Production technology of spiral steel pipe
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Spiral steel pipe production process: is a strip coil as raw material, often temperature extrusion molding, automatic double wire double-sided submerged arc welding process from the spiral seam steel pipe.
(1) raw materials that are coil, wire, flux. In the investment before going through rigorous physical and chemical testing.
(2) strip head and tail docking, the use of single or double wire submerged arc welding, rolled into steel pipe after the use of automatic submerged arc welding.
(3) before forming, the strip through the leveling, cutting edge, planing edge, surface cleaning and delivery to the edge of the treatment.
(4) the use of electrical contact pressure gauge on both sides of the conveyor to control the pressure of the cylinder to ensure the smooth delivery of the strip.
(5) the use of external control or internal control roll forming.
(6) the use of weld gap control device to ensure that the weld gap to meet the welding requirements, diameter, misalignment and weld gap are strictly controlled.
(7) welding and external welding are used in the United States Lincoln welding machine for single or double wire submerged arc welding, in order to obtain a stable welding specifications.
(8) Welded welds are subjected to an on-line continuous ultrasonic automatic injury inspection to ensure a 100% spiral weld non-destructive testing coverage. If there are defects, automatic alarm and spray marking, production workers at any time to adjust the process parameters, the timely elimination of defects.
(9) the use of air plasma cutting machine to cut a single pipe.
(10) cut into a single steel pipe, the first batch of three steel pipe to carry out a strict first inspection system, check the weld mechanical properties, chemical composition, melting conditions, steel pipe surface quality and after nondestructive testing to ensure that pipe Qualified before they can be put into production.
(11) Where there is a continuous acoustic flaw mark on the weld, after manual ultrasonic and X-ray review, if there is a defect, after repair, again after the nondestructive test until the defect has been identified.
(12) The butt welds of the strip and the pipe of the dies which intersect with the spiral weld are all examined by X-ray or film.
(13) each pipe through the hydrostatic test, the pressure using radial seal. Test pressure and time by the steel pipe hydraulic microcomputer detection device strictly controlled. Test parameters are automatically printed.
(14) pipe end machining, so that the vertical face, bevel angle and blunt edge to be accurately controlled.
Spiral steel pipe features: Longitudinal seam welded pipe production process is simple, high production efficiency, low cost, rapid development. The strength of the spiral welded pipe is generally higher than that of the straight seam welded pipe, and the pipe with larger diameter can be produced with the narrow billet. The pipe with different diameter can also be produced with the same width. However, compared with the same length of the straight pipe, the weld length increased by 30 to 100%, and the production rate is low. Therefore, the smaller diameter of the pipe are mostly used straight seam welding, large diameter welded pipe are mostly used spiral welding
(SY5036-83) is mainly used for conveying oil and natural gas pipelines; high pressure welded steel pipe (SY5038-83) for pressurized fluid transportation with high speed welded pipe for pressurized fluid transportation, High-frequency welding with high-frequency lap welding, high-frequency welded steel pipe for pressurized fluid delivery. (SY5037-83), the use of double-sided automatic submerged arc welding or single-sided welding made of water for the water, steel pipe pressure, Gas, steam and other general low-pressure fluid transmission with submerged arc welded pipe is now commonly used standard spiral pipe is divided into: SY / T5037-2000 (part of the standard, also known as ordinary fluid piping with spiral submerged arc welded pipe), GB (US Petroleum Institute, also known as pipeline steel pipe), SY / T5040-92 (pile of steel pipe), API-5L (American Petroleum Institute, also known as pipeline steel pipe), SY / T5040-92 (GB, Spiral submerged arc welded pipe)
Spiral tube material: Q235A, Q23b, 0Cr13,1Cr17,00Cr19Ni11,1Cr18Ni9,0Cr18Ni11Nb. Q345 L245 L290 X42 X46 X70 X80