TOBO Industrial (Shanghai) Co., Ltd., a premier manufacturer and global supplier of precision-engineered metal products, has announced the expansion of its HVAC/R component portfolio with the introduction of ASME B151 90/10 Copper-Nickel C70600 tubes and ASTM B111 stainless steel welded pipes. This dual-material offering provides engineers, contractors, and system designers with high-performance piping solutions specifically engineered for demanding air conditioning and refrigeration applications where corrosion resistance, thermal efficiency, and long-term reliability are essential.
The ASME B151 Standard: Quality Benchmark for Copper-Nickel Tubes
The ASME SB151 / ASTM B151 standard is the globally recognized specification for copper-nickel alloy plate, sheet, strip, and rolled bar, which serves as the foundation for high-quality tube manufacturing. Compliance with this standard ensures:
Chemical Composition Control: Strict verification of alloy ratios for C70600 (90/10 CuNi): Ni 9.0-11.0%, Fe 1.0-1.8%, essential for optimal corrosion resistance
Mechanical Property Validation: Confirmation of minimum tensile strength, yield strength, and elongation requirements
Dimensional Accuracy: Tight tolerances for perfect fit in system assemblies
Quality Assurance: Full traceability and material certification
Material Excellence: C70600 (90/10 Copper-Nickel) for HVAC/R
The C70600 alloy, commonly known as 90/10 copper-nickel, brings proven marine-grade corrosion resistance to HVAC/R applications. Comprising approximately 90% copper and 10% nickel with controlled iron and manganese additions, this alloy delivers outstanding performance in demanding environments:
Superior Corrosion Resistance: C70600 exhibits exceptional resistance to formicary corrosion ("ants' nest corrosion")—a common failure mode in standard copper tubes caused by volatile organic compounds (VOCs) from insulation, adhesives, and atmospheric contaminants. This makes it particularly valuable for coastal installations and industrial environments
Excellent Biofouling Resistance: The alloy's surface chemistry naturally inhibits the adhesion and growth of biofilm and mineral scale, maintaining heat transfer efficiency and preventing the insulating layers that can drastically reduce system coefficient of performance (COP) over time
Enhanced Mechanical Strength: Compared to pure copper, C70600 offers higher tensile strength (typically 275-450 MPa depending on temper) and superior resistance to vibration-induced fatigue—a critical factor for compressor discharge lines and components subject to constant operational stress
Proven Longevity: Systems utilizing C70600 components have demonstrated service lives exceeding 30-40 years in challenging environments, offering exceptional total cost of ownership
ASTM B111 Stainless Steel Welded Pipes: Versatility and Strength
Complementing the copper-nickel tubes, TOBO's ASTM B111 stainless steel welded pipes provide essential solutions for a wide range of HVAC/R applications. The ASTM B111 / ASME SB111 standard is the globally recognized specification for seamless and welded copper and copper-alloy condenser tubes, but stainless steel variants offer additional options for specific requirements:
Key Features:
Material Grades: Available in 304/304L and 316/316L stainless steel
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 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:
Precision forming of stainless steel strip into tubular shape
Automated welding with inert gas shielding
Controlled atmosphere annealing to optimize microstructure
100% non-destructive testing to verify weld integrity
Technical Specifications and Compliance
TOBO's copper-nickel tubes and stainless steel welded pipes meet or exceed rigorous international standards:
Specification Description
Copper-Nickel Tubes ASME SB151 / ASTM B151
Stainless Steel Pipes ASTM B111 / ASME SB111
Refrigeration Service ASTM B280
European Market PED 2014/68/EU
Quality Management ISO 9001:2015
Available Configurations:
Diameter Range: 1/4 inch to 4 inches (DN6 to DN100)
Wall Thickness: Various schedules to suit pressure requirements
Lengths: Standard 20-foot lengths, with cut-to-size options
Temper Options (CuNi): Annealed (O60) for maximum formability, light drawn (H55) for enhanced strength
End Finish: Plain end, beveled end, or custom configurations
Industry Applications Across HVAC/R Sectors
The combination of ASME B151 copper-nickel tubes and ASTM B111 stainless steel welded pipes serves essential functions across diverse HVAC/R applications:
Residential and Commercial Air Conditioning:
Refrigerant lines for split-system air conditioners
Mini-split and VRF system piping
High-efficiency system installations requiring superior corrosion resistance
Marine and Coastal HVAC:
Air conditioning systems on vessels, offshore platforms, and coastal facilities
Applications exposed to salt-laden air and corrosive environments
Systems requiring extended service life with minimal maintenance
Industrial Refrigeration:
Process cooling systems in food processing and pharmaceutical manufacturing
Refrigeration equipment in chemical plants and industrial facilities
Cold storage warehouse evaporator and condenser circuits
Specialty Cooling Systems:
Data center cooling installations requiring high-reliability connections
Medical equipment and laboratory cooling systems
Clean room and critical environment applications
Heat Pumps and Chillers:
Large-scale chiller heat exchanger tubes
Heat pump refrigerant circuits
Condenser and evaporator coils
Why Choose C70600 Copper-Nickel for HVAC/R?
While standard copper has been the traditional choice for refrigerant lines, C70600 offers significant advantages for demanding environments:
Property C70600 (90/10 CuNi) Standard Copper
Formicary Corrosion Resistance Excellent Poor
Stress Corrosion Cracking Resistance Excellent Moderate
Biofouling Resistance Excellent Poor
Vibration Fatigue Resistance Superior Standard
Service Life in Coastal Environments 30+ years 10-15 years
Manufacturing Excellence and Quality Assurance
TOBO's production facilities employ state-of-the-art manufacturing processes to ensure consistent quality:
Copper-Nickel Tube Production:
Seamless extrusion and cold drawing processes
Solution annealing for optimal microstructure
100% eddy current testing
Hydrostatic pressure testing
Stainless Steel Welded Pipe Production:
Continuous roll forming with 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
Non-Destructive Testing: Eddy current, radiographic, or ultrasonic testing available
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.
Sustainability and Lifecycle Value
The adoption of C70600 tubes in HVAC/R applications aligns with sustainability objectives:
Extended Service Life: 30-40 year service life reduces replacement frequency and associated material consumption
Maintained Efficiency: Corrosion and fouling resistance preserve heat transfer efficiency throughout system lifetime
Reduced Leak Risk: Superior corrosion resistance minimizes refrigerant leakage and associated environmental impact
100% Recyclable: Copper-nickel alloys are fully recyclable without degradation of material properties
Global Supply and Availability
TOBO maintains substantial inventory of ASME B151-compliant copper-nickel tubes and ASTM B111 stainless steel welded pipes, with efficient logistics networks serving international markets. The company offers flexible order quantities, customization options for non-standard dimensions and tempers, and third-party inspection by DNV, ABS, LR, BV, or SGS upon request.
Conclusion: The Smart Choice for Demanding HVAC/R Applications
The introduction of ASME B151 90/10 Copper-Nickel C70600 Tubes and ASTM B111 Stainless Steel Welded Pipes represents TOBO's commitment to providing comprehensive, high-performance solutions for the most demanding HVAC/R applications. By offering both the corrosion-resistant properties of copper-nickel alloy and the versatility of stainless steel, TOBO enables engineers, contractors, and system designers to select the optimal material for their specific environmental conditions and performance requirements.
Whether specified for coastal air conditioning systems requiring C70600's superior corrosion protection, industrial refrigeration demanding long-term reliability, or standard applications utilizing stainless steel welded pipes, these products deliver the durability, reliability, and performance that modern HVAC/R systems demand.
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 HVAC/R, marine, energy, 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.