Who is responsible for conducting tests required to qualify Welding Procedure Specifications according to AWS D1.4 2005?

The responsibility for conducting tests required to qualify Welding Procedure Specifications (WPS) according to AWS D1.4:2005 primarily falls on the contractor. This is because the contractor is often the entity that is directly involved in the welding processes and must ensure that their procedures comply with the applicable standards. The contractor is thus responsible for developing and qualifying WPS to meet the specific requirements of the project.

Design engineers may specify the necessary requirements for welding in a project, but they rely on the contractor to execute the procedures and ensure that the welds meet the appropriate standards. Independent inspectors typically focus on evaluating the work and ensuring compliance rather than conducting the tests for qualification themselves. Material suppliers provide the materials for the welding, but they are not responsible for the procedural aspects of welding qualification.

Therefore, the contractor holds the primary responsibility for conducting the necessary tests to qualify WPS, ensuring that all welding activities conform to standards and specifications outlined in AWS D1.4.