Wye Branch (Bifurcation)

[josftx]

Hello, i'm designing a wye branch for a steel penstock. I use the recomendations and metodology of Bureau reclamation

http://www.usbr.gov/pmts/hydraulics_lab/pubs/EM/EM32.pdf

with very good results in terms of stress. the idea is using 3 cones and a support for merge the principal line of the penstock and the two other derivations. The problems its the weight of the solution, because its so high and i want to optimize them. I found a thesis from china

http://www.12340000.com/science-engineering-c/electric-power-industry/176435.html

with the optmization in therms of weight and structural. Anyone Knows about that class of optimization or some recomendations. The principal line its 1800mm and the secondary lines, about 1300mm.

 

[XL83NL]

The Euronorm for piping (EN 13480) provides a pretty decent section on the pressure design of wye's.
Nayyar's piping handbook also discusses the desing of wye's, and provides some means for manual calculation of SIF's.
Can you detail a bit more on your problem? Is it a pipe stress/flex calculation problem? What is your design code?