The production process of large-diameter welded pipe is mainly divided into the following types:

1. Large-diameter spiral steel pipe, also known as (large-diameter spiral welded pipe, large-diameter submerged arc welded spiral pipe, large-diameter spiral pipe, or double-sided submerged arc welded spiral steel pipe), is mainly based on hot-rolled steel coils as raw materials. Spiral-wound welded steel pipes are called spiral welded steel pipes because their welds are helical. The process is mainly submerged arc welding process.

2. Large diameter straight seam steel pipe, also known as (large diameter straight seam welded pipe, large diameter straight seam pipe, large diameter welded steel pipe, large diameter welded pipe, double-sided submerged arc welded straight seam steel pipe, high frequency welded pipe) is mainly made of hot rolled steel coil, and medium and thick plates as raw materials, the process of rolling and welding, because the weld is one or two straight seams, so it is called straight seam steel pipe.

The process is divided into two types: the first type: is a double-sided submerged arc welding process, mainly large-diameter thick-walled welded pipes. The second is the high-frequency welding process, which is mainly based on small-diameter thin-walled welded pipes. The heat-expanded seamless process is also performed on the basis of high-frequency welded pipes.

3. Large-diameter coiled pipe, the coiled pipe is also called (T-shaped welded pipe, steel plate coiled pipe, thick-walled coiled pipe, steel plate reel, or steel plate coiled circle) mainly uses medium and thick plates as raw materials, and is rolled by a coiling machine. In the process of round calibration and submerged arc welding, because its welding shape is like a T-shaped pipe, it is also called a T-shaped welded pipe. Its advantages are mainly large-diameter thick-walled models, flexible materials, and flexible docking according to the length of the customer. All applications are very convenient.