Install Methods
The CIPP installation methods are the Inversion and Drag in method, both explained below.
CIPP is less disruptive to the environment and the public than the traditional way of excavation.
Inversion Lining Method
Inversion lining is now the Industry standard method of installation for most CIPP applications, certainly where the host pipe is of a diameter greater than 225mm.
During the process, the impregnated needle felt tube is blown into place and pushed along the pipe either from a pressure vessel such as an inversion drum or sluice, or through utilisation of water pressure from a working platform.
The liner is then left to cure once in place, either ambiently or with the assistance of hot water or steam to accelerate the curing schedule. Dependant on the resin type used the CIPP liner will either have a close fit or leak tight finish to the existing sewer pipe.
Lining using the inversion method can be undertaken from a single access point, either up or downstream dependant on the pipe gradient, through use of a calibration hose to open the bottom end of the liner, this method is known as a ‘blind shot’.
Lengths of up to 900 metres have been installed in one shot using this installation method, coupled with a hot water cure. –Source :- UKSTT July 2013.
Characteristics:
- Suitable for liners of long length & large diameter
- Lining can be undertaken from a single access point
- A leak tight finish when specialist resins are used
- Can be used in conjunction with al resin types
- Process is more user friendly & efficient than drag in
Drag In Lining Method
Drag in lining or pull in place lining is the industry standard method of installation for small diameter repairs, where there are two points of access to the sewer.
The process involves pulling into place a needle felt sock impregnated with a thermosetting resin, that is pulled from one manhole to another and inflated using a calibration hose. The liner is then cured insitu to form a seamless, jointless repair to the pipe, effectively creating a new pipe within an
existing pipeline.
The drag in method provides a cured liner with a close fit finish, the liner is often sealed with epoxy putty at each end to improve the leak tight characteristics of the cured liner.
UV Liners
The drag In installation method is also utilised when curing using UV light. The liner is usually manufactured from glass fibre and impregnated with polyester resin,. It is winched into place and inflated using a blower system, the UV light train is then pulled through the inflated tube and cured in situ.
Characteristics:
- Suitable for short length applications
- Must be 2 points of access to the sewer
- For small diameter/short length applications and UV lining
- Liner provides a close fit finish to the host pipe
