Installation Guide

101
Trenching
The following trenching and burial procedures should be used
to protect the piping system.
1 . Excavate the trench in accordance with applicable codes
and regulations, ensuring that the sides will be stable
under all working conditions.
Underground Installation
INSTALLATION PROCEDURES
5. Apply primer
between the mark
and pipe end on
both pipe ends.
4
5
6
7
7. Push the repair
coupling toward
the gap until you
reach the mark on
the other pipe end.
A bead of cement
will be present
around the entire
diameter of the
pipe and coupling.
6. Apply heavy body
cement between
the mark and pipe
end on both pipe
ends.
4. Place the repair
coupling on the
pipe with the
larger pipe ID
(inside diameter)
end facing the gap
between the pipe
ends. (The larger
pipe ID of the
2. The trench should be wide enough to provide adequate
room for the following.
A. Joiningthepipeinthetrench;
B. Snaking the pipe from side to side to compensate for
expansionandcontraction,ifrequired;and
C. Filling and compacting the side fills.
The space between the pipe and trench wall must be wider
than the compaction equipment used in the compaction
of the backll.Minimum width shallbe not less than
the greater of either the pipe outside diameter plus 16
inches or the pipe outside diameter times 1.25 plus 12
inches. Trench width may be different if approved by the
design engineer.
3. Install foundation and bedding as required by the en-
gineer according to conditions in the trench bottom.
Provide firm, stable and uniform bedding for the pipe
barrel and any protruding feature of its joint. Provide a
minimum of 4 inches of bedding unless rock or unyield-
ing material is encountered in the bottom of the trench,
in which case a minimum of 6 inches of bedding shall
be used. For more severe conditions the guidelines in
ASTMD2321shouldbefollowed.Blockingshouldnot
be used to change pipe grade or to intermittently sup-
port pipe over low sections in the trench.
4. To prevent damage to the pipe and disturbance to pipe
embedment, a minimum depth of backfill above the pipe
should be maintained before allowing vehicles or heavy
construction equipment to traverse the pipe trench.
Pipe should always be installed at least below the frost
level. The minimum depth of cover should be established
by the design engineer based upon an evaluation of spe-
cific project conditions. In the absence of an engineer-
ing evaluation, Charlotte Pipe recommends referring to
Section7.6inASTMD2321“UndergroundInstallation
of Thermoplastic pipe for Sewers and Other Gravity-
FlowApplications.”
Bedding and Backfilling
1. Even though sub-soil conditions vary widely from place
to place, the pipe backfill should be stable and provide
protection for the pipe.
2. The pipe should be surrounded with an aggregate material
which is easily worked around the sides of the pipe.
Backfilling should be performed in layers of 6 inches
witheachlayerbeingsufcientlycompactedto85%to
95%compaction.
coupling has raised quarter mark lines on the outside
diameter of the coupling.)