SFP Liner

In recent years, several network operators (CPCU, Fötáv Rt, Ekaterinburg Vodokanal, Ville de Montréal, etc.) have requested that a solution be found to develop a structural liner capable of rehabilitating entangled and difficult-to-access metal pipes used for distribution, where the advanced degree of corrosion leads to a total loss of mechanical properties. To date, there is no sheath that is both structural and flexible. Corrosion leads to numerous leaks, with significant economic, environmental and safety impacts. 

What's more, the growing urbanisation phenomenon means that networks are subject to increasing static stress, and are difficult to access because they are located under roads or buildings, for example. These difficulties clearly show that it is complicated, if not impossible, to replace waste pipes in urban areas. 

SPF Liner aims to remedy the problem of a combination of loss of mechanical properties and leaks in the metal pipes that make up drinking water and high-temperature networks.  Lack of investment, ageing pipes and, last but not least, corrosion are the main causes. Our lining technology does not require the pipes to be replaced; on the contrary, we reinforce and, above all, seal them from the inside. This faster renovation process uses a flexible, structuring textile sheath impregnated with an epoxy resin to form a composite that is cured in the pipe.  The product will have to meet a number of mechanical, chemical and approval requirements in order to offer an additional 50 years' life expectancy to the renovated section.

To validate the high-pressure resistance and water tightness of the pipes, Centexbel installed a high-pressure test bench, composed of a mechanical structure containing the liner and a progressive pressure control system with instruments to record the pressure rise, temperature and time of measurement. A high-pressure pump delivers pressure up to 120 bar.

The objectives of the project are to develop a system that is able to adapt to changes in direction (bends) in an entangled network, while withstanding the static, pressure and temperature stresses (in the case of a system that will rehabilitate pipes with high-temperature effluent) to which it will be subjected. This means that the system developed must be Class A structural (the liner is independent of the host pipe, with no adhesion) and flexible during installation. The system will consist of a reinforced textile liner, an appropriate resin depending on the final application (drinking water or high temperature), and possibly a support material, all of which will be assembled during installation using a suitable method. This method is based on a range of parameters that vary according to the type of liner to be installed and the type of pipe, but will be based on the CIPP (Cured In Place Pipe) principle.