Which grades of carbon steel for MDMT = -52¦C
Which grades of carbon steel for MDMT = -52¦C
(OP)
Dear all,
I'm wondering which grades of carbon steel are suitable for an MDMT = -52°C for pressure vessel as par ASME VIII Div 1?
I assume that I have to follow the UCS68 rules.
Is PWHT mandatory ?
Impact test value as per UCS68(b) ?
What are the other specific requirements, due to MDMT=-52°C that I have to follow.
Thank by advance for your help
I'm wondering which grades of carbon steel are suitable for an MDMT = -52°C for pressure vessel as par ASME VIII Div 1?
I assume that I have to follow the UCS68 rules.
Is PWHT mandatory ?
Impact test value as per UCS68(b) ?
What are the other specific requirements, due to MDMT=-52°C that I have to follow.
Thank by advance for your help





RE: Which grades of carbon steel for MDMT = -52¦C
If your vessel does not fall under these you MAY PWHT per UCS-68(c) and gain a 30F reduction in MDMT, but it is not mandatory. You may for example be able to gain the needed reduction per UCS-66(b), in which case reduction per UCS-68 is not needed.
You will likely need lo-temp qualified weld procedures, see UCS-67.
To answer your original question the "usual suspects", SA-516-70, SA-333-6, SA-334-6, SA-350 LF2, perhaps SA-105, SA-106-B, and so forth, are potentially usable.
Csn't really answer your last question, too much unknown, except to say:
You will need to carefully read Part UCS, especially UCS-66 and -67, and anything referenced by them to insure you are in compliance.
Regards,
Mike
RE: Which grades of carbon steel for MDMT = -52¦C