Cold-drawn pipe is a kind of steel pipe, that is, it is classified according to different production processes, which is different from hot-rolled (expanded) pipes. It is processed by multi-pass cold drawing in the process of expanding the diameter of the blank or raw tube, usually on a single-chain or double-chain cold drawing machine.

Pipeline transportation engineering Construction of pipelines for transporting oil products, natural gas and solid slurry. Including pipeline line engineering, station depot engineering and pipeline ancillary engineering. In a broad sense, pipeline engineering also includes the supply of equipment and equipment.

The production process of large-diameter thick-walled steel pipe generally includes hot rolling, hot coiling, casting and other production methods. Large-diameter thick-walled steel pipes are mostly produced in double-sided submerged arc welding (SSAW pipe). After bending, jointing, internal welding, external welding, straightening, and flattening, the products meet the standards of the American Petroleum Institute.

At present, there are three types of steel piles commonly used in engineering construction, namely steel pipe piles, section steel piles, and steel sheet piles. Compared with other steel piles, steel pipe piles have their unique advantages in many aspects. Such as bending stiffness, single pile bearing capacity and many other aspects.

High-frequency welded pipe is a steel pipe that uses the skin effect and adjacent effect generated by high-frequency current to connect steel plates. The emergence and maturity of high-frequency welding technology is a key process in the production of ERW pipe. The quality of high-frequency welding directly affects the overall strength, quality level and production speed of welded pipe products.

Submerged arc welding (including submerged arc surfacing and electroslag surfacing, etc.) is a method in which the arc burns under the flux layer for welding. Its inherent advantages such as stable welding quality, high welding productivity, no arc light and little smoke make it the main welding method in the manufacture of important steel structures such as pressure vessels, pipe section manufacturing (mainly SSAW pipes and LSAW pipes), and box-shaped beams and columns.