Elbows (reducing fittings) are pipe fittings used to change the pipe diameter. Common forming processes include reducing extrusion, expanding extrusion, or a combination of both. For certain sizes of elbows, stamping forming can also be used.

Contraction/Expansion Forming

The reduction forming process for reducing elbows involves placing a billet with a diameter equal to the large end of the reducing elbow into a forming die. Through pressure along the axial direction of the billet, the metal moves within the die cavity and shrinks into shape. Depending on the size of the diameter change in the reducing pipe, it is divided into single forming or multi-forming.

b. Stamping & Forming

In addition to producing elbows using steel pipes as raw material, elbows of certain specifications can also be manufactured using sheet steel via 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 cutting is stretched into shape using the die.