Page 315 - Trenchless Technology Piping Installation and Inspection

Construction and Inspection for Cur ed-in-Place Pipe 279

Pipeline Type Suitable
Sewers Yes
Gas pipelines Yes
Potable water pipelines Yes a
Chemical/industrial pipelines Yes b
Straight pipelines Yes
Pipelines with bends Yes
Circular pipes Yes
Non-circular pipes Yes c
Pipelines with varying cross-sections Yes d
Pipelines with lateral connections Yes e
Pipelines with deformations Yes f
Pressure pipelines Yes g

a Several CIPP lining systems are approved for lining potable water pipelines and
can be combined with other lining systems to provide sufficient strength.
b As each manufacturer uses different types of resin, reinforcement, etc., the
chemical resistance of liners varies. If special characteristics are required, indi-
vidual manufacturers should be contacted in order to help finding the most
suitable product for specific requirements with regard to chemical content, con-
centration, temperature, etc.
c All the described methods are suitable for lining main pipelines with circular,
egg-shaped, or V-shaped cross-sections.
d Some proprietary liner systems allow CIPP techniques to be used in pipelines
with varying cross-sectional area.
e Laterals can be reinstated using a robotic cutter. It is presently possible to reopen
laterals on pipelines with a diameter of more than 4 in. (100 mm). In man-entry
systems, laterals are reopened manually. With some CIPP systems, watertight
connectors can be fitted between laterals and main lines.
f CIPP can be used where deformities are minor.
g A few liner manufacturers can supply laminates suitable for pressure
pipelines.
TABLE 7.1 Overview of CIPP Applications and Possible Limitations

7.2.1 Effects of Pipe Defects
While cured-in-place pipe can be installed in a variety of shapes and
configurations, levels of pipeline defect may dictate where the CIPP
may not effectively renew the existing pipe or when additional reme-
dial work is required before CIPP installation. With a thorough
knowledge of pipeline defects, the designer can determine if a pipe
can be renewed or must be replaced, what renewal or replacement
method to use, or if the pipe must initially be spot repaired.