SIF for D/T > 100

For CAESAR II to calculate sif properly as per Appendix D note 7 of table D , do we have to activate any key ? As per my understanding of CAESARII , since we input D and thickness the program knows whether D/T > 100 and takes corrective action accordingly. Correct me if I am not correct.
Regards,
Godbole

Dear,

Caesar-II warns when D/T > 100 SIFs are used.You have to take suitable corrective action.

You can have some factor of safety to counter the inaccuracy in SIF for D/T >100. By using FEA software like FE/Pipe we can accurately find SIF & use the same as user SIF in Caesar-II. Otherwise, we can increase the thickness near the fittings to meet D/T <=100 limitation.

regards,

sam

Quote sggodbole:

“As per my understanding of CAESAR II , since we input D and thickness the program knows whether D/T > 100 and takes corrective action accordingly.”

Stand corrected, C2 follows the rules of Appendix “D” without variance. The Code does not provide the reader any suggestions for “corrective action”. It is up to the piping engineer to provide any variation from Appendix “D” rules that he/she deems appropriate.

An important thing to remember when you are using Caesar II is that it does exactly what is mandated by the Code. The Code in some cases warns you about specific piping design issues without offering a strategy for addressing them. In these cases (no suggestions from the Code) C2 cannot help you. The Code tells you that if you have better (more applicable) data, you should use it (and I will add, document it). Regarding SIF's, remember that the Code SIF's were developed from experiments using NPS 4, standard wall, carbon steel pipe and fittings. The SIF's are based upon extrapolation down to NPS 1/2 (not too much of a stretch) and up to NPS 72 (!!!). If you can find (or develop from e.g., testing or FEA) better data for the system at issue use it. Just part of being a piping engineer.