This standard is part of a series of standards, details of this series are given in prEN ISO 15607:2000, annex A. This standard specifies how a preliminary welding procedure specification is qualified by welding procedure tests. This standard defines the conditions for the execution of welding procedure tests and the range of qualification for welding procedures for all practical welding operations within the range of variables listed in clause 8. Tests shall be carried out in accordance with this standard. Additional tests may be required by application standards. This standard applies to the arc welding of titanium, zirconium and their alloys in all product forms. Arc welding is covered by the following processes in accordance with EN ISO 4063. 131 — metal inert gas welding, MIG welding 141 — tungsten inert gas welding, TIG welding 15 — plasma arc welding The principles of this standard may be applied to other fusion welding processes.