![](https://www.polypipe.com/sites/default/files/styles/113x160/public/pre-insulated_brochure_.png?itok=L6zymX29)
![](https://www.polypipe.com/sites/default/files/styles/113x160/public/pre-insulated_brochure_.png?itok=L6zymX29)
The medium pipes are made from cross-linked PE-Xa with an orange coloured oxygendiffusion barrier for the flow line, and a blue coloured for the return. The colour code enables easy identification of flow and return during installation, even with mounted shrink end caps.
The multi-layer thermal insulation is made from cross-linked, microcellular PE-X foam with a water-repellent closed cell structure, characterised by its durable, non-ageing insulation performance, and its permanent elasticity, maximizing the thickness of the insulation layer, even after bending multiple times.
The high-grade, black coloured UV-resistant, double walled, corrugated HDPE sleeve shields the pre-insulated pipe system against mechanical impacts and moisture, whilst maintaining maximum flexibility.