Reduced Bends (Reducing Elbows) are pipe fittings used for changing pipe diameters. Common forming processes include reaming, expanding, or a combination of both reaming and expanding. For certain sizes of reducing elbows, stamping forming can also be used.

Contraction/Expansion Forming

The reduction forming process for male and female ends involves placing a tube blank with a diameter equal to the male end of the reducing tee into a forming die. Through pressing along the tube blank's axial direction, the metal moves and shrinks into shape within the die cavity. Depending on the size of the diameter change in the eccentric pipe, it is categorized as single-stage or multi-stage forming.

b. Stamp forming

In addition to producing elbows using steel pipes as raw materials, elbows of certain specifications can also be manufactured using sheet steel through the stamping forming process. The shape of the stamping die used for stretching is designed according to the internal surface dimensions of the elbows, and the sheet steel after blanking is stamped and stretched into shape using the die.