Classification of welded steel pipes: 1. Ordinary carbon steel wire casing (GB3640-88) is a steel pipe used to protect wires in electrical installation projects such as industrial and civil buildings, installation of machinery and equipment. 2. Welded steel pipe Straight seam electric welded steel pipe (YB242-63) is a steel pipe with the weld seam parallel to the longitudinal direction of the steel pipe. Usually divided into metric electric welded steel pipe, electric welded thin-walled pipe, transformer cooling oil pipe and so on. 3. Spiral seam submerged arc welded steel pipe for pressurized fluid transportation (SY5037-2012) is made of hot-rolled steel coil as a tube blank, often spirally formed at warm temperature, and welded by double-sided submerged arc welding. It is used for pressurized fluid transportation. Spiral seam steel pipe. The steel pipe has strong pressure bearing capacity and good welding performance. After various strict scientific inspections and tests, it is safe and reliable to use. The diameter of the steel pipe is large, the transportation efficiency is high, and the investment in laying pipelines can be saved. GB/T9711-2017 is mainly used for pipelines for transporting oil and natural gas.

Due to the high material and technical performance and production technology requirements of hot-rolled coils, on the one hand, there are fewer domestic manufacturers that meet the standards than steel plate manufacturers. Rolled steel. This is the main reason why the market price of spiral welded pipe is higher than that of straight seam welded pipe. For the composition of the sales price of steel pipes, the material price is the dominant or even decisive factor. Carefully examine the price difference between the spiral welded pipe and the straight seam welded pipe. The price of the spiral welded pipe is slightly higher than that of the straight seam welded pipe due to the price difference of the main materials. However, the production of steel pipes is only a part of the project. If the overall quality of the project and the overall cost of the project are considered, the spiral welded pipe still has overall advantages.