ERW pipes are manufactured from the welding of steel

　　ERW pipes are manufactured from the longitudinal welding of steel. The welding process for ERW pipes is continuous as opposed to welding of distinct sections at intervals. ERW process uses steel coil as feedstock.

　　The High Frequency Induction Technology (HFI) welding process is used for manufacturing ERW pipes. In this process the current to weld the pipe is applied by means of an induction coil around the tube. HFI is generally considered to be technically superior to “ordinary” ERW when manufacturing pipes for critical applications, such as for usage in the energy sector In addition to other uses in line pipe applications, as well as for casing and tubing.

　　We have adopted advanced production equipment and technologies to manufacture our welded steel pipe and oil pipe,which can not only improve product quality, but also save raw materials. Our products have high strength, good toughness and resistance to corrosion.

　　Large-diameter pipe (25 centimetres (10 in) or greater) may be ERW, EFW or Submerged Arc Welded ("SAW") pipe. There are two technologies that can be used to manufacture steel pipes of sizes larger than the steel pipes that can be produced by seamless and ERW processes. The two types of pipes produced through these technologies are Longitudinal submerged arc welded (LSAW) and Spiral submerged arc welded (SSAW) pipes. LSAW are made by bending and welding wide steel plates and most commonly used in oil and gas industry applications. Due to their high cost, LSAW pipes are seldom used in lower value non-energy applications such as water pipelines. SSAW pipes are produced by spiral (helicoidal) welding of steel coil and have a cost advantage over LSAW pipes as the process uses coils rather than steel plates. As such, in applications where spiral-weld is acceptable, SSAW pipes may be preferred over LSAW pipes. Both LSAW pipes and SSAW pipes compete against ERW pipes and seamless pipes in the diameter ranges of 16"-24"