Brief introduction to the production process of stainless spiral steel pipe

Stainless spiral steel pipe is a spiral seam steel pipe made of strip steel coil as raw material, extruded at regular temperature, and welded by automatic double-wire double-sided submerged arc welding process.
(1) Raw materials are steel coils, welding wire, and flux. Before putting into use, they must go through strict physical and chemical tests.
(2) The head-to-tail butt joint of the steel strip adopts single-wire or double-wire submerged arc welding, and automatic submerged arc welding is used for repair welding after being rolled into steel pipes.
(3) Before forming, the steel strip is leveled, edge trimmed, planed, surface cleaned, conveyed, and pre-bent.
(4) Electric contact pressure gauges are used to control the pressure of the cylinders on both sides of the conveyor to ensure the smooth conveying of the strip.
(5) Adopt external control or internal control roll forming.
(6) The weld gap control device is used to ensure that the weld gap meets the welding requirements, and the pipe diameter, misalignment amount and weld gap are all strictly controlled.
(7) Both internal and external welding use American Lincoln welding machine for single-wire or double-wire submerged arc welding, so as to obtain stable welding specifications.
(8) All the welded seams are inspected by the online continuous ultrasonic automatic flaw detector, which ensures 100% non-destructive testing coverage of the spiral welds. If there is a defect, it will automatically alarm and spray the mark, and the production workers can adjust the process parameters at any time according to this to eliminate the defect in time.
(9) Use an air plasma cutting machine to cut the steel pipe into single pieces.
(10) After cutting into single steel pipes, each batch of steel pipes must undergo a strict first inspection system to check the mechanical properties, chemical composition, fusion status of the welds, surface quality of steel pipes and non-destructive testing to ensure that the pipe-making process is qualified After that, it can be officially put into production.
(11) The parts marked by continuous acoustic wave testing on the welds shall undergo manual ultrasonic and X-ray re-examination. If there are indeed defects, after repairs, they shall undergo non-destructive inspection again until it is confirmed that the defects have been eliminated.
(12) The tubes where the strip steel butt welds and the D-joints intersecting with the spiral welds are located have all been inspected by X-ray television or film.
(13) Each steel pipe has passed the hydrostatic pressure test, and the pressure is radially sealed. The test pressure and time are strictly controlled by the steel pipe water pressure microcomputer detection device. The test parameters are automatically printed and recorded.
(14) The pipe end is machined to accurately control the verticality of the end face, the bevel angle and the blunt edge.