Manufacturing Techniques of Seamless Reducing Pipes

Stainless steel reducing pipeline is a kind of pipe fittings that applied to tapered pipes. In general situation, the forming technologies are reducing suppression, expansion suppression or reducing and expansion suppression. For some reducing pipes with special specifications, stamping forming is also available. 

 

 

With diameter reducing forming technology, manufactures put tube blank, which has the same diameter with the large end of the reducer, into forming die and suppress along the axial direction of tube blank. In this way, metal moves along die cavity and compression molding is finished. According to sizes of reducing pipes, times of this process can be one or more. 

 

 

Diameter expansion forming utilizes tube blank which has smaller diameter than the large end of the reducer. It uses a punching die inside and expands the inner diameter to shape. This technology is often used to manufacture reducing pipes with large variable diameters. Sometimes, due to different materials and requirements for products molding, two methods are used together. 

 

During diameter reducing or expansion pressing process, the detailed pressing methods are decided depending on materials and diameters. There are cold pressing and hot pressing. Cold pressing is the mainly used method. Nevertheless, for those that suffer from serious work hardening after several times of diameters changes, have thick wall thickness or made of alloy steels, hot pressing is suggested. 

 

 

Except for steel pipes, steel plates can also be used as materials of some reducing pipes. And then, stamping forming technology is employed. Stretching shape of the trimming die according to diameters of the reducing pipe. Then, stamping and stretch steel plates to required shapes.