Hello everyone,

I need the SIF for 2" weldolet Tee branch point connected on 2" header.
Is there formula for calculating the SIF of weldolet in ASME B31.3 appendix D?

I have stress output for 2"x2" weldolet, but it is shown the SIF 1.00. I am not sure it is correct value. I think it would be higher than 1.00.

My situation is below.
- 2" Header : CS steel, OD 2.375", THK.0.218" (Corrosion 0.0625")
- 2" Branch (Weldolet branch) : SS steel, OD 2.375", THK.0.154" (No corrosion)

Also, When I use the SIF calculation tool (SIFs intersections) into CAESAR, the result, SIF (both in and out) is calculated with 1.179. Could anyone explain me the reason that SIF is different from?

Is the 2x2 weldolet shown in material spec? Usually for same size we use welding tee. Anyway, maybe this is a special requirement.

Warm Regards,

If you're reading the stress result from Sustained case, it's probably not the SIF you're reading, but the Index. If you read B31.3 Par 320.2, Index I = 0.75*sif or 1.00, whichever is greater. 1.00>0.75*1.179. Therefore I = 1.00.