Under what condition must a welder be requalified?

A welder must be requalified when there is a change of filler metal classification from Group 1 or 2 to Group 3 due to the implications that such changes can have on the properties and behavior of the welds. Filler metal classifications define the chemical composition and mechanical properties of the filler metal used in the welding process.

Transitioning to a different group may introduce new variables that can affect weld integrity, such as differences in strength, ductility, or corrosion resistance. As a result, the API 1104 standard requires requalification to ensure that the welder has the necessary skills and knowledge to handle the new materials and produce welds that meet specified quality standards.

In contrast, changes in employment, welding direction, or outside diameter groups may not necessitate requalification, as they do not inherently impact the fundamental skill set required for welding. Therefore, requalification focuses specifically on scenarios where material properties could significantly change, reinforcing the importance of adaptability in maintaining high-quality welding practices.