Thank you so much for your response. What I am curious about is that the substitute for SA-212-B which is SA-515-70 has an
allowable stress of 2500 psi at 1000F, but yet you say that it is only 1500 psi for SA-212-B; this really throws my calculations way off. Would you be so kind as to please verify this for me and if so, would it also be possible to please look up the stress values for SA-212-B at 700, 750, 800, 850, 900 and 950?
With much appreciation,
Tom