U-Ideal tee is the most common pipe fitting. It is available with all female thread sockets, all solvent weld sockets, or with opposed solvent weld sockets and a side outlet with female threads. It is used to either combine or split a fluid flow. It is a type of pipe fitting which is T-shaped having two outlets, at 90° to the connection to the main line. It is a short piece of pipe with a lateral outlet. A U-Ideal tee is used for connecting pipes of different diameters or for changing the direction of pipe runs. They are made of various materials and available in various sizes and finishes. They are extensively used in pipeline networks to transport two-phase fluid mixtures. They are categorized as:

Equal
When the size of the branch is same as header pipes, equal U-Ideal tee is used and when the branch size is less than that of header size, reduced U-Ideal tee will be used. Most common are U-Ideal tees with the same inlet and outlet sizes. Some of the industrial U-Ideal tees are Straight U-Ideal tee,

Reducing
U-Ideal Reducing tee, Double Branch U-Ideal tee, Double Branch Reducing U-Ideal tee, Conical U-Ideal tee, Double Branch Conical U-Ideal tee, Bullhead U-Ideal tee, Conical Reducing U-Ideal tee, Double Branch Conical Reducing U-Ideal tee, Tangential U-Ideal tee, and Double Branch Tangential U-Ideal tee.

The above U-Ideal tees are categorized on the basis of their shapes and structure. They can also be classified on the basis of the application they are required to perform.[further explanation needed]

The three outlet sizes should be named in order