Dear Engineers,

My concern is about B31.3 Appendix D note 7.
In calculating SIF & Flexibility factor, how large is the diameter and how thin is the wall of elbows and bends that we can consider note 7 in Appendix D?

Any responce with this topic is highly appreciated!


Regards,
Nald

Generally a D/t ratio of 100 is considered the limit.

Nald, you're correct, those are very ambiguous terms used in Appendix D. Fortunately in "Interpretation 12-11", dated Sept 17, 1993 this question was asked.

"Quote"

Question: In accordance with ASME B31.3-1990 Edition, what is the definition of "large diameter thin wall elbows" mentioned in Note (7) to Table D-1?

Reply: A large diameter thin wall elbow is one in which the presure significanlty affects the calculated values of K and I when corrected by the equation in Note (7).

"End Quote"

The easiest thing to do is let CAESAR II compute and use these values.

Thank you Mr. Ay & Moverz for your responce.!
Actually I'ved planned to investigate that query
by comparing manual calculation to Caesar II results.
If the results of Caesar II Matched with my calculation
considering Note 7, then I can conclude that is it consider as large & thin pipe.



Regards,
Nald