C71500 Copper Nickel Pipe is a 70/30 copper-nickel alloy - meaning it contains 70% copper and 30% nickel, with small additions of iron and manganese to improve strength and corrosion resistance. It is one of the most corrosion-resistant Cu-Ni alloys, especially in seawater and marine environments.
c71500 copper nickel properties
Excellent Corrosion Resistance: Outstanding resistance to general corrosion, pitting, crevice corrosion, impingement attack (erosion-corrosion due to high-velocity fluids), and stress corrosion cracking.
Resistance to Biofouling: The nickel content helps inhibit the attachment and growth of marine organisms (barnacles, algae, etc.), reducing maintenance and improving efficiency in marine applications.
Good Mechanical Properties: Moderate to high strength, excellent ductility and formability, good weldability using various methods, and good creep resistance at elevated temperatures.
Thermal Properties: Good thermal conductivity (though lower than pure copper) and low thermal expansion.
Other Properties: Good fabricability and machinability (rated around 20% of free-cutting brass), retains properties at cryogenic temperatures, and has antimicrobial properties.
What is c71500 material?
C71500 is a copper nickel alloy known as 70/30 Copper-Nickel, meaning it contains approximately 70% copper and 30% nickel, along with small additions of iron and manganese to improve strength and corrosion resistance.
Chemical Composition:
| Copper Alloy UNS Nos. | Copper incl Silver | Nickel incl Cobalt | Lead max | Iron | Zinc | Manganese |
|---|---|---|---|---|---|---|
| C71500 | remainder | 29.0 to 33.0 | 0.05 | 0.40 to 1.0 | 1.0 | 1.0 max |
c71500 mechanical properties (tube/pipe)
| Standard Temper | Former Temper | Copper Alloy UNS Nos. | Tensile Strength, min, ksi (MPa) | Yield Strength, min, ksi (MPa) | Rockwell B Hardness 30T |
|---|---|---|---|---|---|
| 060 | Soft anneal | C71500 & C71520 | 52 (345) | 18 (125) | 51 max |
c71500 density and physical properties
| Property | Value |
|---|---|
| c71500 density | 8.94 g/cm³ |
| Melting Point | 1170 – 1240°C |
| Thermal Conductivity | 29 W/m·K |
| Electrical Conductivity | 4 – 5% IACS |
ASTM B466 UNS C71500 seamless pipes specification
| Specification | Details |
|---|---|
| Specifications | ASTM SB 466 |
| Size | 1/2" TO 6" IN OD & NB IN Various SWG & SCH |
| Outer Diameter | 4.00 to 22.00 mm |
| Wall Thickness | Between 0.15mm and 1.50 mm |
| Length | Single Random, Double Random & Required Length |
| Schedule | SCH20, SCH30, STD, SCH80, XS, SCH60, SCH120, SCH140, SCH160, XXS |
| Form | Round Pipes/Tubes, Square Pipes/Tubes, Rectangular Pipe/Tubes, Coiled Tubes, "U" Shape, Pan Cake Coils, Hydraulic Tubes |
| End | Plain End, Beveled End, Threaded |
| Grades | Copper Nickel 90/10 (C70600), Cupro Nickel 70/30 (C71500), UNS C71640 |
Standards and specifications
C71500 copper-nickel pipe is often manufactured to various industry standards, including:
ASTM B466: Standard Specification for Seamless Copper-Nickel Pipe and Tube
ASME SB-466: ASME Boiler and Pressure Vessel Code, Section II, Materials
ASTM B111: Standard Specification for Copper and Copper-Alloy Seamless Condenser Tubes and Ferrule Stock (for heat exchanger applications)
Other international standards (e.g., DIN, EN) may also apply depending on the region and application.
Copper nickel 70/30 pipe dimensions (preferred wall thicknesses)
| SPS | Outside Diameter in. [mm] | Wall Thickness Regular in. [mm] | Wall Thickness Extra Strong in. [mm] |
|---|---|---|---|
| 1/8 | 0.405 [10.3] | 0.058 [1.47] | 0.062 [1.57] |
| 1/4 | 0.540 [13.7] | 0.065 [1.65] | 0.072 [1.83] |
| 3/8 | 0.675 [17.1] | 0.065 [1.65] | 0.072 [1.83] |
| 1/2 | 0.840 [21.3] | 0.065 [1.65] | 0.072 [1.83] |
| 3/4 | 1.050 [26.7] | 0.065 [1.65] | 0.083 [2.11] |
| 1 | 1.315 [33.4] | 0.065 [1.65] | 0.095 [2.41] |
| 1 1/4 | 1.650 [42.4] | 0.072 [1.83] | 0.095 [2.41] |
| 1 1/2 | 1.900 [48.3] | 0.072 [1.83] | 0.109 [2.77] |
| 2 | 2.375 [60.3] | 0.083 [2.11] | 0.120 [3.03] |
| 2 1/2 | 2.875 [73.0] | 0.083 [2.11] | 0.134 [3.40] |
| 3 | 3.500 [88.9] | 0.095 [2.41] | 0.165 [4.19] |
| 3 1/2 | 4.000 [102] | 0.095 [2.41] | 0.180 [4.57] |
| 4 | 4.500 [114] | 0.109 [2.77] | 0.203 [5.16] |
| 5 | 5.552 [141] | 0.125 [3.18] | 0.220 [5.59] |
| 6 | 6.625 [168] | 0.134 [3.40] | 0.259 [6.58] |
What is copper-nickel pipe used for?
Marine Piping Systems
Seawater cooling systems
Ballast systems
Bilge and firefighting systems
Desalination plants
Shipboard HVAC and condensers
Heat Exchangers and Condensers
Offshore Oil & Gas Platforms
Industrial Applications: Chemical processing, paper and pulp mills, brine and slurry transport
What are the benefits of copper-nickel?
Excellent Corrosion Resistance
Biofouling Resistance
Strong Yet Ductile
Good Thermal Conductivity
Good Resistance to Scaling
Long Lifespan in Harsh Conditions
Excellent Weldability and Fabrication
Low Maintenance
Resistance to Hydrogen Embrittlement
Is copper-nickel better than stainless steel?
| Feature | Copper-Nickel (Cu-Ni) | Stainless Steel (e.g., 316L) |
|---|---|---|
| Seawater Corrosion Resistance | ⭐⭐⭐⭐⭐ Excellent (especially 70/30 alloy) | ⭐⭐⭐ Moderate to Good (susceptible to crevice corrosion) |
| Biofouling Resistance | ⭐⭐⭐⭐ Natural antifouling, less marine growth | ⭐⭐ Needs coatings or treatments |
| Thermal Conductivity | ⭐⭐⭐⭐ Good – ideal for heat exchangers | ⭐ Lower thermal conductivity |
| Strength & Hardness | ⭐⭐ Moderate (tough, but softer than steel) | ⭐⭐⭐⭐ High mechanical strength |
| Weldability | ⭐⭐⭐⭐ Very good | ⭐⭐⭐ Requires care to avoid heat-affected zone issues |
| Maintenance | ⭐⭐⭐⭐ Low (resistant to scaling and buildup) | ⭐⭐⭐ Moderate – needs cleaning in marine applications |
When Copper-Nickel is Better:
Marine environments (ships, offshore platforms, seawater piping)
Desalination plants
Systems exposed to seawater or brackish water
Heat exchangers needing corrosion and fouling resistance
Long-term performance with low maintenance
When Stainless Steel is Better:
High pressure systems needing extra mechanical strength
Clean water systems
Hygienic environments (food processing, pharma)
General industrial use where seawater isn't involved
FAQ
Q1: What is C71500 copper nickel pipe used for?
C71500 copper nickel pipe is used for marine piping systems, seawater cooling, ballast and bilge systems, desalination plants, heat exchangers, condensers, and offshore oil & gas platforms. The alloy offers excellent corrosion resistance in seawater, biofouling resistance, and good thermal conductivity. It is also used in chemical processing, paper mills, and brine transport applications.
Q2: C71500 vs C70600 – which one has better corrosion resistance?
C71500 has better corrosion resistance than C70600, especially in high-velocity and aggressive seawater. C71500 contains 30% nickel while C70600 contains only 10% nickel. For marine environments, offshore platforms, and applications with high fluid velocity, choose C71500. For lower velocity clean seawater, C70600 is more economical.
Q3: What ASTM standard covers C71500 seamless pipe?
ASTM B466 and ASME SB-466 cover C71500 seamless copper-nickel pipe. For condenser tube applications, ASTM B111 applies. Pipe sizes range from 1/2" to 6" OD with schedules from SCH20 to SCH160.
Q4: What is the density of C71500 for pipe weight calculation?
C71500 density is 8.94 g/cm³ (0.323 lb/in³). For pipe weight calculation: (OD - wall) × wall × 10.68 = lb per foot. For a 1" OD × 0.095" wall pipe, weight is approximately 0.92 lb per foot.
Q5: What is the tensile strength of C71500 pipe?
Annealed C71500 pipe has minimum tensile strength of 52 ksi (345 MPa) with minimum yield strength of 18 ksi (125 MPa). Maximum Rockwell B hardness is 51. The product must have fully recrystallized grain structure even though no minimum grain size is specified.
Q6: Is copper nickel better than stainless steel for seawater?
Yes, copper nickel (C71500) has excellent seawater corrosion resistance and natural biofouling resistance, making it better than 316L stainless steel for most marine applications. Stainless steel is susceptible to crevice corrosion in seawater and requires coatings or treatments to prevent marine growth. C71500 also has better thermal conductivity for heat exchangers.
Q7: What forms of C71500 pipe are available?
Round pipes/tubes, square pipes/tubes, rectangular pipes/tubes, coiled tubes, U-shape, pan cake coils, and hydraulic tubes. Ends can be plain, beveled, or threaded. Schedules include SCH20, SCH30, STD, SCH80, XS, SCH60, SCH120, SCH140, SCH160, and XXS.
Q8: What is the chemical composition of C71500?
C71500 contains Cu remainder, Ni 29.0-33.0%, Fe 0.40-1.0%, Mn 1.0% max, Pb 0.05 max, Zn 1.0 max. For welding applications, tighter limits apply: Zn 0.50% max, Pb 0.02% max, C 0.05% max. Silicon and titanium are limited to 0.03% max each.
Q9: Does C71500 resist biofouling?
Yes, the nickel content in C71500 helps inhibit the attachment and growth of marine organisms such as barnacles and algae. This biofouling resistance reduces maintenance requirements and improves efficiency in marine applications like seawater cooling systems and shipboard condensers.
Q10: What are the benefits of copper nickel 70/30 pipe?
Excellent corrosion resistance, biofouling resistance, high strength with good ductility, good thermal conductivity, good weldability, low maintenance, and long lifespan in harsh conditions. The alloy also retains properties at cryogenic temperatures and has antimicrobial properties.
Quality Control for C71500 Copper Pipe
Chemical verification: Each batch tested for Ni 29-33%, Fe 0.40-1.0%, Mn 1.0% max, Pb 0.05 max, Zn 1.0 max, Cu remainder.
Mechanical testing: Tensile (52 ksi min / 345 MPa min), yield (18 ksi min / 125 MPa min), hardness (51 HRB max).
Flattening test: Ensures ductility for pipe forming.
Hydrostatic testing: Each pipe pressure tested per ASTM B466.
Eddy current testing: When specified, per ASTM E243.
Dimensional inspection: OD, wall thickness, length checked per ASTM B466 tolerances.
Traceability: Test reports linked to heat numbers.
Packaging for C71500 Copper Pipe
Bundling: Pipes formed into hexagonal bundles with steel straps, plywood separators between layers.
End protection: Plastic caps on both ends.
Bundle weight: Maximum 2000 kg per bundle.
Cut length packaging: Shorter lengths packed into wooden crates.
Labels: Alloy (C71500), heat number, OD × wall, length, quantity, PO number, net/gross weight.
Factory Equipment for C71500 Copper Pipe
| Equipment | Purpose |
|---|---|
| Induction melting furnace | Precise control of Ni 29-33%, Fe 0.40-1.0% |
| Continuous caster | Produces billet for pipe extrusion |
| Extrusion press | Forms hollow pipe shell |
| Cold pilger mill | Reduces OD and wall thickness |
| Draw bench | Final sizing, straightening |
| Annealing furnace | Produces soft annealed (060) temper |
| U-bend bender | Forms U-shape pipes |
| Eddy current tester | Non-destructive testing |
| Hydrostatic tester | Leak testing |
| Metallurgical lab | Composition and mechanical verification |
