ERW Longitudinal Welded Pipe

When the application demands precision, strength, and efficiency in fluid or gas conveyance, the ERW Longitudinal Welded Pipe stands out as a premier engineering solution. Manufactured through the Electric Resistance Welding (ERW) process, this pipe category is characterized by its straight, parallel weld seam running the length of the tube. This method ensures a uniform, high-integrity weld with minimal heat-affected zones, resulting in superior dimensional accuracy and consistent wall thickness. Often referred to as a Straight Seam Welded Steel Tube, it is a fundamental component across numerous heavy-duty industries. Its robust construction makes it ideal for structural applications, piling, and framework, while its reliable sealing properties are crucial for low to medium-pressure pipelines in oil, gas, and water distribution. The versatility of the Straight Welded Seam Steel Pipe is further enhanced by its availability in a wide range of diameters and wall thicknesses, catering to specific project specifications. As a specific type of Longitudinal Seam Welded Tube, it is produced from coiled steel skelp, formed cold into a cylindrical shape, and then welded along its length. This process is renowned for producing pipes with excellent concentricity and a smooth interior surface, minimizing flow resistance. For engineers and procurement specialists seeking a reliable product known for its cost-effectiveness and performance, the Electric Resistance Welded Straight Pipe remains a cornerstone of modern industrial infrastructure.


The manufacturing excellence of an ERW Longitudinal Welded Pipe is defined by its precise technical parameters and rigorous quality controls. This pipe is produced to meet and exceed international standards such as API 5L, ASTM A53, ASTM A500, and EN 10219, ensuring global compatibility and reliability. The core attributes of this product are detailed in the specifications below.

Key Features & Material Specifications

  • Manufacturing Process: Cold-formed, Electric Resistance Welding (ERW).
  • Common Materials: Carbon Steel (Grades B, X42 to X70), ASTM A53 Gr. B, API 5L PSL1 & PSL2.
  • Welding Standard: The longitudinal seam is continuously welded, followed by heat treatment to normalize the weld zone and eliminate stress.
  • End Finish: Plain end, beveled end, or threaded and coupled as per requirement.
  • Surface Treatment: Bare (mill finish), black painted, varnished, galvanized (hot-dip or electroplated).
  • Testing & Inspection: Each pipe undergoes hydrostatic testing, non-destructive testing (NDT) like ultrasonic or eddy current, and visual inspection to guarantee weld integrity and dimensional conformity.

Standard Size & Dimensional Tolerances

Parameter Range / Specification Standard Tolerance
Outer Diameter (OD) 1/2" (21.3 mm) to 24" (610 mm) and larger ± 0.75% of nominal OD or ± 0.5 mm, whichever is greater.
Wall Thickness (WT) SCH 10, 20, 30, 40, STD, XS, XXS; 1.0 mm to 25.0 mm ± 10% of nominal wall thickness.
Length Single Random (5-7m), Double Random (11-13m), or Cut to Length +10 mm / -0 mm for specified fixed lengths.
Straightness Full length Maximum deviation: 0.15% of total length.
Weight per Unit Length Varies based on OD, WT, and material density Typically within ± 5% of theoretical weight.

Mechanical Properties (Typical for API 5L Gr. B / ASTM A53 Gr. B)

Property Value Test Method
Tensile Strength, min 415 MPa (60,200 psi) ASTM A370
Yield Strength, min 240 MPa (34,800 psi)
Elongation, min 28% (on 2-inch gauge length)
Hardness (Brinell) ≤ 197 HBW ASTM E10

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