Expanding and Forming of Reducing Pipes

Expanding forming is the process of using a pipe blank with a diameter smaller than the larger end of the reducing pipe, and expanding it along the inner diameter of the pipe blank using an internal punching die. The expansion process mainly solves the problem of large diameter reducing pipes being difficult to form through reduction. Sometimes, the methods of expansion and reduction are combined according to the needs of materials and product forming.
In the process of reducing or expanding deformation and pressing, cold or hot pressing is determined based on different materials and diameter changes. In general, cold pressing is preferred, but hot pressing is recommended for severe work hardening caused by multiple diameter changes, thicker wall thickness, or alloy steel materials.