Large diameter penstock branch design 1

[tambraton]

Hello

I'm looking into the design of large diameter branch (59")off a 120" penstock with an internal pressure of 50psi. I'm having trouble finding a suitable guide for calculating the stresses at the branch/penstock interface.

We are planning to use do some FEA but I would like something to back it up. I've looked into using the WRC 107/297 bulletins but I don't think they are very accurate for such large d/D ratios (.49).

Any suggestions?

 

[Canadieng]

Some of the best, modern manual calculations/design of penstocks is due to the pioneering work/research for the "Boulder Canyon Project", aka The Hoover Dam; particularly the document:

Boulder Canyon Project Final Reports; Part V - Technical Investigations. Bulletin 5 - Penstock Analysis and Stiffener Design. US Department of the Interior. 1940.

Other references, which are largely based on the above work, include:

Design of Wye Branches for Steel Pipe. Journ. AWWA 47:6:581 (June 1995)

AISI Steel Plate Engineering Data Volume 4

AWWA M11

ASCE MOP No. 79 - Steel Penstocks

Bureau of Reclamation Engineering Monograph 3 - Welded Steel Penstocks, available @

http://www.usbr.gov/pmts/hydraulics_lab/pubs/EM/EM03.pdf

Structural Mechanics of Buried Pipe - ISBN 0849323959; Chapter 18 - Special Sections

 

[tambraton]

Canadieng

Thanks so much for your comments and list of documents, much appreciated. I've managed track many of them down and have some of in house.

I also found the following thread that had some suggestions (many of the same):

http://cr4.globalspec.com/thread/39974/Pressure-Pipe-Opening-Reinforcement

Of particular interest is the "Structural Mechanics of Buried Pipes" by Watkins and Anderson, that has a section on the design of wyes.

Looks like I have some reading to do.

Regards

tb

 

[Canadieng]

That was me in a former life. (user XMech that is)