Appendix 2 Flange Made from Rolled Ring w/ Butt Joint ?

[bayardwv]

Has anyone been asked to modify the Appendix 2 thickness calc because of a welded ring.
Here's my situation....
We use Loose type Flanges designed in accordance with ASME Sect. VIII Div.1, 2013 Appendix 2, fabricated from a rolled and welded ring using the lower stress values per Note G5 in Sect. II-D. This 14.75" od x 12.75" id x 3.25" thick ring is welded together with a full penetration butt weld in accordance with code. I'm being asked to apply an "E" efficiency factor to the design of the flange or perform 100% x-ray on this seam. I've responded that the Flange meets all Appendix 2 design requirements and that applying a Efficiency factor is not required. Has anyone been asked to modify the Appendix 2 thickness calc because of a welded ring?

 

[Nfroh]

You cannot use joint efficiency factor in an App.2 calculation, since there is no any mentioned. Of course if you want, you can reduce the allowable stress for the flange to be conservative, but you do not need to. If the flange is 3,25” thick made of ferritic steels you’ll need to perform 100% radiography since it’s a butt weld and the discussion is finished.

 

[SnTMan]

bayardwv, Apx 2 makes no mention of loose flanges fabricated in this way, thus no special requirements. However, other parts of the Code govern whether your butt-weld shall be examined or heat treated. See Parts UW, UCS, UHA, etc.

Regards,

Mike

 

[bayardwv]

Than you for responding. I have someone insisting that this isn't a safe design because I've neglected to address this joint,as is required on a rolled and welded shell.
Yes I'm aware of the other requirements regarding the material & design of this 3/4" wide x 3-1/4" tall rolled & welded ring. It's weleded to an 11 gauge shell in accordance with Fig. 2-4(3a), and no additional testing or design modification is required.

 

[SnTMan]

bayardwv, you in turn may insist this seam is not primarily pressure retaining, as in a shell. You may insist Appendix 2 place no restrictions on such a construction.

If dimensions are suitable (not clear from your posts) you might consider in the future just burning a ring from plate, rather than roll and weld.

Regards,

Mike

 

[dineshakabari]

Hi SnTMan, I will like to add one point the welded thickness of flange needs to consider while work out MDMT (Minimum Design metal Temp.). This may call for Impact test requirement.
Regards, dinesh

 

[bayardwv]

Thanks everyone,
I don't believe burning an OD/ID ring from 3-1/2" thick plate would be cost effective.
Example: We start with a piece of FB or PL, 1" thick x 3-1/2" wide x 43-1/4" lg, roll it to a 12.75" ID ring and weld ends together with a full Penetration weld.
We now have the 12.75" ID X 14.75" OD X 3.5" high lockring. It is then attached to the shell like a slip-on flg with a fillet in &out. The 1" thickness is the determining factor as to whether or not Impact testing is required, not the 3-1/2".

 

[GenB]

Ring but weld will need RT or derate per E in UW12.
Shell to ring S/O or lap welds E per UW-12 type of weld used.