The tees are pipe fittings and pipe connectors.Also called pipe fitting tee or tee, tee joint, used in the main pipe to branch pipe.A tee is provided with three openings, that is, one entrance and two exits;Or a chemical pipe fitting with two entrances and one exit, in t-shape and Y-shape, with equal diameter pipe orifice or reducing pipe orifice, used at three converging points of same or different pipes.The main function of the tee is to change the direction of the fluid.Branches with diameters different from the other two are called reducing tees.Those with the same diameters at both ends are called equal diameter tees.Reducing three-way is widely used in the construction and overhaul of petrochemical industry, petroleum and natural gas, liquefied gas, chemical fertilizer, power plant, nuclear power plant, shipbuilding, papermaking, pharmaceutical industry, food sanitation, urban construction and other industries.