The first CIPP liner installed in London in 1971 was pulled into position within the host pipe and then inflated and cured. However, within a few years, an inversion installation process had been developed in which the impregnated liner was contained within a plastic handling layer and was unfurled (inverted) within the host pipe using water or air pressure. This method causes the liner to unwrap itself within the host pipe without the need to drag the prepared liner through the host pipe. The first commercial installation of UV cured CIPP was installed in Sweden in 1985, by the inversion process using air. The handling layer remains on the inside of the finished liner and the impregnated felt/fabric winds up in direct contact with the host pipe. In both cases, Winched-In-Place or Inverted process, there is normally a handling/sealing layer on both the outer and inner surfaces of the liner. The inside polymeric layer is often a temporary internal membrane used to separate process fluid (typically water or air) from the resin system during liner insertion, and is withdrawn after the resin cure. This allows the liner to be pulled in place and then for the inflation and curing process to be accomplished from inside the liner. Both methods are effective for thermal curing and UV curing, the choice can depend on job circumstances or contractor preference.
Description published by the International Society for Trenchless Technology within its parent technique's article.