Why doesn't cupronickel have a PREN?

Because PREN is an index specific to stainless steel's pitting corrosion resistance, a different mechanism from cupronickel's — the question doesn't apply to this family.

Does cupronickel work in fresh water?

Yes, but its main advantage — resistance to marine biological fouling — is mostly relevant in seawater or brackish water; in fresh water, stainless is often just as suitable and cheaper.

What is the lead time for a cupronickel tube order?

5 working days standard from partner stock, 48 hours for urgent needs from partner stock, or a mill lead time for planned volume — same as the rest of the catalogue.

Do you offer cupronickel as finned tube?

Yes, see the dedicated finned tubes page, available from the mill only.

COPPER ALLOYS · CUPRONICKEL

Cupronickel tube

Cupronickel 90/10 and 70/30 is the reference for marine condensers and exchangers: good thermal conductivity, natural resistance to biological fouling, seawater resistance with no PREN to calculate. Available from partner stock and mill volume.

Request a quote

What is cupronickel?

Cupronickel is a copper-nickel alloy (90/10 or 70/30 depending on the ratio), used as tube for condenser and exchanger bundles in seawater. Its corrosion resistance doesn't rely on the same mechanism as stainless steel — no applicable PREN — but on a protective oxide film forming on the surface.

How to choose it?

90/10 covers most everyday uses at a lower cost. 70/30, richer in nickel, is needed for high flow velocities and warm seawater, where 90/10 erodes faster.

Available grades

CuNi 90/10 (C70600) and 70/30 (C71500) are the two references; CuNi 95/5 is available on request for specific needs.

CuNi 90/10 (C70600)
CuNi 70/30 (C71500)
CuNi 95/5

My grade isn't listed →

Applicable standards

ASTM B111
ASME SB111
EN 12451

Partner stock or mill?

Cupronickel tube is available both from partner stock and mill volume, unlike finned tubes and tubesheets in the same cluster.

From partner stock: 48 hours for urgent needs, 5 working days as standard.

We go through the mill when volume and lead time make sense — typically container-load quantities, sometimes less, with a lead time of a few months including transport. That arbitration is ours to make: when buying at source works out cheaper for you, we say so.

Frequently asked questions

Why doesn't cupronickel have a PREN?: Because PREN is an index specific to stainless steel's pitting corrosion resistance, a different mechanism from cupronickel's — the question doesn't apply to this family.
Does cupronickel work in fresh water?: Yes, but its main advantage — resistance to marine biological fouling — is mostly relevant in seawater or brackish water; in fresh water, stainless is often just as suitable and cheaper.
What is the lead time for a cupronickel tube order?: 5 working days standard from partner stock, 48 hours for urgent needs from partner stock, or a mill lead time for planned volume — same as the rest of the catalogue.
Do you offer cupronickel as finned tube?: Yes, see the dedicated finned tubes page, available from the mill only.