ISO 15876-2:2017 specifies the characteristics of pipes for polybutene-1 (PB-1) piping systems intended to be used for hot and cold water installations within buildings for the conveyance of water whether or not intended for human consumption (domestic systems), and for heating systems, under design pressures and temperatures appropriate to the class of application (see ISO 15876-1). The designation polybutene is used together with the abbreviation PB throughout this document. ISO 15876-2:2017 covers a range of service conditions (application classes), design pressures and pipe dimension classes. For values of TD, Tmax and Tmal in excess of those in ISO 15876-1, this document does not apply. NOTE 1 It is the responsibility of the purchaser or specifier to make the appropriate selections from these aspects, taking into account their particular requirements and any relevant national regulations and installation practices or codes. It also specifies the test parameters for the test methods referred to in this document. In conjunction with the other parts of ISO 15876, this document is applicable to PB pipes, their joints and to joints with components of PB, other plastics and non-plastics materials intended to be used for hot and cold water installations. It is applicable to pipes with or without (a) barrier layer(s). NOTE 2 In the case of plastics pipes provided with a thin barrier layer, e.g. to prevent or greatly diminish the diffusion of gases and the transmission of light into or through the pipe wall, the design stress requirements are totally met by the base polymer (PB).