Pipe tee is used for distributing or collecting the fluid from the run pipe. It is a short piece of pipe with a 90-degree branch at center. There are two types of Tee used in piping, Equal / Straight Tee and Reducing / Unequal Tee.
Straight Tee : In straight tee, the diameter of the branch is same as the diameter of the Run (Header) Pipe.
Reducing Tee : In reducing tee, diameter of the branch size is smaller than the diameter of the Run (Header) Pipe
Barred Tee : A barred tee which is also known as a scrapper tee is used in pipelines that are pigged. The branch of the tee has a restriction bar welded internally to prevent the pig or scrapper to enter the branch. The bars are welded in the branch in a way that it will allow restriction free passage of the pig from the run pipe.
Wye Tee / Lateral : It is a type of Tee which has the branch at a 45° angle, or an angle other than 90°. Wye tee allows one pipe to be joined to another at a 45° angle. This type of tee reduces friction and turbulence that could hamper the flow. Wye tee is also known as a lateral.