Manufacturing Process of Spiral Steel Pipe
(1) raw materials are steel coil, wire and flux. You have to go through rigorous physical and chemical testing before you invest.
(2) the end and end of the strip are connected by single wire or double wire submerged arc welding, and the automatic submerged arc welding is adopted after the steel tube is rolled.
(3) before forming, the strip is smoothed, cut and planed, and the surface is cleaned, transported and curved.
(4) the electric contact pressure gauge is adopted to control the pressure of the oil cylinder pressed down on both sides of the conveyor to ensure the smooth conveying of strip steel.
(5) external control or internal control roller molding.
(6) the welding seam clearance control device is adopted to ensure that the welding seam clearance meets the welding requirements. The pipe diameter, the amount of wrong edge and the weld clearance are strictly controlled.
(7) both internal and external welding adopt Lincoln welding machine of the United States for single wire or double wire submerged arc welding, so as to obtain stable welding quality.
(8) all the welded welds have been inspected by on-line continuous ultrasonic automatic flaw detector, which ensures 100% non-destructive testing coverage of spiral welds. If there is any defect, it will automatically alarm and spray the mark, and the production workers will adjust the process parameters at any time to eliminate the defect in time.
(9) adopt air plasma cutting machine to cut the steel tube into a single root.After cut into single pole
(10) the head of every batch of steel pipe should be strictly check system, check the weld mechanical properties, chemical composition, amalgamation, steel tube surface quality and the nondestructive flaw detection, ensure that qualified pipe process, can be formally put into production.
(11) have continuous acoustic detection of weld mark parts, after manual ultrasonic and X-ray check, if there are defects, after repair, again through the nondestructive inspection, until defects have been eliminated.
(12) the pipe where the butt weld of strip steel and the type d joint intersected with the spiral weld are all inspected by X-ray TV or film.
(13) each steel tube is subjected to hydrostatic test and the pressure is sealed in radial direction. The test pressure and time are strictly controlled by the microcomputer detection device of steel tube hydraulic pressure. Test parameters are automatically printed and recorded.
(14) the pipe end is machined so that the vertical degree of the end face, groove Angle and blunt edge are accurately controlled.