High Quality Copper Nickel (CuNi) 70/30 Pipes & Tubes
Seamless • Welded • Durable & Precise
Get a QuoteWhat is Copper Nickel 70/30?
Copper Nickel 70/30, also known as Cu-Ni 70/30 or UNS C71500, is an alloy consisting of approximately 70% copper and 30% nickel. It exhibits exceptional resistance to seawater corrosion, stress corrosion cracking, and biofouling. The higher nickel content provides enhanced mechanical strength and superior resistance in high-velocity seawater environments. This alloy is widely used in marine engineering, heat exchangers, condensers, and desalination plants where both durability and performance are essential.
Copper Nickel 70/30 Chemical Composition
Copper (Cu)
Nickel (Ni)
Iron (Fe)
Manganese (Mn)
Lead (Pb) Max
Zinc (Zn) Max
Carbon (C) Max
Phosphorus (P) Max
Sulfur (S) Max
Types of Copper Nickel 70/30 Pipes & Tubes
Ratnadeep Steel & Engg. Co. offers a comprehensive range of Copper Nickel 70/30 seamless and welded pipes & tubes. These are engineered for use in marine heat exchangers, desalination plants, offshore platforms, and other critical seawater systems where corrosion resistance and long service life are crucial.
Seamless Cu-Ni 70/30 pipes are manufactured by extrusion and drawing processes, providing high mechanical integrity and smooth internal surfaces. These pipes exhibit excellent resistance to seawater flow, erosion, and biofouling, making them the ideal choice for high-pressure marine and heat exchanger systems.
Welded Cu-Ni 70/30 pipes are fabricated using precision welding techniques to ensure reliability and consistent quality. These pipes are ideal for large-diameter and low-to-medium pressure applications such as shipbuilding, cooling systems, and desalination plant piping networks.
Specification of Copper Nickel 70/30 Seamless / Welded Pipes and Tubes
| Specification | Details |
|---|---|
| Specification | ASTM B466, B467, B111 / ASME SB466, SB467, SB111 |
| Standard | ASTM, ASME and API |
| Size | 1/2″ TO 6″ IN OD & NB IN Various SWG & SCH |
| Outer Diameter | 4.00 to 22.00 mm |
| Wall Thickness | Between 0.15mm and 1.50 mm |
| Type | Seamless / ERW / Welded / Fabricated Pipes |
| Form | Round, Square, Rectangular, Oval, Hydraulic Etc |
| Length | Single Random, Double Random & Required Length |
| End | Plain End, Beveled End, Treaded |
| Schedule | SCH20, SCH30, SCH40, STD, SCH80, XS, SCH60, SCH80, SCH120, SCH140, SCH160, XXS |
| Inspection, Test Reports | Mill Test Certificates, EN 10204 3.1, Chemical Reports, Mechanical Reports, PMI Test Reports, Visual Inspection Reports, Third Party Inspection Reports, NABL Approved Lab Reports, Destructive Test Report, Non Destructive Test Reports |
| Packing | Packed in Wooden Boxes, Plastic Bags, Steel Strips Bundled, or as per Customers Requests |
| Specials | Sizes and Specifications other than above can be manufactured on request |
CHEMICAL COMPOSITION OF COPPER NICKEL 70/30 PIPES & TUBES
| Grade | Cu | Mn | Pb | Ni | Fe | Zn |
|---|---|---|---|---|---|---|
| Cu-Ni 70-30 | 65.0 min | 1 max | 0.05 max | 29-33 | 0.4-1.0 | 1 max |
MECHANICAL PROPERTIES OF CU-NI 70/30 PIPES AND TUBING
| Properties | Metric | Imperial |
|---|---|---|
| Tensile strength, ultimate | 372-517 MPa | 54000-75000 psi |
| Tensile strength, yield (depending on temper) | 88.0-483 MPa | 12800-70100 psi |
| Elongation at break (in 381 mm) | 45.0% | 45.0% |
| Charpy impact | 107 J | 78.9 ft-lb |
| Machinability (UNS C36000 (free-cutting brass) = 100%) | 20% | 20% |
| Shear modulus | 57.0 GPa | 8270 ksi |
| Poisson’s ratio | 0.34 | 0.34 |
| Elastic modulus | 150 GPa | 21800 ksi |
PHYSICAL PROPERTIES OF CUPRO NICKEL 70/30 PIPES & TUBES
| Properties | Metric | Imperial |
|---|---|---|
| Density | 8.94 g/cm³ | 0.323 lb/in³ |
| Melting point | 1171°C | 2140°F |
💡 Practical Applications of Copper Nickel 70/30
Use Copper Nickel 70/30 when: superior corrosion resistance in seawater and marine environments is required, combined with excellent biofouling resistance.
→ Example: seawater cooling systems, condensers, heat exchangers, marine piping.
Choose CuNi 70/30 over other alloys when: long-term reliability in saltwater applications is critical and resistance to seawater velocity effects is needed. → Example: offshore platforms, shipbuilding, desalination plants, power station condensers.
Uses of Copper Nickel 70/30 Pipes and Tubes
The uses are defined by their exceptional resistance to seawater corrosion, biofouling resistance, and good mechanical properties in marine environments.
- Marine and Offshore Applications: This is the primary application. Used for seawater piping systems, condenser tubes, heat exchangers, and various components exposed to saltwater environments where corrosion resistance is paramount.
- Power Generation Cooling Systems: Ideal for condenser and heat exchanger tubes in power stations using seawater cooling, providing long service life and reliability.
- Desalination Plants: Excellent for handling highly corrosive seawater and brine solutions in multi-stage flash and reverse osmosis desalination systems.
When to Choose Copper Nickel 70/30 vs Other Alloys?
This is a critical decision based on specific marine and corrosive environment requirements. Copper Nickel 70/30 offers unique advantages in seawater applications.
Choose Copper Nickel 70/30 when:
- Superior seawater corrosion resistance is the primary requirement
- Excellent resistance to biofouling and marine growth is needed
- Applications involve high seawater velocity and impingement attack
- Long-term reliability in marine environments is critical
Consider alternatives when:
- Higher strength requirements exceed CuNi 70/30 capabilities
- Applications involve strong oxidizing acids or ammonia
- Cost constraints favor lower-cost materials for less corrosive environments
- Very high temperature applications beyond its operating range
Industries That Use Copper Nickel 70/30 Pipes and Tubes
Copper Nickel 70/30 alloys are essential in industries requiring exceptional seawater corrosion resistance and reliability in marine environments. Here are the most prominent applications:
This is the largest consumer of CuNi 70/30 due to its outstanding resistance to seawater corrosion and biofouling.
Uses
Seawater piping systems, fire mains, cooling systems, condenser tubes, heat exchangers, and hull piping in ships and vessels.
Why CuNi 70/30?
Superior resistance to seawater corrosion, excellent biofouling resistance, and good resistance to impingement attack.
Critical for offshore platforms and floating production systems exposed to seawater.
Uses
Seawater cooling systems, ballast water piping, firefighting systems, and process cooling on offshore platforms.
Why CuNi 70/30?
Excellent resistance to seawater corrosion in splash zones and submerged applications, with long service life.
Essential for coastal power stations using seawater for cooling and condensation.
Uses
Condenser tubes, heat exchanger tubes, cooling water systems, and auxiliary cooling circuits in power plants.
Why CuNi 70/30?
Reliable performance in seawater cooling systems, resistance to corrosion under heat transfer conditions.
Critical for handling highly corrosive seawater in water treatment processes.
Uses
Heat exchanger tubes, evaporator tubes, brine heaters, and seawater intake systems in desalination facilities.
Why CuNi 70/30?
Excellent resistance to pitting and crevice corrosion in high-chloride environments at elevated temperatures.
Used in various industrial applications located near seawater.
Uses
Cooling water systems, heat exchangers, and process piping in refineries, chemical plants, and industrial facilities near coastlines.
Why CuNi 70/30?
Superior resistance to seawater corrosion in coastal atmospheric conditions and seawater cooling applications.
Essential for military vessels requiring reliable seawater systems.
Uses
Seawater cooling systems, fire mains, ballast systems, and various piping applications on naval ships and submarines.
Why CuNi 70/30?
Proven reliability in critical naval applications, excellent corrosion resistance, and non-magnetic properties.
Used in marine farming and research facilities exposed to seawater.
Uses
Water circulation systems, heat exchangers, and piping in fish farms, aquariums, and marine research facilities.
Why CuNi 70/30?
Excellent biofouling resistance reduces maintenance, while corrosion resistance ensures long service life.
Used in specific chemical applications involving seawater or brackish water.
Uses
Cooling systems, heat exchangers, and process equipment handling seawater or brackish water in chemical plants.
Why CuNi 70/30?
Good resistance to various chemicals combined with excellent seawater corrosion resistance.
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