Section VIII Div 1 versus Div II 1

[bob330]

Hi Guys,

What is the difference between Section VIII div 1 and Div 2? Also, what is the differnce between allowable stress value "S" and design stress intensity "Sm"?

Thanks,
bob

 

[CodeRef]

If you make an advanced search on this site by using Div.2 as the keyword you'll get a lot of stuff to read on the subject.



see thread

http://www.eng-tips.com/viewthread.cfm?qid=63572&page=86

There are three kinds of people in this world; those who can count and those who can't.

 

[metengr]

bob330;
By the nature of your repeated posts regarding ASME B&PV Code, do you actually have a copy of the applicable Code sections?

 

[Shmulik]

thread292-135630

 

[vesselguy]

bob,

Your question requires one to write a paper to answer properly. The short answer is Div. 1 is design by rules (follow the formulas in the Code and you must follow it to a "T"), where as Div. 2 is design by detailed analysis to justify the design.

Suggest you read this short paper. Link below:

http://absa.ca/faq/SectionVIIIcomparison.PDF

To get the answer, read the Codes. Best take a training course. ASME have 2 great courses to answer your questions.

 

[bob330]

Thanks to all you guys.

 

[napoleonm]

Basiclly. Div 1 is a "concervative way to design" a pressure vessel based by rule (following equations).

Div 2, is a alternative way to design a pressure vessel, in a more "Economical" point of view; regarding with the requeried material thickness: you will get less material thickness, but the material inspection is more hard and more demanding than Div 1, as well Div 2 allow you to design by "stress analysis" using a FEA software for example (appendix 4), so design by analysis is allowed.

Div 1 and Div 2 uses diferent values os "allowble stress" due to the fact of the nature of the assumption taken during their formulation.

hopping that will help you a little bit.