1. Examples of Failing Welds: Sample #1 (Destructive Testing)
Cold Welds
Hot Welds
Failure was as the weld
Poor fusion of the filler rod / wire to the tubes
Weld bead radius is smaller than tube wall thickness
Little to no heat discoloration
The fitted / coped edges of the tube are visible after separation
Failure was at the weld
Weld / tube thickness was very small at point of failure
Weld bead radius is distinctly larger than tube wall thickness
Extreme heat discoloration

2. Examples of Failing Welds: Sample #2 (Destructive Inspection)
Inconsistent and unclearly defined fusion line
Weld bead radius is smaller than tube wall thickness
Weld bead does not adequately contact and fuse the both tubes 1

3. Sample #1 – Destructive Testing Sample #2 – Destructive Inspections
Examples of Passing Welds
Sample #1 – Destructive Testing
Sample #2 – Destructive Inspections
Moderate Heat Discoloration
Weld bead radius is approximately the same as tube wall thickness
Clearly defined and substantially uniform width fusion line, no burn - through
Failure was not at the weld
Weld bead radius is approximately the same as tube wall thickness
Moderate Heat Discoloration 2