1.1 This part of ISO 9330 specifies the technical delivery conditions for electric resistance and induction welded tubes of circular cross-section having wall thickness up to and including 16 mm, made of unalloyed and alloyed steels with specified elevated temperature properties. These tubes are intended for pressure purposes, in cases when the material is also subjected to elevated temperatures, e.g. for the construction of steam generating equipment and for interconnecting pipework. The requirements of appropriate international application standards and relevant national legal regulations shall be taken into account by the user. For boilers and pressure vessels, ISO/R 831 and ISO 5730 are available. The following parts of ISO 9330 are now available or are being prepared: — Part 1: Unalloyed steel tubes with specified room temperature properties (partial revision of ISO 2604-3:1975 and of ISO 2604-6:1978). — Part 3: Electric resistance and induction welded unalloyed and alloyed steel tubes with specified low temperature properties (partial revision of ISO 2604-3:1975). — Part 4: Submerged arc-welded unalloyed and alloyed steel tubes with specified elevated temperature properties (partial revision of ISO 2604-6:1978). — Part 5: Submerged arc-welded unalloyed and alloyed steel tubes with specified low temperature properties (partial revision of ISO 2604-6:1978). — Part 6: Longitudinally welded austenitic stainless steel tubes (revision of ISO 2604-5:1978). NOTE 1 The English words "tube" and "pipe" are synonymous. 1.2 See ISO 404 for general technical delivery requirements.