SIF assumption for special geometry .

Hi,

In one of the piping system I have a special geometry ( A barred tee) which is considered as a stiffer geometry in comparison to a normal welded tee. In such case what would be the appropriate SIF value that could be assumed so that my calculations are more realistic. At present the project is in preliminary stage where I am not in a position to get a value from the barred tee supplier.

As there is no standard barred tee design, there is no standard way to calculate the "real" SIF or stiffness.

I could suggest:

1. Have CAESAR calculate the welding tee SIF.
2. Uncheck and recheck the SIF, and input the SIFs manually.

This should eliminate the flexibility at the joint (i.e. make it stiff).

If the stresses in a barred tee with X force applied are to be less than a standard welding tee with X force applied, then applying the welding tee SIFs should be conservative.

Just another opinion: Use EXTRUDED TEE B31.3 SIFs, which are higher than B16.9 Welding Tee's SIFs and it's likely to be on the conservative side of SIF assessment. I agree that NO FLEXIBILITIES are to be employed.

Regards,

Thank you for the reply. Should I be entering the values of the SIF in all the 3 nodes of the junction or is it fine if i just enter at the middle point?