The basic process of Stainless Steel Weld Elbow is: blanking, rolling and welding to form a closed ring shell and internal pressure forming segments of the ring shell. The usual processing technology is to use a mold to press out multiple shells and then weld them to complete. Many processes require different fixtures or molds. The manufacturing cost is high and the cycle is long. The processability of large thin-walled parts is poor.

For the processing of thin-walled parts, the process is more difficult. The development of hydraulic expansion technology provides a new way for the forming and processing of large thin-walled parts. Moldless hydraulic expansion technology is a new type of hydroforming technology, which has significant features such as low cost, short processing cycle, and good forming. The basic process is: first, a flat plate or a roll-bent single-curvature shell plate is welded into a closed multi-faceted shell.

Then pressurization is applied in the closed polyhedral shell. Under the action of internal pressure, the shell undergoes plastic deformation and gradually tends to the ideal shape. The basic process of large stainless steel elbow is: blanking → rolling bending → welding into a closed ring shell → pressure forming inside the ring shell → segmentation. The usual processing technology is to use a mold to press out multiple shells and then weld them to complete. Many processes require different fixtures or molds. The manufacturing cost is high and the cycle is long. The processability of large thin-walled parts is poor. The development of hydraulic expansion technology provides a new way for the forming and processing of large thin-walled parts.