B31.3 Lower temperature of sa-333 gr.6

[vladass]

Hello, we might soon start working on a project according b31.3 in Russia with the lowest outside temperature of -49°C. I would very much like to use SA-333 gr.6 but according to table a1 it is only good for -45°C. Can I lower allowable temperature?

 

[weldstan]

You can purchase it impact tested at -49C. Then it will be OK. But understand that the lowest ambient temperature need not be the MDMT. It can be higher depending on actual pressure-temperature operating conditions. It can also be lower if Joules-Thompson cooling occurs during decompression.

 

[BigInch]

You may be able to do that, if you do Charpy testing at -49 or lower and also secure the owner's permission in writing to use that specially tested material.