Div. 1 Appendix 1-10 Nozzle with Div. 2 Part 4.5.14 Weld Strength...Code Case 2695?

[dtn6770]

For Division 1 Appendix 1-10 nozzle designs, does the use of Division 2 Part 4.5.14 to satisfy the U-2(g) weld strength requirements (in lieu of UG-41) trigger Code Case 2695, specifically its fabrication tolerance and Manufacturer’s Data Report requirements?

I understand that the D1 1-10 method is very similar to (evolved with) D2 Part 4.5 which is why D2 Part 4.5.14 is a generally accepted way to verify/meet the weld strength requirements. So at the end of the day the nozzle technically has D1 DNA (evolved from D2) as well as D2 DNA…a D1-D2 hybrid nozzle design. Enough to trip CC 2695’s list-o-conditions?

 

[MrPDes]

It will depend on your AI's confusion threshold. It sounds like you are mixing and matching Div 1 App1-10, Div 2 4.5.14, CC 2695 and U-2(g). Completely safe in most instances, however potentially very confusing, creating an opening for disagreement.

Appendix 1-10 is apparently considered an outdated version of Div 2 Section 4.5.

For simplicity, consider using only U-2(g) to in turn use Div 2 Section 4.5 for both nozzle reinforcement and weld strength design. This will achieve what you need while using the most up to date ASME design methods that will likely become the primary Div 1 methods in future ASME code revisions.

 

[MrPDes]

Appendix 1-10 does say that strength requirements of UG-41 are not applicable and shall be replaced by U-2(g). So that steers you away from being required to use CC 2695.

 

[TGS4]

Please note that for the 2017 Edition of ASME Section VIII, Division 1, both Appendix 1-9 and 1-10 will be removed in their entirety. MrPDes is correct - Appendix 1-10 is an outdated version of Div 2, Part 4.5.

 

[dtn6770]

MrPDes & TGS4, thanks for taking the time to entertain my question and reinforce what I’ve picked up on recently about 1-10, D2, and the 2017 Edition.

I’ve recently gotten back into the pressure vessel design scene after being pretty much hands-off over the period 1-9 and 1-10 evolved into options to UG-37. I’m part of a relatively new ASME QC audit team at my company and we’ve been vetting suppliers/fabricators which is where I’ve come across the 1-10 / D2 P4.5.14 approach…as presented by Code calculation reports generated by Codeware Compress and accepted by the respective AI. Les Bildy and the gang at Codeware have my respect for integrating the 1-10 / D2 P4.5.14 method into the software but their responsibility (liability) only extends so far in that it’s beyond their scope to identify and implement other Code aspects like the ones in CC 2695, if applicable.

I’ll spare you the details but my audit team role expanded into being the company’s pressure vessel engineering responsible for performing the Code calculations for one of those suppliers/fabricators and I’ve reeled them back to UG-37 nozzle designs until such time as I’m ‘good’ with the 1-10 / D2 P4.5.14 method that their AI turned them on to a while back. I’m just about there but I’m not convinced that satisfying the fabrication tolerances specified in D2 P4.3 & 4.4, per CC 2695, isn’t important since being out of tolerance could reduce the applicability of the D2 equations/methods being discussed (P4.5.14 or the outdated stuff that became D1 1-10).

Come on 2017 Edition…

 

[MrPDes]

For a nozzle designed to div 2 rules, CC2695(d) gives the option of designing the shell/Head with either Div 1 or Div 2 rules. When deciding to use the div 1 head design method, I don't use the tolerance requirements of the div 2 method. However as a precaution, I do make sure the head thickness is at least as thick as the div 2 method (which has always been the case so far).

Compress is a bit of a pain in that there is not an option to design a CC2695 nozzle on a div 1 designed head. You have to set the head to be designed to CC2695 and then ALL of the nozzles on the head are designed to div 2 rules. I often just want to isolate one nozzle. It's all or nothing.

 

[dtn6770]

Fun fact...to the best that I've researched, the respective D2 fabrication tolerances are the same as those in D1, ironically.

 

[Bobfromoh]

MrPDes said,
Compress is a bit of a pain in that there is not an option to design a CC2695 nozzle on a div 1 designed head.

When I run into a situation like this, I just make a separate model and combine the documents in the final report.
It's a little bit more work but I get the report I want.