This part of 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 ISO 1452-2, ISO 1452-3, ISO 1452-4 and ISO 1452-5, 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 the 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 part of ISO 1452 is also applicable to components for the conveyance of water and waste water up to and including 45 °C. For temperatures between 25 °C and 45 °C, Figure A.1 of ISO 1452-2:2009 applies.NOTE The producer and the end-user can come to agreement on the possibilities of use for temperatures above 45 °C on a case-by-case basis.