Dear all,

I have a case in my model using hot tapping split tee which requires the SIF value, my question is :

Can I assume input value of the SIFi and SIFo which got from Appendix D ASME B31.3 Table D300 with unreinforced fabricated tee that thickness is accumulated from the pipe header thickness plus hot tap tee thickness. Or from reinforced fabricated tee with pad/saddle thickness as the hot tap tee thickness it self?

Regards,

SInce the inner wall of your split tee will be exposed to line pressure you should base your sif's on the split tee alone.

Hi, Moverz

You're right for the branch one, It's exposed to line pressure, how about the header, it seems like the pipe is wrapped with the split tee.

You are really interested in the mechanical behavior of the tee under external loads, presuming that the split tee is properly designed to resist pressure.

Split tees are normally welded at the ends to the header, and thus there is no physical (welded) connection to the header actually at the branch location. Consequently bending loads acting from the branch will be transferred by the shell of the split tee, and the sifs should reflect that situation.