ASME Sec. VIII Div. 1; Shell reinforcement justification

[ALC_jr]

Hello, I am attempting to justify the use of a reinforcing ring (10mm thick by 100mm length by 1265 OD)around the circumference of a shell (10mm thick by 1500mm length by 1245 OD)in-between the shell and the flange. This is reinforcement at the head ends of the shell. ASME BPVC.VIII.1-2015 1-1 (a)(1) requires 10mm thick shell but production insists on 10mm x 100mm reinforcing ring between flange and shell at ends. Flange is App.2. Thanks in advance for your input!

 

[marty007]

I have no idea what I'm looking at... So confused!

 

[ALC_jr]

Hello Marty007, my apologies. The previous pic is a detail of a section view of a spiral HX (see attached). We are trying to reinforce the shell at the shell-flange-head interface with a flat ring on shell in between shell and ASME sec VII D1 appendix 2 flange. My AI is reluctant to accept as drawn and production is insisting the reinforcement ring is necessary even though Code does not require it. We are about to thicken the entire shell from 10mm to 20mm to capitulate... Any input, asme justification for the ring, comment is most welcome!

 

[SnTMan]

Nasty detail in my opinion, no wonder your AI is reluctant. You won't find straightforward Code rules for it. U-2(g).

BTW, second sketch doesn't help any.

Regards,

Mike



The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[ALC_jr]

Thanks for the input! Does the attached iso view without flat heads help clarify further? Still U-2(g) consensus...? or can anyone point me to a possible asme design rules for the ring in between the shell and flange??? Thanks again for the council!

 

[SnTMan]

Might a person ask what the ring is supposed to provide reinforcement against? Would not seem needed for a properly designed shell & flange.

As to a sketches, I think a simple cross section of the (presumably three) parts involved, only, with perhaps weld details would be much more clear. Maybe something like the attached...

Regards,

Mike



The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[cbPVme]

How are you planning to weld this band? With a properly designed flange to Appendix 2, this is likely to create more issues than it would solve. A properly designed flange should be thick enough to limit rotation at the connection to the shell without further reinforcement.

 

[ALC_jr]

Thanks SnTMan! This is exactly what we would like to justify. I just didn't take the time to create a sketch... I will in the future. Typically we follow Code for weld geometries but I have been unsuccessful finding Code design rules for this scenario.
Thanks cbPVme! I completely agree with you (and our AI) regarding the mechanical soundness of the design if Code is followed but I am outranked and the ring must be incorporated so the only design calc. solution we have been able to identify, other than U-2(g) w/ UG-101 proof test, is increasing the the shell thickness and removing the ring...
I really appreciate everyone's input! I look forward to participating in the forum in the future! ... and will include better sketches next time