description
ERW (Electric Resistance Welded) steel pipe is manufactured by cold-forming a ribbon of steel into a cylindrical shape. Utilizing high-frequency induction (HFI) current, the edges are heated and fused together without the addition of filler metal. This process ensures a clean, high-strength weld seam that is virtually invisible after heat treatment.
Our ERW pipes are known for their high dimensional accuracy and uniform wall thickness. They are the preferred choice for cost-effective solutions in oil and gas gathering lines, water transportation, and structural applications where reliable performance and tight tolerances are required.
Product Name: ERW Steel Pipe, HFW Steel Pipe, High Frequency Welded Pipe
Specification
- Outer Diameter: 21.3mm to 660.4mm
- Wall Thickness: 1.0mm to 22.2mm
- Length: 5.8m / 6m / 11.8m / 12m or Custom
- Ends: Square cut (Plain ends) / Bevelled ends / Threaded and Coupled (T&C)
- Surface Treatment: Bare, Black Painting, Varnished, Hot-dipped Galvanized, Anti-corrosion coating (3LPE, FBE).
Standard and Steel Grade
| Standard | Available Steel Grades |
| API SPEC 5L | Gr.B, X42, X46, X52, X56, X60, X70 (PSL1 & PSL2) |
| ASTM A53 | Grade A, Grade B |
| ASTM A500 | Grade A, B, C, D |
| EN 10219 / 10217 | S235JR, S275JR, S355JR, S355J0, S355J2 |
| AS/NZS 1163 | C250, C350, C350L0 |
| ASTM A252 | Grade 1, Grade 2, Grade 3 |
ERW Steel Pipe Manufacturing
Detailed ERW Steel Pipe Manufacturing Process
1.Uncoiling & Levelling: Steel coils are unrolled and passed through leveling machines to ensure a flat, stress-free strip before forming.
2.Shearing & End Welding: The head and tail of steel coils are sheared precisely and butt-welded together to maintain a continuous production line.
3.Roll Forming: The flat steel strip is incrementally bent by a series of high-precision rollers until it is formed into a open cylindrical shape.
4.High-Frequency Welding (HFW/HFI): Utilizing the skin effect and proximity effect of high-frequency electric current (HFI/HFW), the strip edges are heated to a molten state and squeezed together without filler metal.
5.Weld Flash Removal (Scarfing): Special carbide tools immediately trim the external and internal weld beads (weld flash/burrs) to create a smooth, flush surface.
6.Weld Seam Heat Treatment (Annealing): The welded seam undergoes online induction heat treatment (normalizing) to refine grain structure and eliminate residual stresses in the heat-affected zone (HAZ).
7.Sizing & Straightening: After air and water cooling, the pipe passes through sizing mills to achieve exact outer diameter tolerances and roundness.
8.Flying Rotary Cutting: The continuous ERW steel pipe is cut into specified target lengths (e.g., 5.8m, 6m, 11.8m, 12m) using flying cut-off saws.
9.Hydrostatic & NDT Inspection: Every pipe undergoes 100% full-length hydrostatic pressure testing and online Eddy Current/Ultrasonic Flaw Detection to ensure zero leakage.
10.End Beveling & Inspection: Pipe ends are machined to standard bevel angles (30°–35°) for field welding, followed by final dimensional checks and marking.
Main application
ERW steel pipes are widely used across multiple sectors due to their versatility and efficiency:
- Oil & Gas Transport:Low and medium-pressure gathering lines for crude oil and natural gas, as well as refined product pipelines.
- Water & Fluid Supply:Urban water supply systems, industrial fire protection systems, and agricultural irrigation networks.
- Structural Engineering:Scaffolding, building framework, fencing, and greenhouse structures where high strength-to-weight ratios are needed.
- Machinery & Infrastructure:Piling for light foundations, rollers for conveyor systems, and automotive structural components.
- Heating & Cooling:Distribution pipes for HVAC systems and low-pressure steam transportation.
Real-world projects involving ERW STEEL PIPE
advantages
- High Dimensional Accuracy:The cold-forming process ensures excellent roundness, straightness, and highly uniform wall thickness.
- Cost-Efficiency:Faster production speeds and lower manufacturing costs compared to seamless and LSAW pipes, providing an economical choice for bulk projects.
- Superior Surface Quality:Smooth internal and external surfaces facilitate easier coating application and better flow characteristics.
- Consistent Weld Integrity:High-frequency welding creates a reliable bond that is as strong as the parent material, verified by 100% NDT (Non-Destructive Testing).
- Versatility in Sizes:Available in a vast range of diameters and wall thicknesses to meet specific project engineering requirements.
- Easy Processing:Ideal for secondary operations such as bending, threading, and welding on-site.
packing
To ensure our ERW pipes reach the site in perfect condition, we follow international shipping standards:
- Bundling:Small to medium diameter pipes are securely bundled with steel strips in hexagonal shapes for easy handling.
- Surface Protection:Black painting or oil coating is applied to prevent atmospheric corrosion during sea transit.
- End Protection:Plastic pipe caps are fitted to both ends to protect the bevels and keep the interior free from debris.
- Logistics:
- Container Loading:Maximized efficiency for 20GP/40HC containers, typically for lengths up to 11.8m.
- Bulk Shipment:Suitable for large-scale orders where pipes are stowed in the ship’s hold with proper dunnage to prevent shifting.
- Identification:Each bundle/pipe is clearly marked with heat numbers, size, grade, and the Allland Pipes logo for full traceability.
FAQ
Q1: What is the difference between ERW and LSAW steel pipes?
ERW (Electric Resistance Welded) is made by cold-forming steel coils and welding via high-frequency induction without filler metal, ideal for diameters up to 26″. LSAW (Longitudinal Submerged Arc Welded) uses filler metal and is designed for larger diameters (up to 60″) and much thicker walls.
Q2: ERW vs. Seamless Steel Pipe: Which is more suitable for my project?
ERW pipes offer high dimensional accuracy and are significantly more cost-effective for medium-pressure fluid transport and structural use. Seamless pipes are preferred for ultra-high-pressure or critical thermal applications where a weld seam is not permitted.
Q3: What is the maximum wall thickness you can produce for ERW pipe?
For our ERW production lines, the maximum wall thickness is 22.2mm (Sch 80) for larger diameters. If your project requires thicknesses up to 60mm, we recommend our LSAW steel pipe process.
Q4: Do you provide internal weld bead (flash) removal for your ERW pipes?
Yes, we offer internal bead removal (scarfed) as a standard service for fluid transportation. This ensures a smooth internal surface, reducing friction and preventing any material buildup, which is essential for water and gas pipelines.
Q5: What types of anti-corrosion coatings do you offer for ERW pipe?
We provide a full range of coatings, including Hot-Dipped Galvanized, Black Painting, FBE (Fusion Bonded Epoxy), and 3LPE (3-Layer Polyethylene) to ensure long-term service life in buried or marine environments.
