Model	Diameter of Welded Pipe（mm）	Thickness of Welded Pipe（mm）	FormingPerspective
LH529	219～529	5.0～10.0	40°～66°
LH630	219～630	5.0～10.0	40°～66°
LH820	219～820	6.0～12.7	40°～70°
LH1020	219～1020	6.0～12.7	40°～72°
LH1220	219～1220	6.0～16.0	40°～72°
LH1420	219～1420	6.0～16.0	40°～72°
LH1620	219～1620	6.0～19.0	40°～76°
LH1820	508～1820	6.0～20.0	40°～76°
LH2540	508～2540	6.0～25.4	40°～76°

The spiral welded pipe production line is designed to manufacture spiral welded pipes ,either from the same size of the steel strips to different diameters of pipes or from different widths of steel strips to the seam diameter of pipes . As the key equipment of the line ,the forming mill is used to roll metal strips continously into spiral tube blanks ,applying the theory of three-roll plate bending machine ,and then weld them into spiral pipe through one-side welding ,both-side welding or high frequency welding .