Hii friends,

I have a little doubt.

While running an underground pipeline model this morning,I noticed that the value of allowable streeses were displayed as zero in the stress report (W+T1+P1 : Stresses combination) for a large number of nodes in series.
Then I activated the "Allowable stresse" but even then, I am faing the same problem.

Please suggest what went wrong and what remedialaction should I take??


Thanks & Regards,

Which Code are you attempting to apply ? Is there a stress check required for a T+P+W case ? Have you read the code ?

There have been many questions on this topic, try the forum search facility.

Hello SIr,

I tried searching the forum queries but couldnt find, I'll be happy if anyone can help me in this regard.

Well, I am using B 31.4 for the buried pipeline analysis. One more observation - If I check the stress report against sustained and expansion load case, it considers the value of allowable stress for all the nodes, but when I am chekcing the stress against operating case , the allowable stress value for a seriese of nodes is shown zero.

Kindly guide...

Thanks & Regards,

B 31.4 has other allowables as for example B31.1 or B31.3. Check the code for the allowables that have to be checked. For piping that has large axial stresses an extra stress check is needed. Apperently this is incorporated in the operational cases in CII. I've seen this myself and figured it should be these extra stresses that are checked. Maybe someone from Coade can give some extra explanation about how the B31.4 allowables are incorporated in CII?

The equations used can be found in the Quick Reference Guide. There is a difference (in behavior) between "restrained" and "unrestrained" lines, and hence different equations for "code stress" and "allowable stress".

Hello all,

I'm facing this problem in above ground piping model in CAESAR II Ver 7. I'm using ASME B31.4 and the operating allowable are 0 in one model and 31500 in another model with the exactly the same material, code and load cases. Does it happen in Caesar or I'm missing something?

Please review B31.4. Depending on the state of a particular element (restrained or unrestrained) some load cases have no allowable. In this instance, CAESAR II will print zero in the stress report.