TOBO Industrial (Shanghai) Co., Ltd., a premier manufacturer and global supplier of precision-engineered metal products, has announced the expansion of its advanced piping portfolio with the introduction of ASME B151-compliant 70/30 and 90/10 Copper-Nickel (CuNi) tubes alongside high-quality stainless steel welded pipes. This comprehensive dual-material offering provides engineers and project managers with optimized solutions for the most demanding marine, offshore, chemical processing, and industrial applications where corrosion resistance and long-term reliability are paramount .
The ASME B151 Standard: The Quality Benchmark for CuNi Products
The ASME SB151 / ASTM B151 standard is the globally recognized specification for copper-nickel alloy plate, sheet, and strip, which serves as the foundation for high-quality tube and pipe manufacturing . This standard ensures:
Chemical Composition Verification: Strict control of alloy ratios—for C70600 (90/10), Ni 9.0-11.0%, Fe 1.0-1.8%; for C71500 (70/30), Ni 29.0-33.0%, Fe 0.4-1.0%—essential for optimal corrosion resistance
Mechanical Property Validation: Confirmation of minimum tensile strength (C70600: 275 MPa, C71500: 400 MPa), yield strength, and elongation requirements
Dimensional Accuracy: Tight tolerances ensuring consistent fit and performance in system assemblies
Pressure Integrity: Compliance with rigorous testing requirements to verify product soundness
Material Excellence: C70600 and C71500 Copper-Nickel Alloys
C70600 (90/10 Copper-Nickel) – The Versatile Workhorse:
Composition: Approximately 90% copper, 10% nickel with 1.0-1.8% iron
Corrosion Resistance: Outstanding resistance to seawater corrosion, with rates typically below 0.025 mm per year, significantly outperforming standard stainless steels in chloride-rich environments
Natural Biofouling Resistance: The alloy’s surface chemistry inherently inhibits marine growth, reducing maintenance requirements by up to 60%
Mechanical Properties: Minimum tensile strength of 275 MPa, elongation of 30%, with excellent formability and weldability
Thermal Conductivity: Approximately 40 W/m·K, ideal for heat exchanger and condenser applications
Applications: Seawater cooling systems, desalination plants, marine piping, and power plant condensers
C71500 (70/30 Copper-Nickel) – The Premium Grade:
Composition: 29-33% nickel content with 0.4-1.0% iron for enhanced performance
Superior Corrosion Resistance: Exceptional performance in high-velocity seawater, acidic environments, and sulfide-bearing conditions. Of all commercial copper alloys, C71500 offers the best resistance to aqueous corrosion, with high resistance to stress corrosion cracking and impingement corrosion
Enhanced Strength: Minimum tensile strength of 400 MPa, significantly higher than 90/10 alloy, enabling thinner walls and reduced weight while maintaining pressure integrity
High-Temperature Stability: Maintains mechanical properties in continuous service up to 400°C
Applications: Offshore oil and gas platforms, naval vessels, chemical processing equipment, and critical heat exchangers
Stainless Steel Welded Pipes: Durability and Versatility
Complementing the copper-nickel tubes, TOBO’s stainless steel welded pipes provide essential solutions for a wide range of industrial applications :
Material Grades: Available in 304/304L and 316/316L stainless steel, with duplex and super austenitic grades available for specialized requirements
Corrosion Resistance: 316L grade offers molybdenum enhancement for improved chloride resistance, ideal for marine and chemical environments
Mechanical Strength: High tensile strength and excellent fatigue resistance for demanding pressure applications
Weld Quality: Automated TIG, plasma, and laser welding systems ensure precise, repeatable joints with controlled heat input
Surface Finish: Smooth internal and external surfaces for optimal fluid flow and corrosion resistance
Welded Pipe Manufacturing Excellence:
TOBO’s stainless steel welded pipes are produced using state-of-the-art manufacturing processes:
Precision Forming: Continuous roll forming of stainless steel strip into tubular shape
Automated Welding: High-frequency induction welding or TIG welding with inert gas shielding
Heat Treatment: Controlled atmosphere annealing to optimize microstructure and restore corrosion resistance
NDT Inspection: 100% eddy current or ultrasonic testing to verify weld integrity
Sizing and Finishing: Precision sizing and surface finishing to meet dimensional specifications
Comprehensive Size Range and Technical Specifications
TOBO’s ASME B151 copper-nickel tubes and stainless steel welded pipes are available in a complete range of dimensions:
Copper-Nickel Tubes:
Diameter Range: 1/4 inch to 24 inches (DN6 to DN600)
Wall Thickness: Schedule 5S through XXS
Lengths: Standard random lengths of 18-24 feet, with cut-to-size options
Temper Options: Annealed (soft) for maximum formability, or light-drawn for enhanced strength
Stainless Steel Welded Pipes:
Diameter Range: 1/2 inch to 48 inches
Wall Thickness: Schedule 5S to XXS
Lengths: Standard 20-foot lengths, with custom lengths available
Surface Finish: Mill finish, pickled, or polished as specified
Industry Applications Across Critical Sectors
The combination of ASME B151 copper-nickel tubes and stainless steel welded pipes serves essential functions across diverse industries:
Marine and Offshore Engineering:
Seawater cooling systems for main engines and auxiliary equipment
Ballast water management and fire-fighting pipelines
Offshore platform piping and subsea equipment
Naval vessel systems requiring maximum reliability
Power Generation:
Steam condenser tubing in coastal and nuclear power plants
Feedwater heaters and heat exchangers
Cooling water systems for thermal power stations
Auxiliary cooling circuits
Desalination and Water Treatment:
Multi-stage flash (MSF) evaporator tube bundles
Reverse osmosis (RO) plant high-pressure piping
Brine heater and heat recovery sections
Intake and discharge lines handling high-salinity seawater
Chemical and Process Industries:
Heat exchanger and condenser tubes for corrosive media
Process piping in chemical plants handling aggressive fluids
Pollution control systems and industrial water treatment
Oil and Gas Industry:
Seawater injection lines for reservoir pressure maintenance
Topside and subsea cooling water systems
Firewater systems on platforms and FPSO vessels
Manufacturing Excellence and Quality Assurance
TOBO’s production facilities employ state-of-the-art manufacturing processes to ensure consistent quality across all product lines:
Copper-Nickel Tube Production:
Seamless extrusion and cold drawing processes for optimal grain structure
Solution annealing for uniform mechanical properties
100% eddy current testing per ASTM E243
Hydrostatic pressure testing for pressure integrity verification
Stainless Steel Welded Pipe Production:
Continuous roll forming with precision dimensional control
Automated TIG or HF induction welding
Controlled atmosphere annealing
100% non-destructive examination
Quality Assurance Protocols:
Material Certification: Mill Test Reports (MTRs) verifying chemical composition and mechanical properties
Dimensional Verification: Precision measurement ensuring compliance with specifications
Mechanical Testing: Tensile, yield, and hardness verification
Corrosion Testing: ASTM G48 for pitting resistance where specified
Third-Party Inspection: DNV, ABS, LR, BV, SGS available upon request
TOBO operates in accordance with ISO 9001:2015 quality management systems, ensuring consistent product quality and complete traceability for regulated industries.
Economic Advantages and Lifecycle Value
The selection of ASME B151 copper-nickel tubes and stainless steel welded pipes delivers compelling economic benefits:
Extended Service Life: 30-50 year service life for copper-nickel alloys in seawater applications, 20-30 years for stainless steel in appropriate environments
Reduced Maintenance: Natural corrosion resistance minimizes cleaning requirements and chemical treatments
Operational Reliability: Prevention of corrosion-related failures avoids costly unplanned downtime
Lower Total Cost of Ownership: Despite premium initial investment, the combination of longevity and reduced maintenance delivers superior long-term value
Conclusion: The Global Standard for Critical Piping Systems
The introduction of ASME B151 copper-nickel tubes and stainless steel welded pipes represents TOBO’s commitment to providing comprehensive, high-performance solutions for the most demanding fluid transport applications. By offering both the proven corrosion resistance of copper-nickel alloys and the versatility of stainless steel, TOBO enables engineers and project managers to select the optimal material for their specific environmental conditions and performance requirements.
Whether specified for seawater cooling systems on offshore platforms requiring C71500 copper-nickel, desalination plants utilizing C70600 tubes, or chemical processing facilities demanding stainless steel welded pipes, these products deliver the durability, reliability, and longevity that modern industry demands.
About TOBO Industrial (Shanghai) Co., Ltd.
TOBO is a professional manufacturer and exporter of precision-engineered metal products based in Shanghai, China. With robust production capacity and a commitment to metallurgical excellence, TOBO serves customers worldwide across marine, energy, chemical, and industrial sectors. The company specializes in copper-nickel alloys, stainless steels, and associated products for demanding applications, with strict quality control and complete traceability .