What are the differences between thin-walled and thick-walled spiral welded steel pipes

First, what is a thin-walled spiral welded steel pipe? 
The strip steel is fed into a pipe welding unit and rolled by multiple rollers, gradually forming a circular pipe blank with an open gap. The pressure of the extrusion rollers is adjusted to control the weld gap to 1-3mm, ensuring the two ends of the weld are flush.
1. If the gap is too large, the proximity effect is reduced, resulting in insufficient eddy current heat and poor intergranular bonding in the weld, leading to incomplete fusion or cracking.
2. If the gap is too small, the proximity effect is increased, resulting in excessive welding heat and weld burnout; or, after extrusion and rolling, deep pits may form in the weld, affecting the surface quality.
After heating the two edges of the pipe blank to the welding temperature, under the pressure of the extrusion rollers, common metal grains interpenetrate and crystallize, ultimately forming a strong weld. If the extrusion pressure of a spiral welded steel pipe is too low, the number of common crystals formed will be small, resulting in decreased weld metal strength and cracking under stress. If the extrusion pressure is too high, the molten metal will be forced out of the weld, not only reducing weld strength but also producing numerous internal and external burrs and even causing defects such as weld overlap.

Second, what are the applications of thin-walled spiral welded steel pipes? 
National standard spiral welded steel pipes are mainly used in water supply projects, the petrochemical industry, chemical industry, power industry, agricultural irrigation, and urban construction. They are one of the twenty key products developed in my country. For liquid transportation: water supply and drainage. For gas transportation: coal gas, steam, and liquefied petroleum gas. For structural use: as piling pipes, bridge pipes; pipes for docks, roads, and building structures, etc.

Third, what is a thick-walled spiral welded steel pipe? 
It refers to a spiral welded steel pipe with a slightly thicker wall than ordinary spiral welded steel pipes. The advantages compared to ordinary thick-walled spiral welded steel pipes are: higher pressure resistance, higher impact resistance, higher safety performance, and longer service life. The execution standards include 5037, 9711, and API.

Fourth, what is the forming process of thick-walled spiral welded steel pipes?
1. Before forming, Spiral welded steel pipes are manufactured using advanced double-sided submerged arc welding technology, allowing for welding at specific locations. This reduces the likelihood of defects such as misalignment, weld deviation, and incomplete penetration, and facilitates control over welding quality and position. The special welding process ensures precise welding at the correct locations, eliminating any errors or defects and guaranteeing the pipe's qualification and quality.
2. During forming: The steel plate must deform uniformly with minimal residual stress and avoid surface scratches. Therefore, careful selection of the steel plate is crucial, ensuring a uniform surface free of scratches. Processed spiral welded steel pipes offer greater flexibility in diameter and wall thickness specifications, especially in the production of high-grade thick-walled pipes, particularly small- and medium-diameter thick-walled pipes. This provides unparalleled advantages over other processes, meeting a wider range of user requirements for spiral welded steel pipe specifications. The diameter and size specifications of spiral welded steel pipes should be flexibly determined to leverage their inherent advantages.

Fifth, what is the development trend of thick-walled spiral welded steel pipes?
With industrial development, engineering projects are placing higher demands on the use of spiral welded steel pipes. The reason for the emergence of thick-walled spiral welded steel pipes is that the pressure generated by some media cannot be withstood by ordinary spiral welded steel pipes. If straight seam steel pipes or seamless steel pipes were used instead, it would significantly increase project costs. For hazardous media, increased costs are unavoidable. Therefore, the selection of pipelines is determined by the media to be transported and the pressure they will generate.