This Part of DIN EN ISO 1452 specifies the general aspects of unplasticized poly(vinyl chloride) (PVC U) solid-wall piping systems intended for water supply and for buried and above ground drainage and sewerage under pressure. In conjunction with Parts 2 to 5 of DIN EN ISO 1452 it is applicable to PVC-U pipes, fittings, valves and ancillary equipment, their joints and to joints with components of other plastics and non-plastics materials intended to be used for the following: a) water mains and services buried in ground; b) conveyance of water above ground for both outside and inside buildings; c) buried and above ground drainage and sewerage under pressure. It is applicable to piping systems intended for the supply of water under pressure up to and including 25 °C (cold water) intended for human consumption and for general purposes as well as for waste water under pressure. This document is also applicable to components for the conveyance of water and waste water up to and including 45 °C.