Spiral steel pipe production process: It 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 strip steel coils, welding wires, and fluxes. Before putting into use, they must go through strict physical and chemical tests.
(2) The head-to-tail butt joint of strip steel 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 strip steel is leveled, trimmed, planed, surface cleaned, transported, 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 that the pipe diameter, misalignment amount, and weld gap are strictly controlled.
(7) Both internal welding and external welding use American Lincoln welding machines for single-wire or double-wire submerged arc welding, to obtain stable welding specifications.
(8) The welded seams are all 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, the first three steel pipes of each batch must undergo a strict first inspection system to check the mechanical properties, chemical composition, fusion status of the weld, the surface quality of the steel pipes, and non-destructive testing to ensure the quality of the pipe-making process. Only after passing the test can it be formally put into production.
(11) The part marked by continuous ultrasonic flaw detection on the weld shall undergo manual ultrasonic and X-ray re-examination. If there is a defect, after repair, it shall undergo non-destructive inspection again until it is confirmed that the defect has been eliminated.
(12) The tubes where the strip steel butt welds and the D-joints intersected with the spiral welds are all inspected by X-ray TV 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.
Spiral steel pipe and its standard classification: spiral seam submerged arc welded steel pipe SY5036-83 for pressure fluid transportation is mainly used for pipelines for oil and natural gas; spiral seam high frequency welded steel pipe SY5038-83 for pressure fluid transportation, with high-frequency lap Spiral seam high-frequency welded steel pipes welded by butt welding for pressurized fluid transportation. The steel pipe has strong pressure bearing capacity, and good plasticity, and is convenient for welding and processing; the spiral seam submerged arc welded steel pipe SY5037-83 for general low-pressure fluid transportation is made by double-sided automatic submerged arc welding or single-sided welding for water, gas, Submerged arc welded steel pipes for conveying general low-pressure fluids such as air and steam.
Post time: Jun-07-2023