Butt-welded crosses are pipe fittings made of steel by hot pressing or forging. Its connection form is to directly butt-weld the crosses with steel pipes. The main manufacturing standards for butt-welded crosses are generally GB/T12459, GB/T13401, ASME B16.9, SH3408, SH3409, HG/T21635, HG/T21631, SY/T0510. Butt-welded crosses are divided into equal diameters and reducing diameters. The ends of the equal diameter crosses are all the same size; the main pipes of the reducing crosses have the same size, while the branch pipes are smaller than the main pipe. Butt-welded cross is a kind of pipe fittings used at pipeline branches. For the use of seamless pipes to manufacture butt-welded crosses, the currently commonly used processes include hydraulic bulging and hot press forming. Hydraulic bulging The hydraulic bulging of the butt-welded cross is a forming process in which the branch pipe is expanded by 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 butt-welded four-way pipe. The two horizontal side cylinders of the hydraulic press synchronize the centering movement to extrude the tube blank. The volume of the tube blank becomes smaller after being squeezed. The pressure of the liquid in the billet increases as the volume of the billet becomes smaller. When the pressure required for the expansion of the butt-welded four-way branch pipe is reached, the metal material flows along the cavity of the mold under the dual action of the side cylinder and the liquid pressure in the billet. Expand the branch pipe. The hydraulic bulging process of the butt-welded cross can be formed at one time, and the production efficiency is higher; the wall thickness of the main pipe and the shoulder of the butt-welded cross are increased. Due to the large tonnage of equipment required for the hydraulic bulging process of seamless butt-welded crosses, it is currently mainly used in the manufacture of standard wall thicknesses less than DN400 in China. The applicable forming materials are low-carbon steel, low-alloy steel, and stainless steel with a relatively low tendency of cold work hardening, including some non-ferrous metal materials, such as copper, aluminum, and titanium. Hot-press forming butt-welded cross-tube hot-press forming is to flatten the tube blank larger than the diameter of the butt-welded cross-tube to the size of the butt-welded cross-tube diameter, and open a hole in the stretched branch tube; the tube blank is heated and placed Into the forming die, and insert a punching die for stretching the branch pipe in the tube blank; the tube blank is radially compressed under the action of pressure, and the metal flows in the direction of the branch tube during the radial compression process and forms the branch tube under the stretching of the punching die. . The whole process is formed by the radial compression of the tube blank and the stretching process of the branch tube. Different from the hydraulic bulging butt-welded four-way, the metal of the hot-pressed butt-welded four-way branch is compensated by the radial movement of the tube blank, so it is also called the radial compensation process. Since the butt-welded cross is pressed after heating, the equipment tonnage required for material forming is reduced. Hot-pressed butt-welded crosses have wide adaptability to materials, and are suitable for low-carbon steel, alloy steel, and stainless steel; especially for crosses with large diameters and thicker pipe walls, this forming process is usually used. 1. Divide carbon steel, cast steel, alloy steel, stainless steel, copper, aluminum alloy, plastic, argon leaching, ppc, etc. by material. 2. According to the production method, it can be divided into topping, pressing, forging, casting, etc. 3. According to the manufacturing standard, it can be divided into national standard, electric standard, water standard, American standard, German standard, Japanese standard, Russian standard, etc.