Before
Insertion
Before insertin pulling tape or innerduct,
make sure the duct is rodded free of debris and is repaired
if necessary.
Inserting Innerduct
When a rodding line is used for cleaning,
it also can serve as a winch line for inserting the innerduct.
Just hook the innerducts onto the rodding line when you recover
it and it will pull the innerducts through. Otherwise a jetline
can be blown into the existing duct.
Before installing your Endocor
innerduct, release the bundle of pull tape on the innerduct
ends by untaping it. DO NOT CUT THE PULL TAPE. Stuff
the released tape back inside the innerduct, to provide some
tape slack.
The leading ends of the innerduct
are sealed together and a pulling head is attached to the
assembly. Attach the END of the pull tape to the pulling
eye or the stocking (basket) you are using. The most common
set-ups involve using threaded pulling eyes or a basket type
pulling head. However, a number of different methods and materials
can be used.
The lead end of the innerduct
and the pulling head are inserted into the duct. As pulling
commences, water-based lubricant is applied through the manhole
opening to reduce tension on the innerduct. On longer pulls,
additional lubrication points also may be used. The maximum
pulling load for the innerduct is 600 pounds of tension. The
rate of pull varies with the conditions of each job and should
be dictated by the tension on the line. Common pull rates
average approximately 100 feet per minute.
Allow extra footage of pull line
to compensate for the natural stretch that occurs when innerducts
are pulled. Temperature and tension on the pull will affect
to what extent the innerduct will shrink back into the existing
duct.
After your pull, allow the duct
to shrink back, then remove the pulling eye or basket and
secure the pull tape to the outside of the innerduct. Have
the crew at the reels cut the innerduct allowing 10 to 12
feet for racking and pull through all the extra tape from
the beginning of the duct. Additional pull line may be attached
using a double bowline knot.
Plow In
Endocor may also be direct
buried using standard plowing techniques. A plow-in direct burial
is ideally suited for open terrain applications where a minimal
number of obstructions occur. Plow-in allows large areas of
land to be covered relatively quickly.
A typical plow-in apparatus is
shown in the drawing below. Note that modifications may be
required to insure that the Endocor innerduct is not
subject to a bending radius more severe than 10 - 25 times
its nominal diameter. The plowing apparatus should be chosen
to maintain the trench width as narrow as possible.
It may be desirable to use a
larger size Endocor innerduct than required to permit
longer cable pulls with less resistance.
Trench and Backfill
Due to the ease of handling Endocor,
it may be readily placed in the trench, thus necessitating a
minimum amount of open trench.
The trench width will vary depending
on its depth and type of soil. The trench dimensions should
provide adequate space for the crew to make the installation.
Normally the excavated material,
if it is rock-free and well broken up by the ditcher, will
provide a suitable bedding material.
The trench bottom should be relatively
smooth and free of rock. When rocks, boulders, or large stones
are encountered which may cause point loading on the pipe,
they should be removed and the trench bottom padded using
4" - 6" of tamped bedding material below and on all sides
of the pipe and fittings. The bedding should consist of a
free flowing material such as sand, silty sand, or clayey
sand that is free of stones or hard particles larger than
1/2".
After laying the duct, snaking
and twisting should be removed by securing one end and stretching
the line. Removing the undulations in the line insures a low
friction factor during the cable pull operation.
The purpose of backfilling the
trench is to provide firm, continuous support around the pipe.
The best initial backfill material is sand. For sections laid
under the road, the innerduct should be placed in a PVC or
metal duct.
Inserting Cable
After the innerduct is in place,
you are ready to begin pulling the cable. Endocor innerduct
is available with a pull tape or rope already in place, enabling
the cable to be pulled in directly. Some customers use pull
tape to pull in the winch line.
Feel Free to Call Endot
If you should have any questions about your Endocor
innerducts, feel free to call Endot Industries at 1-973-625-8500
or 1-800-44-ENDOT. We are happy to lend support so your pull with Endocor
innerduct is easy and trouble-free.
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