What is a prequalified (PQ) CJP groove weld?

• A. It is defined as a joint welded from both sides, or from one side with backing, having complete penetration and fusion of weld and base metal throughout the thickness of the joint.
• B. It is a weld that does not require testing.
• C. It is a weld made with backing only.
• D. It is a fillet weld only.

Answer: (A)

Complete joint penetration means the weld metal fuses with both base metals through the full thickness of the joint, leaving no un-welded root. A prequalified groove weld is a joint that, when welded from both sides or from one side with backing, achieves complete penetration and fusion throughout the thickness. This allows the design to be accepted under the code without a separate welding procedure qualification for that specific geometry and process, provided the materials and thickness meet the prequalified criteria. The description aligns with how PQ CJP groove welds are defined.