ERW (Electric Resistance Welding) is a pipe manufacturing process where high-frequency current heats and fuses the edges of a steel strip under pressure. The method offers high efficiency and low cost, making ERW pipes widely used in medium- and low-pressure steam transport systems.
Key Advantages of ERW Steam Pipes
High Efficiency & Cost-Effectiveness
Continuous forming and welding enable faster production than seamless (SMLS) and submerged arc welded (SAW) pipes, resulting in lower costs while meeting performance requirements.
Dimensional Accuracy & Smooth Surfaces
Manufactured from cold-rolled strip or coil, ERW pipes achieve precise control of diameter and wall thickness, with clean inner and outer surfaces superior to hot-rolled seamless pipes.
Strong Weld Quality
High-frequency welding produces narrow weld seams and minimal heat-affected zones. With in-line heat treatment, weld strength can match that of the base metal. NDT ensures weld integrity.
Long Pipe Lengths
Continuous production allows lengths over 12 m, reducing the number of joints and improving system reliability.
Critical Requirements for Steam Applications
Material Selection
Common Standards: ASTM A106 Gr. B, ASTM A53 Gr. B, GB/T 3087.
High-Temperature/Pressure: Alloy steels (ASTM A335 P11/P22).
Steel Type: Fully killed fine-grain steel is required; rimmed steel is prohibited.
Manufacturing & Process Controls
Weld Treatment: In-line heat treatment to restore toughness and eliminate welding stresses.
NDT: 100% weld inspection via ultrasonic and eddy current testing; high-pressure steam service may require RT.
Hydrostatic Testing: Each pipe is tested at 1.5× design pressure for leak-proof strength.
Dimensional Accuracy
Pipes must comply with standards such as ASTM A53 and ASME B36.10M for OD, wall thickness, ovality, and straightness.
Inspection & Certification
Third-Party Inspection (BV, SGS, etc.) is often required for critical projects.
Material Test Certificates (MTCs) must include chemical composition, mechanical properties, heat treatment records, hydrostatic results, and NDT reports.
Usage & Installation Notes
Pressure/Temperature Rating: Select pipe grade and schedule per design codes (e.g., ASME B31.1).
Application Limits: Seamless pipes are still preferred for ultra-high temperature/pressure service, but ERW pipes are widely used in medium- and low-pressure steam systems.
Installation: Follow approved welding procedure specifications. Welders must be certified, and secondary welding or drilling over the seam is prohibited.
Conclusion
ERW steam pipes combine precision, cost efficiency, and reliable weld performance. With strict adherence to material standards, welding quality, and inspection requirements, they serve as a dependable choice for most industrial steam distribution and power plant applications, especially in medium- and low-pressure systems.
United Steel Industry As the most important steel pipe manufacturer and exporter in China, in the past 20 years, we have completed more than 100 projects, with partners in more than 100 countries, and established relationships with oil and gas and EPC companies in many countries business relationship.
For more information about the product price, catalog and rolling mill inspection certificate,
please consult:Email:Sales@usisteels.com
