Note: Descriptions are shown in the official language in which they were submitted.
INSERTION TOOL FOR REHABILITATION TUBULAR LINER IN PIPES AND
PIPELINES
FIELD OF THE INVENTION
[0001] The present invention relates to a method and apparatus for
rehabilitating underground conduits or pipes and more specifically to a method
and
apparatus for inserting a tubular liner impregnated with a hardening resin
into the
conduits or pipes to be rehabilitated.
BACKGROUND OF THE INVENTION
[0002] Underground and surface pipes, either potable water pipes,
waste water =
pipes or sewer pipes, are typically made of rigid materials such as reinforced
concrete,
cast iron, ductile iron, steel and hard polymers such as PVC, HDPE, etc., that
are
durable and adapted to resist internal fluid pressure and the external
pressure of the
weight of the soil above them. Underground and surface pipes networks provide
essential services to homes and businesses and have been deployed in cities,
towns
and villages for more than a century. Buried and surface pipes connected
together in a
network extends over long distances, spreads out in all directions to provide
services
to residential homes or businesses over a wide area. Underground and surface
pipes
are subject to normal wear and degradation over extended periods of time due
to
cyclical loads, earth movements, corrosion, increased porosity, cracks and
overall
deterioration. As a result of their long service life, underground and surface
pipes will
become damaged and require repair or replacement.
[0003] Replacement of damaged sections or portions of a pipe
network is an
expensive, disruptive and time-consuming operation requiring heavy equipment
for
accessing, removal and replacement. Replacing older networks of underground
water
conduits with new ones is unrealistic because of the sheer magnitude of the
work that
would be involved and is avoided as much as possible. However, repairing and
rehabilitating existing water networks without the need to excavate represents
a
feasible alternative. Methods exist for repairing the walls of pipes and other
conduits.
One such method involves the use of a tubular liner impregnated with a cured-
in-
place resinous material, referred to as cured-in-place pipe (CIPP) which re-
lines the
inner walls of the conduit or pipe to repair the network of conduits or pipe.
The liner
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is impregnated with a resin capable of curing and hardening to form a new
inner wall
for the aging or damaged pipes. A length of CIPP liner is inserted in the
conduit or
pipe and is pulled inside the conduit or pipe through a specific segment of
the conduit
or pipe from one entrance point to an exit point. Once in place, pressurized
water is
introduced inside the CIPP liner to press the CIPP liner against the pipe
wall. The
resin is then allowed to cure and harden, thereby creating a new sealed
interior pipe
wall.
[0004] The tubular liner is typically a flat textile material or
felt material
which is rolled into tubular form and stitched along its seam or a seamless
tubular
textile jacket made of warps and wefts woven into tubular form. When the
tubular
liner inserted into the entrance point of the conduit or pipe and pulled
inside the
segment of the conduit or pipe to be rehabilitated, the tubular liner often
drags on the
edge of the conduit's entrance opening thereby increasing the force required
to pull
the length of tubular liner through the segment of the conduit or pipe. In the
process,
the tubular liner end up being stretched unevenly over its length, it may form
folds
and wrinkles and it may get damaged.
[0005] Tubular liners made of rolled material stitched along the
seam are
particularly vulnerable as the seam is the weak portion of the tubular liner
and the
stitches may break under load thereby ripping the tubular liner at the seam
and
creating gaps which render the rehabilitation of the underground or surface
pipe
ineffective. Seamless tubular textile jackets are stronger because they do not
have a
seam that can be torn apart. However, seamless tubular liners may be unevenly
stretched or wrinkles, bulges and/or folds may be formed when the seamless
tubular
liner is pulled and dragged on the edge of the conduit's entrance opening and
the
quality of the rehabilitation liner once cured may be affected.
[0006] Thus, there is a need for a method and an apparatus for
inserting a
tubular liner into a host conduit or pipe to be rehabilitated that prevents
stretching,
wrinkling, bulging, folding or damaging the tubular when it is pulled inside
the host
conduit or pipe.
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SUMMARY OF THE INVENTION
[0007] It is an object of the present invention to ameliorate at
least some of the
inconveniences present in the prior art.
[0008] In one aspect, the invention provides an insertion and
guiding tool
comprising a cylindrical segment having an edge and a conical segment having
an
edge, the cylindrical segment and the conical segment connected together at
their
edges to form a passageway adapted to guide a CIPP tubular liner inside a host
pipe.
[0009] In an additional aspect, the insertion and guiding tool
comprises at
least one anchoring device adapted to secure the tool onto an opening of a
host pipe.
[0010] In an additional aspect, the invention provides a method of
inserting a
CIPP tubular liner into a host pipe comprising the step of reducing the width
of the
CIPP tubular liner using a conical insertion tool positioned at the opening of
the host
Pipe.
[0011] Embodiments of the present invention each have at least one
of the
above-mentioned objects and/or aspects, but do not necessarily have all of
them. It
should be understood that some aspects of the present invention that have
resulted
from attempting to attain the above-mentioned objects may not satisfy these
objects
and/or may satisfy other objects not specifically recited herein.
[0012] Additional and/or alternative features, aspects, and
advantages of
embodiments of the present invention will become apparent from the following
description, the accompanying drawings, and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] For a better understanding of the present invention, as well
as other
aspects and further features thereof, reference is made to the following
description
which is to be used in conjunction with the accompanying drawings, where:
[0014] Figure 1 is a perspective view of an insertion and guiding
tool in
accordance with one embodiment of the invention;
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[0015] Figure 2 is a side elevational view of the insertion and
guiding tool
illustrated in Figure 1;
[0016] Figure 3 is a top plan view of the insertion and guiding
tool illustrated
in Figure 1;
[0017] Figure 4 is a schematic side elevational view of a work site
in which a
tubular liner is inserted and guided into a host pipe using the insertion and
guiding
tool illustrated in Figure 1; and
[0018] Figures 5 is a schematic top plan view of the work site
illustrated in
Figure 4.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] With reference to Figures 1, 2 and 3, there is shown an
insertion and
guiding tool 10 in accordance with a preferred embodiment of the invention.
The
insertion and guiding tool 10 includes two main portions: A cylindrical
insertion
segment 12 adapted to fit inside the opening of a host pipe and a conical
guiding
segment 14 or lip adapted to guide a tubular liner inside the host pipe by
gradually
and smoothly reducing the width of the tubular liner to fit inside the host
pipe and
protecting the tubular liner from the edges of the opening of the host pipe.
The
cylindrical insertion segment 12 is preferably made of a sheet metal
approximately
0.1 inch thick which is bent in the form of an approximately 2/3 cylinder
leaving an
opening 18. Similarly, the conical guiding segment 14 is preferably made of a
sheet
metal approximately 0.1 inch thick which is bent in the form of an
approximately 2/3
conical lip defining an opening aligned with the opening 18. The edges of the
two
segments 12 and 14 have similar profiles and are typically welded or riveted
together
at their junction 20 to form a passageway 19 for a tubular liner. The
preferred
embodiment of the insertion and guiding tool 10 is made of sheet metal
however,
other materials such as molded plastics or composite may be used.
[0020] The outer diameter of the cylindrical insertion segment 12
is
specifically adapted to fit inside a host pipe having a specific diameter. For
example,
for a host pipe having an 8 inch inside diameter, the outer diameter of the
cylindrical
insertion segment 12 would be approximately 7.8 inch to ensure easy
installation.
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[0021] Fasteners or anchoring devices 16a, 16b and 16c are
positioned along
the outer circumference of the insertion and guiding tool 10, at the junction
20 of the
cylindrical insertion segment 12 and the conical guiding segment 14: A first
and
second anchoring device 16a and 16b positioned on each side of the insertion
and
guiding tool 10, and a third anchoring device 16c positioned at the bottom of
the
insertion and guiding tool 10. As illustrated in Figure 3, each anchoring
device 16a,
16b and 16c consists of an anchor 22 made of steel having a leg 23 spaced
apart from
the cylindrical insertion segment 12 and a bolt 24 inserted through a threaded
hole
(not shown) in the leg 23.
[0022] With reference to Figures 4 and 5, in operation, the
insertion and
guiding tool 10 is inserted into the opening 32 of an underground host pipe 30
to be
rehabilitated with a CIPP tubular liner 40 whereby the conical guiding segment
14
protrudes from the edge of the opening 32 and covers the edge of the entrance
or
opening 32 of the underground host pipe 30. The legs 23 of the anchoring
devices
16a, 16b and 16c extend outside the host pipe 30 and the insertion and guiding
tool 10
is secured to the host pipe 30 by tightening the bolts 24 of the anchoring
devices 16a,
16b and 16c.
[0023] The CIPP tubular liner 40, which is still in a flat state,
is routed from
aboveground through a series of rollers 45 down to the entrance or opening 32
of the
host pipe 30. The flat CIPP tubular liner 40, which is wider than the opening
32, is
then bent manually to reduce its width and inserted into the passageway 19 of
the
insertion and guiding tool 10 and guided inside the host pipe 30 where it
assumes a
partially circular shape 40a. The opening 18 is preferably positioned upward
to
provide easier access to technicians for inserting cables and other equipment
for
example. The CIPP tubular liner 40a is pulled via a cable or other means as
indicated
by arrow P.
[0024] The conical guiding segment 14 of the insertion and guiding
tool 10
guides the C1PP tubular liner 40 into the host pipe 30 by gradually and
smoothly
reducing the width of the CIPP tubular liner 40 to fit inside the host pipe 30
and
simultaneously prevents the CIPP tubular liner from dragging on the edge of
the
entrance or opening 32 of the host pipe 30 thereby protecting the CIPP tubular
liner
40 from potential damage from the edges of the opening 32. Furthermore, the
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guidance and gradual reduction of the width of the CIPP tubular liner 40 by
the
insertion and guiding tool 10 prevents uneven stretching of the CIPP tubular
liner 40
caused by uneven friction with the edge of the opening 32 and also prevents
the
formation of wrinkles, bulges and/or folds on the CIPP tubular liner 40 when
the latter
is pulled inside the host pipe 30 thereby ensuring a high quality CIPP
rehabilitation
liner once cured.
[0025] The insertion and guiding tool 10 also has the beneficial
effect of
reducing the force P required to pull the length of CIPP tubular liner 40
through the
host pipe 30 as it reduces friction at the opening 32 of the host pipe 30.
[0026] Modifications and improvements to the above-described
embodiments
of the present invention may become apparent to those skilled in the art. The
foregoing description is intended to be exemplary rather than limiting. The
scope of
the present invention is therefore intended to be limited solely by the scope
of the
appended claims.
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