Longitudinal welded pipes are made of steel plates or strips that are bent and then welded. According to the weld form, it is divided into straight seam welded pipe and spiral welded pipe. According to the purpose, it is divided into general welded pipe, galvanized welded pipe, oxygen blown welded pipe, wire casing, metric welded pipe, idler pipe, deep well pump pipe, automobile pipe, transformer pipe, electric welded thin-walled pipe, electric welded special-shaped pipe and spiral welded pipe. Among them, according to different purposes, there are different post-production processes.
The spiral welded pipe unit is used to produce large-diameter steel pipes with a diameter of (89-2450)mm×(0.5-25.4)mm and a length of 6-35m. Its production methods are continuous and discontinuous. The unit adopts spiral forming, and the welding adopts two steps of pre-welding and final welding. Forming and pre-welding (spot welding) takes place on a spiral former, followed by internal and external submerged arc welding on the final welding machine. The equipment layout of the spiral welded pipe is shown in Figure
The seamless steel pipe is made by perforating the whole round steel, and the steel pipe without weld seam on the surface is called seamless steel pipe. According to the production method, seamless steel pipes can be divided into hot-rolled seamless steel pipes, cold-rolled seamless steel pipes, cold-drawn seamless steel pipes, extruded seamless steel pipes, and pipe jacking.
It is used to build the main structure of high-rise buildings, such as steel structure frames, stairs, handrails, etc. Its high strength and stability enable buildings to withstand greater loads and external forces, improving the safety and durability of buildings.
Straight Seam Steel Pipe is a high-strength environmental protection steel pipe manufactured by straight seam welding technology. Compared with the traditional steel pipe production process, Straight Seam Steel Pipe does not need the traditional spiral welding process, thus avoiding the consumption of a large amount of welding heat energy, reducing energy waste and carbon dioxide emissions.
Straight Seam Steel Pipe is a steel pipe manufactured by straight seam welding technology. It is made of high-strength steel and has excellent compression and corrosion resistance.
