Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02597668 2007-08-16
1 PIPELINE WEIGHTING DEVICE AND METHOD
2 FIELD OF THE INVENTION
3 This invention relates to a pipeline weighting device a method of filling
such a
4 device with weighting fill material, and a method of weighting a pipeline
with such a
device.
6 BACKGROUND OF THE INVENTION
7 Pipelines transporting liquid or gaseous materials often extend through
areas
8 where the pipeline needs to be weighted to avoid having the pipeline being
lifted or
9 heaved by buoyant forces or frost. Such areas include, for example,
underwater,
marsh, muskeg, and other unconsolidated environments. A trench is typically
formed,
11 the pipeline is installed in the trench, and sections of the pipeline are
anchored, coated,
12 or weighted with concrete, clamp on weights, or bag weights filled with
weighting fill
13 material. The weighted or anchored pipeline must thereafter resist
hydrostatic forces of
14 flooding, or freeze-thaw cycles.
Early pipeline weights included simple or complex concrete or concrete-
16 containing devices which could be placed on or strapped around the
pipeline.
17 Exemplary patents include U.S. Patent 2,662,552, issued December 15, 1953
to Rowe
18 et al.; Canadian Patent 1,021,952 issued December 6, 1977 to Bunn; U.S.
Patent
19 4,166,710, issued September 4, 1979 to Spiridonov; Canadian Patent
1,021,952 issued
December 6, 1977 to Bunn; Canadian Patent 2,158,801 issued July 14, 1998 to
Key-
21 May Industries Ltd.; French Patent Application No. 2,716,251 Al of Bouygues
Offshore
22 Societe, published August 18, 1995; and U.S. Patent 5,443,329 issued August
22,
23 1995 to Spuncon Pty. Ltd. and Marecon Pty.
24 Bag weights for pipeline weighting have been more recently used. They are
advantageous in that they can be filled with inexpensive weighting fill
materials such as
CA 02597668 2007-08-16
1 sand and gravel at remote locations during pipeline installation. The bag
weights limit
2 damage to a pipeline protective coating. Exemplary patents include U.S.
Patent
3 3,793,845 issued February 26, 1974 to Keith; Canadian Patent 2,075,006,
issued July
4 16, 2002, to Connors; Canadian Patent 2,277,523 issued February 17, 2004, to
Jewell;
and Canadian Patent Application 2,527,790 published May 22, 2006 to Tiger
Ridge
6 Resources Ltd.
7 Several of the bag weights of the above patents present problems in the
filling
8 and installation operations. The bag weights, once filled, may be very large
and heavy,
9 for example in excess of 10,000 pounds. The Connors' device has side saddle
bags
that are open along its upper longitudinal edges, making spillage of the fill
material
11 problematic. As well, these open bags allow water to enter the bag, causing
the bag
12 contents to freeze in cold climates where these bags are often used.
Installation of
13 frozen bags is problematic, both in terms of awkward handling, and pipe
damage. The
14 Connors' device has been altered from that shown in the patent to include
drawstrings,
partial stitching or flaps to close or partially close these upper edges.
These efforts
16 have complicated both the manufacturing of the bags, and the filling and
installation
17 process, without fully addressing the problems of spillage and freezing.
The Jewell
18 device requires a difficult under the pipeline strapping and cinching
operation to fix the
19 bag weights onto the pipeline. Since the bag weights are placed over the
pipeline in the
close confines of a trench, the strapping operation can be difficult and
dangerous for
21 workers, particularly for very large bags which hang well below the pipe.
Both the
22 Connors' and Jewell devices cause difficulties with the large bag sizes,
since the bag,
23 to provide the needed weight, enlarge both the depth and width dimensions
of the
24 weighted pipeline. This in turn increases the depth and size of the trench
that is
needed to accommodate the weighted pipeline.
26 The Tiger Ridge device uses a circumferential cinch that requires workers
to
27 wrap a strap more than one circumferential distance around the bag and
pipeline, which
28 can be a difficult operation in the confines of the pipeline trench. As
noted above, large
2
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1 bag weights that extend either too far above, or too far below the pipeline
require the
2 trench to be excavated to depths that may be uneconomical. The Tiger Ridge
device
3 attempts to address this problem by filling with heavy barite material,
however, barite
4 material is not always readily available or available at low cost.
As well, the heavy bag weights are typically end filled by suspending the bag
6 weight above ground from the open bag ends, and filling each bag from an
overhead
7 hopper (see for example Canadian Patent 2,431,281, issued June 13, 2006 to
Jewell).
8 The bag ends must then be individually rolled over and tied to close the
ends, a labor
9 intensive process. As well, the ends can open after tying, spilling fill
material.
A simple, inexpensive pipeline weighting device is still needed to address one
or
11 more of the above-noted problems.
12 SUMMARY OF THE INVENTION
13 Broadly stated, the present invention provides a pipeline weighting device
to
14 straddle the longitudinal axis of a pipeline. The device is formed of a
plurality of
interconnected, generally tubular-shaped lobes arranged to straddle the
pipeline in a
16 balanced manner along the longitudinal axis of the pipeline. The lobes are
formed of a
17 flexible, water permeable fabric to hold weighting fill material. Each lobe
has an inner
18 side wall, opposed and closed longitudinal side edges, and opposed ends,
one end
19 being a closed end, and the other end forming an open or partially open
filling end.
Each lobe is formed with a self-closing filling sleeve or filling flap at the
open or partially
21 open filling end, the filling sleeve or flap extending into the interior of
the lobe and
22 providing an opening into the lobe in a manner such that, when each of the
lobes is fully
23 charged through the opening with the fill material, and the pipeline
weighting device is
24 turned on its longitudinal axis, the filling sleeve or filling tube becomes
trapped within
the fill material to close the lobe and to contain the fill material.
3
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1 Preferably, the filling sleeve or filling flap is fixed to an inner side
wall of the lobe,
2 such as by stitching, to prevent dislodgement by the fill material during
charging.
3 In a preferred embodiment which includes the self-closing filling flap, the
pipeline
4 weighting device includes a pair of facing filling flaps extending into the
interior of the
lobe and have facing side edges which are fastened together along all or part
of their
6 length, for example by stitching. Preferably, the pair of facing filling
flaps extends into
7 the interior of adjacent lobes, such as two adjacent lobes, in order to fill
the adjacent
8 lobes in one filling operation.
9 The pipeline weighting device most preferably includes a filling sleeve
which is
fixed, for instance by stitching, to the inner side wall of the lobe to
prevent dislodgement
11 by the fill material during charging. The filling sleeve is preferably
formed of the flexible,
12 water permeable fabric and is contiguous with the lobe. The filling sleeve
and extends
13 into the interior of the lobe so as to form opposed open sleeve ends, one
open sleeve
14 end being an exterior open sleeve end at or adjacent the filling end of the
lobe, and the
other open sleeve end being an interior open sleeve end which forms the
opening into
16 the lobe. The filling sleeve has preferred dimensions such that it extends
into the
17 interior of the lobe by a distance which is greater than the opening at the
interior open
18 end of the filling sleeve.
19 In a preferred embodiment of the invention, the pipeline weighting device
is
formed such that one filling sleeve extends into the interior of adjacent
lobes in order to
21 fill the adjacent lobes in one filling operation. In this embodiment, one
filling sleeve is
22 formed between two adjacent lobes such that a portion of the filling sleeve
extends into
23 the interior of the adjacent lobes, and is partitioned to form interior
open ends which
24 open into each adjacent lobe. This is most efficiently achieved by forming
the plurality
of lobes from a web of the flexible, water permeable fabric, stitched along a
longitudinal
26 axis to form the plurality of lobes arranged in side by side relationship,
with each of the
27 plurality of lobes being generally equal in size, the closed side edges and
closed ends
4
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1 of each lobe being formed by one or both of folding and stitching of the
web. The filling
2 sleeve is most preferably stitched to both fix the filling sleeve to the
inner side wall of
3 the lobe and to partition to form the interior open ends into the adjacent
lobes. Most
4 preferably, the filling sleeves are formed from the web to be integral with
the lobes, and
the filling sleeves are formed by stitching along all or part of their side
edges, and
6 folding into the interior of the lobes.
7 The pipeline weighting device preferably includes an even number of lobes to
8 balance on the pipeline, with one filling sleeve arranged to fill each pair
of adjacent
9 lobes. Most preferably, four symmetrical lobes are formed, with one filling
sleeve being
provided for each two adjacent lobes.
11 Additional preferred features include first lifting loops connected at the
filling end
12 of the lobes, for lifting the weighting device during charging, and second
lifting loops
13 connected along the longitudinal side edges of one of the lobes, for
lifting the filled
14 weighting device into position to straddle the pipeline, first reinforcing
straps stitched
longitudinally along the stitching lines forming the lobes, and ending in
loops which form
16 the first lifting loops, second reinforcing straps stitched transversely
across the lobes,
17 and ending in loops which form the second lifting loops. Optionally, one or
more
18 fastening straps are connected to one or more of the lobes to hold the
weighting device
19 on the pipeline.
The pipeline weighting device is preferably formed from a single web of woven
or
21 non-woven geotextile fabric, most preferably woven polypropylene. The first
and
22 second reinforcing straps are preferably formed of a woven or non-woven
geotextile
23 strapping material, most preferably woven polypropylene strapping material.
24 The invention also broadly extends to a method of filling a pipeline
weighting
device with weighting fill material, comprising:
26 a) providing a pipeline weighting device comprising a plurality of
interconnected,
5
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1 generally tubular-shaped lobes, each lobe having opposed and closed
longitudinal side
2 edges and opposed ends, one end being a closed end, and the other end
forming an
3 open or partially open filling end, the plurality of lobes being formed of a
flexible, water
4 permeable fabric to hold the weighting fill material, and each lobe being
formed with a
self-closing filling sleeve or filling flap at the open or partially open
filling end, the filling
6 sleeve or flap extending into the interior of the lobe and providing an
opening into the
7 lobe;
8 b) charging the plurality of lobes through the opening formed by the filling
9 sleeves or filling flaps with the weighting fill material until each lobe
includes a
balanced, full charge of the weighting fill material; and
11 c) turning the pipeline weighting device on its longitudinal axis to cause
the filling
12 sleeves or filling flaps to become trapped withing the weighting fill
material to thereby
13 close the lobes and to contain the weighting fill material.
14 In yet another broad aspect, the invention extends to a method of weighting
a
pipeline along its longitudinal axis, comprising:
16 a) providing a pipeline weighting device comprising a plurality of
interconnected,
17 generally tubular-shaped lobes, each lobe having opposed and closed
longitudinal side
18 edges and opposed ends, one end being a closed end, and the other Land
forming an
19 open or partially open filling end, the plurality of lobes being formed of
a flexible, water
permeable fabric to hold the weighting fill material, and each lobe being
formed with a
21 self-closing filling sleeve or filling flap at the open or partially open
filling end, the filling
22 sleeve or filling flap extending into the interior of the lobe and
providing an opening into
23 the lobe;
24 b) charging the plurality of lobes through the opening formed by the
filling
sleeves or filling flaps with the weighting fill material until each lobe
includes a
26 balanced, full charge of the weighting fill material;
27 c) lifting the pipeline weighting device and turning it on its longitudinal
axis to
28 cause the filling sleeve or filling flap to become trapped withing the
weighting fill
29 material and thereby to close the lobes and to contain the weighing fill
material;
6
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1 d) positioning the pipeline weighting device above the pipeline, with the
2 longitudinal axes of the pipeline weighting device and the pipeline being
aligned, such
3 that the plurality of lobes are balanced on the pipeline; and
4 e) optionally fastening the pipeline weighting device to the pipeline.
The invention also broadly extends to a method of weighting a pipeline along
its
6 longitudinal axis, comprising:
7 a) providing a pipeline weighting device comprising a plurality of
interconnected,
8 generally tubular-shaped lobes, each lobe having an outer side wall, opposed
and
9 closed longitudinal side edges, and opposed ends, one end being a closed
end, and
the other end forming an open or partially open filling end; one or more
fastening straps
11 connected along the longitudinal side edge of an outermost lobe, and one or
more
12 buckle means connected to the outer side wall of a lobe which is opposite
the
13 outermost lobe to which the one or more fastening straps is connected; and
the plurality
14 of lobes being formed of a flexible, water permeable fabric to hold the
weighting fill
material;
16 b) charging the plurality of lobes with the weighting fill material through
their open
17 or partially open filling ends until each lobe includes a balanced, full
charge of the
18 weighting fill material, and closing the open or partially open filling end
of each lobe;
19 c) positioning the pipeline weighting device above the pipeline, with the
longitudinal axes of the pipeline weighting device and the pipeline being
aligned, such
21 that the plurality of lobes are balanced on the pipeline; and
22 d) fastening the pipeline weighting device to the pipeline by threading the
one or
23 more fastening straps through the one or more buckle means.
24 As used herein and in the claims, a reference to "longitudinal", "centre",
"side"
etc. are terms meant to describe the pipeline weighting device when in place
on the
26 longitudinal axis of the pipeline, with side referring to a longitudinal
edge, parallel to a
27 longitudinal axis. The ends of the bag or lobe may be referred to as
referring to the
28 closed or open ends, being along the width, or transverse edge of the bag
or lobe,
7
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1 unless the context otherwise requires. The ends are also sometime referred
to as
2 "top", "bottom", these being the positions when the bag is in an upright
filling position.
3 "Interior" refers to location within the inner side wall of the bag or lobe,
and "exterior"
4 refers to a location outside the bag or lobe, such as on an outer side wall.
BRIEF DESCRIPTION OF THE DRAWINGS
6 FIG. 1 is a side sectional view of a pipeline weighting device of the
present
7 invention shown on the pipeline (looking down the longitudinal axis of the
pipeline), with
8 the optional fastening straps.
9 FIG. 2 is a schematic, side sectional view of a pipeline weighting of the
present
invention when fastened to the pipeline in a preferred balanced position with
four lobes
11 being positioned symmetrically around the pipeline.
12 FIGS. 3 - 5 show the pipeline weight of this invention during progressive
13 assembly stages, in which:
14 FIG. 3 is a top plan view showing the pipeline weight fabric pattern as a
single
web of geotextile fabric, prior to folding and sewing, with the dotted line
indicating the
16 center fold line;
17 FIG. 4 is a top plan view showing the pipeline weight after folding on the
center
18 line, stitching the longitudinal side edges and fastening the longitudinal
lifting straps;
19 and
FIG. 5 is a top plan view showing the pipeline weight after stitching to
divide into
21 four lobes, fastening the transverse lifting straps, and forming the self-
closing fill chutes
22 at the filling ends.
8
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1 DESCRIPTION OF THE PREFERRED EMBODIMENTS
2 Having reference to FIG. 1, the pipeline weighting device 10 is shown in a
3 balanced position on pipeline P, with a main bag 12 divided into a plurality
(four shown)
4 of symmetrical, generally tubular shaped lobes 14, to be arranged in a
preferred and
balanced position around the pipeline P. A plurality of lifting loops 16 are
shown being
6 formed along the longitudinal side edges 17 of the outermost lobes 14 (i.e.,
along a
7 longitudinal axis). Optionally, one or more fastening straps 18 may be
connected to the
8 side edge 17 of one of the outermost lobes 14, for instance by threading
through the
9 lifting loops 16 or by stitching directly to the lobe 14. These fastening
straps 18 may be
used to fasten the weighting device 10 on the pipeline P. Optionally, one or
more
11 buckle means such as D-rings 20 may be provided on the outer side wall of
the lobes
12 14, preferably to a lobe opposite the outermost lobe to which the fastening
straps are
13 connected, as shown in the figures. The fastening straps 18 may be threaded
through
14 the buckle means to retain the fastening straps 18, as shown in Figure 1,
in order to
secure the weighting device 10 to the pipeline. Alternate strap and buckle
means may
16 be used to permit tightening and fastening through a buckle means.
Exemplary
17 alternatives include, without limitation, ratchets, cinches, buckles,
slides, clips, rings
18 such as D-rings or 0-rings, cam lock sliders, tie downs and hooks. Figure 2
shows
19 another sectional view, not showing the straps 18 or lifting loops 16, but
showing the
preferred, symmetrical and balanced configuration of the weighting device 10
on the
21 pipeline P.
22 The assembly of the device 10 from a fabric pattern is shown in one
embodiment
23 in Figures 3, 4 and 5, described below.
24 Assembly
An exemplary fabric pattern for a pipeline weighting device 10 is shown in
Figure
26 3, in its unassembled form with a main web 22, having a longitudinal length
dimension L
9
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1 that is twice the desired finished length of the weighting device 10, and a
transverse
2 width dimension W that allows for at least two, and preferably four or more
lobes 14 to
3 be subdivided such that an even number of lobes 14 will lie in a balanced
manner on
4 the pipeline P in a balanced configuration (see Figures 1 and 2). Fill
sleeves 24 extend
from the transverse (width) ends 19 of the web 22. It will be understood that
Figure 3
6 shows only one possible fabric pattern, with other patterns being possible
within the
7 scope of this invention. For instance, the pattern could provide for folding
along a
8 longitudinal axis, such that the pattern had a width dimension twice the
desired finished
9 width. Still alternatively, the pattern could provide for two or more fabric
sections to be
stitched together to form the end device in a manner that will be evident to
those skilled
11 in the art.
12 The fill sleeves 24 are preferably located to be adjacent the longitudinal
side
13 edges 17 of the lobes 14 (to be subsequently formed). As shown in Figure 3,
the
14 sleeves 24 are preferably located to straddle the side edges 17 of two
adjacent lobes
14 to be subsequently formed.
16 It will be understood that an alternative to the filling sleeves 24 are
filling flaps
17 (not shown), which are arranged to extend into the interior of the lobes,
adjacent the
18 longitudinal side edges 17, in a manner so as to form openings to admit
fill material into
19 the lobes, but to become trapped within the fill material when the fully
charged lobes
are turned on the longitudinal axis of the device. Preferably, when a self-
closing filling
21 flap is included, it comprises a pair of facing filling flaps forming an
opening into the
22 lobe between the facing flaps. The facing flaps preferably have side edges
which are at
23 least partially joined to each other such as by stitching along part or all
of their side
24 edges.
The web 22 is folded lengthwise along fold line 26 to assume the shape shown
26 in partially assembled view of Figure 4. Alternatively, the web 22 could be
formed in
27 two identical sections which are stitched together to assume the shape
shown in Figure
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1 4. The fold line 26, (or a stitched line in the case of two web sections)
closes the end of
2 the main bag 12 to form the closed ends 27 (bottom ends) of the lobes 14. In
Figure 4,
3 the web 22 is stitched along its outermost longitudinal side edges 17 to
close the sides
4 of the main bag 12. In this assembly operation, flexible lifting straps 30
are preferably
simultaneously stitched on both sides of the web 22, along the outermost and
inner
6 most longitudinal side edges 17. The main bag 12 is also stitched along its
longitudinal
7 centre line 32, preferably also simultaneously stitching a further flexible
lifting strap 30
8 on both sides of the web 22 in this centre line of stitching. The flexible
lifting straps 30
9 form or end in lifting loops 35 at the filling ends 36 to assist in the
filling operation, as
described below. The main bag 12 is further partially stitched along its
filling end 34
11 (top end) between the filling sleeves 24 (such that openings into lobes 14
are through
12 the filling sleeves 24). In this manner, the filling end 34 of the main bag
12, and of the
13 lobes 14, are open or partially open, as provided for by the filling
sleeves 24). The
14 filling sleeves 24 are stitched along part or all of their side edges 37,
and are then
folded into the interior of the main bag 12, along the fold line 38. In this
manner, the
16 filling sleeves 24 form opposed open ends, namely an exterior open end 36a,
generally
17 contiguous with the filling end 34 of the bag 12, and an interior open end
36b interior of
18 each lobe 14 (see Figure 5).
19 The final steps in the assembly are shown in Figure 5. The fill sleeves 24
are
shown to include a chute portion 40 extending upwardly from the filling ends
34 of the
21 bag 12. This filling chute 40 is sized to accept a filling tube or the like
(not shown) of an
22 overhead hopper (also not shown) during the later filling operation.
Although the chute
23 portion 40 is formed by folding the filling sleeve 24 along a fold line 38
located above
24 the filling ends 34 of the main bag 12, it will be understood that the fold
line 38 could be
flush with the filling ends 34 of the main bag 12. In either embodiment, the
exterior
26 open ends 36a are generally contiguous with the filling end 34 of the main
bag 12. An
27 interior portion 42 of the filling sleeve 24 extends into the interior of
the main bag 12.
28 The main bag 12 is stitched along quarter lines 44 in order to sub-divide
the main bag
29 12 into the preferred four symmetrical lobes 14. This stitching line along
quarter lines
11
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1 44 also preferably stitches through the interior open ends 36b of the
filling sleeves 24,
2 interior of the bag 12, such that the filling sleeves 24 are partitioned to
provide openings
3 46 into each of the lobes 14. The stitching also serves to fix the filling
sleeve 24 to the
4 inner side wall of each lobe 14. The openings 46 are sized to allow fill
material to freely
flow into the lobes 14 during the filling operation. To provide adequate
openings, the
6 assembly may include stitching that extends only partly along the sides 37
of the filling
7 sleeves 24, so the sleeve stitching ends before the ends that subsequently
form the
8 interior open ends 36b. Alternatively, the shape of the filling sleeve 24
might be flared
9 at the open ends 36b, to increase the size of the openings 46.
Additional flexible lifting straps 48 are attached transversely across the
main bag
11 12, with stitching at the intersections with the first set of lifting
straps 30, and optionally
12 at the intersections with the quarter lines 44. The flexible lifting straps
48 end in, form
13 or connect to the lifting loops 16, as shown in Figure 1.
14 To ensure that the filling sleeve 24 does become adequately trapped during
filling, the filling sleeve 24 preferably extends into the interior of the bag
by a distance
16 that is greater than the width of the openings 46 formed at the interior
open ends 36b of
17 the sleeves. This ensures that when the sleeve 24 becomes trapped in the
fill material
18 during and after filling, there is adequate fabric in the collapsed sleeve
to cover and
19 thus close the openings 46 at the open end 36a.
It should be understood that the lifting straps 30 and 48 serve to reinforce
the
21 main bag 12 in both the longitudinal and transverse directions, and are
thus also
22 termed reinforcing straps. These straps 30, 48 also serve to form or
connect to the
23 lifting loops 35, 16 at their ends in a manner to prevent tearing or
straining of the lobes
24 14 of the weighting device 10, once filled with fill material. Smaller bags
have a lesser
need for the lifting straps 30, 48.
26 It should also be understood that the fastening straps 18 and D-rings 20
are
12
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1 optional, particularly for very large, heavy bags, which remain balanced on
the pipeline
2 P due to their weight factor. Also, other fastening strap embodiments will
be evident to
3 one skilled in the art, such as mentioned above, within the scope of the
present claims.
4 Filling Operation
During the filling operation, the main bag 12 is lifted, for example by a fork
lift
6 device, by the lifting loops 35 (also termed first lifting loops) to
position the chute
7 portions 40 of the filling sleeves 24 below the fill tubes or nozzles (not
shown) of an
8 overhead hopper (not shown) filled with weighting fill material (not shown).
As the fill
9 material enters each of the lobes 14 through the openings 46 of the filling
sleeves 24, it
is divided between the adjacent lobes 14. Once the lobes 14 are fully charged
with fill
11 material, the fill tubes or nozzles are removed. The main bag 12, and lobes
14 are
12 turned along their longitLidinal axis, by lifting the filled bag 12 by the
lifting loops 16 (also
13 termed second lifting loops), or by the transverse straps 48. This rotation
of the bag 12
14 on its longitudinal axis shifts the fill material within the lobes 14 in a
manner so as to
collapse and trap the fill sleeves 24, preventing the fill material from
escaping from the
16 bag 12 and lobes 14. In this manner, the bags 12 of the present invention
are self-
17 closing, and also self-sealing.
18 The filling sleeves 24 of the preferred embodiment of this invention have
been
19 found to work particularly well in self-closing, as fill material wedges
itself between the
inner side wall of the lobes 14 and the outer wall of the filling sleeve,
causing the sleeve
21 24 to substantially self-close on itself even during the filling operation.
This self-closing
22 action might be envisioned as the collapsing action of a inner flexible
sleeve within an
23 outer concentric tubular as the annulus between the sleeve and outer
tubular is filled
24 with fill material.
13
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1 Pipeline Placement
2 The filled pipeline weighting device 10 is lifted, for example by the
lifting loops
3 16, or the transverse straps 48. A fork lift or crane (not shown) is used to
lift the heavier
4 bags. The bag 12 is moved alongside the pipeline P. The weighting device 10
is
placed longitudinally along the pipeline, with the centre line 32 along the
top center of
6 the pipeline, so as to balance an equal number of lobes 14 on and around the
pipeline
7 (as shown in Figures 1 and 2). While the weight of the weighting device 10
itself is
8 often sufficient to secure the device 10 to the pipeline P, optional
fastening straps 18
9 might be threaded through the lifting loops 16 to fasten more securely to
the pipeline P.
As described above, particularly for smaller, lighter weight bags 12, optional
D-rings 20
11 might be located on the lobes 14 to accept and retain the fastening straps
18, in a more
12 secure cinching manner.
13 The number of lobes 14 in the pipeline weighting device 10 can vary, with
an
14 even number being preferred to balance around the pipeline P. Most
preferred are four
symmetrical lobes 14, as shown above. However, any other even number such as
two,
16 six or eight, may be used with a balanced effect. Alternatively, the lobes
14 might be
17 formed asymmetrically, such that one lobe is positioned on top of the
pipeline, with an
18 equal number of side lobes extending down the sides of the pipeline in a
balanced
19 manner. This configuration is less preferred than shown in the Figures
however, since
the trench to contain the weighted pipeline might need to be deeper.
21 While the preferred embodiment includes lobes 14 equally divided from a
main
22 bag with stitching, thus forming lobes which are directly connected to each
other, and
23 closed, along their longitudinal edges, it should be understood that
connecting webs
24 (not shown) might be included between adjacent lobes. For example, a
connecting web
might be formed between two sets of side lobes, such that the connecting web
overlies
26 the top of the pipeline. It is believed that the embodiment of the Figures
is preferable
27 over these alternate configurations in order to best minimize any excessive
height or
14
CA 02597668 2007-08-16
1 depth which the lobes add to the weighted pipeline, so as to minimize any
extra trench
2 depth that is needed to contain the weighted pipeline. If additional weight
is needed,
3 rather than add extra lobes which will hang well below the bottom of the
pipeline, it may
4 be preferable to fasten extra side lobes to the main bag 12, for example by
stitching the
extra lobes along quarter lines 44. This adds extra width and weight to the
weighted
6 pipeline, without extending the height or depth of the weighted pipeline.
7 Stitching is preferred to divide the main bag 12 into symmetrical lobes 14.
8 However, gluing and/or thermal welding might be used, particularly for
smaller bags.
9 The device might include interconnected lobes which are formed separately,
and then
connected together, for example by stitching. The stitching is done with heavy
weight
11 thread, having tensile strength at least as strong as the straps and fabric
being used, to
12 prevent tearing or breakage.
õ
13 Flexible fabric used to make the bags may be woven or non-woven fabric of
14 sufficient strength to contain the fill material. Preferred fabrics include
woven or non-
woven geotextile fabrics such as polypropylene, with woven polypropylene being
most
16 preferred. A fabric weight of 200g/m2 is exemplary (for example 4516 non-
woven
17 polypropylene geotextile). The lifting straps and lifting loops may be
formed of suitably
18 strong industrial strapping materials. Preferred is woven polypropylene,
such as 5000
19 lb/in wide straps. Heavy thread and double (or more) stitching is
preferred, using
thread which is preferably higher tensile strength than the straps.
21 It will be understood that, particularly for larger, heavier weighting
devices, the
22 bag 12 may be formed as a multiwalled bag, for example by starting from
multiple webs
23 22, one on top of another.
24 One example of suitable dimensions will serve to exemplify the invention.
For a
10 inch diameter pipeline, a four lobe pipeline weighting device can be
constructed with
26 dimensions of 6 ft X 6 ft (length and width dimensions, not filled), to
provide a filled
CA 02597668 2007-08-16
1 weight of about 1100 lb. This produces a pipeline weight which, once placed
in a
2 balanced position straddling the pipeline, extends about 7 inches above the
pipeline,
3 and 7 inches below the pipeline. While the dimensions may vary, it should be
4 understood that larger lobes, or a greater number of lobes can increase the
size of the
pipeline weight extending above or below the pipeline itself, increasing the
size of the
6 trench needed to bury the weighted pipeline.
7 Ballast material or fill material includes weight enhancing materials
including,
8 without limitation, crushed rock, cement, aggregate, barite or other ores.
Dirty
9 aggregate, river rock and sand are less preferred as filling with such
materials is more
difficult, with clogging being possible.
11 It will be understood that all of the above-mentioned alternatives,
inciuding other
12 alternatives evident to those skilled in the art, are included within the
scope of the
13 claims.
14 Advantages:
Some of the advantages provided by the present invention include:
16 1. The filling and closing of the weighting device are less labour-
intensive, saving
17 time and expense in these operations, and reducing the overall cost of a
18 weighted pipeline with the device of the present invention.
19 2. The filling and closing operations, as well as the pipeline installation
operation
are simpler, reducing the likelihood of injury to workers.
21 3. End filling of the bags is more convenient than open topped bags,
lessening
22 spillage and injury to workers thereby.
23 4. The self-closing and self-sealing filling sleeves lead to reduced
spillage,
24 improved dust control.
5. The lifting straps are simple to attach in the fabrication of the device,
and offer
16
CA 02597668 2007-08-16
1 excellent reinforcement to the bag, with convenient location of the lifting
loops.
2 6. The weighting device can be simply formed from a single web of geotextile
fabric
3 in an inexpensive and economical manner.
4 7. !n its preferred embodiment, with equal, even number of lobes (most
preferably
four symmetrical lobes), the weighting device can be balanced (i.e., with
weight
6 equally distributed) around the pipeline, and the depth of the trench needed
to
7 contain the pipeline is minimized.
8 All references mentioned in this specification are indicative of the level
of skill in
9 the art of this invention. All references are herein incorporated by
reference in their
entirety to the same extent as if each reference was specifically and
individually
11 indicated to be incorporated by reference. However, if any inconsistency
arises
12 between a cited reference and the present disclosure, the present
disclosure takes
13 precedence. Some references provided herein are incorporated by reference
herein to
14 provide details concerning the state of the art prior to the filing of this
application, other
references may be cited to provide additional or alternative device elements,
additional
16 or alternative materials, additional or alternative methods of analysis or
application of
17 the invention.
18 The terms and expressions used are, unless otherwise defined herein, used
as
19 terms of description and not limitation. There is no intention, in using
such terms and
expressions, of excluding equivalents of the features illustrated and
described, it being
21 recognized that the scope of the invention is defined and limited only by
the claims
22 which follow. Although the description herein contains many specifics,
these should not
23 be construed as limiting the scope of the invention, but as merely
providing illustrations
24 of some of the embodiments of the invention.
One of ordinary skill in the art will appreciate that elements and materials
other than
26 those specifically exemplified can be employed in the practice of the
invention without
27 resort to undue experimentation. All art-known functional equivalents, of
any such
28 elements and materials are intended to be included in this invention. The
invention
17
CA 02597668 2007-08-16
1 illustratively described herein suitably may be practiced in the absence of
any element
2 or elements, limitation or limitations which is not specifically disclosed
herein.
3 As used herein, "comprising" is synonymous with "including," "containing,"
or
4 "characterized by," and is inclusive or open-ended and does not exclude
additional,
unrecited elements. The use of the indefinite article "a" in the claims before
an
6 element means that one or more of the elements is specified, but does not
specifically
7 exclude others of the elements being present, unless the contrary clearly
requires that
8 there be one and only one of the elements.
18
