ASTM B111 C71640 Copper Nickel Tube | CuNi 70/30 Seawater Condenser Tubes (EN CW353H)
ASTM B111 C71640 copper nickel tubes (CuNi 70/30) are seamless alloy tubes specifically designed for seawater condenser and marine heat exchanger applications. With superior resistance to seawater corrosion, biofouling, and erosion-corrosion, they are widely used in power plants, desalination systems, and offshore industries.
What is ASTM B111 C71640?
ASTM B111 is the standard specification for seamless copper and copper alloy tubes used in condensers and heat exchangers.
C71640 (CuNi 70/30) is a high-performance copper-nickel alloy containing:
- ~30% Nickel
- Iron and manganese additions
👉 Compared with CuNi 90/10, it offers:
- Higher strength
- Better resistance to seawater corrosion
- Improved performance in high-velocity systems
Equivalent Standards
| Standard | Grade |
|---|---|
| ASTM | B111 C71640 |
| UNS | C71640 |
| EN | CW353H |
Chemical Composition – C71640 (%)
| Element | Composition |
|---|---|
| Cu | Balance |
| Ni | 29.0 – 32.0 |
| Fe | 1.7 – 2.3 |
| Mn | 1.5 – 2.5 |
| Pb | ≤ 0.05 |
| Zn | ≤ 1.0 |
Iron and manganese improve resistance to erosion and biofouling
Mechanical Properties
| Condition | Tensile Strength | Yield Strength |
|---|---|---|
| O61 (Annealed) | 63 ksi | 25 ksi |
| HR50 (Stress Relieved) | 81 ksi | 58 ksi |
Key Advantages of CuNi 70/30 Tubes
- Excellent seawater corrosion resistance
- Strong resistance to biofouling
- High erosion-corrosion resistance
- Long service life in marine environments
- Suitable for high-velocity seawater systems
- Good weldability and fabrication
Manufacturing & Supply Condition
- Type: Seamless copper nickel tube
- Process: Cold drawn / Annealed
- Condition: Soft annealed or light drawn
- Surface: Cleaned and degreased
Manufactured strictly according to ASTM B111 tolerances
Size Range
- OD: 6 mm – 120 mm
- Wall Thickness: 0.5 mm – 6 mm
- Length: Up to 12 m
- U-bend and cut-to-length available
Inspection & Testing
All tubes undergo strict quality control:
- Chemical analysis
- Mechanical testing
- Eddy current testing
- Hydrostatic testing
- Dimensional inspection
- Visual inspection
Certification:
- EN 10204 3.1
- Third-party inspection (BV / SGS / DNV)
Applications of ASTM B111 C71640 Tubes
Widely used in:
- Seawater condensers
- Power plant heat exchangers
- Desalination systems
- Offshore oil & gas platforms
- Marine cooling systems
- Shipbuilding
Ideal for high-salinity and aggressive environments
CuNi 70/30 vs CuNi 90/10
| Property | CuNi 70/30 (C71640) | CuNi 90/10 (C70600) |
|---|---|---|
| Strength | Higher | Lower |
| Seawater Resistance | Excellent | Very Good |
| High Velocity | Better | Moderate |
For severe marine environments, 70/30 is preferred
Specification Summary
- Material: C71640 (CuNi 70/30)
- Standard: ASTM B111
- Type: Seamless condenser tube
- Feature: Seawater corrosion resistance
- Application: Marine, desalination, power plants
FAQ: C71640 Copper Nickel Tubes
Q1: What is C71640 used for?
Used in seawater condensers and marine heat exchangers.
Q2: Why choose CuNi 70/30 over 90/10?
Because it provides higher strength and better corrosion resistance in harsh seawater conditions.
Q3: Is C71640 suitable for seawater?
Yes, it is specifically designed for seawater and marine environments.
Q4: What is the maximum length available?
Typically up to 12 meters, with customization available.
Related Products
ASTM B111 C70600 Copper Nickel Tubes
ASTM B111 C71500 Copper Nickel Tubes
