This method is used for the rehabilitation of pipelines made of steel, cast iron, asbestos cement, reinforced concrete, PVC, etc., which have been damaged as a result of various effects, such as corrosion, subsidence, cracking, hydraulic shocks, deposition. It is applicable for inner diameters between 150mm and 1220mm, divided in sections up to 250 – 350m (depending on the diameter and other factors).
This method fully eliminates leaks, strengthens the durability of the pipeline in case of earth movement, vibrations, hydraulic shocks and improves its hydraulic properties and wear resistance, by creating a smoother inner surface at the cost of neglectable reduction of the inner diameter. The method increases the life expectancy of the pipeline with 50 and more years of structural durability.
As a preparation for the rehabilitation, the pipeline section needs to be cleaned with a pressure washer. The rehabilitation itself represents the installation of a waterproof liner in the form of a flexible seamless pipe, made of a reinforcing layer(s) of polyester or glass fibers and sealing wear-resistant layer of polyethylene into the inner side of the existing pipeline. The resin impregnated felt tube is installed as a result of an eversion process (inside-out), utilizing compressed air. When installed, the liner gets tightly fitted to the inner side of the pipeline and the resin gets hardened, with steam or UV lamps (for resins containing photosensitive reagent). At the end a cutting robotic is used to reinstate any branch line connections.