Welded steel pipe, also known as welded pipe, steel pipe steel sheet or strip after curl forming welded steel. Welded steel pipe production process is simple, high production efficiency, variety specifications, less capital equipment, but the general strength less than seamless steel tubes. Since the 1930s, with the progress of high-quality steel rolling production as well as the rapid development of welding and inspection techniques, and continuously improve the quality of welds, welded steel pipe increasing varieties and specifications, and in more and more areas instead of no pipe joints. Welded steel pipes in the form of weld into Longitudinal and spiral welded pipe.

   Longitudinal production process is simple, high production efficiency, low cost, rapid development. Spiral Welded Longitudinal generally higher than, can narrow the billet production of large diameter pipe, you can also use the same width of the billet production of different pipe diameters. However, compared with the same length of straight seam pipe, weld length of 30 to 100%, and lower production rate. Therefore, smaller diameter pipe is mostly a straight seam welding, large diameter spiral welded pipe for the most part.

    1. The low pressure liquid delivery welded steel pipe (gb / t3092-1993), also known as general welded pipe, commonly known as the clarinet. Welded steel pipe is used for transporting water, gas, air, oil and heating steam and other general low pressure fluid and other uses. Then divided into ordinary steel pipe wall thickness and thicker steel; take over the side into the form without steel tube (fluorescent tubes) and with steel pipe. Pipe specifications with nominal diameter (mm), said nominal diameter is the diameter of the approximation. Traditionally commonly expressed in inches, such as 11/2 and so on. Low pressure liquid delivery welded steel pipe in addition to direct for conveying fluids, but also widely used as a low pressure fluid delivery galvanized welded steel pipe of the original tube.

    2. The low pressure fluid delivery galvanized welded steel pipe (gb / t3091-1993), also known as galvanized welded steel pipe, commonly known as white tube. Is used for conveying water, gas, air and steam heating oil, warm water, etc. are generally lower pressure fluid or other uses hot-dip galvanized welded (furnace brazed or welded) steel pipe. Pipe wall thickness then divided into ordinary galvanized steel and thicker galvanized steel; take over the side into the form of threaded galvanized steel and non-threaded galvanized steel band. Pipe specifications with nominal diameter (mm), said nominal diameter is the diameter of the approximation. Traditionally commonly expressed in inches, such as 11/2 and so on.