Sec.8 Div.2 Fatigue analysis 2007 2

[CLAUDE47]

Hi
I have to perform a fatigue analysis for a valve without any welds. There used to be fatigue curves, giving max. allowable stress by the number of cycles. This curve isn't present in the 2007 version anymore, or at least I couldn't find it.
Does anybody know where to look now in Division 2, considering non-welded fatigue analysis? Thanks
Claude

 

[CodeRef]

It appears that adoption of the 07 Edition of VIII-2 is causing some difficulty for U2 Certificate Holders.
ASME has responded with Code Case 2575.
Here is link to all of VIII-1 Commitee's approved Code Cases where you will find 2575

http://cstools.asme.org/csconnect/pdf/CommitteeFiles/25094.pdf

If you are lazy and want to go directly to the Case, here is a direct link to the Code Case:

http://cstools.asme.org/csconnect/PDF/CodeCases/1040.pdf

 

[TGS4]

You are looking in Annex 3.F, right? What is your material?

 

[CLAUDE47]

Thanks for the two replies.

The material is A350 LF2

I was looking pretty much everywhere, I'm just starting out with the ASME code.

 

[TGS4]

As described by Table 3.A.1, SA-350 LF2 is nominally Carbon Steel, therefore I would use the Carbon Steel curves in 3.F.

Just out of curiosity, when you dropped into the fatigue analysis in 5.5.3.2(e), it told you to go to Annex 3.F. Why would you look elsewhere?

Just so you know, it's not that there were merely fatigue curves in the 2004 Edition of Division 2, there was also a fatigue design procedure. Well, now in the 2007 Edition, that procedure is spelt out in even more detail. Check it out, and if you have questions, feel free to write back here.

 

[CLAUDE47]

The situation is the following.
The valve I'm calculating has been designed after european code. Now the model is going to be installed in canada, and has to be checked by the asme code.
So the design is already put, and hopefully doesn't have to be changed.
Thanks for the help, if I have further problems, or questions I sure will gladly post them.
Have a nice weekend.
Claude

 

[CLAUDE47]

I have another question.
Using the formula (3.F.2) in div 2 annex 3.F, is it allowed to determine the stress amplitude by finite element calculation?
Thanks

 

[TGS4]

Yes - See 5.5.3.2. Just so you know, you're really going about this backwards. You should be referring to Annex 3.F coming from Part 5, and not the other way around.