Cupro Nickel 66/30/2/2 (C71640)
The desalination variant of 70/30. Raising iron and manganese to about 2% each stabilises the protective film under high velocity, sand-laden and partly deaerated brine, which is exactly the duty inside MSF evaporator heat recovery and reject sections. Where 70/30 tubes thin at the inlet ends, C71640 holds.
- Iron and manganese enhanced film stability for sand-laden brine
- Highest allowable velocity of the cupro nickel family
- Standard retube material for MSF desalination plant
- Supplied to EEMUA 144 / 146 with EN 10204 3.1 certification
Available forms & sizes
| Form | Size range |
|---|---|
| Seamless Pipes & Tubes | 1/8" - 12" NB seamless, 6 - 108 mm OD tube, 0.8 - 6 mm wall |
| Plates | 3 - 50 mm thk condenser plate and tube sheet (ASTM B171) |
| Fittings | 1/2" - 24" butt weld elbows, tees, reducers and stub ends |
| Flanges | 1/2" - 24", 150# - 300#, slip-on and weld neck |
Chemical composition (%)
| Element | Min | Max |
|---|---|---|
| Cu | Remainder | - |
| Ni | 29.0 | 32.0 |
| Fe | 1.70 | 2.30 |
| Mn | 1.50 | 2.50 |
| Pb | - | 0.02 |
Mechanical properties
| Property | Value | Unit |
|---|---|---|
| Yield Strength (0.2%) | 170 min (annealed) | MPa |
| Tensile Strength | 415 min (annealed) | MPa |
| Elongation | 28 min | % |
| Hardness | 90 - 120 | HV |
Physical properties
| Property | Value | Unit |
|---|---|---|
| Density | 8.90 | g/cm3 |
| Thermal Conductivity | 27 | W/m.K |
| Max Service Temperature | 400 | C |
| Max seawater velocity | 5.0 | m/s |
Typical applications
Frequently asked
[ 02 ] Other grades in Cupro Nickel
Cupro Nickel 90/10 Seamless Pipes
Mill indentThe default seawater alloy. 90% copper with 10% nickel and a controlled iron addition builds a protective cuprous oxide film in seawater, and the inherent copper toxicity stops macrofouling — barnacles and mussels do not settle, so cooling lines stay clean without chlorination. Specified for ship and platform seawater systems, firewater ring mains and condenser tubing where the velocity stays below about 3.5 m/s.
Cupro Nickel 70/30 Seamless Pipes
Mill indentThe higher-duty cupro nickel. Tripling the nickel to 30% raises strength, erosion-corrosion resistance and the allowable seawater velocity to around 4.5 m/s, and lifts the service temperature well above 90/10. It is the grade for pump and valve-adjacent piping, hot brine and MSF desalination heat recovery, and any line where turbulence or sand loading would strip the film off 90/10.