Home > Welded Pipes > Copper Nickel Welded Pipes
Inox Steel India is a leading manufacturer and global supplier of Duplex and Super Duplex Welded Pipes in grades UNS S31803, S32205 (Duplex 2205) and UNS S32750 (Super Duplex 2507), produced as per ASTM A790 and ASTM A928 standards.
These high-strength, corrosion-resistant welded pipes are engineered for extreme service environments involving high-pressure, high-chloride, seawater, brine, acids, and critical offshore conditions.
Duplex & Super Duplex Welded Pipes combine ferritic and austenitic microstructures, offering twice the strength of conventional stainless steels, superior pitting resistance, and exceptional resistance to chloride stress corrosion cracking (SCC). With PREN values exceeding 35 (Duplex) and 40+ (Super Duplex), these pipes are ideal for aggressive and corrosive environments.
Inox Steel India manufactures welded duplex & super duplex pipes using GTAW root + SAW/ERW multi-pass welding, followed by solution annealing and pickling to ensure uniform corrosion resistance and mechanical properties equal to or better than the base metal.
Our products are supplied to offshore platforms, desalination plants, chemical processing units, and marine engineering companies worldwide.
Copper Nickel Welded Pipes are engineered from copper-nickel alloys containing:
These alloys provide:
Cu-Ni 90/10 is widely used for seawater cooling and general marine service, while Cu-Ni 70/30 offers higher strength and superior performance in more aggressive seawater systems (offshore & naval).
Types of Copper Nickel Welded Pipes We Manufacture
1️⃣ Raw Material Inspection
Plates/coils undergo PMI test to verify copper and nickel content.
2️⃣ Edge Preparation
Beveling ensures clean fusion and proper weld penetration.
3️⃣ Plate Rolling & Forming
Plates are rolled into cylindrical shape with precise tolerances.
4️⃣ Root Pass Welding – GTAW (TIG)
Produces a high-purity internal weld suitable for seawater handling.
5️⃣ Fill Passes – GMAW/SAW
Multi-pass welding ensures complete fusion and structural integrity.
6️⃣ Annealing (Mandatory)Relieves stresses, improves corrosion resistance, and restores ductility.
7️⃣ Pickling & Surface Cleaning
Ensures a clean, corrosion-resistant internal and external finish.
8️⃣ Eddy Current / UT / Visual Testing
Non-destructive testing ensures weld integrity and defect-free surfaces.
9️⃣ Hydrostatic Pressure Testing
Ensures leakproof performance in marine and cooling systems.
🔟 Final Inspection & Marking
Pipes are marked with grade, OD, wall thickness, ASTM standard & heat number.
Marine & Shipbuilding
Used in seawater piping, ballast systems, firefighting lines, bilge systems & cooling networks.
Desalination & Water Treatment Plants
Cu-Ni 90/10 & 70/30 are used extensively in evaporators, brine heaters & high-salinity environments.
Offshore Oil & Gas Platforms
Pipes withstand marine corrosion, wave impacts & fluctuating seawater temperatures.
Heat Exchangers & Condensers
Ideal for thermal transfer systems due to excellent conductivity.
Naval & Defense Applications
Non-magnetic Cu-Ni pipes are used in submarines and naval vessels.
Power Plants
Used in cooling water lines and condenser piping systems.
Copper Nickel (Cu-Ni) Welded Pipes are globally trusted for marine, offshore, desalination, cooling water and heat exchanger applications due to their outstanding resistance to seawater corrosion, biofouling, and erosion.
ASTM B466 governs the manufacturing of welded Cu-Ni pipes, ensuring chemical balance, mechanical strength, weld integrity, annealing, and NDT compliance.
Cu-Ni 90/10 (C70600) is the most widely used marine alloy, while Cu-Ni 70/30 (C71500) provides higher strength and superior resistance in high-velocity seawater flows found in offshore & naval systems.
Inox Steel India manufactures Cu-Ni welded pipes using GTAW/GMAW root passes, followed by multi-pass welding and annealing, ensuring every pipe meets ASTM B466 standards with verified corrosion performance.
| Parameter / Property | Cu-Ni 90/10 (C70600) | Cu-Ni 70/30 (C71500) | Standard Requirements – ASTM B466 |
|---|---|---|---|
| Material Type | Copper-Nickel Alloy (90% Cu, 10% Ni) | Copper-Nickel Alloy (70% Cu, 30% Ni) | Welded Copper Nickel Pipes |
| UNS Number | C70600 | C71500 | As per grade |
| Manufacturing Standard | ASTM B466 | ASTM B466 | Mandatory chemical + mechanical compliance |
| Corrosion Resistance | Excellent in seawater | Superior seawater & biofouling resistance | As per ASTM |
| Key Features | Anti-fouling, good weldability, corrosion resistance | Higher strength + better erosion resistance | Must meet weld integrity |
| Typical Composition | Cu: 88.6–90%, Ni: 9–11%, Fe: 1–1.8% | Cu: 66–70%, Ni: 29–33%, Fe: 0.4–1% | Defined in ASTM B466 |
| Temperature Resistance | Up to 300°C | Up to 300°C | As per ASTM limits |
| Seawater Resistance | Very high | Extremely high | — |
| Mechanical Strength (TS) | 275–340 MPa | 310–380 MPa | Per grade |
| Yield Strength (YS) | 105–130 MPa | 125–180 MPa | Per grade |
| Density | 8.94 g/cm³ | 8.95 g/cm³ | — |
| Weld Type | GTAW / GMAW / SAW | GTAW / GMAW / SAW | Weld quality as per ASTM B466 |
| Heat Treatment | Annealed | Annealed | Required |
| NDT Requirements | UT, Eddy Current | UT, Eddy Current | As per ASTM B466 |
| Hydro Test | Required | Required | Mandatory |
| OD Range | ½” – 24” | ½” – 24” | As specified |
| Wall Thickness | SCH 10 – SCH 80 / Custom | SCH 10 – SCH 80 / Custom | Specified in ASTM |
| Typical Applications | Marine cooling systems, heat exchangers, shipbuilding | Offshore platforms, naval systems, condensers | Marine-grade service |
| Surface Finish | Annealed | Annealed | ASTM B466 compliant |
| Testing Documentation | MTC 3.1 / PMI / EC test | MTC 3.1 / PMI / EC test | Required |
| HSN Code | 7411.10 | 7411.10 | Copper alloy pipes |
✔ Cu-Ni 90/10 (C70600)
✔ Cu-Ni 70/30 (C71500)
✔ Applicable Standard
✔ For seawater cooling & condenser systems
Select Cu-Ni 90/10 (C70600)
→ Excellent corrosion + biofouling resistance.
✔ For high-velocity seawater or offshore platforms
Select Cu-Ni 70/30 (C71500)
→ Superior erosion resistance + high strength.
✔ For desalination plants (evaporators, heat brine systems)
Use Cu-Ni 90/10 or 70/30 depending on velocity.
✔ For naval & defense systems
Use Cu-Ni 70/30
→ Higher strength & non-magnetic properties.
| Application | Recommended Grade | Reason |
|---|---|---|
| Seawater cooling lines | Cu-Ni 90/10 | Excellent corrosion + biofouling resistance |
| Naval & marine systems | Cu-Ni 70/30 | High strength, erosion resistance |
| Desalination evaporators | Cu-Ni 90/10 | Thermal conductivity + seawater performance |
| Offshore platforms | Cu-Ni 70/30 | Superior durability in harsh marine conditions |
| Heat exchangers | Cu-Ni 90/10 / 70/30 | High thermal conductivity |
| Ballast water & firefighting systems | Cu-Ni 90/10 | Reliability & long corrosion life |
| Parameter | Capability |
|---|---|
| Outside Diameter (OD) | ½” – 24” |
| Wall Thickness | SCH 10 – SCH 80 / Custom |
| Length | 6 m / 12 m |
| Weld Type | GTAW root + GMAW/SAW |
| Heat Treatment | Annealed |
| Ends | Plain / Bevelled |
| Finish | Annealed & Cleaned |
| Copper Nickel Grade | Price (INR/kg) | Price (USD/kg) |
|---|---|---|
| Cu-Ni 90/10 (C70600) | ₹ 1,200 – ₹ 1,800 | $ 15 – $ 22 |
| Cu-Ni 70/30 (C71500) | ₹ 1,500 – ₹ 2,400 | $ 18 – $ 30 |
| Welded Cu-Ni Pipe (Annealed) | +₹ 80 – ₹ 150 extra | +$ 1 – $ 2 extra |
| Marine/Export Grade Testing | +₹ 50 – ₹ 120 extra | +$ 0.5 – $ 1 extra |
Pricing depends on OD, thickness, annealing, eddy current testing & export documentation.
7411.10 — Copper-Nickel Alloy Pipes
✔ NDT Testing
✔ Hydrostatic Test
✔ Mechanical Testing
✔ Corrosion & Seawater Testing
✔ PMI Testing
Ensures correct Cu-Ni chemical composition.
✔ Documentation
✔ Third-Party Inspection
SGS, BV, DNV, TÜV, Lloyd’s available.
Inox Steel India exports Copper Nickel Welded Pipes to:
Middle East:
Africa:
Europe:
Americas:
Asia Pacific:
Used extensively in offshore, shipbuilding, desalination, marine cooling & defense industries.
Copper Nickel (Cu-Ni) Welded Pipes are widely regarded as the world’s most reliable marine piping materials, requiring defect-free welding, corrosion stability, and strict NDT standards.
Inox Steel India is one of the leading suppliers of Cu-Ni 90/10 and Cu-Ni 70/30 welded pipes, manufactured as per ASTM B466, fully annealed, and tested for seawater performance.
Why clients trust our Cu-Ni welded pipes:
Inox Steel India is a preferred partner for offshore projects, desalination plants, marine engineering, and shipbuilding companies worldwide.
Marine & Offshore Engineering
Pipes for seawater cooling, ballast systems, firefighting lines, and offshore utility networks.
Shipbuilding & Naval Architecture
Cu-Ni 70/30 preferred for naval vessels due to non-magnetic & corrosion-resistant properties.
Desalination Plants
Used in evaporators, brine heaters, RO systems, and seawater intake/discharge lines.
Heat Exchangers & Condensers
High thermal conductivity makes Cu-Ni alloys ideal for heat transfer systems
Oil & Gas (Marine Environments)
Cooling water circuits, platform utilities, and subsea system tubing.
Power Plants
Condenser piping, cooling water lines & auxiliary marine systems.
Copper Nickel Welded Pipes require corrosion-controlled and impact-protected packaging.
✔ Standard Export Packaging Includes:
✔ For Marine Exports:
✔ Ports of Dispatch:
JNPT • Mundra • Hazira • Chennai
✔ Export Destinations:
GCC • Europe • USA • Latin America • Southeast Asia • Africa
Looking for Copper Nickel Welded Pipes (Cu-Ni 90/10, 70/30) for marine, offshore, desalination, heat exchangers, or naval engineering?
52-A, Mulji Thackersi Bldg, Islampura Street, Shop No. 10, Near Alankar Cinema, Mumbai – 400 004
steel@inoxsteelindia.in
+91 9930796690
ASTM B466 for welded, annealed copper-nickel pipes.
Yes — Cu-Ni is the most reliable anti-corrosive alloy for seawater systems.
Yes — Eddy Current, UT & Hydro testing are mandatory.
Yes — Cu-Ni 70/30 is non-magnetic & spark-resistant, ideal for defense vessels.
Yes — supplied to 45+ countries with full export documentation.
We provide technical support, NDT reports, PMI certificates, and worldwide delivery.