Appendix 1-10 and UG-37 1

[5pointslow]

I have designed a vessel with nozzle calculations in accordance to Appendix 1-10. I used Compress to design the vessel.
Authorized Inspector has requested UG-37 calculations. My interpretation of UG-36(a) is that UG-37 calculations are only required when you use Appendix 1-7. This stance seems to be confirmed by Compress, as UG-37 calculations are only performed when you use Appendix 1-7 and not Appendix 1-10.
I cannot use Appendix 1-7 and therefore UG-37 calculations due to the fact that Rn/R > 0.7, so I cannot easily satisfy the Inspector's request.
Does any one have an opinion on this?
Has there been an Interpretation on this by ASME that i am unaware of?
Thanks.

 

[TomBarsh]

I'm sure there are lots of differing opinions on this.

The methodology for calculating the reinforcement requirements in accordance with UG-37 supplemented with Appendix 1-7 rules for large openings is based on area replacement. The methodology for calculating the reinforcement requirements in accordance with Appendix 1-10 is based on pressure area and results in a stress analysis.

Since the methodologies of UG-37 and Appendix 1-10 are not the same, there never was an intent to require both calculations be performed. The intent is that either UG-37 with supplemental rules of Appendix 1-7 be used or Appendix 1-10.

My understanding is tht the Code committee has reviewed the problem with the current words in UG-36 and has approved changes that will be published in the 2010 Edition of Section VIII, Div 1. [The Code committee item is Item 08-973; Authorized Inspection Agencies, etc, should have access to this information.]

full disclosure:
Tom Barsh
Codeware