freschif
Industrial
- May 26, 2009
- 7
Dear All,
I have the following general question about origin of allowable stresses in ASME VIII div 2.
Are these allowables directly depending and associated with the collapse theory adopted in the formulation or depend more on testing and experience on vessels fabricated with the restricted prescriptions for material choice, fabrication, NDT, testing indicated in Code? In other words, which risk could I take if some of these prescriptions on material choice, fabrication, NDT, testing are not strictly followed (of course I’m speaking of non-Stamp item)? Alternatively do someone have an idea if it is possible/advisable to reduce allowables or use allowables of Div 1 in such case (I know existence of CodeCase 2695 for example, even if I didn’t read it yet)?
Additionally I have the following question about using EN materials in ASME VIII div 2 and defining correct allowable stresses:
I know that some EN materials are already included in ASME II and some others are threated in Code Cases, but this would be a more general case.
My idea is to start from Mandatory appendix 10 of ASME II D, even if I know that only Committee has the faculty to do this, based on their experience and test they have performed.
Questions are:
1) Which risk could I take if I perform the evaluation by myself (please let me know if you have some experience in this sense)?
2) Is the risk mostly associated to collapse theory or on other factors?
3) Do someone have some example of this self-definition of allowables?
Thank you
Federico Freschi
I have the following general question about origin of allowable stresses in ASME VIII div 2.
Are these allowables directly depending and associated with the collapse theory adopted in the formulation or depend more on testing and experience on vessels fabricated with the restricted prescriptions for material choice, fabrication, NDT, testing indicated in Code? In other words, which risk could I take if some of these prescriptions on material choice, fabrication, NDT, testing are not strictly followed (of course I’m speaking of non-Stamp item)? Alternatively do someone have an idea if it is possible/advisable to reduce allowables or use allowables of Div 1 in such case (I know existence of CodeCase 2695 for example, even if I didn’t read it yet)?
Additionally I have the following question about using EN materials in ASME VIII div 2 and defining correct allowable stresses:
I know that some EN materials are already included in ASME II and some others are threated in Code Cases, but this would be a more general case.
My idea is to start from Mandatory appendix 10 of ASME II D, even if I know that only Committee has the faculty to do this, based on their experience and test they have performed.
Questions are:
1) Which risk could I take if I perform the evaluation by myself (please let me know if you have some experience in this sense)?
2) Is the risk mostly associated to collapse theory or on other factors?
3) Do someone have some example of this self-definition of allowables?
Thank you
Federico Freschi