--The welding of spiral welded pipes is based on the Double Side Submerged Arc Welding (DSAW) process.

--- Arc welding works by utilizing an electric current to create an electric arc in a gaseous atmosphere. The heat of the arc causes the metal to reach the melting point.

Multi-Arc Welding
--Spiral milling cutters combine the advantages of a combination of DC and AC arcs. The multi-arc principle is used both internally and externally. The first weld pass is completed using a DC arc. This allows for large and concentrated penetration. The second pass is done with an AC arc. This allows for a better deposition rate. The result of multi-arc welding on both sides of the coil is a high quality full penetration weld produced in a cost effective manner. The flexibility of the mill is very high due to the use of this system. By selecting the right parameters, a wide range of coil thicknesses (between 10 and 25 mm) can be economically transformed into spiral welded pipes.