English
ERW steel pipe is short for Electric Resistance Welded steel pipe. It is a type of steel pipe manufactured using the electric resistance welding process. The production process involves rolling a steel strip into a cylindrical shape and then welding the seam longitudinally using electric resistance welding technology. This method uses high-frequency electric current to generate heat, melting the edges of the steel strip to form a strong weld. ERW steel pipes are known for their high strength, durability, and cost-effectiveness. They are widely used in various industries for transporting fluids and gases such as oil and natural gas, as well as for structural applications.
| Standard | Grades | Key Features | Applications |
| API 5L | A25, A, B, X42, X46, X52, X60, X70, X80 | High-strength grades for oil and gas pipelines. | Oil, gas, and water transportation pipelines. |
| ASTM A53 | Grade A, Grade B | grades for low to medium pressure. Yield strength: 205-240 MPa. | Plumbing, structural, and low-pressure systems. |
| ASTM A135 | Grade A, Grade B | Similar to A53 but specifically for ERW pipes. | Steam, water, and air systems. |
| ASTM A252 | Grade 1, Grade 2, Grade 3 | Structural grades for piling. Varying strength levels. | Structural piling and foundations. |
| EN 10219 | S235, S275, S355 | Cold-formed welded structural pipes. Yield strength: 235-355 MPa. | Structural and mechanical applications. |
| EN 10255 | Non-alloy steel grades | Tubes for welding and threading. | Water and gas systems. |
| JIS G3444 | STK 400, STK 500, STK 490 | Structural grades. Yield strength: 235-355 MPa. | Structural applications. |
| JIS G3454 | STPG 370, STPG 410 | Pressure service grades. | High-pressure systems. |
| GB/T 3091 | Q195, Q215, Q235, Q295, Q345 | Low-pressure fluid conveyance grades. | General-purpose and structural applications. |
| GB/T 13793 | Structural grades | Structural hollow sections. | Structural and mechanical applications. |
| Standard | Class | Grade | Chemical Analysis(%) | Mechanical Properties(min)(Mpa) | ||||
| C | Mn | P | S | Tensile Strength | Yield Strength | |||
| API 5L | PSL1 | B | 0.26 | 1.2 | 0.03 | 0.03 | 414 | 241 |
| X42 | 0.26 | 1.3 | 0.03 | 0.03 | 414 | 290 | ||
| X46 | 0.26 | 1.4 | 0.03 | 0.03 | 434 | 317 | ||
| X52 | 0.26 | 1.4 | 0.03 | 0.03 | 455 | 359 | ||
| X56 | 0.26 | 1.4 | 0.03 | 0.03 | 490 | 386 | ||
| X60 | 0.26 | 1.4 | 0.03 | 0.03 | 517 | 414 | ||
| X65 | 0.26 | 1.45 | 0.03 | 0.03 | 531 | 448 | ||
| X70 | 0.26 | 1.65 | 0.03 | 0.03 | 565 | 483 | ||
| PSL2 | B | 0.22 | 1.2 | 0.025 | 0.015 | 414 | 241 | |
| X42 | 0.22 | 1.3 | 0.025 | 0.015 | 414 | 290 | ||
| X46 | 0.22 | 1.4 | 0.025 | 0.015 | 434 | 317 | ||
| X52 | 0.22 | 1.4 | 0.025 | 0.015 | 455 | 359 | ||
| X56 | 0.22 | 1.4 | 0.025 | 0.015 | 490 | 386 | ||
| X60 | 0.22 | 1.4 | 0.025 | 0.015 | 517 | 414 | ||
| X65 | 0.22 | 1.45 | 0.025 | 0.015 | 531 | 448 | ||
| X70 | 0.22 | 1.65 | 0.025 | 0.015 | 565 | 483 | ||
| X80 | 0.22 | 1.85 | 0.025 | 0.015 | 621 | 552 | ||
1. Size:
ERW pipes come in diameters from 1/2 inch (15 mm) to 24 inches (600 mm) or more. Wall thickness ranges from 1.24 mm to 25.4 mm or more. Standard lengths are 6 meters (20 feet), with custom lengths available. Dimensional tolerances are specified by standards like API 5L, ASTM, and EN.
2. Material and Grade:
ERW pipes are typically made from low-carbon steel or high-strength low-alloy steel.
Common materials include API 5L: PSL1/PSL2 Gr.A, Gr.B, X42, X46, X52, X56, X60, X65, X70
ASTM A53: GR.A, GR.B,ASTM A500 JIS G3466
EN: S275, S275JR, S355JRH, S355J2H,EN10219-1 ,EN10217-1
3. Surface Treatment:
Surface treatments include black (bare) surface for non-corrosive environments, galvanized (zinc-coated) for water and gas pipelines, hot-dip galvanizing for harsh environments, electro-galvanizing for mild environments, painted or coated with epoxy or polyethylene for additional corrosion resistance, and varnished for temporary anti-rust protection during storage and transportation.
4. End Type:
End types include plain end (PE) for welding or threading, beveled end (BE) for pipeline welding, threaded end (TE) for easy connection without welding, grooved end for mechanical couplings, and capped or protected ends to prevent damage during transportation.
5. Manufacturing Process:
ERW pipes are made by cold-forming steel coils into a cylindrical shape and welding the seam using electric resistance welding.
6. Seam Integrity:
Modern ERW pipes have high-quality seams, often tested using non-destructive testing (NDT) methods like ultrasonic testing (UT).
1. Raw Material Preparation: Steel coils are unrolled, trimmed, and leveled to ensure smooth edges for welding.
2. Forming: The flat steel strip is bent into a cylindrical shape using a series of forming rolls.
3. Welding: The edges are fused using electric resistance welding (ERW) or high-frequency induction welding (HFI) without filler material.
4. Sizing and Shaping: The pipe passes through sizing rolls to achieve the desired diameter and roundness, followed by straightening.
5. Heat Treatment: Optional normalizing or annealing improves mechanical properties and relieves welding stresses.
6. Cutting: The continuous pipe is cut into specific lengths using a flying cut-off saw.
7. Surface Treatment: Ends are deburred, and the pipe is cleaned. Optional galvanizing or coating enhances corrosion resistance.
8. Inspection and Testing: Pipes undergo visual inspection, non-destructive testing (UT, hydrostatic), and dimensional checks to ensure quality.
ERW pipes are widely used in pipelines for transporting oil, natural gas, and petroleum products. They are also used for casing and tubing in oil wells and in refineries for fluid transport.
ERW pipes are essential in municipal water supply systems, sewage and drainage networks, and agricultural irrigation due to their durability and corrosion resistance (especially when galvanized).
These pipes are used in construction for building frameworks, scaffolding, and bridges. They are also employed as foundation piles to support heavy structures.
ERW pipes are used to manufacture mechanical components like rollers, conveyors, and machinery frames, as well as automotive parts such as vehicle frames and exhaust systems.
ERW pipes are popular for fencing in residential, commercial, and industrial properties. They are also used as guardrails on highways and roads for safety.
ERW pipes serve as protective conduits for electrical wiring and telecommunication cables. They are also used in the construction of poles for power transmission and telecom lines.
These pipes are used in HVAC systems for ducting and heat exchange, as well as in residential and commercial plumbing systems for water and gas distribution.
ERW pipes are used in chemical plants for transporting chemicals, in the food and beverage industry for fluid transport, and in pharmaceutical manufacturing for sanitary fluid systems.
