TOBO Industrial (Shanghai) Co., Ltd., a leading manufacturer and exporter of precision-engineered alloy products, has announced the expansion of its high-performance piping portfolio with the introduction of Alloy CuNi 90/10 (UNS C70600) Copper-Nickel Cold Drawn Seamless Pipes. Engineered to meet the most demanding requirements of marine, energy, and industrial processing sectors, these pipes combine the exceptional corrosion resistance of 90/10 copper-nickel alloy with the superior integrity of cold-drawn seamless construction .
Material Excellence: The C70600 Advantage
The newly introduced pipes are manufactured from UNS C70600 (CuNi 90/10), a copper-nickel alloy comprising approximately 90% copper and 10% nickel with carefully controlled additions of iron and manganese . This material composition delivers a suite of performance characteristics essential for critical service environments:
Superior Corrosion Resistance: C70600 exhibits outstanding resistance to seawater, brackish water, and various industrial chemicals, with documented corrosion rates below 0.003 mm per year in marine environments—significantly outperforming standard stainless steels and copper alloys in chloride-rich conditions . The alloy's resistance to seawater corrosion is typically below 0.025 mm per year, ensuring decades of reliable service .
Natural Biofouling Resistance: The alloy's surface chemistry inherently inhibits the attachment and growth of marine organisms such as barnacles and mussels, reducing maintenance requirements by up to 60% and preserving hydraulic efficiency in seawater systems .
Excellent Mechanical Properties: Available in various tempers, C70600 offers tensile strength from 275-370 MPa in annealed condition to 480-800 MPa in hard-drawn condition, with elongation ranging from 20-40% depending on processing . This versatility allows engineers to select optimal properties for specific applications.
Thermal and Mechanical Stability: The alloy maintains reliable performance across a wide temperature range from -100°C to 371°C with no low-temperature embrittlement, making it suitable for both cryogenic and elevated-temperature services . Thermal conductivity is approximately 40 W/m·K, ideal for heat exchanger and condenser applications .
Superior Weldability and Formability: C70600 supports TIG/MIG welding, cold/hot working, and stamping operations, with achievable surface finishes down to Ra 0.1μm for critical applications .
The Cold-Drawn Seamless Advantage
TOBO's new piping employs cold-drawn seamless manufacturing technology, a precision process that delivers significant performance benefits over welded or hot-finished alternatives .
Manufacturing Process: The production begins with hot extrusion of cast billets followed by cold working (cold drawing) and annealing operations . Cold drawing involves pulling the tube through a die to reduce diameter and wall thickness while improving dimensional accuracy and surface finish. Intermediate annealing at 650-750°C relieves internal stresses and restores ductility for subsequent processing .
This multi-stage cold-working process results in :
Homogeneous microstructure with refined grain size
Superior dimensional precision with tolerances as tight as ±0.05mm on wall thickness
Enhanced mechanical properties through work hardening
Improved surface finish ideal for critical flow applications
Quality Assurance and Compliance
TOBO's CuNi 90/10 seamless pipes are manufactured and tested to meet rigorous international standards :
Applicable Specifications:
ASTM B111 / ASME SB111: Standard specification for copper and copper-alloy seamless condenser tubes and ferrule stock
ASTM B466 / ASME SB466: Standard specification for seamless copper-nickel pipe and tube
EEMUA 144 / 234: Recommended practice for copper-nickel fabrication
Comprehensive Testing: Each production batch undergoes rigorous quality verification including chemical composition analysis ensuring precise alloy ratios (Ni 9.0-11.0%, Fe 1.0-1.5%, Mn ≤1.0%), mechanical testing for tensile strength, yield strength, and elongation, non-destructive examination including eddy current testing per ASTM E243, hydrostatic pressure testing to verify pressure integrity, and flattening and expansion tests per ASTM B153 to verify ductility .
Certification Options: TOBO provides comprehensive documentation including Mill Test Certificates (MTCs) and can arrange EN 10204 Type 3.2 certification through independent third-party inspection by recognized agencies such as SGS, BV, or TUV upon request .
Product Specifications and Availability
TOBO's CuNi 90/10 cold-drawn seamless pipes are available in a comprehensive range of dimensions to suit diverse application requirements :
Standard Specifications:
Outer Diameter Range: 2 mm to 150 mm (custom sizes available up to 24" upon request)
Wall Thickness: 0.3 mm to 15 mm
Lengths: Standard 6 meters, with custom lengths available as required
Temper Options: Annealed (O61), light-drawn (H55), or hard-drawn (H80) per ASTM B111 requirements
End Finish: Plain end, beveled end, or threaded as specified
Surface Finish Options: Cleaned and varnished for corrosion protection during transit; electropolished available for critical applications requiring enhanced surface purity.
Industry Applications
TOBO's CuNi 90/10 cold-drawn seamless pipes serve essential functions across multiple critical sectors :
Marine and Offshore Engineering:
Seawater cooling systems for ships and offshore platforms
Firefighting and ballast water pipelines
Hydraulic and pneumatic control lines
Subsea equipment and riser systems
Desalination and Water Treatment:
Multi-stage flash (MSF) evaporator tubes
Reverse osmosis (RO) plant high-pressure piping
Brine heater and heat recovery sections
Power Generation:
Steam condenser tubing in coastal and nuclear power plants
Feedwater heaters and heat exchangers
Cooling water systems for thermal power stations
Chemical and Petrochemical Processing:
Heat exchanger and condenser tubes
Process piping for corrosive media
Reactor cooling coils and jacketing
Oil and Gas Industry:
Offshore topside and subsea piping
Seawater injection lines
Process cooling systems
Total Cost of Ownership Advantages
While CuNi 90/10 alloys command a higher initial material cost compared to carbon steel or standard stainless steels, the Total Cost of Ownership (TCO) presents compelling economic justification :
Extended Service Life: 25-40+ years of reliable operation in corrosive environments, eliminating frequent replacement cycles
Reduced Maintenance: Natural corrosion and biofouling resistance minimize cleaning requirements, chemical treatments, and inspection frequency
Minimized Downtime: Prevention of corrosion-related failures avoids costly unplanned outages, particularly critical in remote offshore and marine installations
Lower Lifecycle Costs: Despite premium initial investment, the combination of longevity and reduced maintenance delivers superior long-term value
Conclusion
The introduction of Alloy CuNi 90/10 C70600 Cold-Drawn Seamless Pipes represents a significant advancement in materials technology for demanding industrial applications. By combining the proven corrosion resistance of copper-nickel alloy with cold-drawn seamless construction and rigorous quality assurance, TOBO provides engineers and procurement specialists with reliable solutions for critical fluid transport systems. Whether specified for seawater cooling systems, desalination plants, or power generation facilities, these pipes deliver the durability, reliability, and performance that modern industry demands.
About TOBO Industrial (Shanghai) Co., Ltd.
TOBO is a professional manufacturer and exporter of precision-engineered alloy products based in Shanghai, China. The company specializes in copper-nickel alloys, nickel alloys, stainless steels, and associated products for demanding industrial, marine, energy, and infrastructure applications worldwide. With robust production capacity and commitment to quality, TOBO serves as a trusted partner for critical projects across the globe .