insider79
Materials
- Nov 22, 2019
- 16
Hello members,
1. I'm calculating WT to purchase A312-TP321H seamless pipes for design conditions 800°C at 3.5kg/cm2. For thk >3/8", ASME B31.3 mentions note 30 against it in Table A-1 which states "For temperatures above 538°C (1,000°F), these stress values
may be used only if the material has been heat treated at a temperature of 1 093°C (2,000°F) minimum".
However I do not find this note for thk <3/8". The WT that I've calculated are lower than 3/8". So, should I apply note 30 to WT<3/8" too as precautionary measure? Please advise.
One of the reason I think note 30 is not mentioned for <3/8" thk could be that if pipes are cold worked then such high temperature treatment could reverse the benefits of cold working. I'm guessing though, not sure.
Thanks
Regards
1. I'm calculating WT to purchase A312-TP321H seamless pipes for design conditions 800°C at 3.5kg/cm2. For thk >3/8", ASME B31.3 mentions note 30 against it in Table A-1 which states "For temperatures above 538°C (1,000°F), these stress values
may be used only if the material has been heat treated at a temperature of 1 093°C (2,000°F) minimum".
However I do not find this note for thk <3/8". The WT that I've calculated are lower than 3/8". So, should I apply note 30 to WT<3/8" too as precautionary measure? Please advise.
One of the reason I think note 30 is not mentioned for <3/8" thk could be that if pipes are cold worked then such high temperature treatment could reverse the benefits of cold working. I'm guessing though, not sure.
Thanks
Regards
