Correct stress value for steel A36 1

[bctarala]

Dear all,

we have a problem regarding on computation for thickness/MAWP for unfired pressure vessel. Our 3rd party inspector used stess value of 12,700 psi last 2011 inspection. but on their 2012 inspection, they used 17,500 psi for stress. Material for pressure vessel is Steel A36,. Thanks for helping me to know correct stress value to be used for computing thickness/MAWP of unfired pressure vessel.

Thanks,
Ben

 

[metengr]

If you are using ASME B&PV Code, the allowable stress for SA 36 plate material is 16,600 psi up to 650 deg F.

 

[bctarala]

Hi metenger,

So 17,500 psi is okay to used. Other info is that they assumed that material used for pressure vessel is SA 36 since no data is available. Is this correct?

Thanks,

 

[metengr]

No, the 17,500 psi is not ok for use. The stress value I provided is what should be used for SA 36.

 

[eliebl]

If no data is available to determine the type of steel then I would be hesitant to do any calculations. I would probably run away, very far away.

 

[MrTank]

Fyi, before you use sa-36 for pressure vessel, read UCS-6. Sa-36 is not allowed for lethal service.

-MrTank

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