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Is titanium or cupro-nickel better for seawater condenser tubes?
Short answer
Titanium Grade 2 is effectively immune to seawater corrosion and erosion, allowing thin walls and high velocities, and often wins on lifecycle cost for long design lives or polluted water. 90/10 and 70/30 cupro-nickel resist biofouling and suit clean seawater at moderate velocity at a lower first cost.
Key takeaways
In brief
- Titanium: Titanium Grade 2 is effectively immune to seawater corrosion and erosion at high velocities, so it can use thin walls.
- Cupro-nickel: 90/10 and 70/30 resist biofouling naturally and are easy to fabricate.
- Verdict: For long design life, polluted water or high velocity, titanium often wins on lifecycle cost.
Titanium
Titanium Grade 2 is effectively immune to seawater corrosion and erosion at high velocities, so it can use thin walls. It's prone to biofouling and needs compatible tubesheets.
Cupro-nickel
Verdict
For long design life, polluted water or high velocity, titanium often wins on lifecycle cost. For clean seawater at moderate velocity, cupro-nickel remains economical.
How the costs really compare
Titanium has a higher price per kilogram, but its low density and thin walls mean far fewer kilograms per metre of tube. On a cost-per-metre basis the gap narrows considerably, and titanium removes most corrosion-related retubing. Cupro-nickel needs thicker walls and velocity control, but it is easier to roll into copper-alloy tubesheets and naturally limits marine growth.
Design points that decide the choice
- Cooling-water quality: sulphide pollution attacks cupro-nickel
- Velocity: titanium tolerates far higher velocities than cupro-nickel
- Fouling control: titanium usually needs chlorination or mechanical cleaning
- Tubesheet and galvanic compatibility with the existing condenser
- Planned design life and outage cost
Related guides, comparisons and articles
Frequently asked questions
Can titanium tubes be fitted into an existing cupro-nickel condenser?
Yes, it is a common retubing route, but the tubesheet material, galvanic coupling and tube support spacing must be checked because titanium walls are thinner.
Which cupro-nickel grade is better for condensers?
70/30 tolerates higher velocities and some polluted waters better than 90/10, while 90/10 is the economical standard for clean seawater.
Which specifications cover these tubes?
Titanium tubes are usually ordered to ASTM B338 and cupro-nickel tubes to ASTM B111.
Does Bright Tubes supply the materials discussed in this article?
Yes. Titanium Grade 2, Cupro-Nickel 90/10 and related products are supplied from stock or mill-sourced, with EN 10204 certificates.
Can I get technical advice for my application?
Yes. Share your service conditions and specification, and our team can help shortlist suitable grades for your engineer to confirm.