Sunflex Metalloy Pvt Ltd specializes in CuNi 90/10 & CuNi 70/30 flanges conforming to ASTM B151, ASTM B466, ASME B16.5, B16.47, ANSI, MSS SP-44, DIN, and EN standards — trusted by global oil & gas, marine, and shipbuilding industries.
Our CuNi flanges are engineered for the most demanding marine, offshore, and industrial environments requiring exceptional corrosion resistance and long service life.

CuNi alloys exhibit outstanding resistance to seawater corrosion, biofouling, and marine organisms — ideal for offshore and marine piping systems.

Manufactured to ASTM B151/B466, ASME B16.5, B16.47, ANSI, MSS SP-44, DIN, EN 1092-1, BS 4504, ISO 7005, API 6A/6D, NORSOK MDS.

Exporting to USA, UK, UAE, Saudi Arabia, Norway, Germany, Singapore, Australia, and 50+ countries with complete MTC and documentation.

Every flange undergoes PMI, Hydrostatic, Ultrasonic, Radiography, Dye Penetrant, and Hardness testing before dispatch.






We manufacture all types of CuNi flanges in grades CuNi 90/10 and CuNi 70/30 conforming to international standards.

High-pressure applications with superior stress distribution. Tapered hub provides strength for extreme conditions in oil & gas and offshore pipelines.
View Details
Cost-effective solution with ease of alignment. The pipe slips into the flange before welding — widely used in low-pressure marine piping systems.
View Details
Used to seal end of piping systems. Essential for pressure testing, blocking off pipeline sections, and future pipeline extensions.
View Details
For small-bore, high-pressure piping (up to DN 50/2"). Excellent leak resistance for shipbuilding and chemical plant use.
View Details
Screwed onto pipe threads — no welding required. Ideal for hazardous environments where welding is not permitted.
View Details
Used with stub end fittings — easily rotatable for bolt hole alignment. Cost-effective for frequent dismantling.
View Details
Specially designed for flow measurement systems with orifice plates to measure fluid flow rates.
View Details
Figure-8 shaped device combining blind and spacer ring — essential safety device in refinery and gas processing units.
View Details
Metal-to-metal seal using octagonal or oval ring gaskets for high-pressure, high-temperature applications.
View DetailsSunflex Metalloy manufactures flanges in exactly two Copper-Nickel grades — each engineered for specific performance requirements:
The most widely used marine alloy. Excellent resistance to seawater corrosion and biofouling. Conforming to ASTM B151 / ASTM B466 / UNS C70600 / WNr 2.0872.
Superior strength and corrosion resistance for high-temperature service. Conforming to ASTM B151 / ASTM B466 / UNS C71500 / WNr 2.0882.
| Property | CuNi 90/10 | CuNi 70/30 |
|---|---|---|
| UNS Number | C70600 | C71500 |
| Copper (Cu) | ~88–90% | ~70% |
| Nickel (Ni) | 9–11% | 29–33% |
| Iron (Fe) | 1.0–1.8% | 0.4–1.0% |
| Manganese (Mn) | ≤ 1.0% | ≤ 1.0% |
| Tensile Strength | 275 MPa min | 380 MPa min |
| Yield Strength | 105 MPa min | 170 MPa min |
| Elongation | 30% min | 30% min |
| W.Nr (DIN) | 2.0872 | 2.0882 |
| ASTM Standard | B151 / B466 | B151 / B466 |
Offshore platforms, subsea pipelines, refinery & petrochemical plants
Naval vessels, commercial ships, offshore support vessels, drillships
SWRO & MSF desalination plants, water treatment facilities worldwide
Coastal power stations, nuclear cooling systems, steam condensers
Engineering, Procurement & Construction for offshore & onshore projects
Corrosive chemical handling, acid plants, chlorine service piping
Subsea manifolds, umbilicals, flowlines, subsea wellhead systems
Navy frigates, submarines, naval base utilities, defence infrastructure
We manufacture all CuNi flanges in-house at our Gujarat facility — ensuring price competitiveness and quality.
All flanges manufactured per ASTM B151, ASTM B466, ASME B16.5, B16.47, ANSI, MSS SP-44, DIN, EN 1092-1, BS 4504, ISO 7005.
Each batch is fully traceable with Heat Number, Mill Test Certificates (MTC) as per EN 10204 3.1 / 3.2.
Ready stock and efficient manufacturing cycles ensure on-time delivery worldwide. EXWORKS, FOB, CIF terms available.
We welcome TPI by Bureau Veritas, Lloyd's Register, DNV-GL, SGS, Intertek, TUV, and all major inspection agencies.
Sunflex Metalloy exports Copper Nickel flanges to major oil & gas, marine, and industrial destinations worldwide with complete documentation.
Send us your specifications and our technical team will respond within 24 hours with a competitive quote and full technical datasheet.