Titanium vs. Copper-Nickel: Material Selection for Desalination Condensers

MSF and MED condenser retubing programmes almost always come down to a choice between titanium and copper-nickel alloys, and the right answer depends on brine chemistry, budget and the plant’s remaining design life more than any single universal rule.

Titanium: the long-life, high-capex answer

Titanium is effectively immune to seawater and brine corrosion across the full range of conditions found in MSF and MED plants, which is why it dominates new-build condenser specifications where a 25-year design life is the target. The trade-off is both material cost and fabrication complexity — titanium tube-to-tubesheet welding requires specialist orbital welding equipment and procedures that not every fabricator carries in-house.

“Titanium doesn’t win on every retubing programme — it wins on the ones where the remaining plant life justifies a 25-year tube.”

Copper-nickel: proven, economical, velocity-sensitive

90/10 copper-nickel has decades of proven performance in desalination service and remains significantly more economical than titanium, both in material cost and in using conventional welding rather than specialist orbital equipment. Its main vulnerability is erosion-corrosion at high brine velocity — tube-side velocity limits are stricter than for titanium, which can constrain condenser sizing where flow rates are high.

How Dolphin Group approaches the selection

For retubing programmes on plants with 10+ years of remaining design life and brine chemistry at the more aggressive end of typical Gulf conditions, titanium is usually the stronger long-term economic choice despite higher upfront cost. For shorter remaining plant life, or where brine velocity can be controlled within copper-nickel’s limits, copper-nickel often delivers better lifecycle economics. We model both options against the plant’s actual remaining service life before recommending either.