The International Organization for Standardization (ISO). Second edition, 2005-12-15. 16р. This part of ISO 3834 provides a general outline of ISO 3834 and criteria to be taken into account for the selection of the appropriate level of quality requirements for fusion welding of metallic materials, among the three levels specified in ISO 3834-2, ISO 3834-3 and ISO 3834-4. It applies to manufacturing, both in workshops and at field installation sites.