A Guide to Copper-Nickel Tubes: Properties, Applications, and Benefits

Copper-nickel (CuNi) tubes are widely used in marine, industrial, and HVAC applications due to their corrosion resistance, high thermal conductivity, and durability. These tubes are ideal for seawater cooling, heat exchangers, and oil and gas operations. Advantages include their resistance to biofouling, ease of fabrication, and low maintenance costs, while disadvantages include higher costs and the need for specialized welding.

Copper-nickel tubes are corrosion-resistant pipes made from an alloy primarily composed of copper and nickel, with small amounts of iron and manganese to improve corrosion resistance and strength. They are available in different grades, including:

• CuNi 90/10 (C70600) – Contains 90% copper and 10% nickel, offering strong resistance to corrosion and good mechanical properties.

• CuNi 70/30 (C71500) – Composed of 70% copper and 30% nickel, providing increased strength and resistance to seawater corrosion.

These alloys are commonly used in industries that require reliability in demanding conditions. Learn more about copper-nickel alloys from the Copper Development Association.

• Corrosion resistance:Works well in seawater, resisting biofouling and erosion.

• Thermal conductivity: Transfers heat efficiently, making it suitable for heat exchangers and cooling systems.

• Durability: Maintains performance under high temperatures and mechanical stress.

• Resistance to biofouling: Limits the growth of marine organisms, reducing maintenance.

• Fabrication: Easy to shape, weld, and install in complex systems.

Copper-nickel tubing and pipes are commonly used in various industries due to their excellent optimized chemical composition and mechanical properties, which enhance their ability to withstand harsh conditions.

• Used in seawater cooling systems, shipbuilding, and desalination plants.

• Installed in fire suppression systems on naval and commercial vessels.

• Applied in offshore platforms and subsea pipelines, where corrosion resistance is critical.

• Found in power plants, chemical processing, and industrial cooling systems.

• Used in HVAC systems for efficient cooling and heating processes.

• Used in offshore drilling rigs and heat recovery systems in refineries.

• Applied in subsea structures where durability is require.

• Found in brake lines and hydraulic systems, where durability under high pressure is necessary.

• Used in aircraft cooling systems for long-term reliability.

• Used in offshore drilling rigs and heat recovery systems in refineries.

• Applied in subsea structures where durability is require.

• Excellent resistance to seawater, making it ideal for marine applications.

• Resistant to biofouling, reducing maintenance needs.

Learn about corrosion-resistant metals from AMPP.

• Transfers heat efficiently, making it suitable for heat exchangers and cooling systems.

• Maintains performance under high temperatures and mechanical stress.

• Long-lasting, reducing replacement and maintenance costs.

• Can be shaped, welded, and installed with relative ease.

Compared to stainless steel and carbon steel, copper-nickel tubes last longer in corrosive environments, are easier to fabricate, and require less upkeep.

Despite its numerous advantages, copper-nickel does have some limitations that should be considered when selecting materials for industrial applications.

• Higher cost: Copper-nickel is more expensive than carbon steel and aluminum, which can impact project budgets.

• Limited strength compared to some alloys: While durable, it may not provide the same level of strength as certain stainless steels.

• Potential for galvanic corrosion: When in contact with dissimilar metals in conductive environments, it may be prone to galvanic corrosion if not properly insulated.

• Specialized welding requirements: Requires specific welding techniques to maintain its integrity and avoid material degradation.

• Heavier than aluminum: Although lightweight compared to some other metals, it is still heavier than aluminum, which may be a concern in weight-sensitive applications.

Several factors affect which copper-nickel tube is best suited for a specific application:

• Operating conditions: CuNi 90/10 works well for most seawater applications, while CuNi 70/30 is used in extreme conditions.

• Pressure and temperature: Higher nickel content increases strength.

• Size and wall thickness: Must fit system design needs.

• Industry standards: Compliance with ASTM, ASME, and ISO specifications ensures quality.

• Welding: Follow recommended procedures to maintain material integrity.

• Regular inspections: Monitor for wear, pitting, or mechanical damage.

• Cleaning: Periodic flushing and protective coatings help extend lifespan.

Copper-nickel tubing is a strong option for industries that require durability, corrosion resistance, and thermal efficiency. It has proven effective in marine environments, heat exchangers, and industrial applications where reliability is essential.

Admiralty Industries supplies copper-nickel tubing that meets rigorous quality standards, ensuring optimal performance across various industries. Get in touch with our team to find the best solution for your specific needs.

“Copper-Nickel Alloys in Marine Environments.” Copper Development Association, www.copper.org/applications/marine/cuni/.

“Corrosion Control Resources.” Association for Materials Protection and Performance (AMPP), www.ampp.org.