Specifications

How ERW pipe is made

ERW pipe is formed from hot-rolled steel coil. The coil is slit to the width needed for the pipe diameter, then formed through a series of rolls into a round open tube. The edges are heated by high-frequency electric current and pressed together, forging a weld without filler metal. The external, and usually internal, weld bead is trimmed flush, and for API 5L and higher grades the weld zone is heat treated to normalise the seam. The pipe is then sized, straightened, cut to length, hydrostatically tested and inspected along the weld by ultrasonic or eddy-current testing. Because it starts from coil, ERW pipe has a uniform wall thickness and a smooth surface.

ASTM A53 Type E

ASTM A53 covers black and hot-dip galvanised steel pipe in Type F (furnace butt welded), Type E (electric resistance welded) and Type S (seamless). Type E Grade B, with a minimum tensile strength of 415 MPa and minimum yield strength of 240 MPa, is the grade normally ordered. A53 ERW pipe is used for water, steam, gas and air lines, sprinkler and firewater systems, and mechanical and structural applications. For high-temperature process piping, ASTM A106 seamless pipe is specified instead.

API 5L ERW line pipe

API 5L ERW pipe is used for onshore and offshore pipelines carrying oil, gas and water. PSL1 is the standard quality level, and PSL2 adds tighter chemistry and carbon equivalent limits, maximum yield and tensile strength, mandatory Charpy impact testing and full non-destructive testing of the weld. Grades from B to X70 are designated by minimum yield strength. For sour service, PSL2 pipe can be supplied to the requirements of API 5L Annex H and NACE MR0175 / ISO 15156 on request.

IS 3589 and IS 1239 pipes

IS 3589 covers electrically welded steel pipe for water, gas and sewage, in grades Fe 330, Fe 410 and Fe 450, and is widely used in India for water mains, pumping lines and infrastructure projects, often with external coating and internal lining. IS 1239 Part 1 covers mild steel tubes in light, medium and heavy classes, supplied black or galvanised, with plain ends or threaded and socketed, for water and gas distribution, plumbing, firefighting, scaffolding and general engineering.

ERW or seamless?

ERW pipe costs less than seamless, has a more uniform wall thickness and is available in long lengths and larger diameters. Seamless pipe has no weld seam and is preferred for high-pressure, high-temperature, cyclic and critical service, and where the design code or project specification requires it. Modern ERW pipe with heat-treated seams and full weld inspection is accepted for many pipeline and utility applications. See carbon steel seamless pipes for seamless options and the welded pipes and tubes page for other welded products and materials.

Ordering carbon steel ERW pipes

Please give the standard and grade, outside diameter or nominal bore, wall thickness or schedule or class, length, end finish, surface finish or coating, quantity and any testing or inspection requirements. Pipes are supplied in bundles or loose for larger sizes, with end caps on bevelled ends, and marked with the standard, grade, size, heat number and the mill's identification.

Applications and related products

Carbon steel ERW pipes are used for water supply and distribution, oil and gas pipelines, firefighting and sprinkler systems, compressed air, low-pressure steam and condensate, HVAC, structural columns and piling, scaffolding, fencing and general fabrication. Matching products include carbon steel flanges, carbon steel pipe fittings and carbon steel fasteners; we also supply carbon steel plates and carbon steel round bars. Material guidance is on the carbon steel page.