Electric Resistance Welded (ERW) Boiler Tubes are steel tubes manufactured using resistance welding technology. These tubes are primarily used for transporting water, steam, and other media in high-temperature and high-pressure environments. Their key advantage lies in the efficient welding process, where electric current generates heat to fuse the steel strip edges, resulting in a cost-effective and high-output production method.
Manufacturing Process of ERW Boiler Tubes
Steel Strip Preparation
Cold-rolled or hot-rolled steel strips are flattened and trimmed to ensure uniformity.
Forming and Welding
The steel strip is shaped into a tube, and high-frequency (HFW) or low-frequency current melts the joint edges.
Pressure is applied to complete the welding process.
Post-Processing
Heat treatment (e.g., normalizing) is applied to the weld to relieve stress.
The tubes undergo sizing, straightening, cutting, and non-destructive testing (such as ultrasonic or eddy current inspection) along with pressure testing.
Material Selection of ERW Boiler Tubes
Common Materials
Carbon Steel: 20G, SA-178C
Low Alloy Steel: Q345, 15CrMoG
Standard Compliance
ASME Standards: SA-178 (carbon steel pipes), SA-192 (high-pressure boiler tubes)
Chinese National Standards: GB 3087
Performance Characteristics of ERW Boiler Tubes
High Strength
Designed for high-pressure environments with excellent load-bearing capacity.
Uniform Weld Quality
High-frequency welding produces narrow, flat welds, minimizing defects.
Dimensional Precision
Cold rolling ensures minimal tolerance deviations (e.g., ±0.10mm for outer diameter and wall thickness).
Temperature Resistance
Heat-treated for improved creep resistance in high-temperature applications.
Cost-Effective
More affordable than seamless pipes, with production cost savings of 20%-30%.
Application Areas of ERW Boiler Tubes
1. Power Plant Boilers (Thermal & Nuclear Power Generation)
Water Walls: Thin-walled (3-8mm), high-precision pipes (outer diameter tolerance ±0.1mm) for dense arrangements.
Materials: SA-210C (medium carbon steel), 15CrMoG (low alloy steel)
Temperature Resistance: 450-600℃
Superheater & Reheater: Requires resistance to oxidation and creep at high temperatures
Materials: SA-213T11 (1.25Cr-0.5Mo), T91 (9Cr-1Mo)
Pipe Size: φ25-50mm, wall thickness 4-8mm
Feature: High-frequency welding ensures uniform welds.
Economizer: Used in medium to low temperatures (200-400℃).
Materials: SA-178C (carbon steel)
Design: Serpentine pipe structure, requiring high bending accuracy.
2. Industrial Boilers (Chemical, Textile, and Food Processing)
Steam Boilers:
Materials: 20G (GB 3087), SA-192 (ASME)
Hot Water Boilers:
Materials: ERW carbon steel pipes (Q235B), often galvanized or coated for corrosion protection.
Waste Heat Recovery Systems:
Materials: 09CrCuSb (resistant to sulfuric acid dew-point corrosion)
Feature: Modular design enables rapid installation.
3. Petrochemical & Energy Equipment
Refining Unit Heat Exchangers:
Materials: 15CrMoG (H₂S corrosion-resistant steel)
Operating Conditions: 300-450℃, 4-10MPa
Feature: Weld normalizing enhances resistance to stress cracking.
Coal Chemical Gasifiers:
Materials: 12Cr1MoVG (high-temperature creep resistant)
Operating Conditions: 500-800℃
Feature: Outer wall sprayed with silicon carbide wear-resistant coating.
LNG Liquefaction Equipment:
Materials: 09MnNiDR (low-temperature impact-resistant)
Operating Conditions: -162℃
Feature: Charpy impact test (-40℃) meets industry standards.
4. Environmental & New Energy Applications
Waste Incineration Boilers:
Materials: 2205 duplex stainless steel (resistant to chloride corrosion)
Feature: Inconel 625 inner wall cladding for enhanced durability.
Biomass Boilers:
Materials: TP347H (resistant to alkali metal vapor corrosion)
Wall Thickness: 8-12mm
Feature: Extended lifespan in alkaline environments.
Solar Thermal Power Generation:
Materials: 316H stainless steel (resistant to 565℃ molten salt oxidation)
Feature: 100% radiographic weld inspection ensures zero leakage.
5. Specialized Industrial Applications
Marine Boilers:
Materials: EH36 marine steel (resistant to salt spray corrosion)
Feature: Epoxy resin coating for high-humidity environments.
Geothermal Development:
Applications: Geothermal well casing and heat exchanger tubes
Materials: Gr.2 titanium alloy (resistant to Cl⁻ corrosion in geothermal fluids)
Conclusion
ERW boiler tubes are essential in various industries due to their efficient manufacturing, superior strength, and high-temperature resistance. Their precise dimensional control and cost-effectiveness make them a preferred choice for power plants, petrochemical industries, environmental projects, and specialized applications. With continued advancements in materials and processing technologies, ERW boiler tubes will remain a critical component in high-performance boiler 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
