About Branch Fittings
A branch fitting is a fitting solid part that you insert at a branch point. It has three (tee) or four (cross) legs. The corresponding pipe solid parts trim to the location of the csys (coordinate system) ports on each leg of the branch fitting. The piping specification designates these branch fittings, and they are available for automatic selection and insertion according to the specification-driven fitting insertion rules.
Cross branch fittings can only be used in the non-specification based piping design.