What C71500 is
C71500 is 70% copper, 30% nickel, with iron and manganese. The extra nickel roughly doubles the strength of 90/10 and raises the velocity at which the protective film breaks down, so it holds up in fast, turbulent, or sulfide-polluted seawater that would erode C70600.
It is the alloy the US Navy specifies for main condensers, and the one chemical plants on the Gulf Coast reach for when 90/10 bundles start failing early.
Third-party verified
Ameritube's C71500 has been approved by customers through independent internal-diameter eddy current testing, on top of our own 100% eddy current inspection. If your specification calls for outside verification, we have done it before and can arrange it again.
Standards we supply to
- ASME SB-111 / ASTM B111, condenser and heat exchanger tube
- ASME SB-466 / ASTM B466, seamless pipe and tube
- MIL-T-16420K, Class 200 through 6000, shipboard piping
- MIL-T-15005F, naval condenser tube
Chemical composition
| Element | Requirement |
|---|---|
| Copper | Remainder (nominal 65.0%) |
| Nickel | 29.0 to 33.0% |
| Iron | 0.40 to 1.0% |
| Manganese | 1.0% max |
| Zinc | 1.0% max |
| Lead | 0.05% max |
Typical mechanical properties, annealed
| Property | Value |
|---|---|
| Tensile strength | 52,000 psi min (360 MPa) |
| Yield strength | 18,000 psi min (125 MPa) |
| Elongation in 2" | 30% min |
| Density | 0.323 lb/in3 (8.94 g/cm3) |
Where it is used
- Naval condensers and heat exchangers, surface ships and submarines.
- High-velocity seawater piping on ships and offshore platforms.
- Chemical process coolers in brackish or polluted cooling water, Gulf Coast refineries and petrochemical plants.
- Power station condensers where 90/10 has shown inlet-end erosion.
- Feedwater heaters and evaporators in marine and industrial steam plants.
Choosing between 90/10 and 70/30
Clean seawater under 10 feet per second: C70600 is usually the economical choice. Polluted, turbulent, or high-velocity water, or a design that needs more strength: C71500. Sulfide-heavy harbor water may push you to C72200. Send us the conditions and we will spec it.
OD, wall, temper, length, quantity, governing spec (SB-111, SB-466, or MIL-T-16420K class), whether ID eddy current or hydrostatic test certification is required, and any U-bend or tube-to-tubesheet requirements.