Hi

can anybody provide the formula for SIF & K for fabricated/lateral tees.

thanks

FE-Pipe, Nozzle Pro and other Proprietary FEA software will help in obtaining these SIF's & K values.. I think the latest version of Caesar has now this capability basically integrating the 1D beam element and using FEA tools (3D element) to get the SIF's and K's at the pipe intersections or junctions such as tees, etc...

There is no formula in the B31 Codes for laterals. As stated above, you will have to use something like FEATools to obtain these values (since at the moment this fitting is outside the scope of the Codes).

I checked in one of the company,they used this formulae for calculation of h(Flexibility characteristics) for lateral tee:1+cot(theta)/2*((T+0.5Tr)^2.5)/(T^1.5*r2).

Did any body know the basis for this?

The only document I have seen that gives any guidance is the French Codeti code. The sif calc is similar to B31.3 App D but includes the sine of the angle in the denominator. I don't recall the h factor details.

I suspect that the Codeti approach is devoid of any theoretical back-up.