The stainless steel tee is a kind of pipe fitting used in the branch of the pipeline. For the use of seamless pipes to manufacture tee, the commonly used processes are hydraulic bulging and hot pressing. The hydraulic bulging of the stainless steel tee is a forming process that expands the branch pipe through the axial compensation of the metal material. The process is to use a special hydraulic press to inject liquid into the tube blank with the same diameter as the tee, and to extrude the tube blank through the synchronous centering movement of the two horizontal side cylinders of the hydraulic press. The pressure of the liquid increases as the volume of the tube blank becomes smaller. When the pressure required for the expansion of the stainless steel tee branch pipe is reached, the metal material flows along the inner cavity of the mold under the dual action of the side cylinder and the liquid pressure in the tube blank to expand the branch pipe. .
The hydraulic bulging process of the stainless steel tee can be formed at one time, and the production efficiency is high; the wall thickness of the main pipe and the shoulder of the stainless steel tee are increased.

Due to the large tonnage of equipment required for the hydraulic bulging process of stainless steel tee, it is mainly used in the manufacture of stainless steel tee with standard wall thickness less than DN400 in China. The applicable forming materials are low carbon steel, low alloy steel and stainless steel with relatively low cold work hardening tendency, including some non-ferrous metal materials such as copper, aluminum, titanium, etc.
According to the manufacturing standard, it can be divided into national standard, electrical standard, water standard, American standard, German standard, Japanese standard, Russian standard, etc., as follows: GB/T12459, GB/T13401, ASME B16.9, SH3408, SH3409, HG/ T21635, DL/T 695, SY/T 0510, DIN 2615.