Cured in Place Pipe (CIPP)
Definition - What does Cured in Place Pipe (CIPP) mean?
Cured in place pipe technique (CIPP technique) is a trenchless technology rehabilitation method to fix and repair existing water, gas, chemical and wastewater pipelines. CIPP has no joints. It is a seamless pipe within a pipe and can rehabilitate pipes having diameters in the range of 4 inches to 110 inches. It is an ASTM approved method for rehabilitating any cracked, damaged or broken infrastructure pipelines.
Corrosionpedia explains Cured in Place Pipe (CIPP)
With cured in place pipe (CIPP) rehabilitation technology, a flexible lining material is placed internally in a damaged pipe so that this material is able to provide both corrosion mitigation and structural improvement. With the help of the CIPP lining process, any type of pipeline made from cast iron, PVC, ABS, HDPE, Orangebur, concrete or corrugated metal can be rehabilitated.
The construction material used in the preparation of CIPP liners are non-woven polyesters that have an exterior polyurethane coating, coated in tubular layers over non-woven polyester. A specified amount of catalyzed thermosetting resin mixture is spread over this non-woven polyester during the rehabilitation process. This step, known as the wet-out process, makes the construction material act as a resin carrier and adds flexibility and strength to the finished liner. After the wet-out process step, the CIPP liner is delivered to the installation site in a refrigerated truck. At the installation site, the liners are positioned in the host pipe by either filling air or water or winched in place. Once the CIPP liner position is adjusted, it is inflated by water column or air pressure, which pushes the material against the host pipe wall. When the CIPP liner is fully inflated, either hot water or steam is circulated inside the CIPP liner to initiate the thermosetting resin's hardening cure. Once the curing process is complete, the liner is allowed to cool slowly to prevent it from shrinking.
This technology was invented in England, but has seen frequent use in many parts of the world. Used at more than 20 sites in the United States, several water utility owners expressed their willingness to use the technology.