The raw material of the SSAW steel pipe includes steel coil, welding wire, flux. All of raw materials must be through strict physical and chemical maintenance before the investment.
The head and tail of steel strip butt joint, uses single or double wire submerged arc welding, after rolled into steel pipe uses automatic submerged arc welding. Before forming, the strip is treated by leveling, cutting edge, planing, surface cleaning and bending. Using of electric contact pressure gauge control the pressure on both sides of the conveyor to suppress the cylinder to ensure a smooth delivery of the strip. Using external control or internal control roll forming.
Using weld gap control device to ensure that the weld gap to meet the welding requirements, diameter, misalignment and weld gap are strictly controlled. Welding and external welding are used in the United States Lincoln welding machine for single or double wire submerged arc welding, in order to obtain chaos welding specifications. Welded welds are checked by continuous ultrasonic automatic wounds, ensuring a 100% loss of non-destructive testing of helical welds. If a defect, automatic alarm and spray marking, production workers at any time to adjust the process parameters, the timely elimination of defects.
The air pipe is cut into single root by air plasma cutting machine. After cut into a single SSAW steel pipe, the first three steel pipes have to carry out a strict first check system, check the weld mechanical properties, chemical composition, melting conditions, spiral steel pipe surface quality and through the nondestructive testing repair, to ensure that the SSAW steel pipe management process is eligible, in order to formally put into production.
There are marks by continuous sonic flaw detection on the weld seam, through manual ultrasound and X-ray review, if confirmed the defect, through the repair, again through the lossless maintenance, until confirmed the defect has been eliminated. The butt welds and the helical welds of the spiral steel pipe intersect the dies of the pipe, all via X-ray or film inspection. Each steel pipe is subjected to hydrostatic test, and the pressure is radially sealed. Test pressure and time by the steel pipe hydraulic microcomputer detection device strictly controlled. Test parameters automatically print records. Tube end machining, so that the vertical face, bevel angle and blunt edge are properly controlled.