I want to do a tee using a welded stub rather than using a tee fitting. ie. The branch tee will be cut and welded into the through tee.

Both legs of the tee are the same diameter and in this case are 150 mm. The branch tee is not perpendicular to through tee. It remains in the same plane but is angled at about 30 degreed from the perpendicular.

   branch tee

        /

____/____  through tee