Copper-Nickel 70/30 Tube Sheet
The premium marine copper alloy — higher nickel content than 90/10 gives better resistance to high-velocity seawater erosion and more aggressive biofouling conditions, the classic choice for demanding condenser duty.
Chemical Composition
| Element | Min % | Max % |
|---|---|---|
| Copper (Cu) | Balance | — |
| Nickel (Ni) | 29.0 | 33.0 |
| Iron (Fe) | 0.40 | 1.00 |
| Manganese (Mn) | — | 1.00 |
Mechanical Properties
| Property | Typical Value |
|---|---|
| Tensile Strength | 360 MPa min (annealed) |
| Yield Strength (0.5% ext.) | 140 MPa min (annealed) |
| Elongation | 30% min |
| Max. Practical Service Temp. | ~300°C |
Equivalent Grades
| Standard | Designation |
|---|---|
| ASTM / UNS | C71500 |
| EN / DIN | CuNi30Fe / CW354H |
70/30 vs. 90/10 — Which One
See the full Copper-Nickel 90/10 datasheet for the more economical grade.
Applications
Marine and offshore seawater condensers, high-velocity cooling water systems, and desalination MSF plants where erosion-corrosion resistance at higher flow rates justifies the nickel premium over 90/10.
Advantages & Limitations
Advantages
- Superior erosion-corrosion resistance at high seawater velocity
- Good resistance to biofouling
- Long service history in marine condenser applications
Limitations
- Lower strength than stainless or duplex alternatives
- Cost premium over Copper-Nickel 90/10
- Not suitable for high-pressure structural applications
FAQ
When flow velocity is high enough to risk erosion-corrosion on 90/10, or where biofouling conditions are unusually severe. For typical seawater cooling at moderate velocity, 90/10 is often entirely adequate and more economical.
Copper-nickel is generally more economical and has a long service track record, while titanium offers better resistance at very high velocities and is significantly lighter. The choice often comes down to project budget and specific velocity/weight requirements.
Available in common diameters, with larger or custom sizes sourced to order — send your specification for confirmed availability.