Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
21S300~
SEALING SYSTEM FOR SEWER AND WATER APPLICATIONS
FIELD OF THE INVENTION
The present invention relates to a method of
sealing a manhole riser and a catch basin, as well as
sealing storm sewer pipes. More particularly, it
relates to an improved, economical method to seal a
manhole riser and catch basin from unwanted water and
other cont~m;n~nts which leak therethrough.
BACKGROUND OF THE INVENTION
Manhole risers, manhole chimneys, all generically
describe the top of the unit which extends from sewer
pipes to the ground surface. In particular, the top
portion of the manhole riser comprises numerous cement
adjusting rings, which sit atop each other and typically
have specific dimensions. Each ring may be added to
increase the height that the manhole riser extends to.
As a road is repaved and new layers of pavement are
added, it often times is necessary to add an additional
ring such that the manhole covers stay flush with the
road.
Catch basins are situated below storm sewer ll
drainage grates found on roads. The storm sewer grates
are collection sites for water drainage from streets
which flow through catch basins. Catch basins generally
comprise a series of rectangular cement rails or
collars. The cement collars are stacked in a manner to
create a rectangular "basin" through which water passes.
Each collar of the basin generally comprises two three-
sided cement rails which, when fitted together, create a
rectangle. The catch basins extend up to the grate,
through which drainage water passes.
21 ~3 o o~
A problem that has existed with manhole risers and
catch basins in the past is surface and interior water
or gasses pass through gaps and spaces in the cement
rings and cement collars. Further, the water will often
times freeze between and within the cement structures,
and the freeze/thaw cycle will deteriorate and break up
the cement structures, requiring them to be replaced.
Installation, repair or replacement of
sanitary/storm manhole risers, storm catch basins, and
storm sewer pipes is a continuous process in maintaining
the infrastructure of municipalities. In this process,
a special skill called "adjustment" or "adjusting"
occurs. Adjustment/adjusting is a process whereby the
manhole riser or storm catch basin is adjusted to the
height of the road surface.
As water utilities are installed, a manhole for
access to the infrastructure system is constructed
according to engineering plans on a straight line. If
the road has a curve, it requires more manholes than a
straight road. The bottom section of the manhole
utility access is called a barrel, and between the
barrel and riser is the "cone". The cone is made of
pre-cast concrete and will not leak because it is one
piece. After the cone is placed in position, the
adjustment process begins at the top of the cone in
order to cause the manhole riser necking to meet flush
with the road surface. By using concrete adjusting
rings and mixed Portland cement on top of the cone,
rings are stacked to bring the manhole and top casting
to the road elevation. The procedure is similar for
storm catch basins.
Poor workmanship, poor cement, improper grouting,
and the freeze/thaw cycle will cause hairline cracks in
the adjustment necking. If a crack develops in the
asphalt, water seeks its lowest level and begins to work
against the cracks. Soon thereafter, the cracks enlarge
and water, dirt and other debris begin to seep into the
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infrastructure.
A further problem occurs at the road surface around
manhole risers and catch basins. When leaks develop,
the soil erodes, and the erosion causes the ground to
sink. This ground sinking action then causes the catch
basin or manholes to protrude, and the road needs to be
repaired. This loss of supporting material causes the
road to collapse around the resultant voids.
Previously, contractors practicing the adjusting
process for utilities and municipalities have not had an
economical solution for the above problems. One
solution, a "filter blanket", has been used in the past.
The filter blanket is a geo-textile fabric material that
is placed on new roads that have poor underlying soils.
15 The filter blanket gives strength to the road surface.
Often times, a contractor will simply cut off a piece of
the filter blanket and wrap around the manhole neck to
help prevent sand and dirt from passing into the
manhole. However, the filter blanket is not adequate
20 for the prevention of water to pass into the adjustment
rings.
Additional problems result from water and gas
attacking the structures from the inside. For a variety
of reasons, water and other liquids attack the interior
25 of the rings and the cement which secure the rings and
casting. Sewer gasses such as hydrogen sulfide are
particularly corrosive, thus there is a need for an
inner seal as well.
These problems are described in U.S Patent Nos.
30 4,475,845 and 4,469,467. These patents describe the
problems of water infiltration into manhole chimney
seals, and attempt to provide a solution. However, the
problem with the solutions proposed in the ' 845 and ' 467
patents has not been satisfactory to date, due to the
35 high cost of the product. The ' 845 patent discloses a
chimney seal having numerous sealing sections and a
securing means for the chimney seal. In particular, the
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sealing means describes a retaining band to be used with
different preformed skirts. The '467 patent discloses a
similar apparatus. The products allegedly covered by
these patents are very expensive, and not feasible for
widespread use as manhole riser sealer systems. Due to
the numerous numbers of manholes which exist and the
increasingly tight budgets of municipalities, there
exists a need for an inexpensive apparatus and method of
sealing, which does not employ the use of "preformed"
rings.
U.S. Patent Nos. 4,540,310, 4,737,220 and Canadian
Patent No. 1,142,009 all claim to have some type of
sealing means which could be used for sealing water from
manhole risers. However, none of these patents address
the problems associated with a need for a low cost
product and a method for sealing. The present invention
addresses such a need, and is disclosed herein.
Further, the above patents and existing solutions are
directed to manhole risers, and do not address the needs
addressed in the catch basin market.
It is the object of this invention to create a
barrier which may be placed over adjustment necks of
manhole risers and catch basins in a manner of minutes
with a one person operation.
It is the object of this invention to have an
economical, cost effective method, in dealing with water
leaks and deterioration of adjustment necks and catch
basins. The present invention eliminates contaminated
water, sand, dirt and other debris from penetrating into
water system infrastructures, and thereby eliminates or
reduces the amount of water treatment needed at the city
water treatment plant.
It is the object of this invention to provide an
economical method of sealing the intersection between
two adjoining pipes.
It is the object of this invention to provide an
inner seal for manhole risers and catch basins such that
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cracks and leakage do not occur from the inside due to
exposure to sewer water and gasses.
The present invention also reduces the amount of
ground erosion associated with cracks and leakage caused
by cracks in manhole risers and catch basins.
SUMMARY OF THE INVENTION
The present invention describes and claims an
improved method for sealing a manhole riser or catch
basin. The invention also describes and claims an
improved kit for sealing manhole risers and catch
basins. The method of sealing a manhole riser, with
adjusting rings, is described as follows:
a. selecting a first and second band of
elastomeric material, said first and second band having
a total height of at least the height of the manhole
riser from the base of the bottom adjusting ring of the
manhole riser to the top edge of the top adjusting ring
of the manhole riser;
b. placing the first band over the manhole
adjustment area and positioning the bottom edge below
the adjustment on the cone; and
c. placing the second band over the manhole
riser, positioning the second band such that it extends
over the top edge of the first band and also extends
over the top edge of the top adjusting ring.
The present invention also discloses a kit for
sealing manhole risers. The kit comprises:
a first and second band of elastomeric material,
the first and second band having a total height of at
least the height of the manhole riser from one inch
below the base of the bottom adjusting manhole riser to
the top edge of the top adjusting ring of the manhole
riser.
The present invention also addresses sealing catch
basins. The method for sealing catch basins comprises
the following steps:
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a. selecting a first and second band of
elastomeric material, the first and second band having a
total height of at least the height of the catch basin
from the base of the bottom adjusting catch basin ring
to the top edge of the top adjusting ring of the catch
basin;
b. placing the first band over the catch basin
and positioning a bottom edge of the band at the base of
the catch basin, a top edge of the first band extending
toward the top of the top adjusting collar; and
c. if necessary, placing the second band over the
catch basin, positioning the second band such that it
extends over the top edge of the first band and also
extends over the top adjusting ring and into the edge of
the catch basin casting.
The present invention also describes a kit for
sealing catch basins. The kit comprises:
a first and second band of elastomeric material,
the first and second band having a total height of at
least the height from one inch below the bottom of the
catch basin from the base of the bottom adjusting catch
basin ring to the top edge of the top adjusting ring of
the catch basin.
In another embodiment, a method to seal pipe
intersections and barrel intersections which are sealed
together underground to support a cone, comprise a tape
having two strips of adhesive applied to one side of the
tape. The tape is dispensed, a release liner is peeled
off of the adhesive, and the tape is tightly wrapped
around the riser, cone or other conduit which needs to
be sealed. The ends are overlapped and sealed with a
block of mastic.
Another aspect of the present invention is an inner
seal for manhole risers and catch basins. The inner
seal comprises at least two bands of elastomeric
material which are adhered to the inner surface of the
catch basin or manhole riser. Preferably, the bands
21 ~3008
have adhesive already applied to them, with a release
tape liner for easy application.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 shows a perspective view of the present
invention sealing a manhole riser.
Figure 2 shows a perspective view of the present
invention sealing a catch basin.
Figure 3 shows individual components of the kit for
sealing a manhole riser.
Figure 4 shows one of the individual components of
the kit of Figure 3.
Figure 5 shows the kit in boxed form.
Figure 6 shows components of the present invention
used in a method to seal pipe junctures.
Figure 7 shows components of the present invention
used to seal barrels supporting a cone.
Figure 8 is a perspective view of a manhole riser
of the present invention with the inner seal in place.
Figure 9 is a perspective view of a rectangular
catch basin of the present invention with the inner seal
in place.
Figure 10 is a perspective view of a circular catch
basin of the present invention with the inner seal in
place.
Figure 11 is a top plan view of the preferred lay
up of the inner seal in a circular structure.
DETAILED DESCRIPTION OF THE INVENTION
The present invention, although describing manhole
risers and catch basins, also is directed to large
standard city sewer manholes which are commonly called
cones or barrels. Power and phone companies also have
underground cones, which are similar to manhole risers.
The present invention envisions the method of sealing a
manhole riser, a catch basin, a pipe juncture or any
large structure with rings or collars secured together.
The present invention may also seal the area between the
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cone and the barrel which often leaks.
As can be seen in Figure 1, the present invention
is a three-piece sealing system shown generally as 10.
The manhole riser is shown as 10, with a break-away as
14. Risers can vary from 4 inches to 16 inches in
height depending on the soil and surface conditions.
The break-away shows the manhole riser with a portion of
the sealing system removed for illustration purposes.
The individual adjusting rings 16, 18, 20, 22 and 24 are
stacked atop one another. The adjusting rings are
generally cemented to one another, with the mortar or
Portland cement visible as 26.
For the purposes of the present application,
"manhole riser" refers to what is shown in Figure 1,
which comprises a plurality of adjusting rings which
lead up to the top casting, which is shown as 12. The
casting 12 is an annular collar, which supports the
manhole cover (not shown). It is intended that the
manhole cover be flush or a bit below the road surface.
Beneath the riser 10, is a one-piece cone (not shown).
The one-piece cone is typically made of concrete, and
need not be shown for the present invention. As
discussed above, leaks occur through the adjusting
rings, particularly between the adjusting rings, and the
present invention discusses a solution to these leaks.
Figure 2 discloses a catch basin generally shown as
50. The catch basin has individual adjusting collars,
which are shown at the break-away portion of the sealing
system 52 as 54, 56, 58, 60 and 62. A top casting is
shown as 63. The collars are secured in place with
Portland cement or mortar, shown generally as 64.
Generally, two collars are fitted together with a point
of intersection shown as 66. It is intended that the
casting 63 with a grate on top (not shown) be marginally
below the road surface, with the road surface tilted in
a manner such that storm water drains into the catch
basin 50. Water passes through a grate which appears on
_ 21 S3008
g
top of the casting 63, through the middle of the
collars, into the storm sewer system. The storm sewer
system typically discharges into areas used as
irrigation, lakes, rivers, etc. This is different from
manhole risers, which typically are involved in the
treatment of water which is thereafter piped to homes
and businesses for consumption. Although the manhole
riser and catch basin perform different functions, as
described above, the same problems apply to both. The
mortar or cement holding the rings or collars in place
often breaks down with the freeze/thaw cycle or with
age. Furthermore, cracks may develop in the rings or
adjusting
collars, whereby water, sand, and other contaminants may
freely pass through the cracks.
The present invention addresses these concerns.
Referring back to Figure 1, there is a three-piece
sealing system, with a bottom band being 30, a middle
band being 32 and a top band being 34. The bands are
large, continuous bands of an elastomeric material, with
the ends secured together to form a continuous loop.
Preferably, the ends are secured together by a
vulcanizing process. The first band 30, is a circular
shaped elastomeric band which is adapted to fit the
bottom of manhole riser 10. The second band, shown as
32, is placed in the mid region of the manhole riser 10.
Preferably, the band is an EPDM elastomeric material
(ethylene propylene diene) or Neoprene. EPDM and
Neoprene materials are abrasion resistant, rubber like
synthetic polymers. Other types of possible elastomeric
materials include, but are not limited to nitrile,
Hypalon, thermoplastic materials including, but not
limited to, CPE (chlorinated polyethylene) rubbers,
block copolymers such as SBS, SIS, Kraton products and
other elastomeric materials.
Preferably some bands of the present invention have
a mastic adhesive on at least a portion the interior of
21~30a8
the band. Preferably, a release liner covers the
exterior of the adhesive. Once the bands are in place,
the release liner is removed. The adhesive thereafter
secures the band to the riser. Figures 3 and 4 disclose
5 the use of an adhesive on the bands. Figure 3 shows the
preferable adhesive positioning. Another preferred
adhesive position is to have an adhesive on the top and
bottom of the interior of the bands with no adhesive in
the middle portion of the band. The top band 34 has
adhesive on about the top half of the band. Band 32,
preferably, has no need for adhesive as it is secured by
the overlapping of bands 34 and 30, preferably, bottom
flange portion 36 has adhesive thereon.
The first band 30 is drawn over the adjustment neck
15 to the bottom of riser 10. If a slab is involved, the
band will automatically flair out and adhere to the slab
catch basin. This "flair" is especially preferred if
the cone is sitting on a cement slab. The "flair"
flares out to meet the cement slab. Preferably, the
20 bottom band extends partially below the base of the
bottom adjusting ring (about one inch).
In the preferred embodiment, the top band 34
terminates at the top of the top adjusting ring 24 on
the bottom edge of the casting 12. Preferably, band 34
25 has an approximate height of 6 inches and is of an
elastomeric material that stretches over the top edge of
the top adjusting ring 24 to the bottom edge of the
casting 28 to create a tight seal. The entire structure
is now water tight.
Thus, to summarize the method, prior to installing
the invention, remove all dirt from around the base of
the riser or basin. Clean the riser or basin so it will
receive the adhesive. Smooth all sharp corners with an
abrasive stone. Wipe clean with a rag. A first ring of
35 material 30 is pulled over the manhole riser 10, and
pulled down to the bottom. The top of the first band
must reach the top of the top adjusting ring. If the
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ll
bottom band does not reach the top adjusting ring, and
extension band must be used. Preferably, adhesive is
previously applied to the inside, and a release liner is
pulled off the band 30. A second band 32 is pulled over
riser 10 and positioned to overlap riser 10 by
approximately 2 inches. After the second band 32 is in
place, the third, smaller top band 34 is put in place
after adhesive is applied or exposed from the inside of
band 34. This extends below the top portion of the
second band 32, and extends over the top portion of the
top adjusting ring, and extends onto the casting 28.
Preferably, this third band is approximately a 6 inch
band. However, the present method and kit may work if
the top band reaches from a mid point region measured
from the base of the riser to the top edge of top
adjusting ring. Thus, the actual size of the bands is
not important, with the criteria that the bands cover
the whole exterior of the manhole riser.
Optionally, the middle third band may or may not be
needed, depending on the number of adjusting rings used.
Regardless of whether there are two bands or three
bands, the system is sealed in place with adhesive,
mortar and the manhole riser is thereafter buried.
Catch basin 50, shown in Figure 2, utilizes a band
system whereby the bands are rectangular in shape. The
first band 68 is placed over the catch basin such that
it is pulled to the base of the catch basin 50. The
bottom band 68 is cut about 1/2 inch on 3 inches either
side of the corner to relieve tension. Flange 74
thereafter contacts the slab, allowing water to run-off.
Top band 22 is thereafter placed on top of the catch
basin 50. The bottom edge of the top band 72 is
positioned below the top edge of the second rectangular
band 70. The top edge of the third band 72 thereafter
extends beyond the top edge of the top adjusting collar
62, and extends on to the bottom edge of the casting 63.
Thereafter, catch basin is sealed and buried.
'_ 2ls3oo8
12
The circular bands used for the manhole riser and
the rectangular bands used for the catch basin of the
present invention are elastomeric material, which is
generally cut from a pattern and is made into a band
from a rectangular cut piece of material with the use of
a vulcanizing process to secure the band. The same
procedure is performed with the rectangular band.
Figure 3 shows a preferred "kit" of bands for the
catch basin and the manhole riser of the present
invention. As is evident, the top band has an adhesive
portion 35 at the top. This is so the top band is
secure to the top collar and/or casting of the catch
basin. The kit includes an extension band 32 and the
bottom band 30, which has an adhesive portion 31 on the
bottom portion.
Figure 4 shows a perspective view of the inside of
band 34 of the present invention.
Figure 5 shows a complete kit of the present
invention, with bands 30, 32 and 34.
In the preferred embodiment, the bottom band is 12
inches high and has is capable of being flaired if a
slab is involved. All of the bands have a thickness of
about 0.06 inches and have a 60 durometer. Adhesive is
applied to the interior surface. The top band lays on
the casting to seal against infiltration. The vertical
part of the top band fits over the top portion of the
bottom or middle band and should overlap at least 2
inches. An extension band with a height of
approximately 8 inches may be used to gain additional
height as described above. The extension piece fits
over the bottom piece and should preferably overlap by
at least 2 inches. The top piece will thereafter fit
over the extension band, which overlaps by at least
about 2 inches over the extension band.
Preferably the extension band should have an
adhesive or strip of mastic on the bottom edge, where
the bottom of the extension band contacts the top of the
13 21$3008
bottom band. Thus, the extension band would have
adhesive on the bottom, inner surface which contacts the
top, outside surface of the bottom band. This ensures
the integrity of the seal. Likewise, the top band
should have adhesive or mastic which is on the interior
surface, and contacts the top, outer surface of the
extension band. Again, this ensures the integrity of
the seal. The sealant used as an adhesive for the bands
is a flexible butyl mastic sealant. Preferably, the
adhesive is a non-hardening butyl rubber mastic,
commercially available from BIDCO Adhesives.
It has also been found that the addition of a
primer to the portion of the concrete or casting that
the sealant will contact provides for an enhanced
adhesive bond between the bands and the cement or
casting. Typically, the primer is applied in the field,
via a spray can or brush, to the intended surface
(concrete rings, mortar, casting, etc.) prior to the
mastic containing band being applied. As the primer
reacts with the sealant, there is no need to apply the
primer anywhere other than where the sealant contacts.
Preferably, the primer is a solvent based primer of
synthetic rubber and resin. The preferred primer is a
heptane based primer commercially available from
Bondline Adhesives Inc. Other primers are envisioned,
with the only requirement being an enhancing of the
adhesion between the band and the structure.
Preferably, the primer dries quickly (meaning quick
evaporation of the solvent) such that the band with the
sealant may be applied without undue waiting.
It is also useful to seal the interior of the
manhole riser or catch basin. This is shown in figures
8, 9, 10 and 11. Oftentimes water, other liquids and
gasses contact the inner surface of the riser or basin,
with the result being the joints are corroded or
deteriorated over time. Thus, an inner seal is
advantageous to prevent the joint destruction from the
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14
interior.
In accordance with the present invention, an inner
seal invention comprises a band with an adhesive.
Preferably, the mastic covers the entire surface which
will contact the inner riser or basin surface. The band
preferably is EPDM but can be other materials as
described above. The adhesive is preferably the same as
described above.
Figure 8 discloses a circular manhole riser 100
with the outer seal denoted as 102. The casting rings
are shown in a break away as 104 and 110. The casting
sits atop the riser, denoted as 106. The inner seal 108
is shown with an overlap portion 112. The overlap
portion is approximately 1 inch, and extends all the way
down to the interior base of riser 100. As is evident
in Figure 8, the preferred embodiment is to have the
inner seal 108 extend up to the casting, and preferably,
approximately 2 inches onto the casting 106. Unlike the
preferred embodiment of the outer seal shown above, the
inner seal preferably has adhesive coated on the full
surface which contacts the interior 110 of structure
100. Most preferably, a primer, as described above, is
first applied to the interior surface 110. Thereafter,
the band, preferably being EPDM, has an adhesive such as
butyl mastic coated on one entire surface, with a
release liner covering the adhesive. If the width of
the band is not approximately the interior height of the
riser, with allowing an overlap onto the casting, either
the band is cut to an appropriate width, or if the band
is not wide enough, two or more bands may be applied.
The band(s) are applied such that an edge 112 is placed
on the interior 110, such that edge 112 is in a vertical
position. The band 108 thereafter is pushed against the
interior 110 all the way around the interior 110, until
there is a partial overlap at edge 112. The top and
bottom horizontal edges of the band, during the
installation process, should be aligned or substantially
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parallel with the horizontal plane defined as the top
and bottom of riser 100. In other words, the band
should be positioned to cover as much interior space as
possible. The band 108 is thereafter cut, either before
or after the previously described process. In other
words, the band 108 may be cut to the appropriate length
either before or after it is applied on the interior
110 .
An alternative method and a preferred method of
applying the inner seal in a circular structure is shown
in Figure 11. In this method, the inner seal is cut
into strips 144 and 146 having a length of approximately
the interior height of manhole riser 100. A plurality
of vertical strips are cut, and applied in a vertical
direction, rather than a horizontal direction. Again,
there is a partial overlap 145 as shown between strips
144 and 146. This method is preferred due to the fact
that often times the interior is askew, thus making it
difficult to apply the band in a square fashion. Thus,
20 several short bands may be cut and applied in the
vertical fashion described above.
Figure 9 discloses a square catch basin 120 showing
an outer seal 122 and inner seal 130 of the present
invention. Grate 128 sits atop casting 126. The inner
25 seal 130 rises up to a point 132, such that when water
flows into grate 128, at a high flow rate, it does not
catch an edge of inner seal 130 and shear off 130 from
the interior. Thus, it is preferred to extend inner
seal 130 as high as possible in the back of casting 126.
30 This is also shown in Figure 10, whereby an additional
inner seal 136 is shown being added to a circular catch
basin 130. The casting 132 is shown with a band 134
having an overlap 138.
The present invention also provides an economical
35 method of sealing the area around a pipe juncture. As
shown in Figure 6, pipes 80 and 82, which may be cement
pipes, are often connected together with a "male" 82 and
21$3008
16
"female" 80 pipe. The male pipe 82 is inserted into an
enlarged, female end of another pipe 80. The tape or
connector has adhesive sections 86, and 88 and has two
ends 90, and 92.
However, often times the juncture 94 or
intersection formed by these pipes is not water tight
or impervious to infiltration. The present invention
addresses these problems with the use of a tape system.
As is shown in Figure 6, a pull away of the tape 92
is illustrated. The method of sealing the pipe juncture
utilizes a roll of elastomeric tape. The tape 92
preferably comes in a dispenser (not shown), with the
tape being 50 feet long, rolled in the dispenser box,
and the tape 92 is made of EPDM and is 8 inches wide
and 0.60 inches thick. The tape 92 has mastic on the
top and bottom of the tape 92 running lengthwise. The
mastic preferably is 1.5 inches x 0.25 inches thick.
Preferably it is the same mastic as described above.
The method involved having two pipes which are
configured as shown in Figure 6 is described below. A
section of elastomeric tape is cut, with the stretched
length of the tape being greater than the circumference
of the pipe juncture that the tape is covering.
The tape has previously applied to it at least two
strips of adhesive extending lengthwise along the tape.
The tape is positioned such that about one-half of the
width of the tape is on one side of the pipe juncture
and the remaining half of the tape is on the other side
of the pipe juncture. The tape is pulled tightly, and
wrapped around the juncture, such that there is a
portion of a first end of the tape extending over the
second end of the tape.
Either prior to, or after the tape has been pulled
tightly around the pipe juncture, a connector 96 is
attached to one end of the tape. The connector 96 is
preferably a square of mastic, with a release liner. As
shown in Figure 6, the connector 96 acts as a splice for
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the two ends 90 and 92 of tape 84. The mastic may be
double sided or single sided and may be attached in
numerous ways. It can be attached to tape 84 prior to
wrapping around the pipe juncture 94, or it can be
placed on the pipe juncture after the tape 84 is wrapped
around the pipe juncture 96.
In addition to pipe junctions, the tape system may
be applied to barrels which support the cone. In this
other embodiment, a method to seal the joint where a
manhole barrel and cone are joined. This is comprised
of a band of predetermined size elastomeric material.
The band has two strips of mastic on the outside edges
of one side. The band is pulled into place over the
joint, the release paper on the mastic is removed and
pressed into panels.
Although the present invention has been described
with reference to preferred embodiments, workers skilled
in the will recognize that changes may be made in form
and detail without departing from the spirit and scope
of the invention.
