Okay, I know this subject has been beat to death, but after searching and searching I could not find an exact match to my question.

Anyways, I am trying to determine what load cases I need to run for temperature. Basically I have a line designed for say 200 F. I have an ambient temperature of 70 F. I have a winter temperature at worse of -20 F. This is to be installed in Oklahoma, where the last 61 years the lowest temp. recorded was -14F.

Of course under normal operation, the line will never get close to even ambient, if there is flow always going through. If the pipe happened to be empty and it was during a record winter, then yeah maybe it could get down below 0 F. So, would load cases be set up such as this?

CASE 1 (OPE) W+T1+P1
CASE 2 (OPE) WNC+T2
CASE 3 (SUS) W+P1
CASE 4 (SUS) WNC
CASE 5 (EXP) L5=L1-L3
CASE 6 (EXP) L6=L2-L4
CASE 7 (EXP) L7=L5+L6

Where T1 = 200 F and T2 = -20 F.

In Example 1 of Appendix S of ASME B31.3 I set up this exact example in Caesar, and used these same load cases as listed above, and my CASE 7 stress results almost matches exactly with the results of Table S301.7.

If for my case, where we may hit minimum temperature once maybe TWICE in the pipe's lifetime, is it still required per code to design to that stress range?

I have attached the B31.3 Caesar model that I made. (Interestingly enough, it wouldn't allow me to attach my .cfg file!)