Threaded Tee is a kind of pipe joint, which is Tshaped. It is the most common threaded pipe fitting and an important part of the pipe system. According to the different outlet diameters, there are two types of pipe fittings: TS equaldiameter tee and TR reducing tee. Equaldiameter tee is also called straight tee. The three outlets have the same outer diameter, while the main pipe of the reducing tee has the same size, while the branch pipe size is smaller than the main pipe size.