TEE is also called three-way pipe fittings or three-way pipe fittings, three-way joints and so on. Mainly used to change the direction of the fluid, used at the branch pipe of the main pipeline. Can be classified according to the size of the pipe. Generally made of carbon steel, cast steel, alloy steel, stainless steel, copper, aluminum alloy, plastic, argon leaching, pvc and other materials.

Reducing TEE refers to the branch pipe with a different diameter from the other two called Reducing TEE. Those with the same diameter at both ends are called equal-diameter tee. Reducing TEE is widely used in the construction and maintenance of petrochemical, petroleum and natural gas, liquefied petroleum gas, fertilizer, power plants, nuclear power, shipbuilding, papermaking, pharmaceuticals, food hygiene, urban construction and other industries. For equal diameter tees, for example, tee means equal diameter tees with an outer diameter of 3 inches. For Reducing TEE, it means a reducing tee with a same diameter of four inches and a different diameter of 3.5 inches.

Reducing TEE is generally a professional term. Tee refers to pipe fittings and pipe connectors, which are used at the branch pipes of the main pipeline. Reducing TEE is one type of tee, and there are two types of tee: general equal diameter tee and Reducing TEE. It is named because the three ends can be connected to the pipe. In the industry, the pressure requirements for this kind of pipe fittings are relatively high, and the maximum pressure can reach 600 kilograms, while the pressure of water pipes in life is relatively low, generally 16 kilograms.

TEE can be used in a variety of industries, and can be divided into the following categories in different types:
1. According to the production method, it can be divided into topping, pressing, forging, casting, etc.
2. According to the manufacturing standard, it can be divided into national standard, electric standard, water standard, American standard, German standard, Japanese standard, Russian standard and so on.