It is the intent of this specification
to provide for installation of up to 300 feet long tubular
resin impregnated sleeve, affixed to the walls in the middle
of a main sewer pipe run, starting from on manhole to
another manhole or to a blind outfall, upstream or
The method involves the impregnation of
an absorbent carrier material; the inversion of the material
into the pipe, the curing of the sleeve leaving behind a
hard plastic sleeve mechanically bonded to the host pipe.
The carrier material
The carrier material shall be of
fibrous absorbent composition tailored to achieve the
the migration of resin from its internal structure by
compressing to a thickness of less than 90% of its
uncompressed thickness under a pressure 1 psi.
material must consist of non degradable fibers such as
polyester or polypropylene or corrosion resistant
material must have an abrasion resistant, chemically
resistant, fully bonded coated surface in the lateral
portion to ensure that on curing a smooth surface free
from blemishes, pinholes or loose non wetted fibers.
fiberglass is used a surface veil or a layer of felt
must be used to act as a barrier to prevent osmosis or
wicking of the strands.
carrier material must be resistant to the resin used and
must withstand any installation forces without losing
The resin must be a
thermosetting resin cured by either heat or chemically via
the use of accelerators, or any other safe energy source
which does not involve the use of electrical current within
the main sewer, unless where evidence can be supplied of the
The resin must give sufficient
working time above ground to enable impregnation of the
fabric, but must cure to sufficient hardness to carry
overburden loads within a maximum of 8 hours from time of
insertion inside the pipe.
On completion of the work a CCTV
survey should be carried out and the repairs must be
verified as per below.
should be no evidence of water ingress within the liner.
sleeve should be watertight internally. Where
bends or other pipe deformities are present the maximum
wrinkling allowed is 3% of the pipe diameter.
If required by the owners bid
documents, testing may take place by placing two push rod
plugs to the beginning and the end of the sleeve. Air
is fed into the isolated area and pressure losses are
Test criteria and acceptable losses to
be determined in advance by the engineer in consultation
with the contractor.
The design is based on the assumption
of a partially deteriorated pipe. The CIPP is designed
to support the hydraulic loads due to groundwater, since the
soil and surcharge loads can be supported by the original
pipe. The groundwater level should be determined by
the purchaser and the thickness of the CIPP should be
sufficient to withstand this hydrostatic pressure without
The pipe must be clean and free from
debris, encrustation, and standing water. Using a
camera measure the length of felt tubing required.
Insert the fiber liner tube into a
Mix the resin and hardener required
and pour the required amount of resin into the tube.
Attach a Vacuum pump to the other end
of the tubes and feed the material through the nip roller,
spacers and conveyor system. Adjust the speed of
impregnation to ensure thorough wet out on both top and
Carefully wind the fiber liner bladder
combination into the tan ensuring tension at all times.
Turn the trailing end of the bladder back on to the nose
cone. Strap the tubes to the cone using a ratchet
Introduce regulated compressed air
(Max 6psi) to the tank and allow sufficient bladder tubing
to extrude out. Deflate the tubing by venting out the
air. Tuck the tubing into the pipe run.
Switch on the compressor and allow the pressure to build up
to 6psi by holding the winding arm.
Gradually unwind the arm at a speed
that maintains 6psi pressure until the bladder tubing is
fully everted into the pipe and comes out at the required
terminations point or the downstream manhole.
Connect the boiler to the shaft of the
tank and introduce warm water at the prescribed temperature
whilst allowing the air to escape through the relief valve.
Continue introducing warm water until
the water level backs up to a level just above the crown of
the pipe. Leave the combination of tubes until the
felt tube cures.
Once cured, puncture the bladder tube
at the upstream end next to where it is clamped on the pipe.
Slowly rewind the arm of the tank to un-invert the bladder
tube thus forcing water out into the manhole.
Cleaning of the Main Pipe
The manhole to manhole section
of main pipe must be free of debris, obstructions, scale or
any other material that reduces the effective bore of the
pipe or loose material which may be pushed forward by the
If inverting upstream, provision needs
to be made for reducing the flow to no more than 15% of the
bore of the pipe.
A videotaped survey must be
done on the main run with a pan and tilt camera to confirm
the proposed repair falls within the limitation parameters
set by the manufacturer on the following aspects: The
presence of bends, groundwater infiltration, flow rates from
laterals and through the main pipe, gradient of pipe run.
On completion of the survey, a report
should be submitted to the Engineer confirming the
feasibility and the required program of works.
Post Repair Survey
On completion of a given run, video
taped evidence must be provided by the contractor. The
repair sleeve should be monitored for excessive wrinkling,
exposed unwetted fibers and pinhole leaks.
Subject to the result of the
Inspection test, the Engineer reserves the right to select
approximately 10% of the repairs for further testing using
water. The test shall comprise of pushing a
plug to the downstream end of the sleeve, inserting a bypass
plug at the upstream end and filling the isolated section
with water. Losses shall be measured and must be
within levels set by the local code.
If the failure rate exceeds 10% and
additional retest area of an equivalent size shall be
selected for further testing.
The workmanship of the works
shall be warranted for a period of 12 months following
substantial completion. The material shall be
warranted as per terms and condition of the manufacturer for
a similar period PROVIDED the contractor applies the product
in accordance with the current guidelines (Standard
Operating Procedure) set out by the manufacturer.
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