Spiral pipe production process
Spiral steel pipe production process: It is a strip coil as raw material, often warm extrusion molding, automatic double-wire double-sided submerged arc welding of spiral welded steel pipe.
(1) raw materials that strip, wire, flux. In the input before going through a rigorous physical and chemical testing.
(2) the head and tail butt joint, using single or double wire submerged arc welding, after rolling into steel pipe using automatic submerged arc welding.
(3) Before forming, the strip is straightened, trimmed, planed, cleaned and delivered to the surface, and then subjected to bending.
(4) The use of electric contact pressure gauge control conveyor pressure on both sides of the press to ensure a smooth strip delivery.
(5) The use of external control or internal roller molding.
(6) The use of weld gap control device to ensure the weld gap to meet the welding requirements, pipe diameter, the amount of the wrong side of the weld gap are strictly controlled.
(7) The internal welding and external welding are using the United States Lincoln welding machine for single-wire or double-wire submerged arc welding, so as to obtain a stable welding specifications.
(8) Welded welds are inspected by ultrasonic automatic continuous online ultrasonic instrument to ensure non-destructive coverage of 100% spiral welded seam. If there are defects, automatic alarm and spray mark, the production workers so adjust the process parameters at any time, promptly eliminate defects.
(9) using air plasma cutting machine will be cut into single root.
(10) cut into a single pipe, the first batch of three steel pipe to the first inspection system to check the mechanical properties of the weld, chemical composition, melting conditions, the surface quality of steel and nondestructive testing to ensure that the pipe making process After passing, can formally put into production.
(11) Where there is a continuous ultrasonic flaw detection mark on the weld, after manual ultrasound and X-ray review, if defective, after repair, it will undergo non-destructive inspection again until it is confirmed that the defect has been eliminated.
(12) The pipe where the butt-welded steel strip and the butt-welded joint intersect the spiral welded seam are all examined by X-ray television or filming.
(13) Each pipe is hydrostatically tested with a radial seal. Test pressure and time by the steel pipe pressure computer testing device strictly controlled. Test parameters automatically print records.
(14) pipe end machining, the end face verticality, bevel angle and blunt edge to be accurately controlled.
Spiral steel pipe features: Longitudinal welded pipe production process is simple, high production efficiency, low cost and rapid development. The strength of spiral welded pipe is generally higher than the straight seam welded pipe, the pipe can be used to produce larger diameter welded pipe with a narrower blank, but also the same width of the blank tube production of different diameter pipe. However, compared with the same length of straight pipe, weld length increased by 30 ~ 100%, and the production rate is low. Therefore, the smaller diameter of most of the use of straight seam welded pipe, large-diameter welded pipe are mostly used spiral welding
Spiral pipe and its standard classification: Pressure transmission fluid spiral submerged arc welded pipe (SY5036-83) is mainly used for transporting oil and natural gas pipelines; pressure transmission fluid spiral welded high frequency welded steel pipe (SY5038-83) Welded with high-frequency lap welding, for the transmission of pressure fluid spiral welded high-frequency welded steel pipe. Strong pressure steel, plastic, and easy welding and machining molding; general low pressure fluid delivery with spiral submerged arc welded pipe (SY5037-83), using double-sided automatic submerged arc welding or single-pass made for water, Gas, air and steam and other general low pressure fluid delivery with submerged arc welded pipe Now commonly used standard spiral pipe is generally divided into: SY / T5037-2000 (Department standard, also known as ordinary fluid pipe with spiral submerged arc welded pipe), GB /T9711.1-1997 (GB, also called oil and gas industry delivery pipe first technical conditions: A grade steel), API-5L (American Petroleum Institute, also known as pipeline steel), SY / T5040-92 Spiral submerged arc welded pipe)
Spiral tube material: Q235A, Q23b, 0Cr13, 1Cr17, 00Cr19Ni11, 1Cr18Ni9, 0Cr18Ni11Nb.Q345, L245, L290, X42, X46, X70, X80