First let me say thank you for your reply.
Burn through:
API just considers length of Burn Through along the total weld length. But my question is about height of the penetration. API 1104 considers maximum 1.6mm height for capping pass but I couldn’t find anything about root penetration.
On the other hand, please mention to this sentence that is considered unacceptable according to API 1104 for Burn Through: “… density of the BT’s image exceeds that of the thinnest adjacent parent metal.” In Radiography Test the thinner plate thickness, the more density. Therefore, Burn Trough is something like lack of penetration or better to say root concavity; not excessive penetration. Isn’t it?
One of my friends is involved to pipe line welding and he asked me these questions.