Copper Nickel Flanges,Copper Nickel 90/10 CUNI Flanges,Cupro Nickel Flanges
Copper Nickel flanges (CuNi 90/10 and CuNi 70/30) are corrosion-resistant alloy flanges widely used in seawater, marine, and offshore piping systems. Grades such as UNS C70600 (90/10) and C71500 (70/30) offer excellent resistance to seawater corrosion, biofouling, and erosion, making them ideal for desalination plants, heat exchangers, and shipbuilding.
What are Copper Nickel Flanges?
Copper Nickel (CuNi) flanges are piping components used to connect:
- Pipes
- Valves
- Pumps
They are commonly used in seawater and marine environments due to their:
- Excellent corrosion resistance
- Good mechanical strength
- High resistance to biofouling
Main Grades of CuNi Flanges
CuNi 90/10 (UNS C70600)
- 90% Copper, 10% Nickel
- Small additions of iron and manganese
- Excellent seawater corrosion resistance
- Good fabrication and weldability
CuNi 70/30 (UNS C71500)
- 70% Copper, 30% Nickel
- Higher strength than 90/10
- Better resistance to high-velocity seawater
- Superior erosion-corrosion resistance
Key Features
- Outstanding resistance to seawater and brine
- Excellent biofouling resistance
- Good resistance to organic compounds and salts
- Easy fabrication (hot and cold working)
- Good weldability
Product Types
We supply a full range of copper nickel flanges:
- Weld Neck Flanges (WNRF)
- Slip-On Flanges (SORF)
- Blind Flanges (BLRF)
- Socket Weld Flanges (SWRF)
- Threaded Flanges
- Lap Joint Flanges
- Spectacle Blind Flanges
Standards & Specifications
- ASTM B151 / ASME SB151
- ANSI / ASME B16.5
- ASME B16.47
- EN 1092-1
- DIN / BS / JIS / EEMUA
Size Range
- Size: 1/2″ – 24″
- Pressure Class:
- Class 150 – 2500
- PN6 – PN64
Flange Face Types
- Raised Face (RF)
- Flat Face (FF)
ASTM B 151 B 151M CUPRO NICKEL 90/10 FLANGES EQUIVALENT GRADES，CUNI Flanges
| STANDARD | WERKSTOFF NR. | UNS |
| Cupro Nickel 90/10 | 2.0872 | C70600 |
Chemical Composition (C70600 90/10)
| Element | Content (%) |
|---|---|
| Cu | ≥ 88.6 |
| Ni | 9 – 11 |
| Fe | ≤ 1.8 |
| Mn | ≤ 1.0 |
| Zn | ≤ 1.0 |
Mechanical Properties (Typical)
| Property | Value |
|---|---|
| Tensile Strength | ≥ 50,000 psi |
| Yield Strength | ≥ 20,000 psi |
| Elongation | ≥ 30% |
Applications
Copper Nickel flanges are widely used in:
- Seawater piping systems
- Desalination plants
- Heat exchangers and condensers
- Offshore oil & gas platforms
- Shipbuilding and naval systems
- Reverse osmosis systems
CuNi 90/10 vs 70/30
| Property | 90/10 (C70600) | 70/30 (C71500) |
|---|---|---|
| Strength | Moderate | Higher |
| Seawater resistance | Excellent | Superior |
| High velocity service | Good | Better |
| Cost | Lower | Higher |
👉 70/30 is preferred for more aggressive marine environments
Fabrication & Processing
- Hot and cold forming
- Excellent weldability
- Machining and finishing available
Quick Summary of Cuni Flanges
- Material: Copper Nickel (CuNi)
- Grades: C70600 (90/10), C71500 (70/30)
- Feature: Seawater corrosion resistance
- Application: Marine, offshore, desalination
FAQ: Copper Nickel Flanges
Q1: What is CuNi 90/10 used for?
Seawater piping and marine systems.
Q2: What is the difference between 90/10 and 70/30?
70/30 has higher strength and better erosion resistance.
Q3: Are copper nickel flanges corrosion resistant?
Yes, especially in seawater environments.
Q4: Are CuNi flanges weldable?
Yes, they have excellent weldability.
