Cured-in-place pipe lining is a trenchless rehabilitation method used to repair old or damaged pipelines most efficiently.
In our water supply networks pipelines have been successfully, economically and quickly rehabilitated with CIPP lining for more than 20 years. The pipelines rehabilitated in this way are permanently protected against leaks, corrosion and deposits, which is synonymous with a lasting improvement in the quality of drinking water and the quality of life.
Methodology/system description
The fabric tubes consist of seamless woven or knitted fabrics on which the appropriate coating is applied depending on the transport medium. The fabric is usually made of polyester and nylon yarns, although reinforced yarns can also be used for special applications. For lining in the water sector, a PE coating approved for potable water is applied to the fabric. The wall thickness of the liner is 2-4 mm depending on the pipe diameter. The resin-impregnated fabric liner tubes are inserted into the pipeline to be rehabilitated using compressed air in accordance with the so-called inverting method, whereby the space required for the start or target excavation pit is minimal.
Application areas
Fabric liner tubes have their main field of application in the lining of water, sewage pressure and gas pipes in distribution, transport and industry. The process covers the diameter range from DN 80 to DN 1200, irrespective of the old pipe materials, and is therefore one of the few rehabilitation processes that has such a wide range of possible applications. Pipelines with operating pressures of up to 30 bar in the gas sector and 25 bar in the water sector can be lined with the fabric lining, whereby the main area of application for rehabilitation in the water sector is 10 bar. The limits of application of the CIPP process result from the process-specific boundary conditions such as pipe diameter, lining length, pipe routing, curing process and accessibility.
Summary
The advantage of the CIPP lining process compared to conventional replacement is in particular a much faster construction. According to the state of the art, the method with the additional advantage of the tightness of the fabric liner after pipe bursts is considered one of the highest quality rehabilitation methods. Since the lined pipeline can be expected to have at least the same service life as a newly laid pipeline if the statics of the old pipe are not weakened, this method is also highly economical. The trenchless construction method using the CIPP lining method is a major advantage, especially in inner-city areas.