The first production method
The tube billet (sheet material, strip material) is directly formed and welded into a tube. The main processes include forming, welding, and sizing the sheet material. Features: Fewer production steps, simple engineering processes, a short production cycle, and slightly lower product precision.
The second production method
The tube billet (sheet material, strip material) is directly formed and welded into a tube of a specific size, which is then cold-drawn or cold-rolled into the finished tube. This is commonly known as DOM electric-welded steel pipe. The main processes include forming, welding, sizing, cold-rolling or cold-drawing (with or without a mandrel), or continuous cold-drawing (i.e., a combined welding and cold-drawing line).
Features: Distributed production processes, long process flow and cycle time, large footprint, high product dimensional accuracy, smooth internal and external surfaces, and excellent mechanical properties and metallographic structure.
The third production method:
After the tube billet (sheet material, strip material) is directly formed and welded into a tube of a specific size, it enters a continuous reducing mill for cold shrinking to form the finished tube. The main processes include forming, welding, and continuous cold shrinking. Features: compact production process, simple process flow, high production efficiency of the unit, fast change in specification range, suitable for the production of small diameter and thin-walled electric welded steel pipes.
