A buttweld tee is a pipe fitting used to combine or split fluid flow in a piping system. It has one inlet and two outlets arranged at 90 degrees, forming a T shape. Tees are available in equal (straight) and reducing types, allowing for the connection of pipes of the same or different diameters. Welded for strength and seamless flow, they are commonly used in industries like oil & gas, petrochemical, and water treatment.