Hi, everybody!
The Allowable displacement stress range (ASME B.31.3) is:
Sa = f*(1,25*Sc + 0,25*Sh)

It should be the same for all nodes. In expansion cases, code stress need to be less than this value. (Se <= Sa)
I was verifying results and noted that the allowable code stress value was different that ASME. The material is API-5LB, Sc = Sh = 137892 Kpa. The allowable code stresse is different for different nodes. For example:
Node Allowable Strees (Kpa)
10 342706
20 343445

Does Anyone know what is happening?

Regards.

I've just verifyed another model and this problem didn´t exist. Then I copied this "right model" and only changed some restrains. So, again the results for allowable code stress was different! It´s strange for me....

There are two equations provided in the B31.1/B31.3 Codes for computing the Allowable Expansion Stress. You listed one, which is NOT the CAESAR II default.

By default, CAESAR II uses Sa = f*(1,25*Sc + 1,25*Sh - Sl)

In many models (but not all), "Sl" varies from element to element, which is why in these models "Sa" varies from element to element. If you want to use the equation you sited, go to the "Special Execution Parameters" dialog and uncheck the checkbox for the "liberal allowable".

I 'm studying this case and checking the stresses values by hand calculations.
I checked that Sh > Sl when Caesar calculated Sa by:
f*(1,25*Sc + 1,25*Sh - Sl); It´s ok!

I couldn´t get same allowable stress. I verifyed that Sl wasn´t equal. What´s the equation for Sl?

Regards,
NaOliveira

Sl is the Sustained stress. Look at the "Code Stress" column for the Sustained load case.

I had analysed more than one sustained load case. Some cases in the model was only for tests. But, these tests are important for this study.

Looking at all sustained cases that I had analysed, I noted that Caesar II uses the sustained case which presents the greatest value for "code stress". Maybe, CAESAR II consider this case like the critical one.

If this is the CAESAR II´s procedure, what do you suggest about the sustained load cases I have to consider for get the right "allowable stress" for expansion case?

Regards,
NaOliveira

Yes of course we take the worst (SUS) case.