Application of different forming processes of stainless steel tees in pipeline fittings
Stainless steel tee fittings are used where pipelines have branches. Due to its convenience and simplicity, it is widely used in chemical industry, civil construction, machinery manufacturing, shipbuilding and other fields. Tee is a kind of fittings used for pipeline branches. At present, there are two commonly used processes for making seamless pipes: hydraulic bulging and hot pressing.
a. Stainless steel tee fittings - hydraulic bulging.
Hydraulic bulging of stainless steel tee fittings is a forming process that bulges the branch pipe through axial compensation of metal materials. In this process, a special hydraulic press is used to inject liquid into the tube blank with the same diameter as the tee, and the tube blank is squeezed through the two horizontal side cylinders of the hydraulic press, so that the volume of the tube blank becomes smaller after extrusion, and the pressure of the liquid in the tube blank increases as the volume of the tube blank becomes smaller. When the pressure required for the expansion of the 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, causing the branch pipe to expand.
b. Stainless steel tee fittings - hot pressing.
The hot pressing forming of stainless steel pipe fittings is to flatten the tube billet larger than the tee diameter to the size of the tee diameter, and open a hole at the part where the branch pipe is stretched. After the tube billet is heated, it is placed in the forming mold, and a mold for stretching the branch pipe is provided in the tube billet; under the action of pressure, the tube billet is radially compressed, and during the radial compression process, the metal flows to the branch pipe, and the branch pipe is formed under the stretching of the mold. The whole process is formed by the radial compression of the tube billet and the stretching of the branch pipe. Unlike the hydraulic bulging tee, the metal of the hot pressing tee branch pipe is compensated by the radial movement of the tube billet, so it is also called the radial compensation process.
By pressing the tee after heating, the tonnage of equipment required for material forming is reduced. Hot pressing stainless steel tees have a wide adaptability to materials and are suitable for low carbon steel, alloy steel, and stainless steel materials; especially for tees with large diameters and thick pipe walls, this forming process is usually used.
