Home · Why Cu-Ni
The material

Why copper-nickel
for seawater.

For marine and offshore seawater piping, copper-nickel is the reference material - it resists corrosion, shrugs off biofouling and lasts for decades. Here is why 90/10 and 70/30 are specified worldwide.

01

Built for seawater

Copper-nickel forms a tenacious protective oxide film in seawater, giving excellent resistance to general corrosion, pitting and erosion-corrosion - even at service velocities that attack other alloys.

02

Naturally anti-fouling

The copper surface resists marine biofouling without biocides, so lines stay clear and flow rates hold over years of service - critical for firewater, cooling and ballast systems.

03

Decades of service life

Proven across shipbuilding and offshore since the 1950s, Cu-Ni seawater systems routinely deliver 25+ years of reliable service with low maintenance.

Grades

90/10 and 70/30 - which one

GradeCompositionTypical useMax seawater velocity
Cu-Ni 90/10~90% Cu, 10% NiGeneral seawater piping, most marine systems~3.5 m/s
Cu-Ni 70/30~70% Cu, 30% NiHigher strength / temperature / velocity duty~4.5 m/s
Applications
Shipbuilding seawater systemsOffshore firewater Cooling & ballastDesalinationOil & gas platforms

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