What is the criteria for a weld to be considered acceptable by visual examination?

• A. Visible cracks allowed
• B. No visible crater cracks or surface cracks
• C. Surface cracks less than 1/16"
• D. No arc strikes and no undercut

Answer: (B)

A weld is considered acceptable by visual examination primarily when there are no visible crater cracks or surface cracks present. Crater cracks can occur at the end of a weld bead where solidification takes place, leading to a significant reduction in the integrity of the weld. Surface cracks indicate a failure in the weld material, which can compromise the overall strength and durability of the tank structure.

In the context of weld quality, the absence of these defects is essential for ensuring that the weld can withstand the stresses and environmental conditions it will face in service. This criterion is crucial in sectors such as oil storage, where the integrity of welded joints directly impacts safety and operational reliability. Hence, the requirement for a weld to be free from visible defects like crater and surface cracks is a key factor in determining its acceptability through visual inspection.