Nozzle weld seam efficiency

[mg75]

Hi all,

With reference to thread292-267966, what would you answer to the following question :

For a set-in 12" nozzle made of welded pipe TP304L Sch80S, that does not have circumferential butt welds in its assembly, Category C fillet welds [such as shown in Fig. 2-4, sketch (3a)] are used to attach its flange and Category D corner joint made with full penetrations welds [such as shown in Fig. UW-16.1, sketch (c)] is used to attach it to the main cylindrical shell.
In accordance with UW-12(e) of Section VIII, Division 1, is it correct to use E = 1.0 and the allowable tensile stress taken from the welded product values of the stress tables for calculations involving circumferential stress in the nozzle welded pipe since no Category B or C butt welds exist in the assembly?

 

[SnTMan]

Yes.

Regards,

Mike

 

[mg75]

Thank you Mike,

I was not too sure about this. Because this is for ASME VIII div1, but when I looked at ASME VIII div 2, the category D corner joint need at least 10% volumetric examination (Table 7.2, joint category D, type of weld 7) to reach a weld efficiency of 0.85. And so even if the allowable stress values are the same for seamless or welded 304L pipe in ASME II table 1A (with G5 note) and Table 5A

So for the same assembly : more control in div 2, at least for volumetric examination (10% vs 0%), but lower weld efficiency then in div 1 (E=0.85 vs E=1).

That was why I was not 100% sure.

Regards.