ERW (Electric Resistance Welded) pipes are manufactured from hot rolled coils by electrically joining the two extremities of the coil. High-frequency current is passed through the rolled coils using copper electrodes.
The opposing flow of electricity between the conductors causes intense heat to concentrate towards the edges, creating resistance. Once a certain temperature is reached, pressure is applied, causing the seams to join together.
Characteristics of ERW Pipes:
●Longitudinal welded seam.
●Made by passing high-frequency current through steel coils and fusing the ends under high pressure.
●Outside diameter ranges from ½ to 24 inches.
●Wall thickness varies from 1.65 to 20mm.
●Typical length is 3 to 12 m, but longer lengths are available upon request.
●Can have plain, threaded, or beveled ends as specified by the client.
●ERW pipes specified under ASTM A53 form the basis of most line pipes used in oil, gas, or vapor liquids.
Manufacturing Process of ERW Pipes:
●Steel coils are the base materials for making ERW pipes.
●Metal strips are slit into specific widths and sizes before being fed to the welding mills.
●Steel coils are uncoiled at the entrance of the ERW mill and passed down the mill to form a tube-like shape with an unclosed longitudinal seam.
●Various techniques such as seam welding, flash welding, and resistance projection welding are used.
●High-frequency, low-voltage electricity is passed through copper electrodes clamping onto the unfinished steel pipe to heat the open edges.
●Flash welding is commonly used as it doesn't require soldering material.
●Arc discharge forms between the edges, and upon reaching the right temperature, the seams are pressed together to weld the product.
●Welding beads are sometimes trimmed using carbide tools, and the welded areas are allowed to cool.
●Cooled tubing may enter a sizing roll to ensure the outside diameter meets specifications.
Applications Of ERW Pipes:
●The most common use of ERW pipes is as line pipes to carry crude oil, natural gas, and other material. They have a higher average diameter than seamless pipes and can meet high and low-pressure requirements, making them invaluable as transportation pipes.
●ERW pipes, especially of specification API 5CT, are used in casing and tubing
●ERW pipes may get used as structure tubes for wind power plants
●ERW pipes are used in the production industry as bearing sleeves, mechanical processing, processing machinery, and more
●ERW pipe uses include gas delivery, hydroelectric power fluid pipeline, and more.
●They also have uses in construction, underground pipelines, water transportation for groundwater, and hot water transport.
Post time: May-22-2024