1-1/4 CuNi 90/10 Pipe
1-1/4" CuNi 90/10 Pipe is a copper nickel pipe made from 90% copper and 10% nickel alloy, commonly identified as C70600, CuNi 90/10, or Copper Nickel 90/10 Pipe. It is widely used in seawater piping, shipbuilding, offshore platforms, desalination plants, heat exchangers and marine engineering projects.
Thanks to its excellent resistance to seawater corrosion, biofouling and erosion, CuNi 90/10 pipe is often selected for systems where long service life and stable performance are required. Compared with ordinary carbon steel or stainless steel in marine environments, copper nickel alloy offers better durability and lower maintenance in many seawater applications.
If you are sourcing other sizes, you can also view our full range of Copper Nickel Pipe or check the complete CuNi 90/10 Pipe product series.
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What Is 1-1/4" CuNi 90/10 Pipe?
A 1-1/4 inch CuNi 90/10 pipe usually refers to a nominal pipe size of 1-1/4". The common outside diameter for NPS 1-1/4 pipe is approximately 1.660 inch / 42.16 mm, while wall thickness can be supplied according to project requirements, such as Schedule 40, Schedule 80 or customized wall thickness.
CuNi 90/10 alloy contains copper as the base element with around 10% nickel, plus small additions of iron and manganese. These elements help improve strength and corrosion resistance, especially in flowing seawater.
For matching components, we can also supply Copper Nickel Fittings, including elbows, tees, reducers, flanges and welding neck fittings for complete piping systems.
Specifications of 1-1/4" CuNi 90/10 Pipe
| Item | Description |
| Product Name | 1-1/4" CuNi 90/10 Pipe |
| Material Grade | C70600 / CuNi 90/10 / Copper Nickel 90/10 |
| Nominal Size | 1-1/4 inch |
| Typical OD | 1.660 inch / 42.16 mm |
| Wall Thickness | SCH 40, SCH 80 or customized |
| Type | Seamless or welded pipe |
| Standards | ASTM B466, ASTM B467, EEMUA 144, DIN, EN or project standard |
| Surface | Pickled, bright, sandblasted or as required |
| Length | Fixed length, random length or cut-to-size |
| Testing | PMI, hydrostatic test, eddy current test, visual inspection, dimensional inspection |
| Application | Marine piping, offshore, shipbuilding, desalination, heat exchangers |
Need a different alloy for higher strength seawater service? You may compare it with CuNi 70/30 Pipe for more demanding marine applications.
Available Supply Options
We can supply 1-1/4" CuNi 90/10 Pipe in different forms to match your project schedule:
- Seamless CuNi 90/10 pipe
- Welded CuNi 90/10 pipe
- Cut-to-length pipe
- Pipe spool fabrication
- Pipe with matching fittings
- Custom wall thickness
- Project-based packing and marking
- Third-party inspection support
If you already have drawings, MTO or project specifications, send them to our team for review through the Request a Quote page.
Key Features of 1-1/4" CuNi 90/10 Pipe
Excellent Seawater Corrosion Resistance
CuNi 90/10 pipe forms a protective surface film in seawater, helping reduce corrosion and extend service life. This makes it a preferred material for marine and offshore piping systems.
Good Resistance to Biofouling
Copper nickel alloy naturally helps limit marine organism attachment, reducing fouling problems inside seawater systems and improving long-term flow performance.
Stable Performance in Flowing Seawater
The alloy performs well in seawater cooling systems, fire water lines, ballast systems and bilge systems, especially where continuous flow and saltwater exposure are involved.
Easy Fabrication and Welding
1-1/4" CuNi 90/10 Pipe can be welded, brazed and fabricated using proper procedures. It is suitable for prefabricated pipe spools and on-site installation.
Lower Maintenance Cost
Although copper nickel pipe may have a higher initial cost than some conventional materials, its corrosion resistance and long service life can help reduce maintenance and replacement costs over time.
Chemical Composition of CuNi 90/10 Pipe
Typical chemical composition of C70600 copper nickel alloy:
| Element | Content |
| Copper | Balance |
| Nickel | 9.0% – 11.0% |
| Iron | 1.0% – 1.8% |
| Manganese | Max 1.0% |
| Zinc | Max 1.0% |
| Lead | Max 0.05% |
| Other Elements | According to applicable standard |
Chemical composition may vary slightly depending on the selected standard and customer specification.
Common Applications
1-1/4" CuNi 90/10 Pipe is commonly used in:
- Shipbuilding seawater piping systems
- Offshore platform fire water lines
- Desalination plant piping
- Seawater cooling systems
- Heat exchanger and condenser lines
- Ballast and bilge piping
- Marine hydraulic lines
- Coastal power plant seawater systems
- LNG and FPSO auxiliary piping
- Naval and commercial vessel piping systems
Why Choose CuNi 90/10 for Marine Piping?
Marine piping systems need materials that can handle saltwater, oxygen, flow velocity and long working cycles. CuNi 90/10 has become a trusted material because it combines corrosion resistance, mechanical stability and good workability.
In many seawater systems, failure is not only caused by general corrosion. Erosion corrosion, pitting, crevice corrosion and fouling can also create maintenance problems. Copper nickel 90/10 pipe helps reduce these risks when the pipe is correctly designed, installed and operated.
For shipyards, offshore contractors and engineering companies, using CuNi 90/10 pipe can support safer operation and more predictable maintenance planning.
Quality Control
Each batch of 1-1/4" CuNi 90/10 Pipe can be supplied with inspection documents according to order requirements. Available quality checks include:
- Material certificate review
- Chemical composition analysis
- Mechanical property testing
- Dimensional inspection
- Wall thickness measurement
- Visual surface inspection
- Hydrostatic pressure test
- Non-destructive testing if required
- Packing inspection before shipment
Packaging and Delivery
To protect the pipe surface during transportation, CuNi 90/10 pipes are usually packed with plastic caps, waterproof wrapping, wooden cases or bundled packing depending on size, quantity and shipping method.
For export orders, clear product marking can be provided, including size, material grade, standard, heat number and purchase order number. Customized marking is also available for project traceability.
FAQs about 1-1/4 CuNi 90/10 Pipe
What is the material grade of 1-1/4" CuNi 90/10 Pipe?
The common material grade is C70600, also known as CuNi 90/10 or Copper Nickel 90/10.
What is the outside diameter of 1-1/4" CuNi 90/10 Pipe?
For NPS 1-1/4 pipe, the typical outside diameter is approximately 1.660 in (42.16 mm).
Can you supply both seamless and welded CuNi 90/10 pipe?
Yes. We supply both seamless and welded CuNi 90/10 pipes according to project specifications, ASTM standards, and customer technical requirements.
Is CuNi 90/10 pipe suitable for seawater service?
Yes. CuNi 90/10 pipe is widely used in seawater cooling systems, desalination plants, offshore platforms, and marine piping because of its excellent resistance to seawater corrosion and biofouling.
What information should I provide to request a quotation?
Please provide the pipe size, wall thickness (or schedule), material standard, quantity, pipe type (seamless or welded), length, destination port, and any testing or certification requirements.
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