Welded joint efficiency, and construction categories

The strength of a welded joint will depend on the type of joint and the quality of the welding. 

The soundness of welds is checked by visual inspection and by non-destructive testing (radiography). 

Category 1 the highest class, requires 100 per cent non-destructive testing (NDT) of the welds and allows the use of all materials covered by the standard, with no restriction on the plate thickness. 

Category 2 requires less non-destructive testing but places some limitations on the materials which can be used and the maximum plate thickness. 

Double-welded butt or equivalent Single-weld butt 1.0 0.85 0.7 

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