018] It should be noted that use of the wireframe centering balls
in this disclosure is not limited to the above-described process of
inserting a liner pipe in the host pipe. Although not specifically
illustrated and described below, the scope of this disclosure
includes optionally including the wireframe balls as centering
devices on the rod string during host pipe cutting and expansion
phases. Throughout the disclosed pipe refurbishment process, the
centering function of the wireframe balls provides several
advantages, including:
[0019] (a) Stabilizing the rods inside the liner pipe during
insertion. As will be described below, in preferred embodiments the
compression "push" delivered by the pusher box to insert the liner
pipe into the host pipe may be up to 85,000 lbs. The wireframe
centering balls stabilize the rod string to minimize lateral
deflection of the rods under such a push load.
[0020] (b) Centralizing the compression force during liner pipe
insertion. As noted above, the compression force is preferably
focused through to the steel head at the leading end of the liner
pipe as it is inserted into the host pipe. The steel head then
pulls the liner pipe into the host pipe.
[0021] (c) When used in the cutting phase, centralizing the path of
the cutting tool during the host pipe cutting phase, thereby
encouraging a true longitudinal cut.
[0022] (d) When used in the expansion phase, centralizing the path
of the pipe expansion tool during the host pipe expansion phase,
thereby encouraging controlled rotation and uniform expansion at
each station.
[0023] According to a first aspect, therefore, embodiments of the
disclosed technology provide a method for refurbishing an existing
pipe, the method comprising the steps of: (a) providing an existing
host pipe; (b) inserting a concatenated string of liner pipe
sections inside the host pipe, step (b) further including: (b1)
providing a plurality of cartridges, each cartridge including (1) a
liner pipe section, (2) at least one rod and (3) at least one
centering ball, wherein each rod and centering ball is received
inside the liner pipe section such that each rod is stabilized
within the liner pipe section via frictional contact between each
centering ball and the liner pipe section; (b2) inserting a first
cartridge into the host pipe; (b3) concatenating the at least one
rod in the first cartridge to the at least one rod in the second
cartridge; (b4) concatenating the liner pipe section on the first
cartridge to the liner pipe section on the second cartridge; and
(b5) inserting the second cartridge into the host pipe; and (c)
withdrawing the rods and centering balls from within the
concatenated string of liner pipe sections.
[0024] In other embodiments, concatenating the liner pipe section
on the first cartridge to the liner pipe section on the second
cartridge is accomplished by a connection technique selected from
the group consisting of: (a) clamping; (b) bolting; (c) riveting;
(d) gluing with adhesive; and (e) welding.
[0025] In other embodiments, concatenating the liner pipe section
on the first cartridge to the liner pipe section on the second
cartridge is accomplished by making a threaded connection
therebetween.
[0026] In other embodiments, the method may comprise, prior to step
(b), the steps of: (aa) providing an expander, the expander having
a longitudinal expander axis, the expander adapted to generate
outward radial force perpendicular to the longitudinal expander
axis when the expander is actuated to expand; (ab) moving the
expander along a path inside the host pipe, the path having
stations at which the expander stops; (ac) expanding the host pipe
during step (ab), step (ac) further including, at each station:
(ac1) stopping the expander; (ac2) responsive to outward radial
force from the expander, increasing an interior diameter of the
host pipe; and (ac3) moving the expander to the next station. In
other embodiments, the method may further comprise rotating the
expander about the longitudinal expander axis and repeating step
(ac2). In other embodiments, step (ab) further comprises
concatenating a plurality of capsules into a string thereof,
wherein the string of capsules is inserted into the host pipe to
follow the expander as it moves.
[0027] In other embodiments, an annular space forms between the
host pipe and the concatenated string of liner pipe sections, and
the method further comprises: (d) at least partially filling the
annular space with grout. In other embodiments, the method may
further comprise the steps of stabilizing the concatenated string
of liner sections with stabilization measures before step (d) and
removing the stabilization measures after step (d).
[0028] In other embodiments, the method may comprise, prior to step
(b), the step of making a longitudinal cut in the host pipe. The
method may further comprise inserting a plurality of capsules into
the host pipe as the longitudinal cut is made, wherein the capsules
are in a concatenated string thereof.
[0029] In other embodiments, the first cartridge has a leading end
and a trailing end as inserted into the host pipe, and a steel head
is connected to the leading end of the first cartridge such that
the at least one rod in the first cartridge is connected to the
steel head. The steel head may be conically shaped. The first
cartridge may also be connected to the steel head. In other
embodiments, the steel head includes a vibrator, and step (b)
further includes vibrating the steel head during insertion. In
other embodiments, the steel head includes an impact hammer, and
step (b) further includes jolting the steel head during
insertion.
[0030] According to a second aspect, embodiments of the disclosed
technology provide a method for refurbishing an existing pipe, the
method comprising the steps of: (a) providing an existing host
pipe; (b) providing an expander, the expander having a longitudinal
expander axis, the expander adapted to generate outward radial
force perpendicular to the longitudinal expander axis when the
expander is actuated to expand; (c) moving the expander along a
path inside the host pipe, the path having stations at which the
expander stops; (d) expanding the host pipe during step (c), step
(d) further including, at each station: (d1) stopping the expander;
(d2) responsive to outward radial force from the expander,
increasing an interior diameter of the host pipe; and (d3) moving
the expander to the next station; (e) inserting a concatenated
string of liner pipe sections inside the host pipe, step (e)
further including: (e1) providing a plurality of cartridges, each
cartridge including (1) a liner pipe section, (2) at least one rod
and (3) at least one centering ball, wherein each rod and centering
ball is received inside the liner pipe section such that each rod
is stabilized within the liner pipe section via frictional contact
between each centering ball and the liner pipe section; (e2)
inserting a first cartridge into the host pipe, wherein the first
cartridge has a leading end and a trailing end as inserted into the
host pipe, and in which a steel head is connected to the leading
end of the first cartridge such that the at least one rod in the
first cartridge is connected to the steel head and the liner pipe
section on the first cartridge is also connected to the steel head;
(e3) concatenating the at least one rod in the first cartridge to
the at least one rod in the second cartridge; (e4) concatenating
the liner pipe section on the first cartridge to the liner pipe
section on the second cartridge; and (e5) inserting the second
cartridge into the host pipe; and (f) withdrawing the rods and
centering balls from within the concatenated string of liner pipe
sections.
[0031] It is therefore a technical advantage of the disclosed
technology to enhance the patented trenchless pipe refurbishment
described in the Prior Application for deployments in a confined
space at one end of the host pipe, where inserting a full length
liner pipe is impractical (if not impossible). In preferred
embodiments, a liner pipe is inserted in sections into an expanded
host pipe, bringing advantages of the Prior Application's disclosed
embodiments to confined space deployments. Further, by inserting
the liner pipe in sections from one end, the amount of work that
must be done in a confined space is minimized. The disclosed
confined space technology has particular application to
refurbishment of pipes or culverts under roads in mountain passes,
where there are often steep inclines on one side of the road and
open waterways nearby on the other side of the road. Nearly all of
the refurbishment work can be done in a confined space off-road on
the incline side, minimizing work required near the waterway, and
avoiding the need to close the road completely during
refurbishment. It will be understood, however, that the scope of
this disclosure is not limited to such applications with steep
inclines on one side of a road and open waterways nearby on the
other side of the road. Other applications, without limitation, may
be when insufficient access to the host pipe for refurbishment is
caused by the presence of private property nearby, where egress
onto such private property is prohibited.
[0032] Another technical advantage of the disclosed technology is
that its "open barrel" design allows for liner pipe sections to
arrive at the pusher box in "cartridge" form, with rods and
wireframe centering balls already pre-loaded inside, such that the
rod/liner pipe section assemblies are ready for immediate insertion
into the host pipe. This feature further minimizes the amount of
work that must be done in a confined space.
[0033] A further technical advantage is that, when space in the
deployment allows, "cartridges" of rod/ball/liner pipe sections may
be made up beforehand using off-the-shelf commercial inventory
lengths of liner pipe (typically in ranges from about 3 feet to 7
feet in length). In this way, the cost of the cartridges may be
standardized and optimized.
[0034] Another technical advantage of the disclosed technology is
that the pusher box provides multifunctional hydraulic components.
This multifunctional feature allows the pusher box to stay in place
and perform multiple tasks during the entire pipe refurbishment
process. Keeping the pusher box in place throughout the entire
operation again minimizes and optimizes the amount of work that
must be done in a confined space.
[0035] Another technical advantage of the disclosed technology is
that expansion forces on the host pipe are controlled and
perpendicular to the host pipe wall. Issues with the host pipe
folding up like an accordion during expansion and/or liner pipe
insertion are obviated. Embodiments of the disclosed technology are
also non-destructive to the host pipe and preserve wherever
possible the integrity of the host pipe, so that the host pipe may
continue to contribute to operational longevity once the pipe
refurbishment job is finished.
[0036] Embodiments of the disclosed technology further expand the
outside diameter of the host pipe by separating the host pipe
either side of a controlled longitudinal cut, leaving the host pipe
larger in diameter than before. Introducing the inner liner pipe
may thus, in certain applications, preserve the operational
diameter of the pipe once the refurbishment job is finished. This
retention of operational diameter may be highly advantageous in
applications where pipe flow or capacity is important.
[0037] Another advantage of the disclosed technology is that in
presently preferred embodiments, the host pipe is completely
expanded before the inner liner pipe is introduced. In the prior
art, and particularly in pipe bursting techniques that are
destructive to the host pipe, the inner liner pipe is generally
inserted to follow right behind the bursting tool as the tool moves
along the host pipe. Causing the inner liner pipe to follow right
behind the bursting tool avoids premature collapse of the
surrounding soil into the tunnel void created by the burst host
pipe. However, coordination of deployment of the inner liner pipe
right behind the pipe bursting can make the logistics of the job
difficult. Further, should there be an unintended collapse of the
surrounding soil before the inner liner pipe can provide support,
the inner liner pipe can become stuck, putting success of the job
in jeopardy.
[0038] By contrast, preferred embodiments of the disclosed
technology fully expand the host pipe, and substantially retain the
host pipe's structural integrity, before the inner liner pipe is
introduced. In some embodiments, the expanded host pipe may also be
temporarily stabilized via the introduction of capsules. The
capsules are removed as the liner pipe sections are inserted.
Since, in preferred embodiments, the host pipe is completely ready
to receive the inner liner pipe, and is still supporting the
surrounding soil, the inner liner pipe sections can be deployed
quickly and efficiently. The disclosed technology is thus
predictive of a much higher job success rate. Moreover, unlike
refurbishment methods of the prior art (such as pipe bursting),
embodiments of the disclosed technology create an annular space in
which grout can be deployed, further enhancing the strength,
performance and longevity of the finished refurbishment job.
[0039] The grout (or other material) injected into the annular
space between the host pipe and new liner pipe provides additional
advantages over conventional trenchless methods, which typically
omit this step. First, it secures the new liner pipe in position so
it does not move or settle. Next, the grout fills voids in the soil
under the host pipe, reducing the likelihood of pipe deflections
from differential settlement. The grout also fills voids in the
soil above the host pipe, which reduces point loads and impacts
caused if those voids collapse (which is a major source of
operational deflection and collapse of culverts). The grout also
distributes point loading on the host pipe/liner pipe construction,
which may deter future cracking during service.
[0040] The foregoing has outlined rather broadly some of the
features and technical advantages of the disclosed trenchless pipe
refurbishment technology, in order that the detailed description
that follows may be better understood. Additional features and
advantages of the disclosed technology may be described. It should
be appreciated by those skilled in the art that the conception and
the specific embodiments disclosed may be readily utilized as a
basis for modifying or designing other structures for carrying out
the same inventive purposes of the disclosed technology, and that
these equivalent constructions do not depart from the spirit and
scope of the technology as described.
BRIEF DESCRIPTION OF THE DRAWINGS
[0041] For a more complete understanding of the embodiments
described in this disclosure, and their advantages, reference is
made to the following detailed description taken in conjunction
with the accompanying drawings, in which:
[0042] FIG. 1 is a view of an exemplary confined space environment
in which deployment of the disclosed technology is applicable;
[0043] FIGS. 2A and 2B depict an excavation E including excavation
pad 100 on which to deploy the pusher box 1150;
[0044] FIGS. 3A through 3G illustrate in more detail a currently
preferred embodiment of pusher box 1150 as shown on FIGS. 2A and
2B, in which: FIGS. 3A and 3B are general exterior views; FIG. 3C
depicts pusher box 1150 in an extended state with exterior features
removed; FIG. 3D depicts pusher box 1150 in a retracted state with
one retract piston 1192 omitted for clarity; FIGS. 3E and 3F depict
pusher box 1150 in a retracted state with extend pistons 1191 and
retract piston 1192 omitted for clarity; and FIG. 3G is a view of
pusher box 1150 in a partially extended state, illustrated with an
exemplary liner pipe section 400;
[0045] FIGS. 4A and 4B illustrate embodiments of rod 410 in
combination with wireframe centering balls 420, and FIG. 4C
illustrates capsule 430;
[0046] FIGS. 5A and 5B illustrate two alternative embodiments of
making a longitudinal cut LC in host pipe H;
[0047] FIGS. 6A and 6B depict one exemplary embodiment of an
expander tool 300 that may be used in embodiments of the disclosed
technology; and FIGS. 6C through 6F are "freeze frame" views
depicting a first exemplary embodiment of an expansion of host pipe
H;
[0048] FIGS. 7A through 7F are a series of "freeze frame"
illustrations depicting expansion of host pipe H;
[0049] FIGS. 8A and 8B are "freeze frame" views depicting a second
exemplary embodiment of an expansion of host pipe H;
[0050] FIG. 9 illustrates steel head 435 and cartridge 405 as
deployed in embodiments for inserting concatenated liner pipe
section 400 into host pipe H;
[0051] FIGS. 10A through 10E are "freeze frame" views depicting a
first exemplary embodiment of insertion of concatenated liner pipe
sections 400 into an expanded host pipe H;
[0052] FIGS. 11A through 11E are "freeze frame" views depicting a
second exemplary embodiment of insertion of concatenated liner pipe
sections 400 into an expanded host pipe H;
[0053] FIG. 12 illustrates a section through liner pipe sections
400 resident inside host pipe H;
[0054] FIG. 13 illustrates grouting of annular space AS;
[0055] FIG. 14 illustrates inflatable bulkhead 500;
[0056] FIGS. 15 and 16 are sections as shown on FIG. 13; and
[0057] FIGS. 17 and 18 are detail views as shown on FIGS. 10B and
10C respectively.
DETAILED DESCRIPTION
[0058] For the purposes of the following disclosure, FIGS. 1
through 18 should be viewed together. Any part, item, or feature
that is identified by part number on one of FIGS. 1 through 18 has
the same part number when illustrated on another of FIGS. 1 through
18.
[0059] As noted above in the "Background" section, FIG. 1
illustrates an exemplary environment in which the disclosed
technology is advantageous to refurbish the underground host pipe
H. To recap, host pipe H on FIG. 1 is buried beneath road R with
steep incline SI on one side and waterway W on the other side. In
the environment illustrated on FIG. 1, access to host pipe H on the
waterway W side is from above only. Access to host pipe H on the
other side is very limited by steep incline SI. In some instances,
host pipe H may be up to 80 feet long, making insertion of a new
one-piece liner pipe into host pipe H impractical, if not
impossible.
[0060] FIGS. 2A and 2B illustrate an excavation E that may be
needed on the steep incline SI side of road R to facilitate some
deployments of the disclosed technology. It will be appreciated
from FIG. 2A that access is needed to the steep incline SI end of
host pipe H, even though such access is in a confined space. It
will be further appreciated from FIG. 2A that in exemplary mountain
highway deployments such as illustrated on FIG. 1, existing
roadside ditches on the steep incline SI side of road R may be of
limited width B (for example, only 3 feet to 6 feet wide). FIG. 2A
illustrates that in order to accommodate pusher box 1150 (as
described in more detail below), embodiments of which may be 9 feet
to 10 feet in length, steep incline SI may need to be excavated to
extended width A around host pipe H (for example, 10 feet to 12
feet). Further, FIG. 2A shows that in illustrated embodiments,
sufficient depth of excavation E is required to set pusher box 1150
at a correct elevation to service host pipe H. Excavation E is made
to provide such clearance and depth. In some deployments (not
illustrated) a retaining wall or other safety measure may be
deployed to stabilize steep incline SI in the presence of
excavation E. Also, as shown on FIG. 2A, the bottom of excavation E
advantageously provides a leveled and compacted excavation pad 100
on which to set, level and stabilize pusher box 1150. FIG. 2B shows
pusher box 1150 positioned in excavation E ready to service host
pipe H.
[0061] FIGS. 3A through 3G illustrate in more detail a currently
preferred embodiment of pusher box 1150 as shown on FIGS. 2A and
2B. FIGS. 3A and 3B are general exterior views. FIGS. 3C through 3F
are various views with some parts omitted to enable the internals
of pusher box 1150 to be seen more clearly. FIG. 3C depicts pusher
box 1150 in an extended state with exterior features removed. FIG.
3D depicts pusher box 1150 in a retracted state with one retract
piston 1192 omitted for clarity. FIGS. 3E and 3F depict pusher box
1150 in a retracted state with extend pistons 1191 and retract
piston 1192 on the foreground side omitted for clarity. FIG. 3G is
a view of pusher box 1150 in a partially extended state,
illustrated with an exemplary liner pipe section 400 in order to
describe pusher box 1150's features with respect to handling liner
pipe sections 400.
[0062] As noted, FIGS. 3A and 3B are general exterior view of a
currently preferred embodiment of pusher box 1150. Preferred
embodiments of pusher box 1150 weigh about 16,000 lbs, and are
designed to deliver up to about 85,000 lbs of horizontal force in
order to insert a liner pipe in sections into host pipe H. Given
these metrics, it will be appreciated that careful positioning,
leveling, alignment and stabilization of pusher box 1150 to address
host pipe H will assist smooth operation of pusher box 1150.
Referring also to FIGS. 2A and 2B, vertical stabilizers 1155 on
FIGS. 3A and 3B extend and retract (advantageously, under hydraulic
power) to level pusher box 1150 on excavation pad 100 and to set
pusher box 1150 to address host pipe H at the correct elevation and
azimuth/angle. Front and back horizontal stabilizers 1156A and
1156B on FIG. 3B extend to stabilize pusher box 150 against the
surrounding vertical excavation walls depicted in excavation E on
FIGS. 2A and 2B. Front and back horizontal stabilizers 1156A and
1156B are again advantageously hydraulically powered. In the
illustrated embodiment of FIG. 3B, front horizontal stabilizer
1156A is a U-shaped plate and is positioned in excavation E on FIG.
2A such that host pipe H is located in the "U". This feature on
front horizontal stabilizer 1156A assists with positioning pusher
box 1150 to address host pipe H at the correct elevation and
azimuth/angle.
[0063] FIGS. 3A and 3B also depict other exterior features of the
illustrated embodiment of pusher box 1150. Control panel 1157 is
positioned for an operator/controller to stand on step 1158 and be
sheltered by protective shoring 1159 from any loose debris that may
fall from above.
[0064] FIGS. 3C through 3G should be viewed together to understand
features of the illustrated embodiment of pusher box 1150. Looking
at FIGS. 3C, 3D, 3E and 3F together, pusher box 1150 provides rod
connector 1160 on rod connector carriage 1190, extend and retract
pistons 1191 and 1192 for extending and retracting rod connector
carriage 1190, rotator mechanism 1162 for rotating rod connector
1160, and raise/lower mechanism 1170 for supporting a workpiece
(such as liner pipe section 400 as described further below) at a
desired elevation with respect to rod connector carriage 1190 while
rod connector carriage 1190 extends or retracts, and/or while rod
connector 1160 rotates.
[0065] Referring to FIGS. 3C and 3D, the illustrated embodiment of
pusher box 1150 provides rod connector 1160 with a hollow
non-circular profile, which allows for greater torque when rotating
a rod attached thereto (as further described below). Rod connector
1160 is attached to rod connector carriage 1190 via rotator
mechanism 1162. Rotator mechanism 1162 is described in greater
detail below with reference to FIGS. 3E and 3F. On FIGS. 3C and 3D,
however, it will be seen that rod connector carriage 1190 moves
within pusher box 1150 between an extended state on FIG. 3C and a
retracted state on FIG. 3D.
[0066] FIGS. 3C and 3D depict extend pistons 1191 positioned
between pusher box back plates 1196 and rod connector carriage
1190. It will be seen on FIGS. 3C and 3D that when extend pistons
1191 are extended, extend pistons 1191 push rod connector carriage
1190 away from back plates 1196, causing rod connector carriage
1190 to travel away from back plates 1196. It will be further
understood that retract pistons 1192 retract while extend pistons
1191 extend. Pusher box 1190 thus moves into an extended state as
illustrated on FIG. 3C.
[0067] It will be further seen on FIGS. 3C and 3D that the converse
occurs to move pusher box 1150 into a retracted state. FIGS. 3C and
3D depict retract pistons 1192 positioned between pusher box front
plates 1197 and rod connector carriage 1190. When retract pistons
1192 are extended, retract pistons 1192 push rod connector carriage
1190 away from front plates 1197, causing rod connector carriage
1190 to travel away from front plates 1197. It will be further
understood that extend pistons 1191 retract while retract pistons
1192 extend. Pusher box 1190 thus moves into an retracted state as
illustrated on FIG. 3D.
[0068] It will be appreciated that as deployed, embodiments of
pusher box 1150 will be more likely to face demand for a heavier
"extend" load and a lighter "retract" load. For this reason, the
illustrated embodiment of pusher box 1150 provides four (4) extend
pistons 1191 and two (2) retract pistons 1192, although the scope
of this disclosure is not limited in either of these regards.
[0069] The embodiment of pusher box 1150 illustrated on FIG. 3C
also shows front plate reinforcement 1193 provided on front plates
1197. Although not specifically illustrated, it will also be
understood that similar reinforcement is advantageously provided on
back plates 1196. Such reinforcement gives front and back plates
1197 and 1196 additional rigidity in order to deter front and back
plates 1197 and 1196 from bending in response to extension of
retract and extend pistons 1192 and 1191 under operational
loads.
[0070] With reference to FIG. 3C and then FIG. 3B, it will be noted
that front horizontal stabilizer plate 1156A on FIG. 3B has been
omitted from FIG. 3C to enable the internals of the illustrated
embodiment of pusher box 1150 to be viewed. FIG. 3C depicts front
horizontal stabilizer pistons 1146A, which will be understood to
actuate horizontal motion of front horizontal stabilizer plate
1156A depicted on FIG. 3B.
[0071] FIGS. 3D, 3E and 3F further show raise/lower mechanism 1170
deployed under the travel of rod connector carriage 1190. As noted
above, raise/lower mechanism 1170 is configured to support a
workpiece (such as liner pipe section 400 as described further
below) at a desired elevation with respect to rod connector
carriage 1190 while rod connector carriage 1190 extends or
retracts, and/or while rod connector 1160 rotates. In the
illustrated embodiment of pusher box 1150 on FIGS. 3D, 3E and 3F,
raise/lower mechanism 1170 is preferably a cradle arrangement that
may be hydraulically raised and lowered from underneath via a
scissors mechanism.
[0072] As noted above, FIGS. 3C and 3D show rod connector 1160 is
attached to rod connector carriage 1190 via rotator mechanism 1162.
FIGS. 3E and 3F illustrate two alternative embodiments of rotator
mechanism 1162. On the embodiment of FIG. 3E, opposing rotator
mechanism pistons 1195 cooperatively extend and retract above/below
rod connector 1160. In this way, opposing 180-degree directions of
rotation combine to provide 360-degree absolute positioning for rod
connector 1160. On the embodiment of FIG. 3F, rotator mechanism
motor 1199 rotates rod connector 1160. Rotator mechanism motor 1199
may be any suitable motor, such as hydraulic or electric, and the
scope of this disclosure is not limited in this regard.
[0073] FIG. 3G is a view of the illustrated embodiment of pusher
box 1150 in a partially extended state. In FIG. 3G, pusher box 1150
is illustrated with an exemplary liner pipe section 400. FIG. 3G
depicts liner pipe section 400 supported from underneath on
raise/lower mechanism 1170. In exemplary deployments according to
this disclosure, rod 410 and wireframe centering balls 420 would be
provided inside liner pipe section 400 (see FIGS. 4A and 4B and
associated disclosure below), but are omitted for clarity on FIG.
3G. Rod 410 would be connected to rod connector 1160 in such
exemplary deployments. It will thus be appreciated that travel of
rod connector carriage 1190 between an extended and a retracted
state as shown on FIG. 3G will cause corresponding extension or
retraction of liner pipe section 400 (or corresponding
extension/retraction of any other workpiece to which rod connector
1160 may be attached via rods 410). Likewise, rotation of rotator
mechanism 1162 will cause corresponding rotation of liner pipe
section 400 (or corresponding rotation of any other workpiece to
which rod connector 1160 may be attached via rods 410).
[0074] FIGS. 4A and 4B illustrate rod 410 in combination with
wireframe centering balls 420. As also described elsewhere in this
disclosure, rods 410 may be concatenated into a string thereof as
rods 410 are inserted, preferably one at a time, into host pipe H
by pusher box 1150. Conversely, rods 410 may be disconnected from a
string thereof as rods are retracted, preferably one at a time, out
of host pipe H by pusher box 1150. Rods 410 may be joined together
end-to-end via any suitable hardware, such as bolts, pins or
threaded connections, and this disclosure is not limited in this
regard. Likewise, rods 410 may be joined to rod connector 1160 on
pusher box 1150 by any suitable hardware.
[0075] Wireframe centering balls 420 provide stability to
concatenated strings of rods 410, especially when such strings of
rods 410 are under compressive load while being "pushed" by pusher
box 1150. It will be understood that there may be some applications
where wireframe centering balls 420 are not needed. However,
preferred embodiments of the disclosed technology deploy rods 410
in conjunction with wireframe centering balls 420. In embodiments
of the disclosed technology described below in which strings of
rods 410 may be deployed to insert or retract tools into host pipe
H (such as to make cuts in host pipe H or expand host pipe H),
wireframe centering balls 420 stabilize such strings of rods 410
directly against host pipe H. In embodiments described below in
which strings of rods 410 are deployed to insert liner pipe
sections 400 into host pipe H, preferred embodiments of the
disclosed technology provide cartridges 405 of rods 410 and
wireframe centering balls 420 within liner pipe sections 400 as
illustrated on FIG. 4B. Cartridges 405 are preferably made up
offsite or away from the confined space in which the disclosed
technology is deployed. However, the scope of this disclosure of
the present application is not limited in this regard. Preferably,
in each cartridge 405, the liner pipe section 400 is approximately
the same length as one of the rods 410. Cartridge 405 may be
assembled as follows: rod 410 is inserted into liner pipe section
400, and is centered and frictionally stabilized within liner pipe
section 400 with wireframe centering balls 420 that are attached to
rod 410 along rod 410's length. Wireframe centering balls 420 are
sized and shaped to frictionally engage the internal surface of
liner pipe section 400 so that liner pipe section 400 may be
inserted into host pipe H by rod 410. In preferred embodiments,
rods 410 are stabilized in each liner section 400 by two (2)
wireframe centering balls 420, although the scope of this
disclosure is not limited in this regard.
[0076] FIG. 4C illustrates capsule 430. In some embodiments
described below, concatenated strings of capsules 430 may be
temporarily inserted into host pipe H in order to stabilize host
pipe H. Capsules 430 will be described below in more detail with
reference to such embodiments in which they may be deployed.
[0077] It will be understood that the scope of this disclosure is
not limited to the wireframe construction of wireframe centering
balls 420 and capsules 430 illustrated on FIGS. 4A and 4B. While
wireframe construction is presently preferred, any suitable
construction (including solid construction and/or from materials
other than metal) is considered within the scope of this
disclosure. However, embodiments of wireframe centering balls 420
and capsules 430 having wireframe construction provide an
additional advantage of allowing water (or other fluid) flow
therethrough. This aspect can be advantageous in deployments where
groundwater, rainfall, snow melt or other fluid flow through host
pipe H or liner pipe sections 400 must be accounted for, and in
which a buildup of such fluid behind solid embodiments of wireframe
centering balls 420 or capsules 430 would be disadvantageous.
[0078] Embodiments of methods for refurbishing an existing host
pipe will now be described. Generally stated, a first phase in
presently preferred embodiments is to make a longitudinal cut in
the host pipe. A second phase is an expansion phase, wherein the
host pipe is expanded, preferably nondestructively, via separation
of the longitudinal cut. A third phase is to insert liner pipe
sections into the expanded host pipe. In the disclosed technology
for deployments in confined spaces, sections of liner pipe are
concatenated end-to-end as they are inserted into the host pipe. In
some embodiments, the expansion phase and the liner pipe section
insertion phase may be combined. Once the liner pipe section
insertion phase is complete, the host pipe and the liner pipe (in
concatenated sections) typically form an annular space between
them. A fourth phase of the presently preferred embodiments is to
grout the annular space.
[0079] FIGS. 5 and 5B illustrate two alternative embodiments of
making a longitudinal cut LC in host pipe H. FIG. 5A illustrates a
longitudinal cut LC being made in host pipe H by cutting machine
200. In the embodiment depicted on FIG. 5A, cutting machine 200 is
a self-propelled cutting tool running on a track as described in
the Prior Application (incorporated herein by reference). Cable 201
on FIG. 5A may be used to supply cutting machine 200 with power if
cutting machine 200 is self-propelled. In other embodiments, cable
201 may also be used to pull cutting machine 200 along if cutting
machine 200 is not self-propelled, or if cutting machine 200 is
only partially self-propelled.
[0080] FIG. 5B illustrates an alternative embodiment in which
cutting machine 200 is connected to concatenated rods 410 inserted
and retracted by pusher box 1150. On FIG. 5B, cutting machine 200
provides cutting machine rod connector 250, to which transitional
rod 210 is attached. Transitional rod 210 is connected to a
concatenated string of rods 410. Rods 410 preferably have wireframe
centering balls 420 attached per the disclosure above associated
with FIG. 4A. It will be understood that the embodiments depicted
on FIGS. 5A and 5B and in the Prior Application are exemplary, and
that the scope of this disclosure is not limited as to specific
cutting tools or methods with which longitudinal cut LC is made in
host pipe H. For example, alternative embodiments may make
longitudinal cut LC starting at the near end of host pipe H to
pusher box 1150 and traveling to the far end, such as are disclosed
in U.S. Provisional Patent Application Ser. No. 62/471,389,
incorporated herein by reference.
[0081] Turning now to an expansion phase, FIGS. 6A and 6B depict
one exemplary embodiment of an expander tool (or "expander") 300
that may be used in embodiments of the disclosed technology. FIG.
6A illustrates expander 300 in a retracted state, with floating pad
301 in a "closed" position. Conversely, FIG. 6B illustrates
expander 300 in an extended state, with floating pad 301 shown in
section in an "open" position. FIG. 6B depicts expander 300
providing an expander rod connector 302 on each end. FIG. 6B
further depicts the internals of expander 300, in which
longitudinally disposed expander pistons 303A/B actuate rams 304A/B
longitudinally away from each other. Rams 304A/B in turn displace
first wedges 305A/B longitudinally against second wedges 306A/B to
create axial displacement of thrust pads 307A/B. Thrust pads 307A/B
are connected to floating pad 301. It will thus be understood that
floating pad 301 may be extended or retracted on expander 300 by
hydraulically extending or retracting expand pistons 303A/B.
[0082] It will be understood that the scope of this disclosure is
not limited to expander 300 as illustrated in FIGS. 6A and 6B. The
embodiment of expander 300 on FIGS. 6A and 6B is comparatively
light and has a comparatively small footprint, making it useful for
deployments in small diameter host pipes. It is also highly
reliable, having few moving parts. Other embodiments of an expander
suitable for use in the disclosed technology are described in the
Prior Application (incorporated herein by reference). It will be
understood that the embodiments depicted on FIGS. 6A and 6B and in
the Prior Application are exemplary, and that the scope of this
disclosure is not limited as to specific expanders for expanding
the host pipe.
[0083] FIGS. 6C through 6F are "freeze frame" views depicting a
first exemplary embodiment of an expansion of host pipe H. On FIG.
6C, expansion begins with pusher box 1150 inserting expander 300
all the way to the far end of host pipe H via concatenation of
inserted rods 410. It will be appreciated that in the embodiment
illustrated on FIGS. 6C though 6F, expansion of host pipe H is
accomplished starting at the far end of host pipe H from pusher box
1150, and then pulling expander 300 through sequential expansion
stations towards pusher box 1150. However, the scope of this
disclosure is not limited in this regard, and in other embodiments,
expansion may start at the near end of host pipe to pusher box
1150, such as is disclosed in U.S. Provisional Patent Application
Ser. No. 62/471,389, incorporated herein by reference.
[0084] Referring again to FIG. 6C, expander 300 provides expander
rod connector 302, to which transitional rod 310 is attached.
Transitional rod 310 is connected to a concatenated string of rods
410. Rods 410 preferably have wireframe centering balls 420
attached per the disclosure above associated with FIG. 4A.
[0085] Referring now to FIG. 6D, floating pad 301 on expander 300
is extended to expand host pipe H at a first expansion station at
the far end of host pipe H from pusher box 1150. As will be
described below in more detail with reference to FIGS. 7A through
7F, expansion of host pipe H preferably comprises extension and
retraction of floating pad 301 at selected rotational positions
about expander 300's longitudinal axis. Rotation of expander 300 is
accomplished using torque on rods 410 connected to expander 300,
where such torque is delivered onto rods 410 by rotator mechanism
1162 on pusher box 1150 (refer to disclosure above associated with
FIGS. 3E and 3F, for example). FIG. 6D further shows that in some
embodiments, the connection between transitional rod 310 and rods
410 may need to pivot to accommodate extension of floating pad 301
on expander 300.
[0086] FIG. 6E illustrates expansion of host pipe H completed at a
first expansion station at the far end of host pipe H from pusher
box 1150, and expander 300 moved to a second expansion station by
retraction of rods 410 by pusher box 1150. At this point, an
expansion of host pipe H at the second expansion station will be
undertaken. It will be understood that once expansion at the second
expansion station is complete, expander 300 will be moved to a
third expansion station by retraction of rods 410, and so on, until
expansion of host pipe H is complete. FIG. 6D shows expansion of
host pipe H as being complete, with expander 300 awaiting removal
while supported by raise/lower mechanism 1170 on pusher box
1150.
[0087] FIGS. 7A through 7F are a series of "freeze frame"
illustrations depicting expansion of host pipe H at an expansion
station, such as illustrated, for example, on FIG. 6D. FIGS. 7A
though 7F will be understood to be end elevation views looking into
the far end of host pipe H from pusher box 1150 on FIG. 6D, for
example, during expansion.
[0088] FIG. 7A depicts expander 300 sitting in host pipe H
immediately before expansion begins. Longitudinal cut LC in host
pipe H is shown in an unseparated state.
[0089] In FIG. 7B, floating pad 301 on expander 300 extends to
commence expansion of host pipe H. In FIG. 7C, expander 300 and
floating pad 301 engage host pipe H to expand in the direction of
the arrows on FIGS. 7B and 7C. Host pipe H deforms in response,
causing initial separation of longitudinal cut LC. In preferred
embodiments, expansion of host pipe H is done nondestructively to
host pipe H. Likewise, separation of longitudinal cut LC is
preferably non-elastic (i.e. plastic) separation.
[0090] Floating pad 301 is retracted between FIGS. 7C and 7D, and
then expander 300 is partially rotated to a new rotational position
about expander 300's longitudinal axis. It will be understood from
disclosure above that such rotation of expander 300 is responsive
to torque delivered by rotator mechanism 1162 on pusher box 1150
and applied via rods 410 connected to expander rod connector 302.
FIG. 7D depicts expansion of host pipe H at a second rotational
position. Longitudinal cut LC continues to separate. Floating pad
301 is retracted again between FIGS. 7D and 7E, and expander 300 is
rotated to a third rotational position. FIG. 7E depicts expansion
of host pipe H at the third rotational position. Retraction,
rotation and expansion continues wherein FIG. 7F depicts expansion
of host pipe H at a fourth rotational position, by which time host
pipe H is substantially uniformly expanded and longitudinal cut LC
is separated.
[0091] While the embodiments of FIGS. 7A through 7F disclose four
rotational positions from which to expand host pipe H, the scope of
this disclosure is not limited in this regard. It will be
understood that users will customize expansion procedures to the
needs of the application, taking into account variables such as,
for example, amount of host pipe expansion and longitudinal cut
separation desired at each expansion station, or number of
rotational positions from which to expand.
[0092] FIGS. 8A and 8B are "freeze frame" views depicting a second
exemplary embodiment of an expansion of host pipe H. The embodiment
illustrated on FIGS. 8A and 8B is similar to the embodiment
illustrated on FIGS. 6C through 6F, except that capsules 430 are
concatenated to follow expander 300 into expanded sections of host
pipe H. Capsules 430 are illustrated and described above with
reference to FIG. 4C. It will be understood from FIG. 8A that
capsules 430 are attached to expander rod connector 302 via entry
into the far end of host pipe H from pusher box 1150. Capsules 430
are concatenated into a string thereof attached to expander rod
connector 302 as expander 300 moves towards pusher box 1150
(responsive to pusher box retracting rods 410). Once expander 300
has completed expansion of host pipe 300 at a first expansion
station, a first capsule 430 is attached to expander 300 via
connection with expander rod connector 302. As expander 300 moves
towards pusher box 1150 and a second expansion station, additional
capsules 430 are concatenated into a string thereof via continued
entry into the far end of host pipe H. Capsules 430 may be joined
together end-to-end via any suitable hardware, such as bolts, pins
or threaded connections, and this disclosure is not limited in this
regard. Likewise, capsules 430 may be joined to expander rod
connector 302 by any suitable hardware.
[0093] FIG. 8B illustrates completion of expansion of host pipe H
with a concatenated string of capsules 430 temporarily resident in
the expanded host pipe H. It will be understood that the embodiment
of FIGS. 8A and 8B is advantageous in deployments where the
expanded host pipe H is unstable, or when collapse of expanded host
pipe H is a concern. The embodiment of FIGS. 8A and 8B is
advantageous when, for example, host pipe H is highly corroded
and/or brittle, or the earthwork surrounding host pipe H is
unstable. In such environments, capsules 430 provide additional
temporary support to expanded host pipe H until a liner pipe can be
introduced.
[0094] The embodiment of FIGS. 8A and 8B is further advantageous in
deployments where expansion efforts are proving difficult to
achieve non-elastic expansion and separation. That is, in
deployments where host pipe H tends to return elastically to its
unexpanded condition despite expansion efforts. Insertion of a
liner pipe in such deployments might prove difficult where the
liner pipe has a comparable diameter to the original, unexpanded
host pipe. The introduction of capsules 430 in such deployments,
such as in the embodiment illustrated on FIGS. 8A and 8B,
temporarily assists maintaining expanded host pipe H at its
expanded diameter until a liner pipe can be introduced.
[0095] Although not illustrated in this disclosure, deployment of
capsules 430 during the cutting phase may also be useful in some
embodiments where the host pipe is particularly unstable after a
longitudinal cut is made (per FIGS. 5A and 5B above with associated
description). With momentary reference to FIGS. 5B and 8A/8B
together, a string of capsules 430 may be deployed in host pipe H
behind cutting machine 200 during the cutting phase in the manner
described on FIGS. 8A/8B with reference to expander 300.
[0096] FIG. 9 illustrates the interoperation of steel head 435 and
cartridge 405 as deployed in embodiments of the disclosed
technology for inserting concatenated liner pipe section 400 into
an expanded host pipe H. It will be recalled from disclosure above
associated with FIG. 4B that cartridge 405 comprises rod 410
inserted into liner pipe section 400, wherein rod 410 is centered
and frictionally stabilized within liner pipe section 400 with
wireframe centering balls 420. Wireframe centering balls 420 are
attached to rod 410 along rod 410's length. Wireframe centering
balls 420 are sized and shaped to frictionally engage the internal
surface of liner pipe section 400 so that liner pipe section 400
may be inserted into host pipe H by rod 410. FIG. 9 illustrates an
initial cartridge 405 for insertion into host pipe H, to which
steel head 435 is attached at the leading end. In greater detail,
steel head 435 is attached to rod(s) 410 inside initial liner pipe
section 400, so that when pusher box 1150 (not illustrated on FIG.
9) inserts initial cartridge 405 into host pipe H by connection to
rods 410, steel head 430 will be driven into host pipe H by rods
410.
[0097] Liner section 400 on FIG. 9 is also preferably connected to
the periphery of steel head 430. In this way, as rods 410 drive
steel head 435 into host pipe H, liner pipe sections 400 will then
be dragged along by steel head 435. With further reference to the
embodiment illustrated on FIG. 8, steel head 435 advantageously has
a dead weight and is conically shaped. Steel head 435 thus promotes
smooth insertion of an entire concatenated string of rods 410/liner
pipe sections 400 into the host pipe H. In particular, steel head
435 protects the leading edge of the first liner pipe section 400
from snagging against corrugations and minor peripheral
obstructions in the interior of host pipe H.
[0098] Although not specifically illustrated, one embodiment of
steel head 435 advantageously provides an internal vibrator.
Another embodiment of steel head 435 (also not illustrated)
provides an internal jar or impact hammer, preferably driven
hydraulically or pneumatically. The vibrator or impact hammer
vibrates or jolts steel head 435 (and at least the leading rods
410/liner pipe sections 400 attached to steel head 435) against the
host pipe H interior as they are inserted into the host pipe H,
thereby encouraging movement of the string in the face of
frictional drag against the interior of host pipe H. In other
embodiments (also not illustrated), the vibrator or impact hammer
could be provided in pusher box 1150.
[0099] FIGS. 10A through 10E are "freeze frame" views depicting a
first exemplary embodiment of insertion of concatenated liner pipe
sections 400 into an expanded host pipe H. When insertion is
complete, a concatenated string of liner pipe sections 400 is left
resident in host pipe H and forms a continuous liner pipe. Liner
pipe sections 400 may be made of any suitable liner pipe material,
such as, without limitation, galvanized metal, aluminized steel,
asphalt coated steel plastic, ceramic or a fiber reinforced resin
compound. Similarly, liner pipe sections 400 may be corrugated or
smooth. Liner pipe sections 400 for any given deployment may also
be uniform in construction or hybrid. The scope of this disclosure
is not limited in any of these regards.
[0100] Referring first to FIG. 10A, pusher box 1150 is inserting an
initial liner pipe section 400 into host pipe H. Throughout FIGS.
10A through 10E, it will be understood that liner pipes 400 are
preferably inserted in the form of cartridges 405 as illustrated
and described above with reference to FIG. 4B, in which liner pipe
sections 400 are deployed with rods 410 and wireframe centering
balls 420 assembled inside. It will be also seen and understood on
FIG. 10A that initial liner pipe section 400 (and rods 410 inside
liner pipe section 400, hidden from view) are connected to steel
head 435 in the manner described above is in association with FIG.
9.
[0101] With continuing reference to FIG. 10A, rod connector 1160 on
pusher box 1150 will be understood to be connected to rods 410
inside liner pipe section 400. Pusher box 1150 inserts steel head
435 and initial liner pipe section 400 into host pipe H as pusher
box 1150 is actuated towards its extended state. Raise/lower
mechanism 1170 on pusher box 1150 is set to a suitable height to
facilitate entry of steel head 435 and initial liner pipe section
400 into host pipe H.
[0102] FIG. 10B depicts where a second liner pipe section 400 has
been concatenated to the initial liner pipe section 400. Pusher box
1150 is shown in its fully retracted state It will be understood
that between FIGS. 10A and 10B, pusher box 1150 was actuated to its
fully extended state, whereupon rod connector 1160 was disconnected
from rods 410 inside the initial liner pipe section 400. Pusher box
1150 was then retracted to its fully retracted state. A second
cartridge 405 was then deployed on raise/lower mechanism 1170. The
rods 410 in the second cartridge 405 were then connected to the rod
connector 1160 at one end, and to the rods 410 inside the initial
liner pipe section 400 at the other end (rod connections hidden
from view on FIG. 10B).
[0103] FIG. 10B also illustrates the two illustrated liner pipe
sections 400 joined together. FIG. 17 illustrates one embodiment of
such joint in greater detail. In the exemplary embodiment
illustrated on FIG. 17, initial and second liner pipe sections 400
are connected with a connector clamp 450 secured by bolts 455. In
other embodiments, not illustrated, initial and second liner pipe
sections 400 may alternatively be connected via rivets in drilled
holes, or via adhesive, or via tack welds once a connection is made
using temporary flanges. The scope of this disclosure is not
limited in this regard.
[0104] FIG. 10C and FIG. 18 illustrate a further exemplary
embodiment of joining two liner pipe sections 400 together, in
which liner pipe sections 400 are threaded together via threaded
connection 460. FIG. 10C illustrates rods 410 and wireframe
centering balls 420 inside liner pipe sections 400. In the
embodiment illustrated on FIG. 10C, rods 410 inside second liner
pipe section 400 are initially only connected to rod connector 1160
on pusher box 1150. Torque T is then delivered to second liner pipe
section 400 via rotation of rods 410 inside second liner pipe
section by rotator mechanism 1162 on pusher box 1150. Rotation of
rods 410 causes corresponding rotation of second liner pipe 400 via
frictional contact of wireframe centering balls 420 against the
inside surface of second liner pipe section 400. (Note that rotator
mechanism 1162 is not illustrated on pusher box 1150 on FIG. 10C.
Refer to FIGS. 3E and 3F above, with associated disclosure, for a
discussion of the operation of embodiments of rotator mechanism
1162). Torque T as shown on FIG. 10C causes rotation of second
liner pipe section 400 at threaded connection 460 (on FIG. 18),
which in turn enables initial and second liner pipe sections 400 to
be threaded together. In some embodiments, the threading together
of initial and second liner pipe sections 400 will take about 2-6
revolutions of second liner pipe section 400 at threaded connection
460, although the scope if this disclosure is not limited in this
regard. Once threaded connection 460 is made, rods 410 on initial
liner pipe section 400 may then be connected to rods 410 on second
liner pipe section.
[0105] Referring now to the exemplary embodiments illustrated on
both FIGS. 10B and 10C, pusher box 1150 may be actuated towards its
extended state once initial and second liner pipe sections 400 are
joined together and rods 410 are connected throughout. Actuation
towards pusher box 1150's extended state will cause insertion of
initial and second liner pipe sections 400 (as attached to steel
head 435) further into host pipe H.
[0106] Comparing FIGS. 10B and 10C to FIG. 10D, pusher box 1150 has
moved to its fully extended state, rods 410 in second liner pipe
section 400 have been disconnected from rod connector 1160 on
pusher box 1150, pusher box 1150 has been retracted to its fully
retracted state, and a third cartridge 405 has been deployed on
raise/lower mechanism 1170. The sequence of operations described
above with reference to FIG. 10B is now repeated with respect to
FIG. 10D, in which rods 410 and liner pipe sections 400 are
connected/joined, liner pipe sections 400 are inserted further into
host pipe H via actuation of pusher box 1150 towards its fully
extended state, rods 410 are disconnected from rod connector 1160,
pusher box 1150 is retracted to its fully retracted state, and
another cartridge 405 is introduced to pusher box 1150.
[0107] FIG. 10E illustrates completion of liner insertion
operations, in which a concatenated string of liner pipe sections
400 are joined together to form a continuous liner pipe inside host
pipe H. FIG. 10E shows steel head 435 being disconnected and
removed from a far end of host pipe H. Although not specifically
illustrated, it will be understood that rods 410 inside liner pipe
sections 400 are now retracted with wireframe centering balls 420
attached. Retraction of rods 410 is essentially the reverse
operation to the insertion operation described immediately above
with reference to FIGS. 10B and 10D. Rod connector 1160 on pusher
box 1150 is connected to rods 410 in a fully extended state. Pusher
box 1150 is then retracted to its fully retracted state, which
causes rods 410 to be withdrawn/retracted out of liner pipe section
400 while leaving liner pipe sections 400 resident inside host pipe
H. In preferred embodiments, the dead weight of the fully
concatenated string of liner pipe sections 400, plus its frictional
resistance from contact with host pipe H along its entire length,
will be sufficient to enable pusher box 1150 to withdraw rods 410
(with wireframe centering balls 420 attached) from liner pipe
sections 400 while leaving liner pipe sections 400 resident in host
pipe H. Alternatively, steel head 435 may be left attached to liner
pipe sections 400 while rods 410 are withdrawn. Once pusher box
1150 reaches a fully retracted state, a first section of rods 410
(with wireframe centering balls 420 attached) may be disconnected
from rod connector 1160 on pusher box 1150 at one end, and from the
concatenated string of rods 410 still inside the liner pipe at the
other end. Pusher box 1150 is then actuated to its fully extended
state. Rod connector 1160 is then connected to a second section of
rods 410 ready for a second retraction of rods 410. The process is
continued until the entire string of rods 410 (with wireframe
centering balls 420 attached) is retracted section by section and
removed.
[0108] FIGS. 11A through 11E are "freeze frame" views depicting a
second exemplary embodiment of insertion of concatenated liner pipe
sections 400 into an expanded host pipe H. Generally speaking, the
embodiment of FIGS. 11A through 11E is similar to the embodiment of
FIG. 9 and FIGS. 10A, 10B, 10D and 10E. However, the embodiment of
FIGS. 11A through 11E depicts insertion of liner pipe sections 400
in deployments when capsules 430 have been left temporarily
resident in host pipe H (per the disclosure above associated with
FIGS. 8A and 8B).
[0109] FIG. 11A is similar to FIG. 9. Capsule 405 (including rods
410 and wireframe centering balls 420 assembled inside liner pipe
section 400) is shown on FIG. 11A connected to steel head 435 in
the manner described above with reference to FIG. 9. Steel head 435
on FIG. 11A may optionally provide a vibrator or impact hammer (not
illustrated) as also described above with reference to FIG. 9. FIG.
11A shows capsules 435 previously deployed in host pipe H per FIGS.
8A and 8B above and associated description.
[0110] FIGS. 11B through 11E are similar to FIGS. 10A, 10B, 10C and
10D. Liner pipe section 400 on FIGS. 11B through 11E is being
inserted into host pipe H in the manner described above with FIGS.
10A, 10B, 10C and 10D. It will be appreciated on FIGS. 11B through
11D, however, that steel head 435 shunts capsules 435 out of the
far end of host pipe H as liner pipe sections 400 are inserted into
host pipe H. It will be understood in the embodiment illustrated on
FIGS. 11A through 11E that, although not specifically illustrated,
retraction of rods 410 (with wireframe centering balls 420
attached) from liner pipe sections 400 is per the description above
associated with FIG. 10E.
[0111] FIGS. 10E and 11E depict an annular space AS formed between
liner pipe sections 400 and the host pipe H once the fully
concatenated liner pipe is inserted and resident inside host pipe
H. FIG. 12 illustrates a section through liner pipe sections 400
resident inside host pipe H per FIGS. 10E and 11E. FIG. 12 shows
annular space AS and longitudinal cut LC (with longitudinal cut LC
separated per the description above associated with FIGS. 7A
through 7F).
[0112] FIGS. 13 and 15 illustrate grouting of the annular space AS.
Grouting may be accomplished by any suitable protocol. FIGS. 13 and
15 illustrate one example of a suitable grouting protocol using
specially developed inflatable bulkheads 500, illustrated on FIGS.
14 and 16, customized to dispense liquid grout into annular space
AS, and then retain the grout while it cures. This disclosure is
not limited, however, to the grout protocol illustrated and
described with reference to FIGS. 13 and 15, or deploying the
inflatable bulkheads illustrated and described with reference to
FIGS. 14 and 16.
[0113] FIG. 14 depicts inflatable bulkhead 500 comprising
inflatable ring 530 inflated via inflation valve 510. Inflatable
ring 530 may be made from conventional inflatable materials, such
as rubber or rubber composites, and inflation valve 510 is
conventional. Inflatable bulkhead 500 also includes at least one
(on FIG. 14, three) grout fittings 520. Grout fittings 520 pass
through inflatable ring 530 and are conventionally sealed at their
points of insertion through the wall of inflatable ring 530. Grout
fittings 520 are adapted to allow liquid grout to pass through.
They may be made of any conventional material such as brass,
stainless steel, etc. Each grout fitting 520 has a connector on one
end suitable for connection with a conventional liquid grout
hose.
[0114] FIG. 13 depicts grout G being injected into annular space
AS. Preferably, annular space AS is completely filled with grout G.
However, in some embodiments annular space AS may be at least
partially filled with grout G. Inflatable bulkheads 500 are
installed into annular space AS at either end of host pipe H, and
thereby seal annular space AS at either end. Since inflatable
bulkheads 500 are advantageously made of rubber (or a rubber-like
material) and are inflatable, the same bulkhead may be used for
several combinations of outside diameters of liner pipe 400 and
corresponding expanded internal diameters of host pipe H. For the
same reason, inflatable bulkheads 500 provide good seals of annular
space AS at either end of host pipe H regardless of surface or
shape irregularities at points of contact with inflatable bulkheads
500. Consistent with the disclosure immediately above with
reference to FIG. 14, liquid grout G is injected into annular space
AS on FIG. 13 through one inflatable bulkhead 500 via grout
fittings 520. Inflatable bulkheads 500 retain grout G in annular
space AS while grout G cures. Once grout G is cured, inflatable
bulkheads 500 may be deflated and removed. At this point, the
assembly of host pipe H, concatenated liner pipe sections 400 and
grout G in annular space AS has a cross-section as shown on FIG.
15.
[0115] It will be appreciated from FIG. 13 that liquid grout G may
be injected into annular space AS from either or both ends. If only
injected from one end, the inflatable bulkhead 500 at the
non-injection end may be a plain bulkhead without grout fittings
520, or else the grout fittings 520 at the non-injection end may be
temporarily plugged.
[0116] FIG. 16 is a cross-section as shown on FIG. 13, and shows
the operational interface between inflatable bulkhead 500 and liner
pipe section 400/host pipe H in more detail. Inflatable ring 530 is
installed between liner pipe section 400 and host pipe H and
inflated via inflation valve 510. Grout fitting(s) 520 dispense
grout into annular space AS between liner pipe section 400 and host
pipe H.
[0117] Although not specifically illustrated on FIGS. 13 through
16, it may be advantageous to stabilize concatenated liner pipe
sections 400 during grouting operations. In some embodiments, such
stabilization may via stabilization measures such as filling
concatenated liner pipe sections 400 with water or pressurizing
with air while the grout cures, in order to prevent possible
deformation or even collapse of the liner pipe under the weight or
pressure of the liquid grout. Once cured, the grout deters
differential settlement of the host pipe/liner pipe as a unitary
grouted structure. Further, with reference to FIG. 13, when fully
pressurized, inflatable bulkheads 500 at either end provide strong
temporary bulkheads that enable grout G to be delivered throughout
annular space AS at pressure. As a result, grout G can fill all
voids in annular space AS, including eroded voids that may be
present in the soil barrier. It will be further understood that the
term "grout" as used in this disclosure is not intended to be
limited to cement-based grout. The scope of this disclosure
includes any suitable injectable grout, also including, without
limitation, epoxy-based grouts.
[0118] Preferred embodiments described in this disclosure have
referred throughout to an embodiment of pusher box 1150 as
described in detail on FIGS. 3A through 3G. It will be understood
that the scope of this disclosure is not limited to such a pusher
box embodiment. Alternative pusher box embodiments are within the
scope of this disclosure, for example as described in U.S.
Provisional Patent Application Ser. No. 62/471,389 incorporated
herein by reference.
[0119] The scope of this disclosure also includes embodiments in
which a host pipe expansion phase is combined with a liner pipe
section insertion phase. In such embodiments, a longitudinal cut is
made in the host pipe per the above disclosure. An oversized liner
pipe is then inserted into the host pipe by the pusher box, in
sections, with a similarly oversized conically-shaped steel head
attached to a leading end of the liner pipe sections per the above
disclosure. The oversized steel head expands the host pipe via
separation of the longitudinal cut as it is inserted into the host
pipe, and the liner pipe sections form a concatenated string
thereof immediately resident in the freshly-expanded host pipe. In
such embodiments, an annular space may or may not form between the
host pipe and the concatenated host pipe sections. Grouting may be
performed if a suitable annular space forms.
[0120] Although the inventive material in this disclosure has been
described in detail along with some of its technical advantages, it
will be understood that various changes, substitutions and
alternations may be made to the described embodiments without
departing from the broader spirit and scope of such inventive
material as set forth in the appended claims.
* * * * *