Overlapping Weld for Vessel per ASME Section VIII

Flush the circunpherential weld, RT for the overlapping weld sector, and weld the pad reinforcement.

Hi,

May i know which code does it tell?

Per ASME code, Section VIII, Div. 1, Para. UW-14 Openings in or Adjacent to Welds, it is acceptable to locate the nozzle hole itself in a vessel head-to-shell weld:

UW-14(b) Single openings meeting the requirements given in UG-36(c)(3) may be located in head-to-shell or Category B or C butt welded joints, provided the weld meets the radiographic requirements in UW-51 for a length equal to three times the diameter of the opening with the center of the hole at mid length. Defects that are completely removed in cutting the hole shall not be considered in judging the acceptability of the weld.

Therefore, you can proceed welding of the reinforcing pad over any butt weld taking into consideration the following:

a. Remove the weld cap (flush) under the reinforcing pad up to be like the outer surface of the vessel .

b. Radiography the buttweld under the pad area up to a distance outside the pad by at least 2" outside the fillet weld of pad-to-shell.

Notes.

1. The radiographed weld distance shall satisfy the min. limits shown by UW-14(b), i.e. that distance shall not not be less than three times the diameter of the opening.

2. The 2" distance outside the pad-to-shell/head fillet weld is recommended by myself as a good recommended practice, and I think (not sure) that recommendation is not included in ASME code, and I think (not sure also) that there are some standards of huge firms in field of design and fabrication have the same recommendation.