Which option correctly pairs Category A and Category B weld joints?

• A. Category A: Circumferential Joint; Category B: Longitudinal Seam
• B. Category A: Longitudinal Seam; Category B: Circumferential Joint
• C. Category A: Butt Joint; Category B: Fillet Weld
• D. Category A: Fillet Weld; Category B: Butt Weld

Answer: (A)

In cylindrical vessels, weld joints are described by how they sit on the surface: around the circumference or along the length. A circumferential joint forms a ring around the vessel, while a longitudinal seam runs along the axis of the cylinder. The pairing in question aligns with this orientation-based classification: Category A corresponds to the circumferential joint, and Category B corresponds to the longitudinal seam. This makes sense because the categories are defined by the joint’s orientation on the vessel, not by whether the weld is a butt weld versus a fillet weld. Swapping these would mix up the fundamental orientation each category represents, and mixing in weld-type terminology would not reflect the intended category definitions.