AWWA INF52152

The water industry in the United Kingdom is being judged on the way that it maintains its underground assets to deliver a sufficient quantity of good quality water at an adequate pressure. In practice this involves rehabilitating the old cast iron mains and the industry is now moving towards using less expensive thin wall polyethylene (PE) interactive linings, which share the internal pressure loads with the host pipe. PE has limitations in long term creep and necking when bridging voids, gaps and internal protrusions. This paper describes a range of Silane cross-linked PE (SPEX) liners that have been developed specifically for use as interactive linings. The liners can be installed as a loose fitting PE pipe, then cross-linked in-situ using the flowing drinking water to produce a fully cross-linked structure having superior long term creep, yield strain and crack resistance to PE. This type of PE-X liner can also be butt fusion welded and extruded using standard PE equipment. Includes 14 references, table, figures.