The primary difference lies in the forming method. Spiral welded pipes are produced by pre-bending and continuously bending steel plates or strips on a forming machine to form a tubular shape with a spiral seam. Spiral welded pipes are characterized by long weld seams and fast production speeds, making them suitable for the production of large-diameter welded pipes.
Spiral welded pipes can be classified into various types based on different criteria, mainly including:
(1) Classification by adjustment method of the forming angle:
Front swing type, Rear swing type.
(2) Classification by feeding method of the forming machine:
Upper roll type (less commonly used, only in special situations)
Lower roll type (more commonly used)
(3) Classification by forming method of the forming machine:
Lower roll bed type forming machine
Sliding friction full-sleeve forming machine
Combined roller and sleeve forming machine
Rolling friction full-roller sleeve forming machine
PRD forming machine (invented by PRD Corporation in the USA, capable of continuously adjusting pipe diameters)
