I am modelling a pipeline with reducers and nozzle connected to tank.
1. While modelling the reducer as a component with uniform dia = (dmax + dmin) / 2, where dmax = max dia of reducer and dmin = min dia of reducer, do I have to enter SIF's ?
If so, what value ?

2. Do I have to enter any SIF for the nozzle ? If so, how ?

Please help

TIA

The piping codes (that CAESAR II addresses) are pretty much split on whether or not reducer elements have SIFs.

For B31.1 and similar codes, the SIF for a reducer is defined as:
2.0 max or 0.5 + .01*alpha* SQRT(D2/t2), where:

- D1 and t1 are the diameter and thickness of the large end.
- D2 and t2 are the diameter and thickness of the small end.
- Alpha is the reducer cone angle in degrees. Alpha = atan( length / (D1-D2)/2 )

Notes: alpha cannot exceed 60 deg
The larger of D1/t1 and D2/t2 can’t exceed 100.

Other codes, such as B31.3 and similar state that the SIF for a reducer element is 1.0.


The question regarding SIFs for nozzles is a little tougher to answer. How is the pipe attached to the nozzle, with a flange, a butt weld, etc? Check Appendix D in both B31.1 and B31.3 for a range of SIFs (from 1 to 2.3).

Richard
Thank you for the reply.