The Difference Between Common Steel Pipe Specifications And Spiral Welded Pipe

The difference between common steel pipe specifications and spiral welded pipe According to the different welding methods can be divided into arc welded pipe, high-frequency or low-frequency resistance welded pipe, gas welded pipe, furnace welded pipe, Bundy tube and so on. According to the weld shape can be divided into straight seam welded pipe and spiral steel pipe.

　　Welded steel pipe used in oil drilling and production and machinery manufacturing.

　　φ219-φ2032, wall thickness 5-18mm, material Q235, Q345, x42-70 grade.

　　Spiral welded steel pipe refers to the steel strip or steel plate bending deformation into a round, square shape, and then welded to the surface of the joint steel pipe.

　　According to the different welding methods can be divided into arc welded pipe, high-frequency or low-frequency resistance welded pipe, gas welded pipe, furnace welded pipe, Bundy tube and so on.

　　According to the weld shape can be divided into straight seam welded pipe and spiral welded pipe.

　　Welded steel pipe used in oil drilling and production and machinery manufacturing.

　　Furnace welded pipe can be used as water gas pipe, large diameter straight seam welded pipe for high-pressure oil and gas transport, spiral welded pipe for oil and gas transportation, pipe piles, piers and so on.

　　Welded steel pipe than seamless steel tube cost is low, production efficiency is high.

　　Straight seam welded pipe production process simple, high production efficiency, low cost, rapid development.

　　The strength of spiral welded pipe is generally higher than that of straight seam welded pipe, it can produce welded pipe with larger pipe diameter with narrower billet, and can produce welded pipe with different pipe diameter with same width.

　　However, the weld length increases 30~100% and the production speed is lower compared with the straight seam tube of the same length.

　　Therefore, the smaller-caliber welded pipe is mostly used straight seam welding, large-diameter welded pipe is mostly used spiral welding spiral seam submerged arc welded steel pipe will be hot-rolled steel strip spiral shape, with submerged arc automatic welding for internal and external seam welding made of spiral pipe (also known as spiral welded pipe, spiral pipe). Spiral Steel Pipe For the following reasons it can be widely used in the production of large diameter steel pipe: 1) As long as changing the forming angle, can use the same width of the steel strip production of various caliber pipe; 2 because it is continuous bending forming, so the length of the steel pipe is not limited; 3 The weld spiral is evenly distributed across the circumference of the steel pipe,

　　So the size of the steel pipe is high, the strength is also high, 4 easy to change the size, suitable for small batch, many varieties of steel pipe production.

　　Production process of steel pipe: Steel head and tail docking, the use of single wire or double wire submerged arc welding, after the coil into the steel pipe with automatic submerged arc welding repair. (3) before forming, the strip has been leveling, trimming, trimming, surface cleaning and conveying and bending edge treatment.

　　(4) Use the electric contact pressure gauge to control the pressure of the oil cylinder on both sides of the conveyor to ensure the smooth conveying of the strip.

　　Spiral Steel pipe flow (high-precision seamless steel tube, DIN2391 precision seamless steel tube, cold drawn precision light pipe): (1) raw materials namely strip coil, welding wire, flux.

　　Before the input must undergo rigorous physical and chemical tests.

　　(2) Steel head and tail docking, the use of single wire or double wire submerged arc welding, after the coil into the steel pipe with automatic submerged arc welding repair.

　　(3) before forming, the strip has been leveling, trimming, trimming, surface cleaning and conveying and bending edge treatment.

　　(4) Use the electric contact pressure gauge to control the pressure of the oil cylinder on both sides of the conveyor to ensure the smooth conveying of the strip.

　　(5) Using external control or internal control roll molding.

　　(6) The welding seam clearance control device is used to ensure that the weld clearance meets the requirements, the pipe diameter, the wrong edge quantity and the weld seam clearance are strictly controlled.

　　(7) internal and external welding are used in the United States Lincoln Welding machine for single or double wire submerged arc welding, so as to obtain a stable welding specifications.

　　(8) The welded welds are inspected by the on-line continuous ultrasonic automatic injury instrument, which guarantees the NDT coverage of 100% of the spiral welds.

　　If there are defects, automatic alarm and spraying mark, the production workers adjust the process parameters at any time, eliminate defects in time.

　　(9) The spiral steel pipe uses the air plasma cutting machine to cut the steel pipe into single root.

　　(10) cut into single steel pipe, each batch of steel pipe head three to carry out a strict first inspection system, check the mechanical properties of the weld, chemical composition, fusion status, the surface quality of steel pipe and through nondestructive testing, to ensure that the pipe process qualified, can be formally put into production.

　　(11) The Weld has a continuous sonic flaw mark on the site, after manual ultrasound and X-ray review, if there is a defect, after repair, again through non-destructive testing, until the identification of the defect has been eliminated.

　　(12) The tube of the steel butt weld and the ding-type joint which intersect with the spiral weld are inspected by X-ray television or film.　(13) Each steel tube after hydrostatic test, pressure using radial seal.

　　The test pressure and time are strictly controlled by the steel tube hydraulic pressure microcomputer detecting device. (14) Pipe end machining, so that the end of the vertical, slope and blunt edge of the angle is accurately controlled.