ASME Section II Part D Stress Values
ASME Section II Part D Stress Values
(OP)
Hello,
I am looking for ASME stress value tables for SA 210 A1 material and I know these are based on certain criteria according to ASME Section II Part D, Appendix 10. However, when I see allowbale stress values for SA 210 A1 at 100-650 F, it is 17100 psi. And this value is not matching to min tensile 60 ksi and min yield 37 ksi per above criteria, unless I am missing Ry value.
I am looking for ASME stress value tables for SA 210 A1 material and I know these are based on certain criteria according to ASME Section II Part D, Appendix 10. However, when I see allowbale stress values for SA 210 A1 at 100-650 F, it is 17100 psi. And this value is not matching to min tensile 60 ksi and min yield 37 ksi per above criteria, unless I am missing Ry value.





RE: ASME Section II Part D Stress Values
RE: ASME Section II Part D Stress Values
Cheers,
gr2vessels
RE: ASME Section II Part D Stress Values
Be sure to apply this allowable stress appropriately, and don't confuse it with allowable compressive stress.
jt
RE: ASME Section II Part D Stress Values
RE: ASME Section II Part D Stress Values
One more thing, I am wondering, is it okay to arrive allowable stress based on tensile stress values, even if the yields are much less than code minimum and 2/3 of yields is higher than tensile based stress values. For eg.60/3.5=17100 psi and 2/3*27Fy=18000 psi. Is this detrimental as long as the material is not stressed to yields for permanent deformation.
RE: ASME Section II Part D Stress Values
What exactly are you playing with? Do you have competent oversight / mentoring?
jt
RE: ASME Section II Part D Stress Values
I am not sure about your question. I am fully aware of the ASME Section I and VIII, and this is a situtation where we have tubes are chromized and in the process the stress values are reduced. Trying to justify the tubes for pressure containment using the allowables within code limits.
RE: ASME Section II Part D Stress Values
jt
RE: ASME Section II Part D Stress Values
RE: ASME Section II Part D Stress Values
Where is this "vessel" going to be installed? What is your jurisdiction's thoughts on this?
RE: ASME Section II Part D Stress Values
Some interpretations I-83-01 & I-95-03 which talks about similar cases. We have not checked with Jursidiction and it's in US.
RE: ASME Section II Part D Stress Values
Typically boiler tubes (Section I) may be chromized for corrosion resistance only, and the diffusion distance for chromizing is such that the argument could be made that bulk properties are unaffected. This is a post fabrication issue that the Code does not address. How and why would one decide on altering the allowable stress values?
The bulk properties are normally unaffected by this process unless you operate in the creep regime and there have been isolated cases where local creep damage has occurred immediately under the chromized layer (where chrome has combined with carbon to produce a lower creep strength ferrite zone). In this case, the orientation of the lower creep strength zone is not oriented in the direction of primary membrane stresses.
RE: ASME Section II Part D Stress Values
jt
RE: ASME Section II Part D Stress Values
Regards,
... a man's got to do what a man's got to do...
RE: ASME Section II Part D Stress Values
Agreed.
jt
RE: ASME Section II Part D Stress Values
RE: ASME Section II Part D Stress Values
why is 3.5 and not 4?
please advise.
RE: ASME Section II Part D Stress Values
Because the code committee, for various reasons, changed the factor against ultimate from 4 to 3.5 starting with the 1999 Addenda. Factors against yield, time dependent, and compressive did not change.
I'm sure you'll find much more on this if you search the forum. If you have a specific question, I'd suggest starting your own thread.
jt