(1) the stock preparation.First cut strip uncoiling, leveling, head to tail, butt welding, and then through the loop device.According to the specifications of the different;Commonly used 5, 7, or 9 roller straightening machine, cutting head and cutting tail generally USES electric inclined blade shears, to achieve continuous headless production, brings mane plate butt welding, and eliminate weld burr.
   (2) heating.Use a more tens of meters long tunnel continuous heating furnace, the use of mixed gas or heavy oil as fuel.Heating process is automatically controlled by the thermal meter, its thermal characteristic is tube billet edges than the middle part of the higher temperature of 40 ~ 80 DHS C, in order to ensure the welding quality and maintain sufficient strength, of the strip is cracking, pulled apart or cause drag mark.General antipyretic temperature is 1250 ~ 1350 DHS C, nozzle should be used after tube billet in heating furnace with compressed air blown into the edge, used to remove iron oxide and make the tube billet edges slightly higher temperature, to facilitate welding.
   (3) the forming of welding.By repeated blowing the pipe before welding, make its edge to molten state, after forming machine swept into cylinder shape and by bonding together.Forming welding machine for 6 ~ 16 commonly two high levels of alternating arrangement, vertical racks, with round or oval pass system.
   (4) the sizing, reducing, out of the forming of welding machine of steel pipe after fly according to section to send sizing and reducing mill area.Sizing is the purpose of both the steel cylindrical shape, size is more conform to the requirements.Sizing mill is commonly 3 ~ 5, in recent years, most units are equipped with tension reducing mill, the tension reducing mill is usually 14 ~ 22, up to 28.After reducing of welded pipe diameter shall be cut to length, finishing, hydrostatic test, galvanized wire, car, packaging warehousing.