What characterizes closed procedures in welding?

Closed procedures in welding are characterized by being tested and approved by recognized standards such as those set forth by the American Society of Mechanical Engineers (ASME) for specific industry applications. These procedures imply a high level of quality control and assurance, which is critical in industries where safety and reliability are paramount, such as in pressure vessels, pipelines, and other critical infrastructure.

The approval process ensures that the welding method has been rigorously evaluated under various conditions to confirm that it meets stringent performance and quality criteria. This level of standardization is vital for ensuring consistent and repeatable results across different projects and fabricators, especially in environments where weld integrity is crucial.

In contrast, the other choices associate closed procedures with unofficial methods, a lack of application to various welding types, or the idea that they are exempt from testing, none of which align with the fundamental concepts of closed procedures in welding.