1) Raw materials include steel coils, welding wire, and welding flux. All must undergo rigorous physical and chemical inspections before use.
(2) Steel strip ends are joined using single or double wire submerged arc welding, and then automatically submerged arc welding is used for patch welding after the steel pipe is coiled.
(3) Prior to forming, the steel strip is straightened, trimmed, deburred, surface cleaned, conveyed, and pre-bent.
(4) The electrical contact pressure gauge controls the pressure of the cylinders on both sides of the conveyor, ensuring smooth steel strip transportation.
(5) Utilize externally or internally controlled roller molding.
(6) Utilize a welding gap control device to ensure the welding gap meets welding requirements; strict control is applied to the pipe diameter, misalignment, and welding gap.
(7) Both inner and outer welds are performed using Lincoln welding machines for single or double wire flux-cored welding, ensuring consistent welding quality.