Now the three-way hydraulic expansion process requires relatively large equipment. The molding materials suitable for this process are mainly low-alloy steel, stainless steel and low carbon steel with low degree of cold hardening. Some non-ferrous metals, such as aluminum and titanium, can also be used.  The three-way hot pressing molding we say is mainly to flatten the large-diameter three-way tube embryo, press to the size of the three-way diameter, and open a hole in the part of the stretching branch pipe;  Before putting the tube embryo into the forming die, the tube embryo is heated, and a punching die for the stretching branch pipe is installed in the tube embryo;  The tube embryo is compressed radially under pressure, and in this process, the metal in the tube embryo flows to the direction of the branch pipe, and finally the branch pipe is formed under the tensile action of the die.  

The whole process of forming is realized by radial compression of tube embryo and extension of branch tube. Compared with the hydraulic expansion tee, the metal of the hot pressing tee is realized by radial movement of the tube embryo. So we call this process radial compensation process. Because the heated tube embryo will restrict the tee, the tonnage required during the material forming process should be reduced. For the practicality of materials, hot pressing tee is relatively wide, more suitable for alloy steel and stainless steel materials; Especially large diameter and thick wall of the tee, will often apply this process.

Tee of the hydraulic expanding technology is through the metal materials of axial compensation rose out of the branch of a molding process, this process must need to use special hydraulic press, to equal to the diameter of the three-way tube embryo injection liquid, using the hydraulic press for the synchronization of two horizontal side urn to squeeze, tube embryos are served as by certain pressure, the overall volume smaller, Due to the change of volume, the liquid inside the tube embryo will change with the change of volume of the tube embryo, and the pressure gradually increases. Once the pressure required by the expansion of the tee branch is reached, the metal material inside will expand out of the branch under the liquid pressure in the tube embryo and the liquid pressure in the side cylinder.