Titanium Marine Charge Air Cooler | Anti-Seawater Corrosion Specification & Advantage
Titanium instantly forms dense TiO₂ passive film (2~5nm) when contacting seawater/oxygen; film self-repairs immediately after scratch/damage, fully blocks chloride ion penetration in seawater.
Corrosion rate in natural seawater: ＜0.001mm/year, immune to pitting, crevice corrosion & galvanic corrosion from saltwater chloride
No corrosion failure under high-temp seawater ≤82℃ (Grade7 Pd-alloy Ti up to 150℃)
Sacrificial zinc anode is NOT required (big difference vs CuNi90/10 & SS316L)
Titanium VS CuNi90/10 Seawater-Cooled CAC Key Comparison
| Item | Titanium CAC (Gr.2) | CuNi90/10 CAC |
|---|---|---|
| Seawater adaptability | Harbor polluted seawater, high sulfide, warm tropical seawater, high flow velocity＞2.5m/s | Clean open ocean seawater only; fails rapidly in polluted/sulfide harbor water |
| Service life | 25~35 years, same service life as vessel hull | 4~7 years, frequent tube pinhole leakage |
| Galvanic corrosion | Zero risk, inert metal | Easy galvanic erosion when connecting steel shell/piping, must install zinc anode regularly |
| Biofouling | Tube inner smooth; no anti-biofouling property, annual simple backwash needed | Natural anti-barnacle/biofouling via copper ion precipitation |
| Maintenance | Minimal; chemical cleaning every 5~8 years | Annual acid pickling + anode replacement + leakage plugging |
| Heat transfer | Thermal conductivity lower than CuNi; design with increased fin area to compensate | High thermal conductivity, compact structure |
| Initial cost | 2.8~4× higher raw material cost | Economical upfront investment |
| Total life cost | Low, nearly zero replacement cost | High, multiple replacement + dock repair cost |
Main Application Scenarios for Titanium Seawater CAC
Offshore platform, FPSO, chemical tanker, scrubber-equipped vessels: Polluted harbor/seawater with H₂S & ammonia (CuNi fails fast here)
Tropical/equatorial fishing vessel & coastal workboat: Year-round high-temperature seawater＞32℃
High flow rate direct seawater cooling main engine CAC (water speed＞3m/s, CuNi prone to erosion corrosion)
Naval & luxury yacht: Strict reliability requirement, avoid emergency dry-dock from cooler leakage
Advantages
✅ Full seawater corrosion resistance, eliminate tube leakage risk of seawater mixing into charge air & engine cylinder
✅ Ultra-long service life, cut lifetime maintenance & downtime loss
✅ Tolerant of dirty, silty, sulfide-contaminated inshore seawater
✅ High mechanical strength, anti-flow erosion under fast seawater circulation
Disadvantages
❌ Higher initial purchase price than CuNi90/10 unit
❌ Lower heat conductivity → slightly larger casing dimension than copper alloy cooler
❌ No natural anti-marine growth, periodic back-flushing to clear shell fouling is needed
