is Appendix 1-10 independent from UG-37? 2

[fonti1977]

I am playing with the inputs in PVELITE and I can't get a result where UG-37 fails while Appendix 1-10 passes (shows local primary stress less than Allowable membrane stress). It seems that if UG-37 area requirements passes it follows that App 1-10 is also passing.

Can I use Appendix 1-10 without considering area requirements as per UG-37?

 

[hakkik]

I strongly recommed you to read UG-37 and Appendix 1-10. Don't just play with the software and try to get some conclusions.

1-10 is an alternative calculation way for "large openings". It is normal to get different results. App 1-10 is less conservative than UG-37, but has some limitations. So read the code...

 

[jamesl]

You can use Appendix 1-10 (in lieu of UG-37)for large opening. For small openings, UG-37 is still required. See UG-36(b)(1).

 

[fonti1977]

Thanks James but I just told our client this morning that we cannot use Appendix 1-10 in lieu of UG-37. I guess I read your reply too late

Anyway, I based this on what UG-36 says, that for large openings App 1-7 shall be satisfied "in addition" to the rules of the paragraph...and App 1-10 can be used in lieu of App 1-7. note that i put emphasis on "in addition."

Furthermore when I run PVElite - Codecalc for large openings it would run UG-37 area calculations and 1-10 or 1-7 (depending on my choice).

I checked codeware's website and i got a different view. They say App 1-10 can be used independently. While App 1-7 must be used together with UG-37.

Did you use App 1-10 independently before for one of your vessels?

 

[jamesl]

For large openings, use UG-37 + Appendix 1-7 or use Appendix 1-10 (without UG-37 and Appendix 1-7). Note Appendix 1-7 are supplemental rules, while Appendix 1-10 is an alternative rules. The methodology in Appendix 1-10 was developed to replace UG-37and Appendix 1-7.

I agree the wording is confusing right now, and I have seen a code interpretation to clarify the issue yet. I trust Compress's approach because Mr. Bildy of Codeware developed the methods in Appendix 1-10. Of course you can always take a conservative approach and require UG-37 + Appendix 1-10.

 

[jamesl]

Sorry in last post, I mean to say I have NOT seen a clarification.

 

[fonti1977]

Thanks a lot James. I'll consider your advice when I encounter the same problem.

 

[TomBarsh]

The stress analysis method of App 1-10 is intended to be used independently of the area replacement method of UG-37. The process of getting the method into the Code resulted in some garbled information. My understanding is that this will be clarified in the next Edition.

This thread discusses the status of the situation:

http://www.eng-tips.com/viewthread.cfm?qid=254136&page=1

 

[fonti1977]

Thanks Tom. Yeah the wordings were quite confusing