Spiral steel pipe is a spiral seam steel pipe welded by automatic double-wire double-sided submerged arc welding process, which is made of strip coil as raw material, often warm extruded and pressed.
(1) raw materials are strip coil, welding wire and flux. We must go through strict physical and chemical tests before putting it into use.
(2) The end-to-end butt joint of strip steel adopts single-wire or double-wire submerged arc welding, and automatic submerged arc welding is adopted for repair welding after being rolled into steel pipe.
(3) Before forming, the strip steel is leveled, trimmed, planed, cleaned, transported and pre-bended.
(4) Electric contact pressure gauges are used to control the pressure of pressing cylinders on both sides of the conveyor, which ensures the smooth transportation of strip steel.
(5) roll forming with external control or internal control. Hebei spiral steel pipe/spiral steel pipe factory/spiral steel pipe price
(6) The weld gap control device is used to ensure that the weld gap meets the welding requirements, and the pipe diameter, offset and weld gap are strictly controlled.
(7) Both internal welding and external welding adopt American Lincoln electric welding machine for single or double wire submerged arc welding, so as to obtain stable welding specifications.
(8) All the welded welds are inspected by on-line continuous ultrasonic automatic flaw detector, which ensures 100% non-destructive inspection coverage of spiral welds. If there is any defect, it will automatically give an alarm and spray marks, and the production workers can adjust the technical parameters at any time to eliminate the defect in time.
(9) Cut the steel pipe into individual pieces by air plasma cutting machine.
(10) After being cut into individual steel pipes, each batch of steel pipes shall be strictly subject to the first inspection system, and the mechanical properties, chemical composition, melting state, surface quality of steel pipes and NDT inspection shall be conducted to ensure that the pipe-making process is qualified before it can be formally put into production.
(11) The parts marked by continuous sonic flaw detection on the weld seam are rechecked by manual ultrasonic and X-ray. If there are any defects, after repair, they are subjected to nondestructive inspection again until it is confirmed that the defects have been eliminated.
