CuNi 90/10 Low Fin Tube: Preferred for Marine & Industrial Heat Exchange
CuNi 90/10 low fin tube (also known as B10 alloy low fin tube, ASTM C70600) is a high-efficiency heat exchange tube roll-formed from 10% nickel copper-nickel alloy. It perfectly combines the seawater corrosion resistance of copper-nickel alloy with the high heat transfer efficiency of the low fin structure, widely applied in heat exchange equipment under severe working conditions such as marine vessels, offshore engineering, power stations and chemical industries. Explore more about CuNi 90/10 low fin tube and advanced industrial low fin tube solutions.
1. Material Core: Composition and Characteristics of CuNi 90/10 Alloy
CuNi 90/10 alloy (90% Copper, 10% Nickel) is one of the most classic copper-nickel grades. To adapt to heat exchange applications, it is usually added with Iron (1.0%-1.8%) and Manganese (0.5%-1.0%) to enhance overall performance.
1.1 Precise Chemical Composition (Grade A Strict Control)
| Element | Content Range | Function |
|---|---|---|
| Cu | 88.0%-90.0% | Alloy matrix, ensures high thermal conductivity |
| Ni | 9.5%-10.5% | Improves corrosion resistance and mechanical strength, resists chloride ion corrosion |
| Fe | 1.0%-1.8% | Enhances erosion and pitting corrosion resistance, suitable for seawater scouring environments |
| Mn | 0.5%-1.0% | Stabilizes alloy microstructure, restrains intergranular corrosion |
| Other Impurities | ≤0.5% | Strictly controls harmful elements such as Lead (≤0.02%) to ensure welding safety |
Excellent Corrosion Resistance
Resists corrosion from seawater, brine and chloride-containing media, with outstanding resistance to pitting, crevice corrosion and stress corrosion cracking. Life far longer than ordinary copper tubes and stainless steel tubes. Alloy releases copper ions to inhibit marine microbial adhesion.
Superior Thermal Conductivity
Thermal conductivity reaches approximately 50 W/m·K. Much higher than stainless steel and titanium alloy, delivering stable heat transfer efficiency for condensers and heat exchangers.
Good Mechanical & Workability
Balanced strength and ductility allow easy bending, welding and brazing, suitable for forming complex heat exchange equipment.
High Structural Stability
Maintains stable microstructure within -50℃ to 200℃ range, moderate thermal expansion coefficient, avoids deformation or leakage.
2. Low Fin Structure: Key Design for High Heat Transfer Efficiency
CuNi 90/10 low fin tube adopts seamless CuNi 90/10 bare tube as the base material. Integral spiral low fins are formed by special rolling equipment.
2.1 Structural Parameters (Regular Specifications)
- Base Tube Outer Diameter: 6.35mm–25.4mm
- Base Tube Wall Thickness: 0.89mm–2.77mm
- Fin Height: 0.4mm–1.5mm
- Fin Density: 0.7mm–3.0mm
- Heat Transfer Area Expansion: 2.5–4 times that of bare tubes
Improved Heat Transfer Efficiency
External fins greatly expand the heat transfer area, enhance turbulence of external fluid and reduce thermal resistance. Efficiency 30%-60% higher than bare tubes, supporting equipment miniaturization and energy saving.
Fouling Resistant & Easy Maintenance
Dirt adheres thinly along fin crests; "accordion effect" inhibits fouling deposition. Easily cleaned by high-pressure water flushing or chemical cleaning.
High Mechanical Strength
Integral rolling process ensures seamless combination between fins and base tube without loosening. Low fin design avoids deformation, offers excellent vibration and impact resistance for marine and power station conditions.
3. Production Process: Precision Manufacturing for Quality Assurance
The whole production process of CuNi 90/10 low fin tube is strictly controlled from raw material to finished product, fully complying with ASTM B111 standards.
- Base Tube Preparation: High-quality CuNi 90/10 alloy ingots are adopted, processed into seamless bare tubes via hot rolling and cold drawing to ensure precise dimensions and zero cracks.
- Surface Pretreatment: Bare tubes undergo degreasing, pickling and passivation to remove oil stains and oxide scales, ensuring tight fin bonding.
- Fin Rolling: Special rolling mills with multiple roller sets are used for progressive rolling to form uniform regular spiral low fins on the outer tube wall. Temperature and pressure strictly controlled.
- Finishing & Inspection: Products are straightened, cut, and each piece undergoes visual inspection, dimensional checking, hydraulic pressure test and eddy current flaw detection. Salt spray testing verifies corrosion resistance.
4. Core Application Scenarios for Severe Heat Exchange Conditions
With comprehensive advantages of corrosion resistance, high efficiency and stable performance, CuNi 90/10 low fin tube is the preferred heat transfer tube for the following industries:
Marine & Offshore Engineering
Ship condensers, seawater coolers and evaporators; heat exchange equipment for offshore oil platforms and cross-sea bridges, adapting to long-term seawater immersion and scouring.
Power & Energy Industry
Condensers and cooling tower tubes for thermal power plants; auxiliary cooling systems for nuclear power plants, resisting chloride corrosion and ensuring long-term stable operation.
Chemical & Petrochemical Industry
Heat exchangers and condensers for corrosive media; seawater cooling systems for petroleum refining units, adapting to complex corrosive environments with acid, alkali and salt media.
Seawater Desalination
Heat transfer tubes for multi-stage flash and reverse osmosis desalination equipment, featuring seawater corrosion resistance and anti-fouling performance to improve desalination efficiency and reduce operating costs.
5. Comparative Advantages: Why Choose CuNi 90/10 Low Fin Tube
| Comparison Dimension | CuNi 90/10 Low Fin Tube | Ordinary Copper Tube | Stainless Steel Fin Tube | Titanium Alloy Fin Tube |
|---|---|---|---|---|
| Seawater Corrosion Resistance | Excellent (resists chloride) | Poor (prone to pitting & leakage) | Average (crevice corrosion risk) | Excellent (extremely high cost) |
| Heat Transfer Efficiency | High (fin-enhanced, area 2.5–4x larger) | Medium (limited bare tube area) | Low (low thermal conductivity) | Medium (high cost & difficult processing) |
| Fouling & Maintenance | Fouling-resistant & easy to clean | Prone to thick fouling, difficult cleaning | Easy fouling with frequent maintenance | Microbial adhesion, high maintenance cost |
| Service Life (seawater) | 15–30 years | 3–5 years | 5–10 years | 20–40 years (premium price) |
| Cost Performance | High (low comprehensive operating cost) | Low (frequent replacement) | Medium (high maintenance cost) | Very low (expensive procurement & processing) |
6. Conclusion
CuNi 90/10 low fin tube represents a perfect integration of premium material properties and structural innovation. The CuNi 90/10 alloy delivers outstanding corrosion resistance and structural stability, while the low fin structure achieves significant improvement in heat transfer efficiency with additional advantages of anti-fouling, easy cleaning and high mechanical strength. Against the global demand for high-efficiency, durable and cost-effective heat transfer tubes in marine engineering, power stations and chemical industries, CuNi 90/10 low fin tube stands as an irreplaceable core choice for heat exchange equipment under severe working conditions, together with advanced industrial low fin tube solutions, supporting energy conservation and long-term service life of industrial facilities.
