Spiral steel pipe flow
(1) raw material, i.e., coil, wire, flux. Before going through the rigorous physical and chemical inspection.
(2) the butt welding of steel strip is carried out by single wire or double wire submerged arc welding.
(3) before forming, the steel strip passes through leveling, trimming, planing, surface cleaning and conveying and bending.
(4) the electric contact pressure gauge is used to control the pressure of the oil cylinder on both sides of the conveyor.
(5) external control or internal control roll forming.
(6) the weld gap control device is adopted to ensure the weld gap meets the requirements of welding, and the pipe diameter, the amount of the gap and the gap of the weld are strictly controlled.
(7) both internal and external welding are carried out by single wire or double wire submerged arc welding in the United states.
(8) the welded seam is checked by the online continuous ultrasonic automatic inspection instrument, which guarantees the nondestructive testing coverage rate of 100%. If there are defects, automatic alarm and spray marking, production workers at any time to adjust the process parameters, timely elimination of defects.
(9) the air plasma cutting machine is used to cut the steel pipe into a single unit.
(10) into a single tube, each batch of steel tube head three to strict inspection system first, chemical composition and mechanical properties of weld, inspection, blending, surface quality of steel pipe as well as a nondestructive inspection, to ensure that the process of good control, can be formally put into production.
(11) the position of the continuous sonic inspection mark on the weld seam, which is checked by manual ultrasonic and X ray, if there is a defect, after the repair, it has passed the nondestructive inspection until the defect has been eliminated.
(12) strip butt weld and intersect with the spiral seam type joint in the tube, all through X ray TV or film examination.
(13) each steel pipe has been tested by hydrostatic pressure. The test pressure and time are strictly controlled by the hydraulic pressure testing device. Automatic recording of test parameters.
(14) pipe end machining, so that the end face verticality, slope angle and blunt edges are accurately controlled.