SIF at lateral connection 45

Posted by: Nirav

SIF at lateral connection 45 - 05/29/08 04:21 AM

1) can you help me out...... which user defind SIF values (inplane & outplane) i should take if i have branch pipe to header pipe connection is lateral(45 deg with header). currently i have entered it as Reinforced connection & RF-PAD thickness.is it O.K. or not?

2) and if userdefined SIF value need to add after defining Reinforce connection on what basis that should i consider?
Posted by: MoverZ

Re: SIF at lateral connection 45 - 05/29/08 04:46 AM

It is definitely NOT ok to use sif's for a 90 deg connection of any kind with your 45 deg lateral. There have been many posts on this subject, use the search facility to find them.
Posted by: CraigB

Re: SIF at lateral connection 45 - 05/29/08 12:59 PM

Yep, this topic was just posted the other day. You need access to some FEA software, either for yourself, through a consultant, or from the fitting vendor.
Posted by: mav

Re: SIF at lateral connection 45 - 05/30/08 03:02 AM

I've investigated this quesion well. FEA software (I've tested Paulin's Nozzle pro and Ansys) produce incorrect results. For 45 degree lateral It give less SIF than for 90 degree connection io(a)~io*0.7. Nature tests doesn't comfirm this. For more information you could look:
- French CODETI code
- WRC 360 (by E.C. Rodabaugh) recomendations
- MCGraw-Hill Piping handbook 7th

CODETI:
io(a)=io/sin(a)^(3/2)
ii=0.75*io(a)+0.25
io - SIF for 90 degree connection

Piping Handbook:
Lateral branch connections (45deg), rb/r > 0.5
i = 0.9/h^(2/3); h = 1.97*t/r

Conservative value is i(45)=i*2.0
Posted by: Nirav

Re: SIF at lateral connection 45 - 05/30/08 03:48 AM

thankx MAV
for giving me information about resources.... from where i can get more info.