Part UW-12 (d) of ASME Section VIII states that E=1.0 for circumferential stress calculations when the requirements for UW-11(a)(5)(b) are met, and E=0.85 when UW-11(a)(5)(b) is not met or when the welds are types 3-6.

Does this cover both type 1 and 2 welds? Is there any situation where the circumferential stress calculations on a seamless vessel section or head would have an E=0.65 due to non-radiographed Category B, type 2 circumferential welds (UW-12 (d) does not specifically identify type 2 welds as it does with the others)?

Thanks,

Response:

Our opinion is as follows:

Paragraph UW-12(d) of ASME Section VIII, Division 1 is stating that if the longitudinal seam (Category A) is either fully radiographed, or is a seamless component then the joint factor is computed as follows:

a)When the requirements of UW-11(a)(5)(b) are met then the joint factor for the circumferential stress is 1.00. For example, in the case of a cylindrical shell the circumferential joints attaching it to the adjoining parts would have to be spot radiographed to satisfy the requirements of UW-11(a)(5)(b).

b)When the requirements of UW-11(a)(5)(b) are not met then the joint factor for the circumferential stress is 0.85. Again, for example, in the case of the same cylindrical shell, if the circumferential joints attaching it to the adjoining parts were not radiographed.

The second part of your question revolves around the case where for example a cylindrical shell is attached to the adjoining components with type 2 joints. In this case, if the type 2 (Category B) welds were spot radiographed, then the circumferential stress calculation for the seamless shell would use a joint factor of 1.0. If the adjoining weld seams were type 3, 4, 5, or 6, then the joint factor for the seamless shell would be 0.85. UW-12(d) makes no mention of lower joint factors than 0.85.

We hope this fully addresses your question.