This standard specifies essential requirements, ranges of approval, test conditions, acceptance requirements and certification for the approval testing of welder performance for the welding of nickel. This standard applies to the approval testing of welders for the fusion welding of nickel. This standard is intended to provide the basis for the mutual recognition by examining bodies for approval relating to welders' competence in the various fields of application. Tests will be carried out in accordance with this standard unless more severe tests are specified by the relevant application standard when these are applied. During the approval test the welder should be required to show adequate practical experience and job knowledge (test non mandatory) of the welding processes, materials and safety requirements for which he is to be approved; information on these aspects is given in Annex A. This standard is applicable when the welder's approval testing is required by the purchaser, by inspection authorities or by other organizations. The welding processes referred to in this standard include those fusion welding processes which are designated as manual or partly mechanized welding. It does not cover fully mechanized and automatic processes (see 5.2). This standard covers approval testing of welders for work on semi-finished and finished products made from wrought, forged or cast material types listed in 5.4. The certificate of approval testing is issued under the sole responsibility of the examiner or examining body.