For welders it is easy. This is directly from D15.1:
5.3.2 Welders or welding operators who are qualified for the materials, processes, and procedures being used in accordance with one of the following specifications shall be considered qualified to weld under this specification.
(1) ASME, Boiler and Pressure Vessel Code, Section IX
(2) AAR M-1002, Specification for Tank Cars, Appendix W
(3) AWS D1.1, Structural Welding Code—Steel
(4) AWS D1.2, Structural Welding Code—Aluminum
(5) AWS D1.3, Structural Welding Code—Sheet Steel
(6) AWS D1.5, Bridge Welding Code
(7) AWS D1.6, Structural Welding Code—Stainless Steel
(8) ASTM A 488, Practice for Steel Castings, Welding, Qualifications of Procedures and Personnel
(9) AWS B2. 1, Specification for Welding Procedure and Performance Qualification (qualification by visual inspection alone is prohibited)
(10) CSA W47. 1, Certification of Companies for Fusion Welding of Steel Structures
(11) CSA W47.2, Certification of Companies for Fusion Welding of Aluminum
For procedure qualification, D15.1 says the following:
5.2.2 Other materials or welding procedures using one of the processes covered by this specification may be used, provided they are qualified by applicable tests as prescribed in Clause 10. The acceptability of qualification
to other standards is the Fabricator’s Engineer’s responsibility, to be exercised based upon the specific structure, or service conditions, or both.
To wit:
Fabricator’s Engineer. A designated individual with design authority employed by the fabricator, manufacturer, or outside repair facility who is responsible for the ongoing activities within the scope of the specification.