D/t ratio larger than 100 for bends

Posted by: pooria1978

D/t ratio larger than 100 for bends - 08/25/20 05:08 AM


I am currently working on a very thin pipeline with D/t ratio larger than 100; I modelled one of the bends in FePipe (module bends with staunchion) in order to have it calculate the actual SIF and flexibility values. (needless to say I input 0 for all the required information for the trunnion)

just to confirm; the primary SIFs as calculated by FePipe would be input for the stress indexes in CII. right?

for the flexibility part, FePipe gives me Ki and Ko, any suggestion on how I can add it up in CII only one input "K-Factor" ?

and by the way, I don't know why but the code computed values by FePipe and CII are different.

many thanks in advance,
Posted by: Bob Zimmerman

Re: D/t ratio larger than 100 for bends - 08/25/20 06:38 AM

Typically the PEAK sifs are input into CII. Depending on the CII version, you can input both the Primary and Secondary (fatigue, "peak') sifs. The difference in the Code value may be affected by pressure input. FEbend may be a better choice than FEpipe since some functions are more automated.

p.s. call me internally if you want to discuss further.