1. Welded steel pipe(GB/T3092-1993) is used for transporting low-pressure fluid, commonly known as black steel pipe. It is applied to low pressure fluid such as water, gas, air, oil and heating steam, as well as other fields. Steel pipe is classified into ordinary steel pipe and heavy steel pipe based on wall thickness; and can be classified into non-threaded steel pipe (light pipe) and threaded steel pipe on the basis of end connection. Nominal size(mm) means the specifications of the steel pipe, and the nominal size is the approximate value of the inner diameter. We often use inch to describe diameter, such as 11/2. Welded steel pipes are not only used for transporting low pressure fluid, but also been widely used for original pipes of galvanized welded steel pipes.
2. Regular carbon steel conduit pipe (GB3640-88) is a kind of pipe that protects electric wire in electrical installation engineering, such as industrial and civil construction, installation of machinery.
3. Steel pipes with a longitudinal electric weld(YB242-63) is a pipe that its seam line is parallel to the steel pipe longitudinally. It is usually classified into metric welded steel pipe, welded thin-walled pipe, transformer cooling pipe, and so on.
4. Spiral seam submerged arc welded pipe(SY5036-83) uses hot-rolled steel strip as billet, forms by thermo-spiral, welded by double-sided submerged arc welding, which is applied to pressurized fluid transportation. It has good bearing ability and welding performance. It is safe and reliable after passing all kinds of strict scientific inspection and test. The steel
pipe has a big diameter, high transport efficiency and can save laying pipeline investment. Which is mainly used for conveying oil and gas pipelines.
5. Generally spiral submerged arc welded steel pipe (SY5037-83) is used for low-pressure fluid transportation, which is made by a hot-rolled steel coil for the billet, formed by spiral under the regular temperature, welded by double-sided automatic submerged arc or single-sided. It is applied to low pressure fluid transportation, such as water, gas, air and steam.
6. Generally high-frequency spiral welded steel pipe (SY5039-83) is made by billet which is made from hot roll steel coil, shaped by spiral under the regular temperature, welded by high frequency. It is used for transporting low-pressure fluid.
7. Spiral welded steel pipe (SY5040-83) for piles, is made by billet which is made from hot roll steel coil, shaped by spiral under the regular temperature, welded by double-sided automatic submerged arc or high frequency. It is used for basic piles for civil construction, dock, bridge, etc.
