A DI tee, or ductile iron tee, is a common component used in plumbing and piping systems to create branches or intersections. It typically consists of a T-shaped fitting with three openings, allowing fluid flow in two directions while diverting flow into a third direction. DI tees are essential for distributing fluids efficiently in a piping network, enabling connections to be made for various purposes, such as joining pipes, adding branches, or accommodating changes in direction. They are commonly used in water distribution systems, sewer lines, and industrial piping.