Low Temp Materials
Low Temp Materials
(OP)
In designing to the US pipeline transportation code (ASME B31.4) I've been tasked with a minimum design temperature of -35 F. Has anyone run into any issues with the fact this code was only intended to apply down to -20 F minimum temperature? While this is probably fine for most of the country, there are regions where the minimum ambient design temp can be much lower (e.g. AK, MN, WI, ND)
Also, for low temp-rated "high yield" fittings, can anyone explain the key differences between ASTM A860 & ASMT A420 material? Both material types are impact tested to at least -50 F (or lower) and both types can be "high yield" (yield strengths above 35 ksi). For example, can a Y52 fitting be spec-ed out to either? Is one material type more costly than the other?
Thank you in advance
Also, for low temp-rated "high yield" fittings, can anyone explain the key differences between ASTM A860 & ASMT A420 material? Both material types are impact tested to at least -50 F (or lower) and both types can be "high yield" (yield strengths above 35 ksi). For example, can a Y52 fitting be spec-ed out to either? Is one material type more costly than the other?
Thank you in advance





RE: Low Temp Materials
By the way, CFR 49 part 195 is the legal design requirement in the US for liquid pipelines. The CFR references the 2006 edition of ASME B31.4, not the latest edition. The CFR has no temperature limitation. It requires that suitable materials be chosen for the temperature environment.
RE: Low Temp Materials
RE: Low Temp Materials
Steve Jones
Corrosion Management Consultant
http://www.linkedin.com/pub/8/83b/b04
All answers are personal opinions only and are in no way connected with any employer.
RE: Low Temp Materials
weldstan - low temp piping materials are needed. Client required for this crude oil system. Buried piping would never reach this temperature, but aboveground pipeline facility piping can. During normal steady operation, the aboveground process piping would obviously not get this low. But during line shutdowns or even aboveground "dead leg" lines (piping not carrying steady flow) during normal operation have had skin temperatures recorded at these low temps.
BigInch - thanks for pointing out that the latest CFR 49, 195 only recognizes the 2006 edition of B31.4. That's always an interesting dynamic. While CFR no has temperature limitation, B31.4 appears to be intended to apply down to only -20 F. Client is requiring compliance to B31.4 (as recognized by CFR 49, 195 in the US).
RE: Low Temp Materials
RE: Low Temp Materials
Steve Jones
Corrosion Management Consultant
http://www.linkedin.com/pub/8/83b/b04
All answers are personal opinions only and are in no way connected with any employer.
RE: Low Temp Materials
RE: Low Temp Materials
Steve Jones
Corrosion Management Consultant
http://www.linkedin.com/pub/8/83b/b04
All answers are personal opinions only and are in no way connected with any employer.