Final answer:
The CSA B51, AWS D1.1 and ASME IX refer to AWS B2.1 for the approved use of Standard Welding Procedure Specifications. This standard is essential in ensuring quality and safety in the welding industry.
Step-by-step explanation:
The CSA B51, AWS D1.1 and ASME IX standards all refer to another standard for the approved use of Standard Welding Procedure Specifications (SWPS). The correct referred standard is AWS B2.1. This standard is a base document that provides the necessary guidelines for the qualification of welding procedures and welders, which ensures the quality and safety of welding processes in various industries. AWS D1.1 deals with structural welding, ASME IX covers welding and brazing qualifications, and CSA standards are focused on Canadian codes for pressure vessels and other structures. These regulations are crucial in providing a framework for consistent Procedure qualifications and maintaining high standards of practice in the welding industry.