Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
INFLATABLE ISOLATION TOOL WITH ENHANCED MONITORING UNIT
INVENTOR: Guy Berube, Graham Brown, Joe Tuskan
ASSIGNEE: Car-Ber Investments Inc.
Field of the Invention
[0001] The present invention relates generally to an improved mechanical
assembly or
isolation tool for use in providing a sealing barrier within a pipe bore
during replacement of a
section of the pipe, and an enhanced monitoring unit for same.
Background of the Invention
[0002] In the fabrication of fluid flow systems, whether for the purposes of
conveying liquid
such as petro-chemicals, or gases such as natural gas, the use of conduits or
pipes is typical. As
pipes can be manufactured only to a finite length, various lengths or elbows
must be connected
together to structure the conduit fluid conveyance means. This is accomplished
by welding butt
ends of pipes together or to elbows etc., or alternatively, to weld the end of
a pipe to a butt flange
and to juxtapose two butt flanges together by means commonly known, for
example, use of bolts
through each juxtaposed annular portions of each butt flange. Generally, such
flanges co-
operatively employ gaskets as sealing elements. The welds are tested to
determine whether there
is any leakage since it is mandated that the amount of fluid escaping from any
weld or
flange/flange interface be reduced to allowable limits.
[0003] The problem relates to creating a safe environment for performing hot
work on
existing pipelines carrying hydrocarbon resources. Canadian Patent No.
2,847,874 (owned by
applicant) describes an isolation tool which safely isolates a line for hot
work to maintain safety
of personnel. The isolation tool is placed into the line upstream of where hot-
work is to be
performed. Once the isolation tool is properly installed and two outer seals
are established,
medium is brought to pressure in the annulus between the seals. Once this
pressure is
established, the seals are actively monitored by the technician to ensure that
no harmful vapors
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are passing beyond the isolation tool into the hot work zone. The problem
encountered by
applicant with this isolation tool is that as the pipe gets bigger, the
isolation tool needs to be
bigger also to seal with the bigger pipe. However, this results in a heavier,
more expensive tool
which is difficult to install or remove. There is also a need to be able to
monitor remotely rather
than in close proximity to the work zone.
10004.1 Accordingly, there is a need in the art for an improved isolation tool
which mitigates
the above problems.
Summary of the Invention
[0005] The present invention relates generally to an improved mechanical
assembly or
isolation tool for use in providing a sealing barrier within a pipe bore
during replacement of a
section of the pipe, and an enhanced monitoring unit for same. It was
surprisingly discovered
that by using the present invention, one or more of the following benefits may
be realized:
= The tool has a pair of identical inflatable front and back seal elements
positioned in the
mid-section of the tool by an annular subassembly which has been specifically
designed
to secure the front and back seal elements in position, preventing them from
dislodging
into the internal cavity of the tool. Having inflatable seals with a
significantly large
radial expansion capability in contrast to solid 0-ring material allows more
flexibility
since the tool can be used within a greater range of pipe diameters, thereby
enabling
many schedules for use with a single tool. This also translates into minimal
manufacturing costs (e.g., fewer sizes of isolation tools to manufacture) and
substantial
operational cost savings for both companies and their clients.
= The inflatable front and back seal elements deform in two directions to
reduce the risk of
leaks ¨ radially inwardly to press and seal against the annular subassembly
and radially
outwardly into sealing engagement with the pipe, thereby combining with the
outer
surface of the tool and the inner surface of the pipe to form a tightly sealed
annular space.
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= The tool "self-centers" within the pipe in its proper position as gas is
pumped into both
front and back inflatable seal elements simultaneously through a single gas
inlet of a
shared plumbing assembly; and provides a sealed annular volume. The tool may
thus
compensate for issues with out-of-round piping applications, which is a common
problem
for larger piping and can be time-consuming for technicians to deal with in
the field.
= The tool can be installed quickly since the tool "self-centers" and time-
consuming
torqueing of studs in a specific pattern is not needed. The technician needs
only to place
the tool within the pipe, adjust the support leg assemblies and gripper
inserts of the tool,
and pump air into the front and back inflatable seal elements until the tool
"self-centers"
within the pipe by the front and back seal elements sealing against the inner
surface of the
pipe. After use, the tool can be removed quickly since the technician needs
only to
deflate the air from within the front and back seal elements, and readjust the
gripper
inserts and support leg assemblies. This is a notably substantial improvement
in
comparison to prior art isolation tools, which require laborious, time-
consuming
assembly inside the pipe by piecing all components of the isolation tool in
place within
the pipe, and torqueing and tightening multiple studs according to a
predetermined
sequence.
= The tool includes gripper inserts which are moveable from resting
unactuated positions
within recesses to actuated positions to extend outwardly from the recesses to
contact and
grip the inner surface of the pipe. The gripper pads are conveniently moveable
and
adjustable to be tightened against the inner surface of various diameters of
pipe in order
to hold the tool stationary in its proper position within the pipe, and to
hold back pressure
without being moved out of the pipe. The tool is thus easy and quick to deploy
and
remains stationary and stable within the pipe during use. The gripper inserts
are formed
of stainless steel for material contact-compatibility considerations. In
particular, there is
little or no risk of carbon contamination of a stainless steel pipe because
the gripper
inserts are formed of the same material (i.e., stainless steel). Further, the
gripper inserts
do not damage the inner diameter of the pipe compared to other prior art
tools.
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= Provision of the gripper inserts eliminates the need to use a
commercially available
standard gripper kit to provide back pressure-retention capability required by
particular
jobs, nitrogen purges, line-stop work, etc.
= The tool includes support leg assemblies which assist with tool
installation and removal,
making the tool quick to deploy. The support legs include roller balls which
are smooth
and will not damage the bottom inner surface of the pipe. The roller balls in
the support
leg are conveniently moveable and adjustable via screw threads to different
distances to
accommodate various pipe diameters.
= The front plate, back plate, and annular subassembly are formed of
aluminum to make the
overall tool lightweight and easy to handle by technicians. The seals may be
formed
from different deformable, resilient materials (for example, nitrile rubber)
having varying
durometers (i.e. EPDM 60-durometer, Buna-N 50-durometer).
= The back plate defines multiple differently sized port connections to
provide any desired
connection with, for example, vent rod strings to address venting (i.e.,
steam, flare line,
nitrogen purge, etc.) or a liquid level alarm.
= The tool includes shoulder eye bolts, lugs, or both through which chains,
cable, rope, and
the like may be threaded to facilitate lifting. A technician may also simply
grip the lugs
to carry or handle the tool manually.
= The tool is electronically monitored by a separate enhanced monitoring
unit so that
information can be relayed back and forth to the technician ¨ for example,
pressure
testing, calibration, amount and pressure of air being pumped into the front
and back
inflatable seal elements, and alarm signal if either or both of the front and
back seal
elements should fail.
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= The enhanced monitoring unit provides analog pressure gauges, and a
"double warning"
by provision of digital pressure switches which measure pressure and display
digital
readings of pressure in green or red such that the readings are highly visible
to the
technician from a distance. The digital pressure switches are connected to a
flasher
which activates LED lights to blink, serving as a second back-up warning
signal to
accompany "red" readings. Visual signals are desirable where alarm bells or
sirens may
not be audible in a noisy environment or from a distance. However, audible
alarms may
also be provided.
= The technician can safely replace the damaged section of pipe downstream
from the tool.
A pump at ground surface may be used to circulate pressurized medium (for
example,
water) down into the sealed space of the annular subassembly and back up to
ground
surface. The medium (for example, water) is brought to pressure in the sealed
spaced
defined by the annular subassembly. The pressure of the medium, which can be
either
static or flowing, is displayed by the analog pressure gauges and digital
pressure
switches, monitored, and provides an indication in real time of seal leakage.
Observation
of the readings will inform the technician if there is a reduction in medium
pressure,
thereby indicating seal leakage.
= The tool can be used for hydrodynamic services. Instead of the medium
(for example,
water) remaining static in the sealed spaced defined by the annular
subassembly, the
medium can be circulated through the tool to remove heat away from the metal
of the
pipe and to protect the downstream or upstream piping from exposure to such
heat. In
one embodiment, the inflatable front and back seal elements can withstand a
temperature
greater than about 1100 F (or about 593 C).
[0006] In one aspect, the invention comprises an inflatable isolation tool for
positioning in a
pipe bore and providing a sealing barrier extending transversely across the
pipe bore for isolating
a section of the bore during replacement of a section of the pipe, the tool
comprising a linear
assemblage of components including:
CA 2997825 2018-03-08
a front plate defining recesses housing gripper inserts moveable from
unactuated
positions within the recesses to actuated positions extending outwardly from
the recesses to
contact and grip the inner surface of the pipe to hold the tool stationary
during operation;
a back plate carrying support leg assemblies for assisting installation and
removal of the
tool within the pipe bore;
an annular subassembly positioned between the front plate and the back plate,
and
comprising an annular core and an annular ring defining grooves for engaging a
pair of identical
front and back inflatable seal elements;
the front and back inflatable seal elements being resilient, deformable and
annular,
wherein when the front plate, the back plate, and the annular subassembly are
compressed, the
front and back inflatable seal elements are prevented from dislodging into the
interior of the tool,
and are inflatable simultaneously to be deformed radially inwardly against the
annular
subassembly and radially outwardly into sealing engagement with the pipe,
thereby combining
with the outer surface of the tool and the inner surface of the pipe to form a
tightly sealed annular
space.
100071 In another aspect, the invention comprises a monitoring unit for use
with the above
inflatable isolation tool. The monitoring unit comprises a housing, a front
panel subassembly, a
back panel, an electrical inlet, and a LED power supply. In one embodiment,
the front panel
subassembly comprises a pair of analog pressure gauges, and a pair of digital
pressure switches
for measuring pressure and displaying digital readings of pressure in color to
provide a first
visual signal, the digital pressure switches being electrically connected to a
flasher for activating
LED lights to provide a second visual signal.
[0008] Additional aspects and advantages of the present invention will be
apparent in view of
the description, which follows. It should be understood, however, that the
detailed description
and the specific examples, while indicating preferred embodiments of the
invention, are given by
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way of illustration only, since various changes and modifications within the
spirit and scope of
the invention will become apparent to those skilled in the art from this
detailed description.
Brief Description of the Drawings
[0009] The invention will now be described by way of an exemplary embodiment
with
reference to the accompanying simplified, diagrammatic, not-to-scale drawings.
In the drawings:
[00010] Figure 1 is an exploded perspective view of one embodiment of an
inflatable
isolation tool, showing all components in greater detail.
[00011] Figure 2 is a front view of the inflatable isolation tool shown in
Figure 1.
[00012] Figure 3 is a cross-sectional view of the inflatable isolation tool
shown in Figure
1.
[00013] Figure 4A is a perspective view of the front plate of the
inflatable isolation tool
shown in Figure 1.
[00014] Figure 4B is a front view of the front plate shown in Figure 4A.
[000/3] Figure 5A is a perspective view of a gripper insert of the
inflatable isolation tool
shown in Figure 1.
[00016] Figure 5B is a side view of the gripper insert shown in Figure 5A,
showing the
inner chamber in hidden lines.
[00017] Figure 5C is a cross-sectional view taken at section line I-I in
Figure 5B.
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[00018] Figure 5D is a side view of a bolt for insertion into the gripper
pad shown in
Figure 5B.
[00019] Figure 6A is a perspective view of the back plate of the inflatable
isolation tool
shown in Figure 1, showing the front face of the back plate.
[00020] Figure 6B is a front view of the back plate shown in Figure 6A.
[00021] Figure 6C is a cross-sectional view taken at section line I-I in
Figure 6B.
[00022] Figure 6D is a perspective view of the back plate of the inflatable
isolation tool
shown in Figure 1, showing the back face of the back plate.
[00023] Figure 6E is a perspective view of a support leg assembly
attachable to the back
plate shown in Figure 6D.
[00024] Figure 7A is an exploded perspective view of the annular
subassembly of the
inflatable isolation tool shown in Figure 1, showing the annular core, annular
ring, and annular
front and back inflatable seal elements.
[00025] Figure 7B is a cross-sectional view taken at section line I-I in
Figure 7A.
[00026] Figure 8A is a front view of one embodiment of an enhanced
monitoring unit for
use with the inflatable isolation tool of Figure 1.
[00027] Figure 8B is an exploded perspective view of the enhanced
monitoring unit main
housing subassembly shown in Figure 8A.
[00028] Figure 8C is an exploded perspective view of the enhanced
monitoring unit front
panel subassembly shown in Figure 8A, showing all inner components in greater
detail.
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Detailed Description of Preferred Embodiments
[00029] Before the present invention is described in further detail, it is
to be understood
that the invention is not limited to the particular embodiments described, as
such may, of course,
vary. It is also to be understood that the terminology used herein is for the
purpose of describing
particular embodiments only, and is not intended to be limiting, since the
scope of the present
invention will be limited only by the appended claims.
[00030] Where a range of values is provided, it is understood that each
intervening value,
to the tenth of the unit of the lower limit unless the context clearly
dictates otherwise, between
the upper and lower limit of that range and any other stated or intervening
value in that stated
range is encompassed within the invention. The upper and lower limits of these
smaller ranges
may independently be included in the smaller ranges and are also encompassed
within the
invention, subject to any specifically excluded limit in the stated range.
Where the stated range
includes one or both of the limits, ranges excluding either or both of those
included limits are
also included in the invention.
[00031] Unless defined otherwise, all technical and scientific terms used
herein have the
same meaning as commonly understood by one of ordinary skill in the art to
which this invention
belongs. Although any methods and materials similar or equivalent to those
described herein can
also be used in the practice or testing of the present invention, a limited
number of the exemplary
methods and materials are described herein.
[00032] It must be noted that as used herein and in the appended claims,
the singular
forms "a," "an," and "the" include plural referents unless the context clearly
dictates otherwise.
[00033j The present invention relates to a mechanical assembly or
"isolation tool" for use
in providing a sealing barrier extending transversely across the pipe bore for
isolating a section
of the bore during replacement of a section of the pipe, and an enhanced
monitoring unit for
same.
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100034] The invention will now be described having reference to the
accompanying
figures. The inflatable isolation tool (1) is shown unassembled in Figure 1,
and assembled and
ready to operate in Figure 3. The tool (1) is inserted into the bore of either
a horizontal or
vertical pipe, and seals against the pipe inner surface when in use. As used
herein, the term
"horizontal" means the orientation of a plane or line that is substantially
parallel to the plane of
the horizon. The term "vertical" means the orientation of a plane or line that
is substantially at a
right angle to the horizontal plane. In one embodiment, the pipe has an inner
diameter of about
20 inches or greater. The purpose of the tool (1) is to provide a sealed
barrier which prevents
flammable fluid from migrating within the pipe bore to the point where
cutting, welding or other
hot-work operations are to be conducted.
1000351 The tool (1) generally comprises the following components: an
isolation assembly
incorporating a linear assemblage of components including a front plate (10),
a front inflatable
seal element (12), an annular subassembly (14), a back inflatable seal element
(16), and a back
plate (18). As used herein, the terms "front" and "back" are used to describe
the positions of
various components of the tool (1). The term "front" refers to a position
closer to the open end
of the pipe. The term "back" refers to a position away from the open end of
the pipe. When the
components are compressed together, the axially spaced apart annular front and
back inflatable
seal elements (12, 16) are then inflated to deform in two directions to reduce
the risk of leaks ¨
radially inwardly to press and seal against the annular subassembly (14) and
radially outwardly
into sealing engagement with the pipe, thereby combining with the outer
surface of the tool and
the inner surface of the pipe to form a sealed annular space. A support leg
assembly (20) assists
with installation and removal of the tool (1) within the pipe bore.
[00036] The tool (1) is shown unassembled in Figures 1, 2 and 4A-7B to show
all the
components in greater detail.
[00037] Referring to Figures 4A-B, the front plate (10) is a circular disk
having a front
face (22), a back face (24), an outer edge (26), an inner edge (28), a
plurality of recesses (30), a
plurality of first holes (32), and a plurality of second holes (34).
CA 2997825 2018-03-08
[00038] The first holes (32) are disposed over at least a portion or the
entirety of the front
face (22) of the front plate (10). In one embodiment, the first holes (32) are
evenly distributed in
a spaced apart manner from adjacent first holes (32) over the front face (22).
In one
embodiment, a first hole (32) is positioned on each side of a recess (30). The
first holes (32)
extend through the front plate (10) from the front face (22) to the back face
(24) for receiving
elongated studs (36) therethrough which are secured by complementary hex nuts
(38) and
washers (39) to facilitate compression and assemblage of the components of the
isolation tool
(1), as shown in Figure 2.
[0003.9] The second holes (34) are disposed over at least a portion or the
entirety of the
front face (22) of the front plate (10). In one embodiment, the second holes
(34) are evenly
distributed in a spaced apart manner from adjacent second holes (34) over the
front face (22). In
one embodiment, a second hole (34) is positioned between adjacent recesses
(30) and between
two first holes (32). The second hole (34) partially extends through the front
plate (10) and
defines threads (not shown) for receiving a complementary threaded shoulder
eye bolt (40), as
shown in Figures 1-4A-B. In one embodiment, four second holes (34) are used
for a 24 inch
diameter tool (1) to receive four shoulder eye bolts (40). However, it is
contemplated that the
number and size of the second holes (34) may vary without departing from the
scope of the
present invention.
[00040] In one embodiment shown in Figure 1, the front face (22) includes a
pair of
opposed lugs (42) formed integral with the front plate (10) and projecting
inwardly away from
the outer edge (26) of the front plate (10). In one embodiment, lugs (42) are
provided on a tool
(1) having a diameter of about 30 inches or greater. On smaller tools (1)
having a diameter
ranging for example, from about 20 inches to about 24 inches, shoulder eye
bolts (40) are
preferred over lugs (42). The tool (1) may be lifted and moved using
conventional oilfield
equipment. Chains, cable, rope, and the like may be threaded through the
shoulder eye bolts
(40), lugs (42), or both to facilitate lifting. A technician may also simply
grip the lugs (42) to
carry or handle the isolation tool (1) manually. In one embodiment shown in
Figure 1, the front
face (22) includes one or more protrusions (44) formed integral with the front
plate (10) and
projecting inwardly away from the outer edge (26) of the front plate (10). In
one embodiment,
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CA 2997825 2018-03-08
the front face (22) includes two protrusions (44). The protrusion (44)
supports a label or other
tool information such as, for example, a serial number or other text.
1000411 The front face (22) defines recesses (30) which are positioned
along at least a
portion or the entirety of the outer edge (26) of the front plate (10). In one
embodiment, the
recesses (30) are evenly distributed in a spaced apart manner from adjacent
recesses (30) along
the outer edge (26) of the front plate (10). In one embodiment, eight recesses
(30) are used for a
36 inch diameter isolation tool (1). However, it is contemplated that the
number and size of the
recesses (30) may vary without departing from the scope of the present
invention. The recesses
(30) are configured for receiving and accommodating complementary moveable
gripper inserts
(48). In one embodiment, the recesses (30) are substantially rectangular-
shaped to receive and
accommodate rectangular-shaped gripper inserts (48). While the Figures
illustrate both
rectangular-shaped recesses (30) and gripper inserts (48), it will be
appreciated by those skilled
in the art that other shapes are included with the scope of the invention.
[00042] As shown in Figures 5A-C, the moveable gripper insert (48)
comprises a
substantially rectangular-shaped body (50) having a top (52), bottom (54), and
protruding edge
(56). As viewed in cross-section in Figure 5B, the top (52) is slightly
concavely curved and the
bottom (54) is substantially flat, while the sides (58a, 58b) are tapered. The
body (50) defines an
aperture (60) which extends through the body (50) for receiving a slotted
spring pin (62)
therethrough (Figure 4A). The slotted spring pin (62) comprises a cylindrical
pin rolled from a
strip of material with a slot to allow flexibility during insertion. The
slotted spring pin (62)
comprises a body having a diameter which is larger than the diameter of the
aperture (60), and a
chamfer on either one or both ends to facilitate inserting the pin (62) into
the aperture (60). The
spring action of the pin (62) allows it to compress as it assumes the diameter
of the aperture (60).
The body (50) of the gripper insert (48) defines an inner chamber (64)
configured to receive and
secure a hex bolt (66) having a head (68), threads (70), and a modified smooth
end (72), as
shown in Figure 5D. A portion of the smooth end (72) has been cut away during
manufacture to
define a stem (74).
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[00043] The front plate (10) defines a plurality of threaded recess
apertures (76) which
extend through the front plate (10) from its outer edge (26) to its inner edge
(28). When
assembled, the hex bolt (66) is threaded into the recess aperture (76) and
extends therethrough
into the inner chamber (64) of the gripper insert (48). As shown in Figures 5B-
C, the aperture
(60) overlaps with the inner chamber (64). Placement of the slotted spring pin
(62) through the
aperture (60) contacts the stem (74) of the hex bolt (66) to retain the hex
bolt (66) to the gripper
insert (48).
[00044] The hex bolt (66) can be rotated manually by the technician to move
the gripper
insert (48) from a resting unactuated position within the recess (30) to an
actuated position to
extend outwardly from the recess (30) to contact and grip the inner surface of
the pipe. The
gripper insert (48) defines a plurality of strip grooves (78) which are formed
in a longitudinal
direction on the top (52) of the gripper insert (48) in order to yield a
gripping, serrated non-slip
surface. The gripper inserts (48) are conveniently moveable and adjustable to
be tightened
against the inner surface of various diameters of pipe in order to hold the
tool (1) stationary in its
proper position within the pipe, and to hold back pressure without being moved
out of the tool
(1). The tool (1) is thus easy and quick to deploy and remains stationary and
stable within the
pipe during use.
[00045] The protruding edge (56) of the gripper insert (48) receives and
secures a
temporary or sacrificial 0-ring (not shown) which is thereby positioned
overtop the front plate
(10) in order to protect the front and back inflatable seal elements (12, 16)
from hot sparks or
slags.
1000461 As shown in Figures 6A-D, the back plate (18) is a circular disk
having front and
back faces (80, 82). The front face (80) may support a label (46) or other
tool information such
as, for example, a serial number or other text.
[00047] The back plate (18) defines a plurality of threaded holes (84)
which are positioned
over at least a portion or the entirety of the front face (80). In one
embodiment, the holes (84)
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are evenly distributed in a spaced apart manner from adjacent holes (84) near
the outer edge (86)
of the front face (80). The holes (84) extend partially into the back plate
(18) for receiving the
complementary threaded ends of the elongated studs (36) which facilitate the
compression and
assemblage of the components of the isolation tool (1).
[00048] The back plate (18) serves as a barrier extending transversely of
the pipe bore. It
also plays a role in the action of compressing the front and back plates (10,
18) and annular
subassembly (14) together. After the components have been compressed together,
the axially
spaced apart annular front and back inflatable seal elements (12, 16) can then
be inflated to
deform radially inwardly against the annular subassembly (14) and radially
outwardly into
sealing engagement with the pipe, thereby combining with the outer surface of
the tool (1) and
the inner surface of the pipe to form a tightly sealed annular space.
[00049] The back plate (18) defines one or more port connections comprising
small,
medium, or large diameter threaded apertures for re-routing any upstream
vapors safely away
from the hot-work area. The upstream activity may also be monitored through a
gauge to further
ensure the safety of hot-work. If any change is detected in upstream activity,
hot-work is
immediately stopped until the situation is resolved. For such purpose, the
back plate (18) defines
port connections extending therethrough to allow for gas venting (for example,
steam, flare line,
nitrogen purge, etc.) or provision of a liquid level alarm. In one embodiment,
the back plate (18)
defines a central threaded aperture (88). In one embodiment, the back plate
(18) defines a
peripheral threaded aperture (87) for receiving a threaded half-coupler (89)
and threaded pipe
plug (91). In one embodiment, the peripheral threaded aperture (87) has a
diameter larger than
the diameter of the central threaded aperture (88).
[00050] The back plate (18) defines two sets of openings (90) in proximity
to the holes
(84) on the lower portion of the back plate (18). In one embodiment, each set
of openings (90) is
positioned above and between two adjacent holes (84). Each set of openings
(90) comprises a
pair of aligned openings through which attachment means such as, for example,
cap screws (92)
extend therethrough for securing a support leg assembly (20).
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[00051] As shown in Figure 6E, the support leg assembly (20) comprises a
substantially
"L"-shaped body (94) having a vertical wall (96) perpendicular to a horizontal
base (98). The
vertical wall (96) defines a pair of openings (100) for receiving attachments
means such as, for
example, cap screws (92) to fasten the support leg assembly (20) to the
undersurface or back face
(82) of the back plate (18). The horizontal base (98) defines an aperture
(110) for mounting a
ball transfer unit bolt fixing comprising a roller ball (112) mounted within
an adjustable bolt
(114). In one embodiment, a pair of support leg assemblies (20) enables the
tool (1) to be easily
centered and deployed. The tool (I) can be rolled upon the movable roller
balls (112) which are
smooth and will not damage the bottom inner surface of the pipe, and can be
easily rested in the
desired position on the bottom inner surface of the pipe. The bolt (114) of
the ball transfer unit
bolt fixing is conveniently moveable and adjustable to different distances to
accommodate
various pipe diameters.
[00052] The support leg assemblies (20) assist with tool installation and
removal, making
the tool quick to deploy. In one embodiment, two support leg assemblies (20)
support a 36 inch
diameter isolation tool (1). However, it is contemplated that the number and
style of the support
leg assemblies (20) may vary without departing from the scope of the present
invention. For
example, in one embodiment (not shown), the roller ball (112) may be replaced
by a wheel. In
one embodiment (not shown), a gripper insert (48) is replaced by a bracket
including movable
roller balls. In one embodiment, a pair of gripper inserts (48) are replaced
by a pair of brackets.
Provision of front movable roller balls may be useful for long-reach
applications.
[000531 As shown in Figures 1 and 7A-B, the annular subassembly (14) is
positioned
between the front plate (10) and the back plate (18), and comprises an annular
core (116) and an
annular ring (118). In one embodiment, the annular core (116) and annular ring
(118) are
manufactured as separate components which are secured together by welding or
other suitable
technique known to those skilled in the art, and then machined to yield the
annular subassembly
(14). The annular core (116) and annular ring (118) are both substantially
ring-shaped. The
annular core (116) has a greater thickness than the thickness of the annular
ring (118). However,
the annular ring (118) has a greater diameter than the annular core (116) in
order to fit and
extend over the annular core (116), as shown in Figures 7A-B.
CA 2997825 2018-03-08
[00054] The annular ring (118) is positioned over the middle of the annular
core (116) to
define grooves (122a, 122b) on the outer surface (120) of the annular core
(116). The grooves
(122a, 122b) engage the front and back inflatable seal elements (12, 16) which
extend over the
annular core (116). The annular ring (118) abuts against the front and back
inflatable seal
elements (12, 16), and separates the front inflatable seal element (12) from
the back inflatable
seal element (16). The annular core (116) and annular ring (118) thereby
prevent the front and
back inflatable seal elements (12, 16) from slipping or collapsing into the
internal cavity of the
tool (1).
[00055] The annular ring (118) and annular core (116) define first and
second opposed
ports (126a, 126b) to receive connect plugs (128a, 128b) which extend
therethrough (Figure 3).
In one embodiment, each connect plug (128a, 128b) comprises a brass connect
plug which offers
good corrosion resistance, low wear resistance, and is softer and easier to
thread compared to
steel plugs. The connect plugs (128a, 128b) couple to other components such
as, for example,
elbows (130a, 130b) and nipples (132a, 132b, 133a, 133b), in order to
ultimately couple to hoses
(not shown) in order to pump water in and out to monitor the competence of the
front and back
inflatable sealing elements (12, 16). One connect plug (128a) serves as the
medium inlet, while
the other connect plug (128b) serves as the medium outlet. Once the tool (1)
is properly installed
and the front and back inflatable seal elements (12, 16) are inflated, the
medium (for example,
water) is brought to pressure in the sealed spaced defined by the annular
subassembly (14). A
pressure gauge is used to display the pressure of the medium. The pressure of
the medium,
which can be either static or flowing, is monitored and provides an indication
in real time of seal
leakage. Observation of the gauge reading will inform the technician if there
is a reduction in
medium pressure, thereby indicating seal leakage.
[00056] The tool (1) provides a pair of identical inflatable front and back
seal elements
(12, 16) positioned in the mid-section of the tool (1) by the annular
subassembly (14). The front
and back inflatable seal elements (12, 16) are annular and formed of
deformable, resilient
elastomeric material, such as ethylene propylene diene monomer (M-class)
rubber (abbreviated
as "EPDM" rubber). In one embodiment, the front and back inflatable seal
elements (12, 16)
comprise EPDM rubber seals having a square profile (DR94, Dynamic Rubber,
Inc).
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CA 2997825 2018-03-08
[00057] As shown in Figure 1, the front and back inflatable seal elements
(12, 16) are
configured with threaded pipe lock nuts (140a, 140b) which couple to tubing
(142a, 142b)
connected to a gas inlet (144) and pressure gauges (146a, 146b) in order to
pump gas (for
example, nitrogen) into the front and back seal elements (12, 16) to inflate
them simultaneously,
and to monitor the pressure of the front and back inflatable sealing elements
(12, 16) during their
expansion. While Figures 1 and 3 illustrate an exemplary "plumbing assembly"
(148) for
inflating the front and back seal elements (12, 16), it will be appreciated by
those skilled in the
art that other assemblies for gas inflation and pressure measurement are
included with the scope
of the invention. The tool (1) effectively "self-centers" within the pipe in
its proper position as
gas is pumped into identical front and back inflatable seal elements (12, 16)
simultaneously
through a single gas inlet (144) of a shared plumbing assembly (148).
[00058] Having front and back inflatable seal elements (12, 16) with a
comparatively large
radial expansion capability allows more flexibility and convenience since the
tool (1) can be used
within a greater range of pipe diameters. This also translates into minimal
manufacturing costs
and substantial operational cost savings for both companies and their clients.
Further, the
provision of two axially separated front and back inflatable seal elements
(12, 16) provides a
safety factor. The spaced inflatable seal elements (12, 16) can be monitored
for seal leakage
which, if detected, may provide an opportunity to terminate welding.
[00059] The tool (1) can be constructed from any material or combination of
materials
having suitable properties such as, for example, mechanical strength, ability
to withstand cold
and adverse field conditions, corrosion resistance, and ease of machining. In
one embodiment,
the front plate (10), back plate (18), and annular subassembly (14) are formed
of aluminum,
making the tool (1) considerably lightweight compared to prior art isolated
tools formed of steel
and other materials heavier than aluminum; for comparison, a prior art steel
isolated tool weighs
about 490 pounds. In one embodiment, the tool (1) of 36 inches diameter has a
weight of about
130 pounds. The front and back inflatable seal elements (12, 14) may be formed
of EPDM
rubber. The attachment means (36, 38, 39, 40, 66, 92, 140a, 140b) (e.g.,
elongated studs, hex
nuts, washers, shoulder eyebolts, slotted spring pins, hex bolt, cap screws,
threaded pipe lock
17
CA 2997825 2018-03-08
nuts) and ball transfer unit bolt fixing (112, 114) may be formed of steel,
for example, stainless
steel, carbon steel, and strength-bearing materials. The connect plugs (128a,
128b), elbows
(130a, 130b), and nipples (132a, 132b, 133a, 133b) may be formed of brass and
the like. The
gripper inserts (48) are formed of stainless steel for material contact-
compatibility
considerations.
[00060] Once assembled, the tool (1) can be quickly deployed in minutes
(for example,
10-15 minutes) rather than hours or days as necessary with prior art isolation
tools. Operation of
the tool (1) generally involves inserting the fully assembled tool (1) into
the pipe bore. The bolts
(114) of the support leg assemblies (20) are pre-adjusted to a distance which
accommodates the
specific diameter of the pipe, and the tool (1) is rolled on the support leg
assemblies (20) to
partially "self-center" into the desired position within the pipe. The hex
bolts (66) are then
rotated manually by the technician to move the gripper pads (48) from their
resting unactuated
positions within the recesses (30) to actuated positions to extend outwardly
from the recesses
(30) to contact and grip the inner surface of the pipe. The plumbing assembly
(148) is then
activated to pump gas through the gas inlet (144) into the front and back
inflatable seal elements
(12, 16) which expand until they seal against the inner surface of the pipe.
In one embodiment,
the pressure of gas being pumped into the front and back inflatable seal
elements (12, 16) may be
monitored visually by reading the pressure gauges (146a, 146b).
[00061] In one embodiment, the pressure of gas being pumped into the front
and back
inflatable seal elements (12, 16) may be monitored remotely by using a
separate enhanced
monitoring unit (150), as shown in Figures 8A-C. The monitoring unit (150)
relays information
back and forth to the technician; for example, pressure testing, calibration,
amount and pressure
of gas being pumped into the front and back inflatable seal elements (12, 16),
and an alarm
signal if the front and back seal elements (12, 16) fail.
[00062] The enhanced monitoring unit (150) generally comprises a housing
(152), a front
panel subassembly (154), and a back panel (156) which are assembled together
to form a
substantially rectangular-shaped box to which a handle (158) may be attached
by suitable
attachment means (160). The back panel (156) is removably attached by
fastening means (162,
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CA 2997825 2018-03-08
164) in order to allow access to the front panel subassembly (154). Various
required labels
(166a, 166b, 166c, 166d) are attached to the monitoring unit (150) including
for example,
certification stickers, notice labels, warning labels, manufacturing labels,
and the like. An
electrical inlet (168) is attached to one side of the housing (152) by
attachment means (170) for
receiving a power cord which connects the monitoring unit (150) to an
electricity supply. In one
embodiment (not shown), internal batteries are provided, negating the need to
connect the
monitoring unit (150) to an electricity supply. An LED green illuminated
rocker switch (171a)
with a protective cover (171b) serves as an "ON/OFF" switch. The electrical
inlet (168) is rain-
tight and water resistant to seal out moisture and debris. A power supply
(172) is electrically
connected through wiring (176) to the front panel subassembly (154) for
powering the LEDs. A
fuse (178a) and fuse holder (178b) provide overcurrent protection of the
electrical circuit.
100063.1 The front panel assembly (154) is shown unassembled in Figure 8C
to show the
inner components in greater detail. The front panel (180) comprises a
substantially rectangular-
shaped plate defining a window (182), window openings (183), top openings
(184), middle
openings (185), bottom openings (186), and corner openings (188).
[00064] The window (182) is configured for receiving and accommodating a
pressure
switch mounting plate (190). The pressure switch mounting plate (190) defines
a pair of
apertures (192) for receiving a pair of digital pressure switches (194) which
are mounted to the
plate (190) by brackets (196), and are attached to a pipe fitting (195) and a
tube fitting (197). A
required label (e.g., certification sticker and the like) (198) may be affixed
to the pressure switch
mounting plate (190). A transparent housing (200) is positioned over the
digital pressure
switches (194) and mounted by attachment means (210). The housing (200) is
secured to the
pressure switch mounting plate (190) by fastening means (212). An optional
identification tag
(214) may be attached to the monitoring unit (150) by suitable attachment
means.
[00065] The top openings (184) receive pressure gauges (187). In one
embodiment, the
pressure gauges (187) are analog pressure gauges. The middle openings (185)
receive LED
lights (218) which are mounted therein. In one embodiment, a first LED light
is red (218a) and a
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CA 2997825 2018-03-08
second LED light is amber (218b). The LED lights (218a, 218b) are electrically
connected to an
electronic flasher (220) by wiring (222).
[00066] The bottom openings (186) receive a nipple (224), a malleable union
fitting (225),
and a connect plug (226) which couple to other components such as, for
example,
complementary fittings (228) in order to couple to tube fittings (230). The
tube fittings (230)
receive tubing (232). The tubing (232) is attached to a tube fitting (233) and
elbows (234) which
in turn are connected to the bottom ported digital pressure switches (194). A
pressure switch
retainer (236) and attachment means (238a, 238b, 238c) secure the digital
pressure switches to
the front panel (180).
[00067] The corner openings (188) receive attachment means (239) which
extend
therethrough to secure the front panel (180) to the housing (152).
[00068] The tool (1) may be electronically monitored by being connected to
the
monitoring unit (150) using suitable hoses (not shown) which connect to each
of the nipple (224)
and the connect plug (226). In one embodiment (not shown), a flow meter is
provided for
monitoring the flow rate of vent gas. In one embodiment, pressure readings are
provided by both
the analog pressure gauges (187) and digital pressure switches (194). Each
digital pressure
switch (194) of the monitoring unit (150) is initially adjusted using buttons
to set the desired
minimum and/or maximum pressure for each of the "VENT" and "TOOL." The digital
pressure
switch (194) measures pressure and displays digital readings of pressure in
green or red such that
the readings are highly visible to the technician from a distance. "Green"
indicates readings of
pressure which meet the minimum and/or maximum set pressure. "Red" indicates
readings of
pressure exceeding the maximum set pressure or pressure falling below the
minimum set
pressure. The digital pressure switches (194) are electrically connected to
the flasher (220)
which activates the LED lights (218a, 218b) to blink, serving as additional
warning signs to
accompany "red" readings. The technician is thus warned of a problem with the
tool (1) by
"double" visual signals. Visual signals are desirable where alarm bells or
sirens may not be
audible in a noisy environment or from a distance. However, audible alarms or
output messages
to hand-held devices, multiprocessor systems, microprocessor-based or
programmable consumer
CA 2997825 2018-03-08
electronics, personal computers, network PCs, mini-computers, mainframe
computers, mobile
phones, smart phones, tablets, personal digital assistants, and the like, may
also be provided. In
one embodiment, such devices may be temporarily or permanently connected to
the monitoring
unit (150) through a wireless communication protocol in order to set, read
and/or monitor the
configuration, programming, operation, and messages from the monitoring unit
(150), and to
allow data storage and retrieval.
[000691 A data acquisition system (not shown) captures and records inputs
from the digital
pressure switches (194). Such data or other information are relayed to the
technician using a
wireless transmitter; for example, pressure testing, calibration, amount and
pressure of air being
pumped into the front and back inflatable seal elements, alarm signal if the
either or both of the
front and back seal elements should fail.
[00070] With the isolation tool (1) and seals (12, 16) securely in place,
and the monitoring
unit (150) operating, the technician can safely replace the damaged section of
pipe downstream
from the isolation tool (1). A pump at ground surface may be used to circulate
pressurized
medium (for example, water) down into the sealed space of the annular
subassembly (14) and
back up to ground surface. The medium (for example, water) is brought to
pressure in the sealed
spaced defined by the annular subassembly (14). The pressure of the medium,
which can be
either static or flowing, is displayed by the analog pressure gauges (187) and
digital pressure
switches (194), monitored, and provides an indication in real time of seal
leakage. Observation
of the readings will inform the technician if there is a reduction in medium
pressure, thereby
indicating seal leakage. After use of the tool (1), the technician needs only
to deflate the gas
from within the front and back seal elements (12, 16) and readjust the gripper
inserts (48) to
remove the tool (1) from the pipe bore.
[00071] The tool can also be used for hydrodynamic services. Instead of the
medium (for
example, water) remaining static in the sealed spaced defined by the annular
subassembly, the
medium can be circulated through the tool to remove heat away from the metal
of the pipe and to
protect the downstream or upstream piping from exposure to such heat. In one
embodiment, the
21
CA 2997825 2018-03-08
inflatable front and back seal elements can withstand a temperature greater
than about 1100 F
(or about 593 C).
100072.1 It
should be apparent, however, to those skilled in the art that many more
modifications besides those already described are possible without departing
from the inventive
concepts herein. The inventive subject matter, therefore, is not to be
restricted except in the
scope of the disclosure. Moreover, in interpreting the disclosure, all terms
should be interpreted
in the broadest possible manner consistent with the context. In particular,
the terms "comprises"
and "comprising" should be interpreted as referring to elements, components,
or steps in a non-
exclusive manner, indicating that the referenced elements, components, or
steps may be present,
or utilized, or combined with other elements, components, or steps that are
not expressly
referenced. Accordingly, various changes and modifications can be made to the
exemplary
embodiments and uses without departing from the scope of the invention as
defined in the claims
that follow.
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