Material strength for calcs
Material strength for calcs
(OP)
Is it permissable to use a suppliers material strength values rather than the ASME section II material strength values when doing pressure vessel thickness calcs. The suppliers material strength values are higher!





RE: Material strength for calcs
Cheers,
gr2vessels
RE: Material strength for calcs
I have been involved with situation and it comes in handy sometimes when the vessel is built and the client decides to changes design conditions at the eleventh hour...
RE: Material strength for calcs
For Div. 1 vessels, UG-23(a) is pretty straightforward. You can only use the max. allowable stress values listed in ASME Section II, Part D. Strength values in Material Test Reports cannot be used in vessel thickness calcs.
RE: Material strength for calcs
RE: Material strength for calcs
I am talking about Australia, where the U-stamp doesn't have much significance, since a recognised authority has to confirm independently that the design is safe and in accordance with the basic safety requirements outlined in AS 1210 and the local fguvernment eregulations. In my opinion, that is the real engineering of a pressure vessel, rather than follow blindly the code, including the mistakes, misprint or other errors of the code.
dmkd1 (the OP) is yet to confess where is he located, inside or outside USA and where is his loyalty, with the code or with the Client.
Cheers,
gr2vessels
RE: Material strength for calcs
Thanks
RE: Material strength for calcs
RE: Material strength for calcs
The original question was about ASME and you replied with an AS 1210 point of view. ASME and AS are two different standards. You can't compare apples to kiwis. : ))
And what do you mean with your opinion about "real engineering of pressure vessel"? Are you implying that an ASME stamped vessel is not properly engineered & designed for safety and that authorized inspectors & jurisdictions in North America are incompetent?
RE: Material strength for calcs
However, one can contribute some additional engineering if is not bound by the U-stamp obligations. Using an approved method for calculating your own allowable stresses and use them in your design, I think that requires judgement and ultimately the chance of optimizing the design, beyond of the confines of the code.
I am not implying anything of your interpretation, anyone knows a vessel built to ASME is a safe one. This was about stepping out of the code confines and still building a safe vessel, that's all. If you must stamp your vessel in US, that's OK. However, outside US the same safe built vessel doesn't have to be stamped. That gives you the flexibility of designing and building a safe vessel lighter, cheaper, easier to manufacture, faster.
Out of all that doki, you took personal offence, that's all you understood. Australia is one example of places with wider possibilities, along the ASME code and AS 1210.
Once again, I have respect for those who put together the ASME, but I take exception in accepting that ASME code must be followed to the letter if you want to design a safe vessel.
Cheers,
gr2vessels
RE: Material strength for calcs
And if you have respect for those who put together the ASME, please refrain from referring to the Code as a cookbook. The ASME Code is not intended to be used as a cookbook or handbook.
Lastly, if you want to respect forum members, please refer to them by their profile names. My name is doct9960, not doki.
Cheers,
doct9960
RE: Material strength for calcs