This part of ISO 9330 specifies the technical delivery conditions for submerged arc-welded tubes of circular cross-section, made of unalloyed or alloyed steel 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 International Standards ISO 831, ISO 2604 and ISO 5730 are available. For the general technical delivery requirements, see ISO 404. NOTE The English words “tube” and “pipe” are synonymous.