Steel tees are widely used in the construction and maintenance of engineering projects in various industries, including petrochemical, oil and natural gas, liquefied petroleum gas, chemical fertilizer, power plants, nuclear power, shipbuilding, papermaking, pharmaceutical, food hygiene, and urban construction.

A steel tee is a type of pipe fitting used at the branch points of pipelines. For the manufacture of tees from seamless pipes, there are currently two commonly adopted processes: hydraulic bulging and hot pressing.

Hydraulic bulging is a forming process that bulges out the branch pipe through axial compensation of the metal material. The process involves using a hydraulic press to inject liquid into a tube blank with a diameter equal to that of the tee. The two horizontal side cylinders of the hydraulic press move synchronously and centripetally to squeeze the tube blank. As the tube blank is squeezed, its volume decreases, causing the pressure of the liquid inside to rise. When the pressure reaches the level required for bulging out the branch pipe of the stainless - steel tee, the metal material, under the dual action of the side cylinders and the liquid pressure inside the tube blank, flows along the inner cavity of the mold to bulge out the branch pipe. The materials suitable for this forming process are low - carbon steel, low - alloy steel, and stainless steel with relatively low cold - work hardening tendency, as well as some non - ferrous metal materials such as copper, aluminum, and titanium.