Note: Descriptions are shown in the official language in which they were submitted.
CA 02459953 2004-03-08
WO 03/024624 PCT/US02/29538
METHOD AND APPARATUS FOR TREATING UNDERGROUND PIPELINE
Field of the Invention
The present invention relates generally to apparatus and methods for
internally
treating pipeline or conduit. Particularly, this invention relates to
treating, bridging, filling
and or sealing pipe joints or other discontinuities in situ in a variety of
different types of
pipeline or conduit, such as live propane, live natural gas, water or sewer
pipeline. Even
more particularly, this invention relates to internally, milling, filling and
sealing pipe joints or
other discontinuities in live propane or natural gas pipeline, and the
automation thereof.
Background of the Invention
A dilemma has arisen in the gas and gas transportation industry. Low-moisture
gas,
such as propane or natural gas, has replaced high-moisture manufactured gas,
such as coal
gas, as a source of domestic and industrial fuel. Traditionally, and for many
decades, coal or
other high-moisture gases were fed to customers by underground pipes.
Typically, these gas
pipelines were constructed of individual lengths of pig or cast iron pipe.
These individual
lengths of pipe were commonly joined together by bell or lap joints that were
sealed with a
combination of a filler material and lead or grout.
Several different types of filler material were used including horsehair,
yarn, jute and
hemp. It was discovered that, as many municipalities converted from high-
moisture
manufactured gas to the relatively low-moisture propane or natural gas, the
filler material in
the pipe joints would dry out. As these filler materials dry out, they
decompose and
disintegrate, thereby causing gas leaks to appear at the pipe joints.
The decay of joint filler due to the conversion to low-moisture gas is not
unique to the
United States. The United Kingdom is experiencing similar decay of their gas
pipe joint
filler. As a preventative measure, and as an attempt to slow down the decay of
filler material,
many gas companies in the United Kingdom, and a few in the United States,
routinely "fog"
their gas lines. Fogging normally involves sending a glycol type product
through the gas
pipeline to enhance the moisture content of the filler. Another method of
maintaining high
moisture in the filler involves a process known in the gas industry as
humidification. This
process requires repeated application of pressurized steam to a gas pipe
system.
Unfortunately, these preventative procedures are only temporary, and can be
quite
costly. Today, to adequately prevent gas from escaping these types of
pipelines, the pipe
joints or other discontinuities must be sealed or replaced. Because many of
these pipelines
-1-
CA 02459953 2004-03-08
WO 03/024624 PCT/US02/29538
are underground and not readily accessible, excavating, removing and replacing
an entire
length of pipeline having deteriorated pipe joints is drastic and quite
costly.
Other pipeline joints and discontinuities, such as those that exist in water
and sewer
pipelines, also require periodic treatment to prevent materials from leaking
into or out of the
pipeline. These leaks are a result of decaying materials such as the material
used in the
construction of the pipeline, certain types of obstructions or debris which
may clog a pipeline,
chemical exposure and or crushing due to overburden pressure. Many pipelines
require
repair to prevent exterior leaking and possible ground water contamination.
Additionally,
without proper treatment, ground water can infiltrate into the broken
pipelines. Further, in
water pipelines, obstructions, cracks or other discontinuities can cause areas
of reduced water
flow, which can result in undesirable bacterial growth.
Today, to adequately prevent gas or liquid from escaping or penetrating these
types of
pipelines, the pipe joints or other discontinuities must be sealed or
replaced. As described
above, because many of these pipelines are also underground and not readily
accessible,
excavating, removing and replacing an entire length of pipeline having
deteriorated pipe
joints is drastic and quite costly.
One method of sealing these pipe joints or discontinuities against gas leaks
includes
excavating an end of the pipe and having someone climb into the pipe to hand
apply a coating
compound. This method can be quite expensive and time consuming. Also, this
method can
be dangerous and is unfeasible for small diameter pipe. Another technique
includes inserting
a permanent lining throughout the entire length of pipe. Again this is quite
costly and may
cause an unacceptable reduction in the flow capacity of the pipe. Also, this
method requires a
large consumption of natural resources to fabricate a lining for an entire
length of pipe, when
typically only the joints are susceptible to leaking.
Still another method, such as U.S. Pat. No. 4,178,875 (1979, Moschetti),
includes
sending a device through the pipe that can remotely detect a joint or other
discontinuity that
needs repair. A coating material is then sent through attached tubing and is
sprayed onto the
inner surface of the pipe at the desired location. However, this and the above-
mentioned
methods are not performed on "live gas pipe" (pipe in which pressurized gas
remains
flowing). These methods require the gas flow to be shut down for long periods
of time.
Depending on the customers being serviced by the gas line, it is normally
unacceptable to
interrupt service for such long periods of time. Another disadvantage of these
methods is that
they require more than a single excavation when coating long lengths of
pipeline.
_2_
CA 02459953 2004-03-08
WO 03/024624 PCT/US02/29538
Still other methods are known whereby the gas remains live while coating,
repairing
or sealing is accomplished. U.S. Pat. Nos. 4,582,551 and 4,627,471 (1986,
Parkes et al.)
disclose a method and device that can remotely seal joints or leaks in a pipe
while the gas
continues flowing in the pipe. The device is inserted into a pipe whose inner
diameter is
S slightly larger than the outer circumference of the device. The device uses
expandable
bladders to form a substantially air-free environment, thereby isolating the
joint or
discontinuity from pressurized gas. The pressurized gas is rerouted through
the interior of the
device. Anaerobic sealant is then pumped to the device and the sealant is
sprayed onto the
interior of the pipe at the desired location. The device remains in place long
enough to allow
the anaerobic sealant to setup. A disadvantage with this device is that it
requires an
environment free from air and flowing pressurized gas in which to apply
sealant. Another
disadvantage with these types of devices is that they are limited in their
ability to maneuver
around corners or other obstacles in the pipeline as they are in close
proximity to the interior
of the pipe. Still another disadvantage with these devices is that they are
slow and time
consuming because they require the device to remain in place while the sealant
sets.
Another method of sealing pipe joints in a live gas pipe is taught in U.S.
Pat. No.
5,156,886 (1992, Kitson). This method involves inserting a nozzle attached to
a hose through
a tapping mandrel to a desired location in a live gas pipe, whereby an
anaerobic sealant is
pumped through the hose to the nozzle. The nozzle sprays the anaerobic sealant
onto the
interior of the pipe. This method works well on relatively short lengths of
pipe. However, as
the length of tubing increases, the viscosity of the anaerobic sealant
prevents it from reaching
the spraying device in adequate quantities. Also, as the length of tubing
increases, static
electric charges build up in the line due to the friction caused by the
sealant rubbing against
the interior of the tubing. This can pose serious problems when working in a
live gas setting.
Another drawback with this device is that the anaerobic sealant tends to pool
in the bottom of
the pipe upon application. An additional drawback of this method is that it
typically requixes
the presence of some filler to properly seal a leaking joint. Because the
above-mentioned
preventative or fogging measures were never routinely performed in the United
States, much
of the filler in United States gas pipe joints has disintegrated, making this
method of sealing
pipe joints impractical.
What is needed is an apparatus and method for coating or sealing the interior
of very
long lengths of underground pipe or other conduit, either at a joint, another
type of
discontinuity or along the entire length of the pipe, while the gas in the
pipe remains live, that
overcomes drawbacks of prior art devices.
-3-
CA 02459953 2004-03-08
WO 03/024624 PCT/US02/29538
Summary of the Invention
It is an object of the present invention to provide an apparatus and method
for coating
or sealing the interior of very long lengths of underground pipe or other
conduit, either at a
joint, another type of discontinuity or along the entire length of the pipe,
while the gas in the
pipe remains live.
It is still another object of the present invention to allow for several
layers of coating
material to be applied at the same site.
It is a further object of the present invention to provide a rapid coating
process, which
does not require the coating device to remain in place while the coating
material sets.
It is a further object of the present invention that it can be inserted into a
live gas pipe
using a variety of methods.
It is a further object ofthe present invention that it can maneuver around
bends and
other obstacles normally found in gas pipe. It is still a fw-ther object of
the present invention
that it applies a polyurethane sealant that will coat the interior of a
variety of different pipe
surfaces, with or without the presence of pressurized gas, with or without the
presence of air
or oxygen and that will not pool in the bottom of the pipe upon application.
It is still a further object of the present invention to provide for repair of
several
hundred feet of live underground pipe from a single excavation point.
One or more of these objects is achieved in one aspect of the invention by
providing
an apparatus and a method for coating or sealing the interior of underground
pipes where the
apparatus is moved through the pipe while the gas is flowing. The coating
device is
connected to reservoirs of coating material and is specially designed to
operate in the
presence of propane or natural gas without incident. In addition, an epoxy-
type coating
material is utilized that will adhere to a variety of surfaces and that will
set-up within a
variety of climates, including a pressurized live gas environment. In one
embodiment, the
sealant material is a 100% solids system that does not rely on evaporation for
curing.
To prevent electric discharge caused by friction, resulting from the
individual
components of coating material traveling to the coating device, the coating
material
components can be pumped to the coating device through grounded tubing. This
makes the
device safer to operate in a live gas environments.
The device can also include scissor-type expansion legs. These scissor-type
legs
allow the device to maneuver around corners and bends in the pipe, and to
adapt to a wide
variety of pipe diameters. Also, the combination of a non-conductive or
electrically
grounded delivery system with a specially designed pushing system, allow
greater lengths of
-4-
CA 02459953 2004-03-08
WO 03/024624 PCT/US02/29538
pipe to be sealed or repaired with fewer excavations than known related art
devices and
techniques.
Embodiments of the present invention provide an economically feasible method
of
repair that allows indefinite postponement of the replacement of thousands of
miles of gas
pipeline, thereby preserving the enormous quantities of natural resources that
would be
required to fabricate replacement pipe. As many of these pipe joints and other
discontinuities
are sealed, the loss of natural or propane gas will be greatly reduced, as
will the consumption
of enormous amounts of glycol and other joint filler preserving compounds.
Other embodiments of the present invention comprises an automated system for
pretreating a section of pipeline, removing an amount of debris there from,
filling or bridging
a gap, joint or other discontinuity found therein, and sealing the same as
described herein.
A particular aspect of the invention is directed to a system for internally
filling a joint
or other discontinuity in a pipeline. The system includes a flexible conduit,
a fill device
removably connected to the flexible conduit, wherein the fill device is
constructed and
arranged to apply a fill material to an interior surface of said pipeline to
fill one or more gaps
in the pipeline, and a propulsion unit connected to at least one of the
flexible conduit and the
fill device that propels the flexible conduit through said pipeline.
The fill device can include a center carriage and at least one scraper coupled
to the
center carriage and constructed and arranged to contact an inner surface of
the pipeline to
move debris on the inner surface. The at least one scraper can be moveably
mounted to the
center carriage and constructed and arranged to be moveable between a
retracted position and
an activated position. The at least one scraper can be a plurality of
scrapers. The system can
further include an entry unit, coupled to the flexible conduit and coupled to
the propulsion
unit that is constructed and arranged to mate with alive pipeline. The fill
device can be
constructed and arranged to spray foam for filling gaps in a pipeline, and to
spray a sealant to
seal a gap in a pipeline. The fill device can be constructed and arranged to
spray fill material
in the presence of pressurized gas in the pipeline. The fill device can
include a carriage
having a first end and a second end, a spraying mechanism detachably connected
to the first
end of the carriage, and a plurality of adjustable legs, each having a first
end and a second
end, the first end connected to said carriage, and the second end constructed
and arranged to
contact an inner surface of the pipeline.
Another aspect of the present invention is directed to a method for internally
filling a
joint or other discontinuity in a live pipeline. The method includes attaching
an insertion duct
to the pipeline, inserting a filling unit through the insertion duct into the
pipeline, the filling
-5-
CA 02459953 2004-03-08
WO 03/024624 PCT/US02/29538
unit having a spraying mechanism to spray foam to fill the joint or
discontinuity, orienting the
filling unit in the pipeline adjacent to the joint or other discontinuity to
be filled using a
flexible conduit operatively attached to the filling unit, the conduit being
sufficiently rigid to
propel the filling unit, and the conduit being sufficiently flexible to
maneuver around bends
or other obstacles in the pipeline, and spraying an interior of the pipeline
at a desired location
with the foam.
The method can include spraying a sealant over the foam and clearing debris
from an area of
the pipeline around the joint or discontinuity prior to spraying the foam.
Clearing debris can
include activating at least one scraper coupled to the filling unit to contact
the interior of the
pipeline. The method can further include inserting a milling device into the
pipeline through
the insertion unit, and operating the milling device to treat an area around
the joint or
discontinuity.
Yet another aspect of the invention is directed to a system for internally
filling a joint
or other discontinuity in a pipeline. The system includes a flexible conduit,
means, coupled
to the flexible conduit, for applying a fill material to an interior surface
of said pipeline to fill
one or more gaps in the pipeline, and a propulsion unit connected to the
flexible conduit that
propels the flexible conduit through the pipeline.
The system can further include means for scraping debris from around the joint
or
other discontinuity, and means for inserting the means fox applying into a
live gas pipeline.
The system can also include means, coupled to the flexible conduit, for
applying a sealant
over the fill material in the pipeline, and means for monitoring application
of the fill material
to the interior surface.
Brief Description of the Drawings
For a better understanding of the present invention, reference is made to the
drawings,
which are incorporated herein by reference, and in which:
FIG. 1 is a detailed side view of a coating device and semi-flexible
containment tube
of one embodiment of the present invention showing the device situated inside
a section of
gas pipe;
FIG. 2 is a cross-sectional view of the containment tube showing the different
dedicated hoses, rods and tubes required for operation of the coating device
shown in FIG. l;
FIG. 3 is a schematic view of an excavation site showing an exposed length of
gas
pipe and a bypass system that allows the gas to remain flowing in the pipe;
-6-
CA 02459953 2004-03-08
WO 03/024624 PCT/US02/29538
FIG. 4 is a schematic view of an excavation site showing a section of gas pipe
removed and an end cap placed on an exposed end and a gas bypass system that
allows the
gas to remain flowing in the pipe;
FIG. 5 is a side view of a containment tube-pushing unit of the present
invention.
FIG. 6 is an enlarged side view of a fly drivewheel and idler wheel from the
containment tube-pushing unit shown in FIG. 5.
FIG. 7 is a side view of an entry unit used with embodiments of the present
invention;.
FIG. 8 shows the entry unit as shown in FIG. 7 attached to a gas pipe with a
coating °
apparatus of the present invention resting within the gas pipe;
FIG. 9 is a schematic view of an excavation site showing the entry unit shown
in FIG.
7 attached to an exposed end of gas pip;.
FIG. 10 is a schematic view of an excavation site showing the containment tube
pushing unit shown in FIG. 5 attached to the entry unit as shown in FIG. 7.
FIG. 11 is a schematic view of an excavation site showing a split sleeve
dresser entry
unit of one embodiment of the present invention attached to a gas pipe;
FIG. 12 is a schematic view of an excavation site showing the containment tube-
pushing unit shown in FIG. 5 attached to the split sleeve dresser shown if
FIG. 1 l;
FIG. 13 is a perspective view of a device in accordance with another
embodiment of
the present invention with scraper blades in an activated state;
FIG. 14 is a second perspective view of the device of FIG. I 3;
FIG. 15 is a perspective view of the device of FIG. 13 with the scraper blades
in a
retracted position;
FIG. 16 is a second perspective view of the device of FIG. 13 with the scraper
blades
in the retracted position;
FIG. 17 is a perspective view of the device of FIG. 13 with extension legs and
the
scraper blades in an insertion mode;
FIG. 18 is a second perspective view of the device of FIG. 13 with the
extension legs
and the scraper blades in the insertion mode;
FIG. 19 is a close-up view of a hinge mechanism of the device of FIG. 13;
FIG. 20 is a second close-up view of the hinge mechanism of the device of FIG.
13;
FIG. 21 is a third close-up view of the hinge mechanism of the device of FIG.
13;
FIG. 22 is a fourth close-up view of the hinge mechanism of the device of FIG.
13;
FIG. 23 is a fifth close-up view of the hinge mechanism of the device of FIG.
13;
CA 02459953 2004-03-08
WO 03/024624 PCT/US02/29538
FIG. 24 is a flow chart of a sealing and filling process in accordance with
one
embodiment of the present invention;
FIG. 25 is a cross-sectional view of a pipeline that has been treated using
the process
of FIG. 24;
FIG. 26 is a perspective view of a milling device in accordance with one
embodiment
of the present invention;
FIG. 27 is a second perspective view of the milling device of FIG. 26.
FIG. 28 is a third perspective view of the milling device of FIG. 26;
FIG. 29 is a fourth perspective view of the milling device of FIG. 26;
FIG. 30 is a perspective view of a combination milling and sealing device in
accordance with one embodiment of the present invention; and
FIG. 31 shows a diagram of a controller coupled to an umbilical in accordance
with
one embodiment of the present invention.
Detailed Description
One embodiment of the present invention will now be described with reference
to
FIGS. 1-12. Referring now to FIG. 1, a coating device, generally designated by
numeral 10,
is shown located resting on an inside surface 12 of a pipe 14. The coating
device 10 is
provided with a centering carriage 20. The centering carriage 20 has a front
end 16 and a rear
end 18. A manifold 82 is attached to the rear end 18. A containment tube 60 is
shown
attached to manifold 82. An air motor 38 is mounted inside the front end 16 of
centering
carriage 20. Air motor 38 turns a rotating slotted head 40. A static mixer 50
is fixed to the
side of centering carriage 20. Individual coating material components are sent
to the static
mixer 50 through intake tubes 86 and 88 where they are thoroughly mixed to
produce a
coating material 48. The coating material 48 is then sent through an outlet
tube 32 where it is
forced into a spray tip 36. Spray tip 36 then meters an appropriate amount of
coating material
48 into rotating slotted head 40, which centrifugally disperses coating
material 48 onto the
inside surface 12 of pipe 14.
The centering carriage 20 is provided with a plurality of adjustable-length
scissor-type
expansion legs 22 for support. Each scissor-type expansion leg 22 is attached
to a
compressed gas powered piston 58, which is mounted inside the reax end 18 of
centering
carriage 20. Wheel assemblies' 28a and 28b are attached to the ends of the
adjustable-length
scissor-type expansion legs 22. The wheel assemblies 28a and 28b are shown in
contact with
the inside surface 12 and allow for lateral movement of coating device 10
through pipe 14.
_g_
CA 02459953 2004-03-08
WO 03/024624 PCT/US02/29538
The scissor-type expansion legs 22 are shown having four hinged members 24,
26, 28, and
30. The number of hinged members may be increased or decreased to accommodate
different
diameters of pipe 14.
An illuminating explosion-proof monitoring camera probe 44 is attached to
centering
carriage 20, by way of a monitoring probe mount 34. An explosion-proof camera
probe cable
70 is attached at one end to the illuminating explosion-proof monitoring
camera probe 44 and
at the other end to a control console. The illuminating explosion-proof
monitoring camera
probe 44, which is powered by the explosion-proof camera probe cable 70, is
positioned to
allow an operator to locate sections of pipe 14 that require treatment by the
coating device 10.
The explosion-proof monitoring camera probe 44 lights the inside surface 12 of
pipe 14, and
relays images of the inside surface 12 back to the control console.
As the coating device 10 is progressed laterally through pipe 14 an operator
is able to
monitor joints or other discontinuities by viewing a monitor on the control
console. The
operator can remotely control the application of coating material 48 to the
inside surface 12
1 S of pipe 14. Upon discovery of a joint or discontinuity, a specific amount
of coating material
48 is metered onto inside surface 12.
In one embodiment, a preferred coating material 48 is two-part epoxy-type
elastomeric polyurethane sold under the name PLASITE PERMA-THANE 2300. Coating
material 48 is capable of filling and coating large joints or other
discontinuities. Coating
material 48 can be used in a variety of environments including pressurized
gas, air or oxygen.
Depending upon the desired thickness of coating material 48 required, an
operator can
reposition coating device 10 and repeat the coating process described above.
Referring now to FIG. 2, a cross-sectional view of containment tube 60 is
shown.
Containment tube 60 houses non-conductive sealant component hoses 62 and 64,
compressed
gas hoses 66, 68 and 78, sealed explosion-proof camera probe cable 70, exhaust
hoses 72 and
74, and an optional flexible stabilizing rod 80. Containment tube 60 serves to
protect the
various hoses, tubes and rods it surrounds from abrasion. Also, containment
tube 60 is
flexible enough to maneuver around tight corners and bends in pipe, and is
rigid enough to
provide for the lateral movement of the coating device I O in long lengths of
pipe.
Additionally, containment tube 60 serves to exhaust the gas used to power the
air motor 38
and operate the scissor-type expansion legs 22 outside pipe 14.
The non-conductive sealant component hoses 62 and 64 provide the individual
coating material components to the intake tubes 86 and 88, respectively. The
compressed gas
hose 66 provides compressed gas for manipulating piston 58, which contxols the
expansion
-9-
CA 02459953 2004-03-08
WO 03/024624 PCT/US02/29538
and contraction of the scissor-type expansion legs 22. Compressed gas hose 68
is used for
powering air motor 38, which in turn powers slotted spray head 40. The sealed
explosion-
proof probe cable 70 is used for powering, lighting and receiving information
from
explosion-proof monitoring probe 44. Exhaust hose 72 exhausts the compressed
and other
gases outside pipe 14. Compressed gas hose 78 supplies compressed gas for
purging any
unused sealant 48 from the coating device 10. The optional flexible
stabilizing rod 80
provides for additional rigidity within containment tube 60 and allows for
additional lateral
force to be applied to the coating device 10.
Referring now to FIG. 3,, a schematic view of an excavated section of live gas
pipe 14,
having a first section 202 and a second section 204 is shown. Tap holes 212
and 214 are
drilled in sections 202 and 204 respectively. Next, a temporary bypass 210 is
connected
between drilled holes 212 and 214 to allow the gas to remain flowing in pipe
14 while a
section is removed to allow for the insertion of coating device 10. The
temporary by-pass
210 is equipped with a pressure gauge 216 and a shut-off valve 218.
Holes 222 and 224 are drilled, tapped and plugged in section 202 and holes 226
and
228 are drilled, tapped and plugged in section 204 of the excavated section of
live gas pipe
14, between the drilled holes 212 and 214. The plugs are then removed from the
drilled holes
222, 224, 226 and 228, and inflatable bladders 232, 234, 236 and 238 are
inserted through the
drill holes 222, 224, 226 and 228 respectively.
Inflatable bladders 232 through 238 are inflated to create a gas impermeable
seal
within pipe 14. Depending upon the pressure and the direction of the gas
flowing in pipe 14,
fewer or additional inflatable bladders may be employed to control the flow of
gas in pipe 14.
Opening the shut-off valve 218 diverts the flow of gas in pipe 14 through the
temporary by-
pass 210. With inflatable bladders 232, 224, 226 and 238 still inflated, a
length of pipe
located between inflatable bladders 234 and 236 is removed.
Referring now to FIG. 4, the now exposed end 206 of section 202 is shown
sealed off
with cap 248. Inflatable bladders 232 and 234 may then be removed without
allowing gas to
escape from pipe 14. The gas in pipe 14 continues to flow through temporary by-
pass 210.
Referring now to FIG. 5 a pushing unit 150 is shown. FIG. 5 shows pushing unit
150
having a first end 156, a second end 158, and an outside surface 160. Pushing
unit 150
controls the movement of containment tube 60 in pipe 14, which in turn
controls the lateral
movement of coating device 10. A power mechanism 154 is attached to outside
surface 160.
A control mechanism 152 is operatively connected to power mechanism 154 and
controls the
rate at which power mechanism 154 operates. Containment tube 60 is shown
entering
-10-
CA 02459953 2004-03-08
WO 03/024624 PCT/US02/29538
pushing unit 150 through first end 156 and exiting pushing unit 150 through
second end 158.
A plurality of flywheels 162 are powered by power mechanism 154 and operate to
maneuver
containment tube 60 through pushing unit 150 and into and out of pipe 14.
FIG. 6 shows an enlarged side view of a single flywheel 162, having a curved
inner
surface for receiving containment tube 60.
Referring now to FIG. 7 a side view of a preferred insertion duct 240 is
shown.
Insertion duct 240 has a first end 242 and a second end 244. Insertion duct
240 is fitted with
a gate-valve 246 in second end 244. Gate valve 246 closes to form a gas
impermeable seal
about containment tube 60, which permits containment tube 60 to pass through
it while
preventing gas from escaping from pipe 14. Insertion duct 240 is shown having
a preferred
curve shape. This design facilitates the insertion of containment tube 60 and
coating device
10 into pipe 14 and allows for a smaller section of pipe 14 to be removed. A
straight or other
shaped insertion duct may also be used.
Referring now to FIG. 8 insertion duct 240 is shown attached to a section of
gas pipe
14. Coating apparatus 10, as shown in FIG. l, is shown situated in pipe 14.
Referring now to FIG. 9, second end 244, of insertion duct 240, is shown
bolted or
otherwise fastened to the now exposed end 208 of pipe 14.
Referring now to FIG. 10, second end 158, of pushing unit 150, is shown
attached to
first end 242 of insertion duct 240. Prior to bolting or otherwise fastening
pushing unit 150 to
insertion duct 240, containment tube 60 is inserted through pushing unit 150
and attached to
coating device 10. Coating device 10, attached to containment tube 60, is then
inserted into
first end 242 of insertion duct 240, through gate-valve 246 and into pipe 14.
Second end 158
of pushing unit 150 is then secured to first end 242 of insertion duct 240.
After pushing unit
150 is secured to insertion duct 240 inflatable bladders 236 and 238 are
deflated and removed
and drill holes 226 and 228 are plugged.
An operator can then laterally relocate coating device 10 hundreds of feet
down pipe
14 away from section 204 to a desired location with control unit 152. Control
unit 152 adjusts
the rate of speed of power mechanism 154, which in turn controls the speed of
flywheels 162.
Flywheels 162 feed containment tube 60 into pipe 14, which laterally moves
coating device
10. The operator can then monitor the inside surface 12 of pipe 14 using the
images sent
back along explosion-proof camera probe cable 70 from the explosion-proof
monitoring
camera probe 44.
Once a joint or other discontinuity has been located the operator may then
remotely
apply coating material 48. The operator controls the thickness of coating
material applied to
-11-
CA 02459953 2004-03-08
WO 03/024624 PCT/US02/29538
inside surface 12 by controlling both the rate of lateral movement of coating
device 10 and by
controlling the flow rate of the individual sealant components. When the
operator has
finished coating and sealing a section of pipe 14 with coating material 48,
the static mixer 50,
the spray tip 36, the outlet tube 32 and the rotating slotted head 40 may be
purged of coating
material 48 by forced compressed gas provided by compressed gas purging line
78.
Once the desired length of pipe 14 leading away from section 204 is sealed,
pushing
unit 150, insertion duct 240 and coating device 10 are removed in reverse
order as above-
described and an end cap 248 is placed over exposed end 208.
To seal the length of pipe 14, leading away from exposed end 202, drill holes
236 and
238 are unplugged and inflatable bladders 236 and 238 are reinserted and
inflated. End cap
248 is removed from section 202 of pipe 14 and insertion duct 240 is mounted
to exposed end
206 in its place. Coating apparatus 10 is then inserted into section 202 and
pushing unit 150 is
attached to insertion duct 240. The inspection and treating procedure is the
same as described
above.
Referring now to FTGS. 11 and 12, a second method is revealed for inserting
coating
device 10 into live gas pipe 14. FIG. 11 depicts an excavated section of live
gas pipe 14. A
two-piece split-sleeve dresser 110, having a first end 102 and a second end
104, is put in
place and bolted around the outer circumference 24 of a section of live gas
pipe 14. Angled
sections 106 and 108, containing gate valves 126 and 128 respectively, are
then attached to
an outer surface 120 of the split-sleeve dresser 110.
FIG. 12 shows pushing unit 150 attached to angled section 106. Pushing unit
150
controls the lateral movement of coating device 10 in the same manner as
described above.
Once the desired length of pipe 14 has been treated and inspected using
coating device 10,
then the coating device may be removed from pipe 14.
Prior to the attachment of pushing unit 150, a drilling unit is mounted to a
faceplate
132 of angled section 106. Gate valve 126, located within angled unit 106, is
opened as the
drilling unit drills a hole 142 (not shown) through the two-piece split-sleeve
dresser 110 and
into pipe 14, at the point where angled section 106 and split sleeve dresser
110 intersect.
Hole 142 is large enough to allow coating device 10, attached to containment
tube 60, to be
inserted into pipe 14. Gate valve 126 is then closed and the drilling unit is
removed.
Containment tube 60 is threaded through pushing unit 150 and attached to
coating
device 10. Coating device 10 is then inserted into angled section 106. Second
end 158 of
pushing unit 150 is then bolted or otherwise fastened to face plate 132 of
angled section 106.
An inflatable packing gland 138 is then inserted into pushing unit 150 and is
positioned
-12-
CA 02459953 2004-03-08
WO 03/024624 PCT/US02/29538
around containment tube 60, to form a gas impermeable seal. Inflatable packing
gland 138
prevents gas from escaping pipe 14 while allowing containment tube 60 to pass
through hole
142 into pipe 14. Once inflatable packing gland 138 is in place, gate valve
126 is opened and
coating device 10 is pushed through hole 142 and into pipe 14.
A length of gas pipe section leading away from split sleeve dresser end 104,
may be
inspected and treated in the same manner as described above. First, an
operator relocates the
coating device 10 the desired distance down pipe 14. The operator then
maneuvers the
coating device 10 back to the split sleeve dresser 110 inspecting and coating
joints or other
discontinuities along the way. After the section of pipe leading away from
split sleeve
dresser end 104 has been treated, the coating device 10 is returned to angled
section 106.
Gate valve 126 is closed and the pushing unit 150 is removed. A cap 136 (not
shown) is then
bolted or otherwise fastened to face plate 132.
In order to inspect and treat the section of gas pipe extending away from
split sleeve
dresser end 102, a hole 144 (not shown) similar to hole 142, is cut into pipe
14, within angled
section 108 and through the two-piece split-sleeve dresser 110. Hole I44 is
large enough to
allow coating device 10, attached to containment tube 60, to be inserted into
pipe 14.
Coating device 10 is then inserted through angled section 108 through hole 144
and into pipe
14. After the section of gas pipe extending away from split sleeve dresser end
I 02 has been
inspected and treated, and coating device 10 has been removed, a cap 146 (not
shown) is
secured to face plated 134. After both sections of pipe 14, leading away from
the split sleeve
dresser 110 have been inspected and treated, and angled sections 106 and 108
have been
capped, the split sleeve dresser 110 is left in place and the excavation is
filled in.
Depending upon the amount of build up of debris on inside surface 12 of pipe
14, a
cleaning device may be attached to containment tube 60 and fed through pipe 14
using the
same methods as described above to recondition the pipe. Preferred cleaning
devices are
sel~ centering, powered by compressed air, and are explosion proof. After
reconditioning, the
cleaning device is removed to allow for the insertion of coating device 10.
Tn embodiments described above, a self propelled coating device is inserted in
pipeline to seal discontinuities in pipelines. The embodiments described above
are
particularly useful for sealing relatively small discontinuities in pipelines.
As will now be
described, in additional embodiments of the present invention, apparatus and
processes are
provided that are particularly useful for filling larger dimension and unique
gaps. At seams
in pipelines, relatively large gaps can form. When multiple coats of sealant
are applied to
large gaps, an effect known as telegraphing can occur where the crack gets
deeper without the
-13-
CA 02459953 2004-03-08
WO 03/024624 PCT/US02/29538
sealant ever filling it or bridging across it. In embodiments of the invention
described below,
prior to the application of sealant to a gap, a filler is applied to the gap,
allowing the sealant
to smoothly bridge the gap. Further, in embodiments described below, using
apparatus of the
present invention, debris can be removed from a pipeline prior to the
application of filler
and/or sealant for the purpose of exposing the pipe wall in order to provide a
surface for
adhesion and sealing.
Referring to Figs. 13 and 14, a debris mover and gap-bridging device 310 in
accordance with one embodiment of the present invention will now be described.
The device
310 may be coupled to a containment tube (also referred to herein as an
umbilical) and
propulsion device, like those described above, to allow the device 310 to be
inserted into and
propelled through a pipeline. The device 310 includes a centering carriage 320
having a front
end 316 and a rear end 318. The manifold of a containment tube, like manifold
82 described
above, couples to the rear end 318. The device also includes three adjustable-
length scissor-
type expansion legs 322, a spray head 336, blade actuators 331, a laser 335, a
camera 337,
and scraper blades 339, 341 and 343. In addition, as understood by those
skilled in the art,
control cables (not shown for clarity) extend from the umbilical to devices
mounted on device
310 for monitoring and controlling the devices.
The expansion legs 322 are similar to expansion legs 22 described above and
operate
in the same manner to provide support for device 310 in a pipeline and to
center the device in
the pipeline. As in the previous embodiments, the expansion legs are
retractable to facilitate
insertion of the device into a pipeline. The expansion legs are shown in an
expanded state in
FIGS 13 and 14 and in a retracted state in FIGS 17 and 18.
The spray head is coupled to the centering carriage 320 using a motor/rotary
union
317 that in one embodiment provides for 360-degree rotation of the spray head
in a single
rotational direction. In other embodiments, the motor/rotary union can
reciprocate, rotating
in one direction and then the other. The laser 335 and camera 337 are mounted
to the spray
head. The camera is coupled through the containment tube to a controller
mounted outside of
the pipeline to provide an operator with images of the interior of a pipeline,
and the laser, also
controlled by the controller, is used to provide illumination of the interior
of the pipeline.
Electrical signals and power for the spray head are provided though a slip-
ring built into the
rotary union.
Each of the scraper blades 339, 341 and 343 are coupled to two of the
expansion legs
using first hinges 346 fox one end of the blades and second hinges 348 for the
other end of the
blades. The first hinges 346 are coupled to one of the actuators 331 though a
piston. The
-14-
CA 02459953 2004-03-08
WO 03/024624 PCT/US02/29538
actuators use the pistons to move the scraper blades between a folded position
shown in
FIGS. 1 S and 16 and the activated state shown in FIGS. 13 and 14. In the
embodiment
shown in FIGS. 13-16, each of the scraper blades includes two rows of teeth
3S8 mounted on
a frame 360. The scraper blades are sized such that in the activated state,
the three blades
S combine to form a substantially circular scraper having an outer diameter
that is
approximately equal to the inner diameter of a pipeline. In one embodiment,
the material
used to make the blades is stainless steel spring steel, and the blades are
manufactured by
cutting the tooth pattern from flat stock stainless steel, and then bending up
the teeth and
spring tempering the blades.
When the expansion legs are in the retracted state, as shown in FIGS. 17 and
18, the
scraper blades become further bent to allow the device 3 I O to be inserted
into pipelines using
an insertion tube having a diameter smaller than the diameter of the pipeline.
In one
embodiment of the present invention, an insertion device having a diameter of
12 inches is
used for pipelines having inner diameters from 16 to 24 inches, so the device
310 is
1 S collapsible to a diameter much smaller than the pipeline for which it is
designed for use. The
thin stainless steel used for the frame 360 and separable teeth 3S8 allows the
scraper blades to
have sufficient rigidity when activated yet be flexible enough to bend inward
with the
retraction of the expansion legs. The flexibility of the scraper blades is
also advantageous in
the activated states in that it allows the scraper blades to bend with the
expandable legs to
adjust for non-uniform pipes.
The operation of the activators 33 l and associated hinges 346, 348 for moving
the
scraper blades will now be discussed with reference to FIGS. 19-23, which
provide partial,
close-up views of the activators and hinges. In FIG. 19, the device 310 is in
the insertion
mode with the legs in the retracted state and the scraper blades retracted and
bent, in FIG. 20,
2S the device 310 is in the travel state with the legs extended and the blades
retracted, and in
FIG. 21, the device 310 is in the scrape mode with the legs extended and the
scraper blades in
the activated state. With reference to FIG. 19, each actuator 331 is coupled
to a piston 362,
which in turn is rotatably coupled at a first pivot point 370 to a first
section 366 of one of the
first hinges 346. The first section 366 of the first hinge 346 is coupled to a
second section
368 of the first hinge 346 at a second pivot point 372. Each scraper blade is
coupled to the
second section 368 of the first hinge. The first hinge 346 is coupled to the
leg 322 using a
mounting block 364. The first hinge is coupled to the mounting block 364 using
a screw 371,
which also functions as a third pivot point for the first hinge. Each mounting
block 364
supports the first hinge for one scraper blade and the second hinge for an
adjacent scraper
-1S-
CA 02459953 2004-03-08
WO 03/024624 PCT/US02/29538
blade. Each of the second hinges (as best seen in FIG. 22) includes a first
section 376 and a
second section 378. The second hinges are substantially identical to the first
hinges, except
that the second hinges are not coupled to an actuator through a piston.
The actuators and hinges operate to control the scrapers as follows. The
actuators 331
are coupled to the controller outside of the pipeline through air lines (not
shown). The
actuators have a retracted position and an extended position, and in one
embodiment of the
invention, the actuators are implemented using an air cylinder actuator, such
as that
manufactured by Festo Corporation of Hauppauge, NY, under part no. DZF-1/2-1-A-
PA. In
the insertion state and in the retracted/travel state of the device 310, the
actuators are in the
retracted position as shown in FIGS. 19 and 20, while in the activated state
of the device 310,
the actuators are in the extended position. In the insertion state, the
combination of the
flexibility of the scrapers and the tension on the scrapers caused by the
folding of the
expansion legs, causes the scrapers to be retracted and bent, so that the
device can be inserted
into a pipeline. In this state, as shown in FIG. 19, the first section 366 of
hinge 346 is rotated
to be substantially parallel with the piston 362, and the second section 368
of the hinge 346 is
rotated to be substantially parallel with the first section 366.
When the expansion legs are moved to the travel state, as shown in FIG. 20,
this
causes the second hinge section 368 to rotate at pivot point 372, and also
causes a slight
rotation of the first hinge section 366 at point 370. The amount of rotation
that occurs is
dependent on the dimensions of each of the parts, but in embodiments of the
invention, when
the legs are extended, the scrapers still remain retracted until the actuator
is actuated. When
the actuator is controlled to move to the extended position, then the piston
362 extends
causing the hinge 346 to move. The force caused by the movement of the piston
causes the
first section 366 of the hinge to rotate at pivot point 370 and causes the
second section of the
2S hinge 368 to rotate at pivot point 372, as shown in FIG. 21, thereby
causing the scraper blade
339 to move to the extended position. In the embodiment shown, the hinge 346
rotates 90
degrees at pivot point 370. The design of the hinges and scrapers provides for
rotation of
each of the scrapers using only one actuator. Rotation of the second hinges
348 are caused by
the translation of the scrapers due to the extension of the pistons, as shown
in FIG. 22. As
shown in FIG. 23, the mounting block 364 has a stop 380 that limits the
movement of the first
section 366 when pushed by the piston 362. The stop 38 is positioned to keep
the second
section, and therefore the scraper, perpendicular to the centerline of the
device 310. Further,
during the scraping action by the scrapers on the inside wall of a pipeline,
the stop 380
maintains the scraper substantially perpendicular to the centerline.
-16-
CA 02459953 2004-03-08
WO 03/024624 PCT/US02/29538
The spray head 336 is configured to spray a two-part, expandable, urethane
foam 360
degrees within a pipeline to fill gaps in the pipeline. In one embodiment, the
spray head
includes a plural-component air purge spray gun available from Gusmer
Corporation of
Lakewood, NJ under the trade name GAP. In the embodiment shown in the
drawings, the
gun is mounted at a right angle to the centerline of the carriage to cause the
foam to be
sprayed on the walls of the pipe. In other embodiments, the spray gun is
mounted along the
centerline, and a right angle adapter is added to the output of the spray gun
to cause the
material to contact the inner surface of a pipe. In one embodiment, the
material used with the
spray head is a two part foam that is supplied to the spray head through the
umbilical using
two separate feed hoses, and the spray gun is designed to receive the two feed
hoses and mix
the final compositions within the gun. In one embodiment, the material used is
available
from Preferred Foam Products of Trenton, NJ, under part no. 9800- 2506.
Operation of the device 310 will now be described with reference to FIG. 24,
which
shows a process 400 of the present invention. When it is desired to fill and
seal seams and
other gaps in a pipeline, then at stage 402 of the process, the device 310 is
first inserted into
the pipeline. For a live gas pipeline, one of the procedures described above
for device 10 can
be used to insert device 310 into the pipeline. In one embodiment, the front
of the carriage
having the spray head is inserted first. After insertion of the device 310, at
stage 404, the
device is propelled some distance down the pipeline. In one embodiment, the
device is
propelled using the containment tube pushing unit described above, under the
control of the
controller. The distance that the device is propelled may be determined either
based on
characteristics of the pipeline, i.e. an end of the pipeline is reached, or
based on the length of
the umbilical cable. While propelled down the length of the pipeline, the
laser and camera
can be used to locate gaps to be treated.
Once the device reaches the end, the propulsion system begins bringing the
device
back toward the insertion point, stage 406, treating each of the seams and/or
gaps along the
way. When a seam is reached, stage 408, the scraper blades are activated just
prior to the
seam, and debris is removed from the area just before and after the seam.
Depending on the
amount and type of debris at a seam, as determined by images generated by the
camera, the
device may be moved back and forth several time to fully scrape all debris
around the seam,
stage 410.
Once the debris has been removed, at stage 412, the device is moved further
towards
the insertion point to align the spray head with the seam. The laser and the
camera are used
to properly align the spray head with the seam. After alignment, at stage 414
filler material is
-17
CA 02459953 2004-03-08
WO 03/024624 PCT/US02/29538
provided to the spray head while the spray head is rotated 360 degrees to
apply filler to the
seam. After full rotation, the device is slowly moved so that the spray head
provides a coat of
filler material from a point just on one side of the seam to a point just on
the other side of the
seam so that the filler material completely bridges the seam. After a coat of
material has been
sprayed on, at stage 416, the camera is used to view the seam to determine if
further coats of
material are needed. If a determination is made that further coats are needed,
then stages 414
and 416 are repeated. Once the seam has been sufficiently filled, the device
310 moves to the
next seam and continues to repeat this process 420, until the device has
returned to the
insertion point and is removed from the pipeline.
In one embodiment of the present invention, multiple coats of filler material
are
provided at each gap with a first coat acting as an insulator between the
pipe, which is often
relatively cool, and the insulating material, which in one embodiment is
applied at a
temperature of approximately 120 degrees Fahrenheit. The first insulation coat
allows the
remaining coats) to properly cure and maintain a foam-like consistency.
After the device 310 is removed from the pipeline, the device 10, described
above,
may be inserted into the pipeline to provide sealant over the filler material
to completely seal
a gap. FIG. 25 shows a section of pipeline 450 having a gap 452 at a joint
between a first
pipe section 453 and a second pipe section 454. The pipeline 450 been treated
using the
process described above. A layer of filler material 457 is shown filling the
gap in the pipe
and a layer of sealant 456 covers the filler material and extends past the
filler material in the
pipe. Also shown in Fig. 25 is a gasket 458 and filler 460. The gasket 458 and
filler 460 are
representative of typical sealing materials used to seal gas pipes at the time
of initial
installation of a pipeline, and these typically degrade over time.
In the embodiment described above, separate fill and sealant devices are
provided. In
another embodiment, the fill device may be configured to spray both the fill
material and the
sealant using one spray head or using two separate spray heads on the same
device. In the
situation where one spray head is used, after the fill process is complete,
the lines and the
spray head can be purged from the controller, and sealant can be sent to the
device instead of
fill material. In still other embodiments, only one material may be used to
both fill and seal a
3 0 gap.
In embodiments of the present invention, in addition to removing debris using
scrapers as described above, it may also be desirable to provide a more
thorough cleaning or
scraping of the interior of a pipe to ensure that the sealant properly seals
the pipe. In another
embodiment of the present invention, a milling device 510 is provided that can
be inserted
-18-
CA 02459953 2004-03-08
WO 03/024624 PCT/US02/29538
into a pipeline in the same manner as the devices 10 and 310 described above.
The milling
device 510, which will now be described with reference to FIGS. 26-29 provides
a milling
operation on each side of a gap prior to the application of filler and sealer.
Debris generated
by the milling operation can be removed from the area to be treated using the
scraper
described above. In addition, in some embodiments of the invention, gas
nozzles that eject
jets of pressurized air (or a compatible gas in gas lines) can be used to
clear debris. Still
further, debris can also be cleared during a purge operation of the spray head
during which
gas is ej ected from the head.
The milling device 510, in one embodiment of the present invention, is mounted
on
the centering carriage 320 of the device 310 and includes the expansion legs
322 and the
motorlrotary union 317 of the device 310. In addition, the milling device 510
includes a
support bracket 512 that supports a piston 514 mounted to a telescoping
assembly 516. The
piston is extendable under control of the controller to move the telescoping
assembly towards
the inner wall of a pipeline where milling is to occur.
The telescoping assembly 516 includes a milling tool motor 518, a chain
sprocket
520, a drive chain 522, a base plate 524, a side plate 526, a milling tool
528, and a control
foot 530. The milling tool motor 518 is mounted to the side plate 526 and is
controlled by the
controller, located outside of the pipeline and coupled to the milling tool
motor through
control lines. The chain sprocket 520 is coupled to the drive chain 522 and to
the milling tool
528, such that the milling tool is driven by the milling tool motor. The
control foot, the chain
sprocket and the milling tool are coupled to the base plate 524.
During operation, the piston 514. is extended under control of the motor until
the
milling tool contacts the inside surface of the pipeline. The motor is then
turned on, and the
inside of the pipeline, where sealant is to be applied, is ground down using
the milling tool.
The motor/rotary union 317 rotates the support bracket, and accordingly the
milling tool 360,
degrees. The control foot is adjustable to set a depth of the cut by the
milling tool in the
pipeline. When a set depth is reached during a milling operation, the curved
outer surface of
the control foot contacts the inner surface of the pipeline to prevent the
milling device from
cutting deeper into a pipeline. In addition, many old pipes are oval rather
than round in
cross-section, and the foot acts as a restraint and allows the milling device
to follow the
nonuniform curvature of a pipe's circumference. As with devices 10 and 310,
the milling
device 510 can be inserted into a pipeline, moved down the pipeline, and then
treat surfaces
of the pipeline as the milling device returns to the insertion point.
-19-
CA 02459953 2004-03-08
WO 03/024624 PCT/US02/29538
In certain embodiments of the present invention, the sealing operations
dictate that it
would be more convenient, and increase quality if the joint filling and
sealing operation
immediately follow the debris moving operation. The reason this is important
is the in situ
robots would otherwise have to drive over the cleaned area and could drag a
significant
S amount of the umbilical along with it thus depositing debris that had
previously been moved
from an area back into the cleaned area. Therefore having a debris mover on
the in situ robot
performing the sealing service is a great advantage.
In one embodiment of the present invention, which will now be described with
reference to FIG. 30, a combination multifunctional device 610 is provided.
The device 6I0
includes a spray and debris moving device 612, a milling device 614 and a
tractor robot 616.
The spray and debris moving device may be implemented using device 310,
described above,
modified to spray both f 11 and sealant, as also described above. The milling
device 614 is
similar to milling device 510, except that the carriage and support bracket in
the device are
designed to receive the umbilical and allow it to pass through to the device
612.
The tractor robot 616 is used to pull the umbilical through the pipeline and
to push
devices 612 and 614 through the pipeline. The tractor robot is used with the
device 610 to
push the device through a pipeline in place of the push rod system described
above for the
other embodiments. The tractor robot provides additional propulsion that is
useful when
pushing the heavier combined device and can increase the range that the device
can be
pushed down the pipeline. In other embodiments, the device 610 may be
implemented in
conjunction with the push rod system so that the tractor robot is not needed.
The txactor robot includes a centering chassis 622, a front end 624, a back
end 626,
three wheel assemblies 628, each of which is coupled to the centering chassis
using folding
brackets 630, that can fold down to allow insertion of the txactor robot. The
back end 626
receives an umbilical coupled to the controller located outside of the pipe
line, and passes the
umbilical out of the front end 624 to device 614. The tractor robot can be
propelled using a
hydraulic motor or electric motor mounted in the center of the tractor robot
and coupled to
the wheels through flexible drive shafts mounted in or adjacent the folding
bracket. In
another embodiment, high-power miniature motors can be mounted directly in the
wheel
assemblies. Further, in still another embodiment, each set of wheels can be
replaced by a
track assembly.
The device 610 is inserted into a pipeline and moved some distance down the
pipeline. The insertion into the pipeline can be accomplished using
embodiments of the
invention described above, except that an extension tube may be needed for the
entry system
- 20 -
CA 02459953 2004-03-08
WO 03/024624 PCT/US02/29538
due to the length of the combined system. Specifically, referring to Fig. 10
for example, an
extension tube can be inserted between insertion duct 240 and the end 158 of
the pushing
unit. Similarly, the insertion duct 240 could be altered to have more of a
bend radius and
extended. Alternatively, the excavation hole could be made larger with the tap
holes moved
further from the end of the pipe to provide Length of pipe to insert device
610. While moved
down the pipeline, the milling tool and the scrapers are maintained in the
travel mode, and are
not in contact with the pipeline. The device 610 is then moved back to the
insertion point,
and at each gap that is to be filled, the milling tool first operates on both
sides of the gap to
provide a smooth surface for the sealant. Next, the scrapers on device 612
clear any debris
from the area around the gap. The spray head on device 612 then sprays filler
into the gap,
and after spraying the filler, sprays sealant across the gap. Once all gaps
have been filled and
sealed, the device 610 is removed from the pipeline.
In embodiments of the present invention described above, a foam filler
material is
used to fill gaps. The foam expands when setting up (curing) thus spreading
into the gap to
be filled as opposed to sagging out of it as with typical non-foaming
coatings.
In embodiments of the present invention, various spray tips may be used on
spray
heads for applying the gap bridging foam or other gap filling material. In one
embodiment of
the present invention, a fan tip is used. In certain other embodiments, the
fan tip may be
rotated with respect to the center line of the pipeline so that a wider area
of material may be
laid down with a single pass of the spray head.
Other advantages include having a debris mover with different scrapers for
different
debris, enhancement of the mixing champers on the spray guns to accommodate
both foam
and sealant and continuous rotation of the spray nozzle or continuous rotation
of the spray
gun.
The gas sealing operation of the present invention is designed to address the
issue or
problem of filling bell joint seams (gaps). Other pipe sealing applications,
such as epoxy
coating water pipes and grouting sewer pipes, may well benefit from this
processes and
apparatus of the present invention. Certainly any situation where a robot was
required to
inspect and/or fill a gap would consist of a potential commercial application
for embodiments
of the invention.
In the present invention, a debris mover and a milling device work mostly in
conjunction with the gap filler but both would certainly be beneficial for any
service robot in
a piping system which was required to perform both a debris or sediment moving
operation in
conjunction with the service being performed albeit - pipe wall inspection,
tapping, etc.
-21 _
CA 02459953 2004-03-08
WO 03/024624 PCT/US02/29538
In embodiments of the present invention described above, a controller outside
of the
pipeline is described as controlling a number of operations of the devices
inserted in a
pipeline. The controller is shown in FIG. 31. In embodiments of the present
invention, the
controller includes various automation sensors, components, computers and
software coupled
with custom programming that oversees and assists in the control and
application of a pipe
sealing system. In one embodiment, the controller can be incorporated in a
truck or trailer to
facilitate moving the controller to different excavation sites. The controller
automates many
of the functions and aspects identified above increasing and enhancing safety,
reliability,
repeatability and process balance control that are both mundane and require a
high skill level.
In embodiments of the present invention, the controller provides a means to
log entities seen
through video cameras on the robot in the pipe system and conveniently save
this data for
future use in an electronic computer readable format as well as document the
work performed
by electronic video capture of before and after photos of the areas sealed.
Since these
operations are performed in the field, the controller also facilitates the
quick transportation of
1S the job specific data to a home office, or other facility, by e-mail since
the data is in an
electronic format. The home office can then quickly produce reports for
distribution and
archive as well as billing information in a more efficient manner than
otherwise conceivable.
According to one embodiment of the present invention, the controller includes
sensors, transducers, motion control devices, a control computer, custom
developed
programming and a MMI (man-machine interface). The sensors and transducers
monitor the
state of the process providing data to the control program. The motion control
devices send
position data to the control program and receive motion instruction data from
the control
program allowing the control program to know the position of a driving element
such as a
motor as well as move the driving element a specified amount. The MMI
interfaces with the
operator and displays information and data from the control program on it's
screen, provides
the interface for data and command input to the control program and also
flashes warning
signals indicating a problem or inappropriate requested action. The control
computer
processes the inputs and outputs, runs the computer program, and writes the
appropriate data
to an electronic storage device. The custom developed programming contains the
code that
performs all the desired functions of the automation.
In embodiments of the present invention, transducers, associated with the
controller,
can be located at desired points in the system and can transmit information to
a remote
indicator or control computer or a combination of both. By transmitting the
sensor
information to the controller's computer, the computer can then compare the
information and
-22-
CA 02459953 2004-03-08
WO 03/024624 PCT/US02/29538
detect and alarm a condition much quicker and more effectively than a human
could
manually. Since weight of the entire system is also a concern, by displaying
the sensor input
information on the MMI system components are eliminated or otherwise combined
into one
device vs. many thus minimizing the weight of the entire system.
Embodiments of the present invention rely on precise motion control for the
most
effective application of the sealant to the pipe walls, and the automation
provided by the
controller enhances this process significantly and is much more effective than
previously
utilized manual systems. Many different factors such as pipe size, ambient
conditions,
substrate conditions etc. influence the operating parameters of the process
and different
recipes (or condition dependent operational parameters) can be stored in the
controller to
provide a reference for the operator to address each condition. This process
is significantly
streamlined with the automation, and quality control is enhanced by virtue of
the automation
systems ability to monitor the process more effectively than a human. Further,
the controller
reviews and controls, on a continual basis, flow rates, heat rates,
application speeds, timing
issues etc. Automation performs this task more efficiently than a human and
minimizes the
operator's requirements for this aspect of the process.
By utilizing the controller, system quality control is enhanced in a way that
is
otherwise not available without significant human intervention susceptible to
human error.
Also the skill level requirements of an operator have been significantly
reduced with the
automation. Since the process of sealing pipelines deals with potential
disruption of utilities
and often requires supervision and Iabor by the owners of the utilities,
anything that can
reduce the amount of time to perform the service minimizes the efforts and
disruption.
A desired and or required aspect of the sealing services is to provide a
document of
the work performed. Prior to the present invention, this was typically
accomplished utilizing
video tape. Video tape is an effective means of documentation, however it
requires sitting
through the viewing of the tape and fast forwarding to the relative
information and or editing
the tape to overlay with text identification information. The automation
system of
embodiments of the present invention has the capability to capture snap shots
and video while
simultaneously overlaying description information critical for documentation
purposes.
Manual editing or editing of the video while the service is performed is labor
intensive and
detracts from the service or requires additional labor.
The controller in embodiments of the present invention may also be used to
perform
inspection services of the pipe Line. Further, in embodiments of the
invention, global
- 23 -
CA 02459953 2004-03-08
WO 03/024624 PCT/US02/29538
positioning systems can be used to detect, map and or record the exact
position of the robot or
other device within a pipeline.
A feature of the present invention is the streamlining of the process, which
significantly reduces human requirements and significantly increases safety,
and quality
control. By streamlining the entire process with automation not only is on
site labor reduced
but documentation and billing procedures are streamlined, further saving costs
and
minimizing human error aspects. The clients of the process benefit by
receiving the
information more quickly and in a more user friendly format at a reduced cost
than would
have otherwise been deliverable (it would have cost more to process the
information to be
presented to the client). From a troubleshooting aspect, since the system has
the capability to
log operational data, one can review the operational parameters after the fact
and effectively
recreate the scenario, which lead to a problem, or failure, which could only
have been
available if someone had manually logged information on a continual basis
during system
operation. Embodiments of the invention facilitate the combination of
inspection and
rehabilitation services into one operation.
Because the available technology in complimentary industries seems to be
limited, the
automation system could be of use for other manufacturing industries, which
rely on sealant
application system performance and quality control issues or could benefit by
streamlining
their operations. In addition, certain embodiments of the present system may
be utilized for
natural gas distribution systems, but could be applied to a whole host of
other pipelines,
including but not limited to propane, water and or sewer pipelines.
In embodiments of the present invention described above, spray heads are used
to
spray foam and sealant in live gas pipes. In some embodiments, particularly
useful for high
velocity gas lines ox water lines, it may be desirable to install a bladder or
tape around the
area to be filled or sealed, prior to the sealing or filling process, to
prevent the high velocity
gas or water from misdirecting the sealant or foam.
Having thus described at least one illustrative embodiment of the invention,
various
alterations, modifications and improvements will readily occur to those
skilled in the art.
Such alterations, modifications and improvements are intended to be within the
scope and
spirit of the invention. Accordingly, the foregoing description is by way of
example only and
is not intended as limiting. The invention's limit is defined only in the
following claims and
the equivalents thereto.
What is claimed is:
-24-
