Stainless steel ERW (Electric Resistance Welded) pipe is a type of welded steel pipe produced using hot-rolled coils as raw material. Through a sequence of processes—including uncoiling, leveling, and forming—the edges of the steel strip are brought together and fused using electric resistance welding, resulting in a straight seam pipe with reliable weld quality and precise dimensions.
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What is Electric Resistance Welding (ERW)?
Electric resistance welding utilizes the heat generated by electrical resistance at the contact point between two metal surfaces. The localized heat brings the steel to a plastic or molten state, and pressure is applied to forge the weld. This method is highly efficient, cost-effective, conserves material, and is easily automated—making it widely adopted in various industrial sectors. In pipeline transportation, stainless steel ERW pipes play a vital role in conveying fluids and gases such as oil and natural gas under a range of pressure conditions.
Key Specifications of Stainless Steel ERW Pipes
Outer Diameter Range: Typically 21.3 mm to 711.2 mm
For architectural applications: 25–50 mm is common
For industrial fluid transport: 100–300 mm is typical
Wall Thickness: Usually ranges from 0.5 mm to 20 mm
Thin-walled (0.5–2 mm): Used in decorative applications or low-pressure systems
Thick-walled (5–20 mm): Suitable for high-pressure applications like gas and oil pipelines
Standard Lengths: 5.8 m, 6 m, and 12 m are common; custom lengths are available upon request
Applicable Standards:
ASTM A53, ASTM A106 (American)
ISO 3183 (International)
GB/T 9711 (Chinese national standard)
These standards govern dimensional tolerances, mechanical properties, chemical composition, and process quality.
Advantages of Stainless Steel ERW Pipe
1. Cost-Efficient Production
The ERW process is simpler and faster than other methods like seamless pipe production. It minimizes material waste and allows high-speed forming, leading to lower manufacturing costs. As a result, ERW pipes are significantly more affordable—especially when used at scale—without compromising on basic performance.
2. Excellent Processability
Thanks to a uniform microstructure and stable mechanical properties, stainless steel ERW pipes cut cleanly with minimal edge deformation or burrs. They can be bent into complex shapes without cracking or wrinkling and are compatible with a wide range of welding methods. This makes them ideal for precise cutting, bending, and welding during installation.
3. High Dimensional Precision
Advanced forming and welding equipment ensures tight tolerances:
Outer diameter tolerance: ±0.5 mm
Wall thickness tolerance: ±0.2 mm
This level of precision improves fit-up during installation, reduces sealing difficulties, and enhances the safety and stability of complex systems such as those in petrochemical pipelines.
Limitations of Stainless Steel ERW Pipe
1. Moderate Corrosion Resistance
Although stainless steel inherently resists corrosion, ERW pipes generally undergo only basic surface passivation. In aggressive environments—such as those with high concentrations of acids, alkalis, or marine salt spray—the protective film may degrade over time. Compared to specially treated pipes (e.g., hot-dip galvanized or nickel-plated), standard ERW pipes may corrode more quickly, risking leaks or failures.
2. Limited Pressure Resistance
The welded seam may not fully match the base metal in strength. This can restrict ERW pipes in ultra-high pressure applications. At pressures exceeding 10 MPa, weld areas may become weak points prone to cracking or rupture, especially under mechanical or thermal stress.
3. Potential Weld Defects
The welding zone experiences different metallurgical transformations compared to the parent material. If welding parameters—such as current, speed, or pressure—are not properly controlled, defects like porosity, slag inclusion, or incomplete fusion may occur. These defects act as stress concentrators, reducing long-term reliability under pressure, vibration, or thermal cycling.
Applications of Stainless Steel ERW Pipes
1. Oil and Gas Industry
Used in fluid transport systems, including portions of major pipeline projects (e.g., West-East Gas Pipeline in China). Their smooth interior surfaces and strong joints ensure efficient flow and safety.
2. Construction and Infrastructure
Applied in structural support for buildings and bridges. Their strength and formability make them ideal for load-bearing applications and architectural elements.
3. Machinery and Equipment Manufacturing
Utilized in the production of mechanical components, such as exhaust pipes in automobiles, sleeves in industrial equipment, and various framework elements.
How to Choose the Right Stainless Steel ERW Pipe
Consider the Operating Environment
For dry, indoor environments with low corrosion risk, 304 stainless steel ERW pipe is usually sufficient.
For harsh environments (e.g., chemical plants or coastal areas), consider using higher-grade stainless steel (e.g., 316L) or pipes with enhanced surface treatments.
Determine Pressure and Flow Requirements
For low-pressure applications (e.g., water or air), opt for thin-walled, small-diameter pipes
For high-pressure transport of oil or gas, choose thicker-walled pipes with appropriate diameter and welding strength
Balance Performance and Cost
Stainless steel ERW pipe prices vary depending on material grade, size, and wall thickness. Compare options across reputable manufacturers and avoid compromising on quality for the sake of cost. Prioritize certified standards compliance, consistent weld quality, and surface finish.