Double-sided spiral submerged arc welded steel pipe is a spiral seam steel pipe made of strip steel coils as raw materials, often extruded and formed by automatic double-wire double-sided submerged arc welding.
(1) Raw materials are strip steel coils, welding wires, and fluxes. Strict physical and chemical inspections are required before investment.
(2) Butt joint of strip steel head and tail, adopt single wire or double wire submerged arc welding, after coiling into steel pipe, adopt automatic submerged arc welding repair welding.
(3) Before forming, the strip undergoes leveling, edge trimming, edge planing, surface cleaning and conveying, and pre-bending treatment.
(4) The electric contact pressure gauge is 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 welding seam gap control device is used to ensure that the welding seam gap meets the welding requirements, and the pipe diameter, the amount of misalignment and the welding seam gap are all strictly controlled.
(7) Both internal welding and external welding adopt American Lincoln electric welding machine for single-wire or double-wire submerged arc welding, so as to obtain stable welding specifications.
(8) The welded seams are all inspected by the online continuous ultrasonic automatic flaw instrument, which guarantees 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 individual pieces.
(10) After cutting into a single steel pipe, the first three steel pipes of each batch must undergo a strict first inspection system to check the mechanical properties, chemical composition, melting condition of the weld, the surface quality of the steel pipe and pass non-destructive inspection to ensure the pipe-making process Only after it is qualified can it be officially put into production.
The characteristics of double-sided spiral submerged arc welded steel pipe: straight seam welded pipe production process is simple, high production efficiency, low cost, and rapid development. The strength of spiral welded pipes is generally higher than that of straight seam welded pipes. A narrower blank can be used to produce welded pipes with larger pipe diameters, and a billet with the same width can also be used to produce welded pipes with different pipe diameters.
Application field of double-sided spiral submerged arc welded steel pipe
1. Mainly used in water conservancy projects, petrochemical industry, chemical industry, power industry, agricultural irrigation, urban construction, etc.
2. Used for liquid transportation: water supply and drainage.
3. For natural gas transportation: natural gas, steam, liquefied petroleum gas.
4. Structural use: such as piling pipes, bridges, piers, roads, structural pipes, etc.