SIFs for Wye Pieces

[SOROURA]

A Wye piece is considered a special type of fitting which is not addressed by the Code, but, nevertheless, is quite a delicate piece of equipment (just like a tee, but maybe more complex). I believe the Code does not address this because of its unique nature and complex non-standard design, and the manufacturer will usually be the one to advise the client of the component's SIF at the main run and branch connections.

My question:
For the sake of a preliminary design/analysis where this information is yet to be provided by the vendor, are there any special formulas, design criteria, or design considerations that could be used for computing SIFs for Wye pieces?

Thanks in advance for your help.

 

[DSB123]

Soroura,
I do not think you will get SIF's from the manufacturer unless you have specifically asked them to provide them. For example manufacturers of butt weld tee's do not provide SIF values to Clients from my experience. Think you need to get a FEA done to confirm SIF's .

 

[SOROURA]

If that is the case, then how do I estimate a SIF for a welded Wye piece, or shall I just treat it as a normal Tee?

Thanks

 

[MJCronin]

This probem has been around for at least 40 years. Are you new to piping stress anaysis ?

There are many component configurations that B31.1/B31.3
does not address in thier appendicies

Consider the use of a computer program developed specificaly for this purpose:

http://www.paulin.com/FESIF.aspx

Is this part of a steam piping system in a powerplant ?

 

[LSThill]

MJCronin (Mechanical), I agree with you, Tony Paulin did the Wye the mid. 1996 seminar.

Stephen

L S THILL