COPPER–NICKEL FOR SEAWATER & HEAT-TRANSFER SYSTEMS
CuNi 90/10 & 70/30 Marine Systems
Specification-controlled sourcing of tube, pipe, fittings, flanges, plate and matching filler metal.
MNK-G.S.A coordinates copper–nickel supply by exact UNS or EN material designation, product standard, seamless or fabricated route, outside diameter, wall, length, fitting or flange standard, testing, inspection documents and delivery destination.
90/10 and 70/30 Are Separate Engineering Material Families
CuNi 90/10 and CuNi 70/30 are not interchangeable shorthand. The exact UNS or EN designation, iron and manganese limits, product form, temper, pressure or heat-exchanger standard, welding route and system design must be verified before quotation.
Material Definition and Supply Scope
CuNi 90/10
UNS C70600 and C70620 / CuNi10Fe1Mn-type families for approved marine piping, condensers, heat exchangers and related components. C70620 is intended for products that will subsequently be welded under applicable ASTM scopes.
CuNi 70/30
UNS C71500 and C71520 / CuNi30Mn1Fe-type families for higher-strength or more demanding service where the system specification explicitly selects 70/30.
Condenser and Heat-Exchanger Tubes
Seamless straight tubes, ferrule stock, replacement lengths and bundle quantities sourced by OD, minimum or average wall, temper, length and test requirements.
Marine Pipe and Tube
Straight seamless pipe and tube for general engineering or marine systems, including cut lengths and selected fabricated assemblies under the correct product specification.
Fittings and Flanges
Butt-weld, socket-weld and capillary fittings, reducers, tees, elbows, couplings, stub ends, solid or backing flanges and custom components by the project standard.
Plate, Tube Sheet and Filler
Plate, sheet, circles, tube-sheet material, clad solutions and ERCuNi-type filler supplied as a coordinated system package when the approved design requires them.
Typical Global Manufacturing Capability
ASTM Condenser Tubes
Diameter limit for the seamless condenser and heat-exchanger tubes covered by ASTM B111/B111M-24: ≤80 mm. Listed alloys include C70600/C70620 and C71500/C71520.
EN Heat-Exchanger Tubes
EN 12451:2012 covers seamless round heat-exchanger tubes within its listed copper and copper-alloy families: outside diameter 6–76 mm; wall thickness 0.5–3 mm.
EN General-Purpose Tubes
The EN 12449:2023 scope covers listed seamless drawn round copper and copper-alloy tubes: outside diameter 3–450 mm; wall thickness 0.3–20 mm. These scope limits do not promise that every CuNi grade is available at every dimensional combination.
Small-Bore Marine Fittings
KME OSNA-10 lists socket-weld and capillary-brazed 90° elbows, equal tees and equal couplings in nominal sizes 1/2–2 in. KME catalogue, PDF pp. 31–34.
Marine Flange Programme
The same programme lists solid blind flanges, Class 150, in nominal sizes 1/2–24 in; Class 300 variants are by enquiry. KME catalogue, PDF p. 25.
Complete Size Confirmation
OD, wall, length, alloy, temper, connection system, pressure class and test plan are confirmed together. Tube-standard limits are not transferred automatically to pipe, fittings or flanges.
Standards and Documentation
ASTM B111/B111M-24
Current specification for seamless copper and copper-alloy condenser tubes and ferrule stock, including listed 90/10 and 70/30 copper–nickel UNS grades.
ASTM B466/B466M-18
Current specification for seamless copper–nickel pipe and tube in straight lengths for general engineering purposes, including C70600/C70620 and C71500/C71520.
ASTM B171/B171M-24
Current specification for copper-alloy plate, sheet and circles for pressure vessels, condensers and heat exchangers, including listed CuNi grades.
EN 12451:2012
European product standard for seamless round copper and copper-alloy tubes for heat exchangers, condensers, evaporators and desalination equipment.
EN 12449:2023
Current European standard for seamless drawn round copper and copper-alloy tubes for general purposes, with defined composition, properties, dimensions and tolerances.
AWS A5.7/A5.7M:2026 / EN ISO Route
ERCuNi filler classification and the corresponding EN ISO designation are verified from the exact product certificate. EN 10204 documentation and any class or WPS approval are specified separately.
Application Context
Seawater Piping
Cooling, ballast, firewater, bilge and other seawater systems where the vessel or project design specifies CuNi and defines flow, pressure and water-quality conditions.
Condensers and Heat Exchangers
Tube, tube-sheet and replacement-bundle sourcing for marine, energy, desalination and industrial heat-transfer equipment.
Ship Repair and Offshore MRO
Small and medium replacement lots of pipe, fittings, flanges and matching filler for yards, offshore operators and maintenance contractors under approved system documentation.
Capability Note
Published dimensional ranges describe demonstrated manufacturing capability across specialist sources, not guaranteed stock and not one universal mill envelope. Diameter, thickness, width, length, condition, tolerance and quantity must be confirmed as one complete combination for each inquiry.
Send Your CuNi 90/10 & 70/30 Marine Systems Inquiry
Provide the material grade or composition, governing specification, product form, complete dimensions, quantity, inspection-document requirements and delivery destination.
Sources for the stated standard scope limits
Reviewed 11 October 2026. These limits describe the scope of the named standards, not guaranteed stock or every possible CuNi product combination.
- ASTM B111/B111M-24 - public scope (B111/B111M-24; public scope checked 2026-10-11, p. Scope 1.1)
- EN 12451:2012 - DIN Media scope summary (EN 12451:2012; DIN EN 12451:2012-08; scope checked 2026-10-11, p. Overview)
- EN 12449:2023 - DIN Media scope summary (EN 12449:2023; DIN EN 12449:2023-08; scope checked 2026-10-11, p. Einfuhrungsbeitrag)