In recent years, the offshore deepwater wharf project in domestic coastal have also been large-scale construction, as a main bearing capacity of pile foundation deep-water wharf, generally used spiral seam of large diameter steel pipe pile; In addition, such as Bridges, roads, high-rise buildings are piling pipe which is the main kind of structural steel pipe.
Commonly used is 219-3620 – mm in diameter, the length of the supply is 8.0-12 m, but according to buyer’s requirements, the supply and demand both sides agreed that the length of the supply is beyond usually length range.
(1) the raw material is steel strip coil, wire, flux. Have to pass strict physical and chemical inspection before investment.
(2) the strip head to tail docking, use single or double wire submerged arc welding, after rolled steel tube adopts automatic submerged arc welding repair welding.
(3) before shaping, strip after flattening, cutting edge, edge planing, transmission and cleaning the surface to the flanging process.
(4) on both sides of the electric contact pressure gauge control conveyor under the pressure of oil cylinder pressure, ensure the smooth delivery of strip steel.
(5) the use of external control or internal control roll forming.
(6) the weld gap control device to ensure that meet the requirements of welding seam clearance, pipe diameter, and quantity of the wrong side of weld gap are tightly controlled.
(7) welding and welding are used within the United States Lincoln welding machine for single or double wire submerged arc welding, to obtain the stable welding quality.
(8) after welding the weld passes the online continuous ultrasonic automatic meter check, ensure the spiral weld nondestructive testing coverage of 100%. If there are defects, automatic alarm and spray tags, production workers to adjust process parameters, in a timely manner to eliminate defects.
(9) by air plasma cutting machine to cut the steel tube into single.
After cut into single pole (10), the head of every batch of steel pipe should be strictly check system, check the weld mechanical properties, chemical composition, amalgamation, steel tube surface quality and the nondestructive flaw detection, ensure that qualified pipe process, can be formally put into production.
(11) have continuous acoustic detection of weld mark parts, after manual ultrasonic and X-ray check, if there are defects, after repair, again through the nondestructive inspection, until defects have been eliminated.
(12) strip steel butt weld and fellowship with spiral weld d joint in the tube, all pass X-ray films and television inspection.
(13) each DSAW steel pipeafter hydrostatic pressure test, radial sealing for the pressure. Test pressure and time are controlled strictly by steel pipe hydraulic microcomputer testing device. The parameters automatically printed out.
(14) pipe end machining, make the end verticality, slope Angle and the blunt edge to get accurate control
If you are interested in this kind of carbon steel pipe,pls contact:hunan great steel pipe co.,ltd