3.04 PRE-LINER/OUTER FILM/OUTER LINER
At all locations where the CIPP liner is inverted or inserted into the host pipe, a pre-liner
tube shall be used to control resin loss, liner thickness, a reduction in physical properties,
contamination of the resin by water or other contaminants, and prevent blocked or
plugged services or laterals. The pre-liner tube shall be reinforced plastic sheet formed
into a tube sized to fit the host pipe being lined and shall be continuous from manhole to
manhole. The pre-liner tube must be a rated gas barrier for styrene. Installation of the
pre-liner tube shall be witnessed by the Owner or Engineer. Failure to install the required
pre-liner tube or installation of pre-liner tube over only part of the segment shall result in
the completed C.I.P.P. for that segment being rejected (regardless of physical tests and
thickness test results). During thickness testing, the pre-liner tube shall be removed from
the thickness test core sample along with the inner liner firm used. If there is any damage
to the pre-liner tube, it should be repaired immediately with styrene-proof tape.
3.05 TUBE INSERTION AND CURING
1. An independent slip sheet, or integrated slip sheet shall be installed on the bottom
half of the pipe prior to liner insertion, for the purpose of smoothing out the bottom of
the liner to increase flow characteristics.
2. The pre-liner tube, or outer film, must be inserted into the pipe prior to inserting the
liner, unless it is manufactured on the exterior of the liner, which is a normal
characteristic of most fiberglass CIPP liners.
3. A constant tension winch should be used to pull the glass fiber liner into position in
the pipe. Once inserted, end plugs shall be used to cap each end of the glass fiber
liner to prepare for pressurizing the liner. The end plugs should be secured with
straps to prevent them from being expelled due to pressure. Liner restraints should be
used in manholes.
4. The glass fiber liner shall be cured with UV light sources at a constant inner pressure.
a. The UV light sources should be assembled according to the manufacture’s
specifications for the liner diameter. For the liner to achieve the required water
tightness and specified mechanical properties, the following parameters must be
controlled during the entire curing process, giving the Engineer a record of the
curing parameters over every segment of the entire length of the liner. This
demonstrates that the entire liner is cured properly. The recording will include:
e Curing Speed
° Light source working & wattage
e Inner air pressure
® Exothermic (curing) temperatures
e Date and time
® Length of liner
2019 CIPP Lining Project CIPP Lining of Existing Sewers (Ultraviolet)
Nashua, NH 02651-10
