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?

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.

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.

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

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