WYE branch design for steel pipes

[robyengIT]

Hi to everybody. I am using AWWA Manual M11 Nomograph for WYE branch design : anybody can tell me, for one plate design, wich is the ratio range Rs/Rb and to wich max diam can be applied ?

Thanks

robyeng - Italy

 

[LSThill]

Stress Analysis of Wye
Branches
UNITED STATES DEPARTMENT
OF THE INTERIOR

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

 

[robyengIT]

thanks for reply LSThill, but my concerns are :

1 - AWWA Manual M11 is referring to "Design of wye branches for steel pipes" - Swanson published by AWWA Journal, 47(6): 1955
2 - on page 595 for one-plate design is stating : 0.3<= Rs/Rb <=0.6 and the Note on page 596 is saying "...deflection angle is close to 90 deg and the diameter of the wye branch is substantially smaller than that of the main pipe"
3 - but on page 622, detailing an example of calculation, says Rs/Rb = 0.7 and deflection 45 deg

conclusion : point 3, to me, is fighting with point 2

Your further comment will be appreciated
thanks