Large diameter erw steel pipe for steam

Large-diameter pipe may be ERW(www.honrypipe.com/267/large-diameter-erw-steel-pipe.html), EFW or Submerged Arc Welded ("SAW") pipe. The two types of pipes produced through ERW 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”.

For pipe sizes less than NPS 14 inch (DN 350), give a nominal value for the OD that is rounded off and is not the same as the actual OD. For example, NPS 2 inch and DN 50 are the same pipe, but the actual OD is 2.375 inches or 60.33 millimetres.
For pipe sizes of NPS 14 inch (DN 350) and greater the NPS size is the actual diameter in inches and the DN size is equal to NPS times 25 (not 25.4) rounded to a convenient multiple of 50.