Single flexible, pre-insulated, self-compensating, underground pipe. Especially suitable for hot and cold potable water, but also for waste­water and other fluids. Corrosion-resistant transport pipe in cross-linked PE-Xa in accordance with EN ISO 15875. Thermal, elastic, CFC-free foam insulation made from cross-linked PE-X with closed microcellular structure. Minimal water absorption capacity of < 1% in accordance with ISO 2896. Corrugated outside casing in HDPE, made in accordance with the closed chamber principle to provide high-grade protection to the piping system.