Copper Nickel Flanges (90/10 & 70/30)| UNS C70600 / C71500
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Copper Nickel Flanges (90/10 & 70/30) | UNS C70600 / C71500 Brochure
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Descriptions
Navkar Metal Syndicate offers premium Cupronickel Flanges engineered for the most demanding marine, offshore, and chloride-bearing industrial applications. Available in 90/10 (UNS C70600) and 70/30 (UNS C71500) alloys, our flanges are manufactured to precise dimensional tolerances ensuring reliable sealing, superior mechanical strength, and long-term corrosion resistance.
Cu-Ni flanges from Navkar Metal Syndicate provide outstanding performance in seawater piping systems, condensers, heat exchangers, desalination plants, and offshore platforms, where biofouling, pitting, and crevice corrosion resistance are critical. Each flange undergoes rigorous quality checks including dimensional inspection, hardness testing, and chemical verification.
Supplied with Mill Test Certificates (MTCs), traceable heat numbers, and export-ready packing, every product meets global project documentation and traceability standards. Available in a complete range of types, pressure classes, and sizes (including weld-neck, slip-on, blind, threaded, socket-weld, and lap-joint), our flanges can also be custom-designed to meet client specifications.
With their superior weldability, fabrication ease, and mechanical integrity, Navkar’s Cupronickel flanges deliver low maintenance costs, extended service life, and reliable system performance even under severe seawater or industrial exposure.
- UNS C70600 (90/10 Cu-Ni) – For cost-efficient seawater systems
- UNS C71500 (70/30 Cu-Ni) – For higher-strength, erosion-resistant applications
- ASTM / ASME Standards: B151, B122, B466 / SB151, SB122, SB466
- Pressure Ratings: Class 150 to Class 2500 / PN 2.5 – PN 400
- Available Types: Weld Neck, Slip-On, Blind, Socket Weld, Threaded, Lap Joint
Note: All flanges are supplied with protective coatings and export-grade wooden crates. Custom machining, drilling, and facing options are available on request.
Chemical Composition
The following table represents the typical chemical composition of Cupronickel Flanges manufactured by Navkar Metal Syndicate in both 90/10 (C70600) and 70/30 (C71500) grades. These compositions ensure excellent corrosion resistance, strength, and weldability for critical marine and industrial applications.
| Element | 90/10 Cu-Ni (C70600) | 70/30 Cu-Ni (C71500) |
|---|---|---|
| Copper (Cu) | 86 – 90 | 65 – 70 |
| Nickel (Ni) | 9 – 11 | 29 – 33 |
| Iron (Fe) | 0.8 – 1.8 | 0.4 – 1.0 |
| Manganese (Mn) | ≤ 1.0 | ≤ 1.0 |
| Lead (Pb) | ≤ 0.02 | ≤ 0.02 |
| Zinc (Zn) | ≤ 0.5 | ≤ 0.5 |
| Others (each) | ≤ 0.05 | ≤ 0.05 |
Note: Copper is the balance element. Composition values are nominal ranges as per ASTM B151 / ASME SB151, ensuring compliance with international Cu-Ni standards for marine, offshore, and heat-exchanger applications.
Mechanical & Corrosion Properties — Flanges Only
The following table outlines the mechanical and corrosion performance of Cupronickel Flanges (grades 90/10 – C70600 and 70/30 – C71500) as supplied by Navkar Metal Syndicate. These values represent typical ranges for annealed and forged conditions used in marine and industrial piping systems.
| Grade | Condition | Tensile Strength (UTS) | 0.2% Proof / Yield Strength | Hardness (HV) | Corrosion / Seawater Performance |
|---|---|---|---|---|---|
| 90/10 (C70600) | Annealed / Soft | 275 – 360 MPa | 90 – 160 MPa | 80 – 110 | Very good general seawater resistance; low uniform corrosion; good resistance to biofouling; suitable for moderate flow piping. |
| 90/10 (C70600) | Forged / Cold-Worked | 350 – 500 MPa | 200 – 350 MPa | 110 – 200 | Maintains corrosion resistance in seawater; suitable for moderate velocity or pressure connections. |
| 70/30 (C71500) | Annealed / Soft | 345 – 420 MPa | 120 – 200 MPa | 95 – 130 | Excellent seawater resistance; lower corrosion rates than 90/10; resistant to pitting and crevice corrosion. |
| 70/30 (C71500) | Forged / Cold-Worked | 420 – 600 MPa | 220 – 400 MPa | 130 – 240 | Excellent erosion and seawater resistance; ideal for high-pressure or high-velocity systems. |
Note: Mechanical values are typical and may vary slightly depending on forging condition, heat treatment, and product dimensions. Data conforms to ASTM B151, B122, and ASME SB151 specifications.
Applications
Cupronickel Flanges supplied by Navkar Metal Syndicate are engineered to deliver long-term reliability in marine, industrial, and offshore environments where corrosion, pressure, and thermal performance are critical. Their exceptional resistance to seawater, biofouling, and stress corrosion cracking makes them an industry standard across various sectors.
- Seawater piping systems and intake manifolds
- Condensers, heat exchangers, and desalination plants
- Offshore oil & gas platforms and riser connections
- Pump and valve flanged assemblies in marine and industrial applications
- High-chloride or aggressive aqueous environments requiring reliable sealing and long service life
- Critical structural joints in shipbuilding, docks, and marine infrastructure
Note: Cu-Ni flanges are widely preferred for their balance of corrosion resistance, strength, and weldability, making them ideal for both new installations and replacement applications in seawater systems.
Types of Cupronickel Flanges Supplied
Navkar Metal Syndicate manufactures and supplies a complete range of Cupronickel Flanges in 90/10 (C70600) and 70/30 (C71500) grades, designed to meet global piping standards and performance requirements. Each flange type is precision-engineered for leak-proof connections, ease of installation, and long-term reliability in marine, offshore, and industrial systems.
- Weld Neck Flanges (WN) – For high-pressure and high-temperature applications; provides excellent stress distribution and secure sealing.
- Slip-On Flanges (SO) – Easy to install and align; ideal for moderate pressure and temperature service.
- Blind Flanges (BL) – Used to seal the ends of piping systems; ensures full-strength and corrosion-resistant closure.
- Socket Weld Flanges (SW) – Best suited for small-diameter piping; provides a strong, leak-proof joint.
- Threaded Flanges (TH) – Require no welding; suitable for systems carrying flammable or explosive fluids.
- Lap Joint Flanges (LJ) – Used with stub ends; ideal for systems requiring frequent disassembly or inspection.
All Cupronickel Flanges are manufactured as per ASTM, ASME, and DIN standards, ensuring precise dimensions, superior metallurgical consistency, and long service life under harsh seawater and chemical conditions.
Standards & International Equivalents:
Navkar Metal Syndicate supplies Cupronickel Flanges manufactured to international standards for global marine, power, and industrial projects. Available in 90/10 (C70600) and 70/30 (C71500) grades, our flanges comply with ASTM, ASME, EN, and DIN specifications ensuring dimensional accuracy and metallurgical consistency.
| Type | 90/10 (Cu-Ni 90/10) | 70/30 (Cu-Ni 70/30) |
|---|---|---|
| Common Name | Cupronickel 90/10 Flange | Cupronickel 70/30 Flange |
| UNS Designation | C70600 | C71500 |
| ASTM / ASME Standards | ASTM B151 / B466 (raw material); ASME B16.5 / B16.47 (flange dimensions) | ASTM B151 / B466; ASME B16.5 / B16.47 |
| EN / European Equivalent | CW352H / EN 12449 | CW354H / EN Equivalents |
| Other Equivalents | BS CN102 / DIN / WNR | BS CN107 / DIN / WNR |
Note: All Cupronickel Flanges are supplied with Mill Test Certificates (EN 10204 3.1 / 3.2) and conform to material and dimensional standards for seawater, desalination, and offshore applications.
Common Names & International Identifiers
Cupronickel Flanges supplied by Navkar Metal Syndicate are recognized globally under multiple naming systems and international designations. Both 90/10 (C70600) and 70/30 (C71500) alloys are widely used and specified in marine, desalination, and offshore applications due to their exceptional corrosion resistance and mechanical reliability.
| Alloy Type | Common Names | UNS | EN / DIN | BS / ISO | CDA Alloy No. |
|---|---|---|---|---|---|
| 90/10 Cupronickel | Cu-Ni 90/10, Copper Nickel 90/10, Cupro Nickel 90/10 | C70600 | CW352H / DIN 2.0872 | BS CN102 / ISO CuNi10Fe1Mn | 706 |
| 70/30 Cupronickel | Cu-Ni 70/30, Copper Nickel 70/30, Cupro Nickel 70/30 | C71500 | CW354H / DIN 2.0882 | BS CN107 / ISO CuNi30Fe1Mn | 715 |
Note: These designations correspond to internationally recognized specifications for Cupronickel flanges, pipes, fittings, and bars used in marine, offshore, and desalination systems.
Common Product Forms & Dimensions
The following table provides standard dimensional data for Cupronickel Flanges (both 90/10 (C70600) and 70/30 (C71500) grades). These dimensions comply with ASME B16.5 / B16.47 standards for Slip-On (SORF) and Weld Neck (WNRF) configurations. Each flange is precision-machined to ensure accurate fit, reliable sealing, and long service performance in marine, desalination, and offshore environments.
| NPS | O.D. (inches) |
Wall (T) |
Raised Face Dia. (R) |
No. of Bolt Holes |
Dia. of Holes |
Bolt Circle (B.C.) |
SORF Bore I.D. (SB) |
WNRF Bore I.D. (WB) |
Hub Base (H.B.) |
Hub Top (H.T.) |
SORF Length (S.L.) |
WNRF Length (W.L.) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1⁄2 | 3.50 | 0.38 | 1.38 | 4 | 0.62 | 2.38 | 0.88 | 0.62 | 1.19 | 0.84 | 0.56 | 1.81 |
| 3⁄4 | 3.88 | 0.44 | 1.69 | 4 | 0.62 | 2.75 | 1.09 | 0.82 | 1.50 | 1.05 | 0.56 | 2.00 |
| 1 | 4.25 | 0.50 | 2.00 | 4 | 0.62 | 3.12 | 1.36 | 1.05 | 1.94 | 1.32 | 0.62 | 2.12 |
| 1¼ | 4.62 | 0.56 | 2.50 | 4 | 0.62 | 3.50 | 1.70 | 1.38 | 2.31 | 1.66 | 0.75 | 2.19 |
| 1½ | 5.00 | 0.62 | 2.88 | 4 | 0.62 | 3.88 | 1.95 | 1.61 | 2.56 | 1.90 | 0.81 | 2.38 |
| 2 | 6.00 | 0.69 | 3.62 | 4 | 0.75 | 4.75 | 2.44 | 2.07 | 3.06 | 2.38 | 0.94 | 2.44 |
| 2½ | 7.00 | 0.81 | 4.12 | 4 | 0.75 | 5.50 | 2.94 | 2.47 | 3.56 | 2.88 | 1.06 | 2.69 |
| 3 | 7.50 | 0.88 | 5.00 | 4 | 0.75 | 6.00 | 3.57 | 3.07 | 4.25 | 3.50 | 1.12 | 2.69 |
| 3½ | 8.50 | 0.88 | 5.50 | 8 | 0.75 | 7.00 | 4.07 | 3.55 | 4.81 | 4.00 | 1.19 | 2.75 |
| 4 | 9.00 | 0.88 | 6.19 | 8 | 0.75 | 7.50 | 4.57 | 4.03 | 5.31 | 4.50 | 1.25 | 2.94 |
| 5 | 10.00 | 0.88 | 7.31 | 8 | 0.88 | 8.50 | 5.66 | 5.05 | 6.44 | 5.56 | 1.38 | 3.44 |
| 6 | 11.00 | 0.94 | 8.50 | 8 | 0.88 | 9.50 | 6.72 | 6.07 | 7.56 | 6.63 | 1.50 | 3.44 |
| 8 | 13.50 | 1.06 | 10.62 | 8 | 0.88 | 11.75 | 8.72 | 7.98 | 9.69 | 8.63 | 1.69 | 3.94 |
| 10 | 16.00 | 1.12 | 12.75 | 12 | 1.00 | 14.25 | 10.88 | 10.02 | 12.00 | 10.75 | 1.88 | 3.94 |
| 12 | 19.00 | 1.19 | 15.00 | 12 | 1.00 | 17.00 | 12.88 | 12.00 | 14.38 | 12.75 | 2.12 | 4.44 |
| 14 | 21.00 | 1.31 | 16.25 | 12 | 1.12 | 18.75 | 14.14 | 13.25 | 15.75 | 14.00 | 2.19 | 4.94 |
| 16 | 23.50 | 1.38 | 18.50 | 16 | 1.12 | 21.25 | 16.16 | 15.25 | 18.00 | 16.00 | 2.44 | 4.94 |
| 18 | 25.00 | 1.50 | 21.00 | 16 | 1.25 | 22.75 | 18.18 | 17.25 | 19.88 | 18.00 | 2.62 | 5.44 |
| 20 | 27.50 | 1.62 | 23.00 | 20 | 1.25 | 25.00 | 20.20 | 19.25 | 22.00 | 20.00 | 2.81 | 5.62 |
| 22 | 29.50 | 1.75 | 25.25 | 20 | 1.38 | 27.25 | 22.22 | 21.25 | 24.25 | 22.00 | 3.07 | 5.82 |
| 24 | 32.00 | 1.81 | 27.25 | 20 | 1.38 | 29.50 | 24.25 | 23.25 | 26.12 | 24.00 | 3.19 | 5.94 |
Note: Dimensions are nominal and may vary based on pressure class (150#–600#) and flange type (SORF/WNRF). For project-specific requirements, contact Navkar Metal Syndicate for detailed engineering drawings or CAD models.
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