inspect the materials and “wet out” procedure. A resin and catalyst system
compatible with the requirement of this method shall be used.
Materials shall be transported to, and stored at, the site in such a manner that they
will not be damaged, exposed to direct sunlight, or result in any public safety
hazard. All materials shall be subject to inspection and review by the Engineer
prior to installation.
D. LINER INSERTION
The impregnated tube shall be inserted through existing or new manholes and the
application of a hydrostatic head, compressed air, or other means sufficient to
fully extend it to the next designated manhole. The liner shall be installed at a rate
greater than 3 feet per minute and less than 10 feet per minute.
The Contractor shall ensure that the pressure in the liner exceeds both the pressure
due to the groundwater head and any pressure due to sewage in laterals or
connecting side sewers
A pre-liner may be required prior to liner installation in sewers with infiltration or
missing pipe sections.
E. CURING
After insertion of the tube is complete, the Contractor shall provide a suitable heat
source and distribution system to circulate hot water, air, and/or steam through the
pipe as recommended by the manufacturer. The equipment shall be capable of
delivering hot water, air, and/or steam to uniformly raise the temperature above
that required to cure the resin. This temperature shall be determined by the
manufacturer based on the resin/catalyst system employed.
The heat source piping shall be fitted with suitable continuous monitoring
thermocouples to gauge the temperature of the incoming and outgoing curing
medium. The temperature of the curing medium shall meet the requirements of
the resin manufacture as measured at the heat source inflow and outflow return
lines. Additional continuous monitoring thermocouples shall be placed between
the impregnated felt tube and the pipe invert at the manholes. The curing medium
temperature in the line during the cure period shall be as recommended by the
resin manufacturer. Care shall be taken during the elevated curing temperature so
as not to over stress the liner materials.
Initial cure shall be deemed to be completed when inspections of the exposed
portions of liner appear to be hard and sound and the remote temperature sensor
indicates that the temperature is of a magnitude to realize an exotherm. The cure
temperature shall be held for the period recommended by the resin manufacture,
during which time the distribution and control of the curing medium shall
continue. Curing the CIPP shall consider the host pipe material, resin/catalyst
system, ambient temperature, moisture level, and thermal conductivity of the soil.
2019 CIPP Lining Project CIPP Lining of Existing Sewers (Hot Water or Steam)
Nashua, NH 02650-9
