ASME 16.5 Press-Temp Rating

[bonkers]

Does anyone know the pressure rating for carbon and stainless steel classes below -20 deg. F? Everything I've researched stops at this temperature. I know some nickel alloys are for low temp (cryogenic service). I have an application for -25 deg. F and need to know the pressure limit.

 

[metengr]

bonkers
The reason for the -20 deg F low temperature limit is that impact testing is not required for use at or above this service temperature. For those material groups that are selected for low temperature service, below -20 deg F, the maximum pressure rating would still apply for the -20 deg F service temperature in ASME B 16.5 provided the code of construction requirements for impact testing are met.

 

[trivedidn]

bonkers
Please refer B16.5 para 2.4 and 2.5.3.
For CS, check the impact testing required or not as per code.
For SS, generally impact testing for low tempreture not required.