Hydraulic bulging of pipe fittings cross

　　The cross is also called pipe fitting cross or cross pipe fitting, which is used at the branch pipe of the main pipe.

　　The pipe fittings cross can be divided into equal diameter and reducing diameter. The nozzle ends of the equal diameter pipe fittings cross are of the same size; the main nozzle size of the reducing pipe fittings cross is the same, and the nozzle size of the branch pipe is smaller than the main nozzle size. A cross is a pipe fitting used at the branch of a pipe.

　　The hydraulic bulging of pipe fittings cross is a kind of forming process of expanding branch pipe by axial compensation of metal material. The process is to use a special hydraulic press to inject liquid into the tube blank with the same diameter as the pipe fittings cross, and extrude the tube blank through two horizontal side cylinders of the hydraulic press synchronously. The volume of the tube blank becomes smaller after being extruded, and the pressure of the liquid in the tube blank increases with the volume of the tube blank becoming smaller. When the pressure required by the expansion of the pipe fittings cross is reached, the liquid pressure in the side cylinder and the tube blank of the metal material is double Under the heavy action, the branch pipe flows along the inner cavity of the mold and expands.

　　The hydraulic bulging process of the pipe fittings cross can be formed in one time with high production efficiency; the wall thickness of the main pipe and shoulder of the cross is increased. Due to the large tonnage of equipment required for the hydraulic bulging process of pipe fittings cross, it is mainly used for the manufacture of standard wall thickness cross 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.