Many welder qualification sections practice what is shown in D 1.1 for plate, Shapes and HSS. However, most of the other codes have significant differences in the way the test is administered, the coupon is prepared and tested, the results are reported and the life span of the qualification. Sheet Steel is different, Re-Bar is different, Sheet Metal is different, Seismic is different, and pipe welding is different. ASME and API are just two of the most common codes other than D 1.1. LIke many other codes, standards, specifications, and recommended practices, they have such significant differences, that usually there is no way to cross qualify with a single test.
Often the D1.5 unlimited test can be substituted for D 1.1 testing, because of the similarities, but seldom can D 1.1 be substituted for D 1.5, unless the D 1.5 requirements are included at the time the test is administered.
EN and ISO standards for welder qualification cannot be harmonized with US standards.
Joe Kane