Re-rating MDMT of a non-carbon/low alloy steel
Re-rating MDMT of a non-carbon/low alloy steel
(OP)
Hello all,
I am trying to find a section in ASME BPVC Section VIII Div. 1 that explains how to lower a pressure vessel’s MDMT (without impact testing) when the material is not carbon or low alloy steel. I’ve read UCS-66, UCS-67, UCS-68, Figure UCS-66.1, and Figure UCS-66.2 but all of those procedures are only for carbon and low alloy steels.
I’m trying to lower the MDMT of a vessel constructed from SA-240 316L by 5oF.
Also, from a curious engineer standpoint I would like to know how to lower the MDMT (without impact testing) for other materials such as other high alloy steels, or aluminum alloys.
Any experience for this situation would be greatly appreciated,
Regards,
Tyler
I am trying to find a section in ASME BPVC Section VIII Div. 1 that explains how to lower a pressure vessel’s MDMT (without impact testing) when the material is not carbon or low alloy steel. I’ve read UCS-66, UCS-67, UCS-68, Figure UCS-66.1, and Figure UCS-66.2 but all of those procedures are only for carbon and low alloy steels.
I’m trying to lower the MDMT of a vessel constructed from SA-240 316L by 5oF.
Also, from a curious engineer standpoint I would like to know how to lower the MDMT (without impact testing) for other materials such as other high alloy steels, or aluminum alloys.
Any experience for this situation would be greatly appreciated,
Regards,
Tyler





RE: Re-rating MDMT of a non-carbon/low alloy steel
RE: Re-rating MDMT of a non-carbon/low alloy steel
Part UCS is specific to carbon and low alloy steels. If you want to look into the rules for other materials, read Parts UHA and UNF.
RE: Re-rating MDMT of a non-carbon/low alloy steel
For anyone else looking for this information, I made a quick list summarizing what is in the codebooks (Minimum temperature without needing impact testing)
ASME B31.3 (2016)
- austenitic stainless steel (w/o filler metal)
- austenitic weld metal (w/filler metal)
ASME Sec. VIII Div. 1 UNF (2017)carbon <= 0.1% -150F
carbon <= 0.1% -150F
carbon > 0.1% -55F
- wrought aluminum -452F
- copper/alloys -325F
- nickel/alloys -325F
- cast aluminum alloys -325F
- titanium alloys -75F
- zirconium alloys -75F
ASME Sec. VIII Div. 1 UHA (2017)carbon <= 0.1% -320F
carbon > 0.1% -55F
castings -20F
carbon <= 0.1% -320F
carbon > 0.1% -55F
castings -20F