Copper Alloy 122 (C12200), also known as DHP Copper Tubing, is a high-performance copper alloy designed for superior thermal conductivity, corrosion resistance, and ease of fabrication. Composed of 99.9% copper with 0.015–0.040% phosphorus, this alloy is deoxidized to improve weldability and resistance to hydrogen embrittlement - making it ideal for high-pressure, high-temperature, and corrosive environments.
Alloy C122 copper tubing is the primary alloy used in heating, cooling and plumbing applications. Due to the small amount of phosphorus, it enhances the deoxidizing properties, making it better resistant to oxidation and other forms of corrosion. GNEE supplies this alloy in various forms compliant with ASTM B111 and other relevant standards.
ASTM B111 Compliance for Heat Exchanger Tubes
ASTM B111 is the standard specification for seamless copper and copper-alloy heat exchanger tubes. C12200 manufactured by GNEE to ASTM B111 is suitable for:
Shell-and-tube heat exchangers
Condensers (including sugar refineries and power plants)
Evaporators
Fluid-to-fluid thermal transfer systems
Key requirements under ASTM B111 for C12200 include:
| Parameter | ASTM B111 Requirement for C12200 |
|---|---|
| Chemical Composition | Cu ≥ 99.9%, P 0.015–0.040% |
| Tensile Strength (O61 temper) | 30–45 ksi (205–310 MPa) |
| Yield Strength (O61 temper) | 10–15 ksi (69–103 MPa) |
| Elongation (O61 temper) | ≥ 35% (in 2″ or 50 mm) |
| Flattening Test | No cracks after flattening to specified distance |
| Expansion Test | No cracks after expanding 30% (for annealed tubes) |
| Hydrostatic Test | Leak-free at specified pressure |
GNEE can supply C12200 tubes fully certified to ASTM B111 with traceable mill test reports.
C12200 Designations & Equivalents
| Standard | Designation |
|---|---|
| UNS Number | C12200 |
| CDA Number | 122 |
| EN Number | CW024A |
| EN Symbol | Cu-DHP |
Chemical Composition
| Element | Percentage |
|---|---|
| Copper (Cu) | 99.9% |
| Phosphorus (P) | 0.015 – 0.040% |
Available Sizes & ASTM B111 Dimensional Tolerances
| Form | Outside Diameter (OD) | Wall Thickness | Length |
|---|---|---|---|
| Straight Lengths | 0.040″ – 2.625″ | 0.004″ – 0.250″ | 0.125″ – 504″ |
| Copper Coils | 0.040″ – 0.875″ | 0.005″ – 0.250″ | Continuous |
| U-Bends | Per ASTM B111 | Per ASTM B111 | Custom radii |
ASTM B111 dimensional tolerances (typical for heat exchanger tubes):
OD tolerance: ±0.002″ for OD ≤ 1″, ±0.003″ for OD 1–2″
Wall thickness tolerance: ±10% of nominal
Temper: O61 (annealed) is standard for bending and expanding
Equivalent Standards
| Standard | Specification |
|---|---|
| ASTM | B42, B68, B75, B111, B88, B280, B360, B447, B543, B743, B395 |
| ASME | SB75, SB111 |
| Military | MIL-T-24107B |
| JIS | H3300 |
| DIN | 12449, 12450, 12451, 1785 |
| EN | 12449, 12450, 12451 |
Most common for heat exchangers: ASTM B111. For general tubing: ASTM B75. For water lines: ASTM B88.
Industry Applications for ASTM B111 C12200 Tubes
| Industry / System | Specific Use Cases |
|---|---|
| Thermal / Power | Cooling systems, heat exchangers, condensers, evaporators, heat-sink components |
| Chemical Processing | Corrosive fluid handling, high-temperature lines |
| Aerospace & Defense | Hydraulic lines, cooling loops |
| HVAC & Refrigeration | Heat exchanger coils, condensers, U-bends, connection lines |
| Fluid & Gas Lines | Medical gas, oil and gas, distillery, hydraulic, refrigeration lines |
| Electrical | Connectors, terminals, heat-sinks |
| Plumbing & Water Systems | Water tubes, fittings, solar thermal panels |
Mechanical Properties (Typical for ASTM B111 O61 Temper)
| Property | Value (Metric) | Value (English) |
|---|---|---|
| Tensile Strength | 205 – 310 MPa | 30 – 45 ksi |
| Yield Strength (0.5% ext.) | 69 – 103 MPa | 10 – 15 ksi |
| Elongation (in 2″ or 50 mm) | ≥ 35% | ≥ 35% |
| Rockwell Hardness (F scale) | 40 – 65 HRF | 40 – 65 HRF |
Physical Properties
| Property | Value (Metric) | Value (English) |
|---|---|---|
| Density | 8.94 g/cm³ | 0.323 lb/in³ |
| Thermal Conductivity @ 20°C | 339 W/m-K | 196 BTU/ft²/ft/h/°F |
| Melting Point | 1083°C | 1981°F |
| CTE, linear @ 20–300°C | 17.7 × 10⁻⁶/°C | 9.8 × 10⁻⁶/°F |
| Specific Heat Capacity @ 20°C | 0.0920 cal/g-°C | 0.0920 BTU/lb-°F |
FAQ
1. What is the main difference between ASTM B111 and ASTM B75 for C12200 tube?
ASTM B111 is specifically for seamless heat exchanger and condenser tubes, with additional testing requirements (flattening, expansion, hydrostatic). ASTM B75 is the general specification for seamless copper tube used in plumbing, HVAC, and mechanical applications. For heat exchanger service, ASTM B111 is required.
2. Does C12200 comply with ASTM B111 for use in shell-and-tube heat exchangers?
Yes, C12200 is listed in ASTM B111 as an approved alloy. It requires a chemical composition of 99.9% Cu min, 0.015–0.040% P, and must meet mechanical properties including ≥35% elongation and passing flattening/expansion tests in the O61 (annealed) temper.
3. What temper of C12200 is typically supplied under ASTM B111?
O61 (annealed) is the standard temper for ASTM B111 heat exchanger tubes. Annealed tubes are soft enough to be expanded into tube sheets and bent into U-bends without cracking. Hard drawn (H80) is not permitted for heat exchanger tubes under ASTM B111.
4. What is the equivalent European standard for C12200 under EN 12451?
Cu-DHP (EN CW024A) under EN 12451 is the direct European equivalent to ASTM B111 C12200. Both standards cover seamless tubes for heat exchangers with nearly identical chemical and mechanical requirements.
5. Can C12200 ASTM B111 tubes be used for U-bends in condensers?
Yes, ASTM B111 includes specific requirements for U-bends. The tube must be annealed (O61 temper) and the bending radius is typically 1.5× to 2× the tube OD. After bending, the tube must show no cracks and still meet the flattening test requirement.
6. What is the maximum operating temperature for C12200 under ASTM B111?
C12200 can be used continuously up to ~300°C (572°F) in heat exchanger service. Above this temperature, creep and oxidation accelerate. For higher temperatures (up to 400°C), consider C70600 (copper-nickel) or stainless steel.
7. Does ASTM B111 require a hydrostatic test for C12200 tubes?
Yes, ASTM B111 requires each tube to withstand a hydrostatic test (or an eddy current test as an alternative). Typical test pressure is calculated based on tube dimensions, with no leakage permitted.
8. What is the yield strength requirement for C12200 under ASTM B111?
ASTM B111 specifies a yield strength of 10–15 ksi (69–103 MPa) for C12200 in the O61 temper (0.5% extension under load). This ensures the tube can be expanded into tube sheets without cracking.
9. Can C12200 ASTM B111 tubes be welded or brazed into a tube sheet?
Yes, C12200 is designed for brazing and welding. The phosphorus deoxidation prevents hydrogen embrittlement. Brazing is most common for tube-to-tube sheet joints in heat exchangers. TIG welding is also possible but less common for thin-wall tubes.
10. What is the difference between C12200 and C14200 for ASTM B111 applications?
C12200 (Cu-DHP) contains 0.015–0.040% phosphorus and is the standard choice for most heat exchangers. C14200 (phosphorus-deoxidized, arsenical) contains 0.15–0.50% arsenic for improved corrosion resistance in ammoniacal environments (e.g., some refinery condensers). For most water and steam applications, C12200 is sufficient and more cost-effective.
11. How can I get a certified mill test report for C12200 to ASTM B111?
GNEE provides traceable mill test reports (MTR) for all C12200 tubing supplied to ASTM B111. The report includes: chemical analysis, tensile results, flattening/expansion test results, hydrostatic test pressure, and heat number. Request directly from GNEE sales with your size and quantity requirements.
Our copper product packaging
Our copper products are carefully packed using strong wooden cases, moisture-proof paper, plastic caps for tube/pipe ends, and steel strapping to ensure protection during long-distance sea or air freight.
Each layer is separated with foam or plastic spacers to prevent scratching and deformation, while standard export seaworthy packaging meets ISPM-15 requirements. Clear product labels (grade, size, quantity, heat number) are attached to each bundle or coil, and additional anti-tarnish paper is added for high-humidity destinations to guarantee that the copper tubes, sheets, rods, wires, and strips arrive in perfect condition at your warehouse.
Our factory
Our factory is equipped with integrated production lines for copper tubes, sheets, rods, wires, and strips, featuring advanced extrusion, rolling, drawing, and annealing machinery. We utilize precision equipment such as continuous casting and rolling lines, high-speed wire drawing machines, and hydraulic presses to ensure consistent dimensions and surface quality. For quality control, we have an in-house testing center equipped with spectrometers, tensile testers, hardness testers, eddy current flaw detectors, and metallographic microscopes, enabling us to monitor material composition, mechanical properties, and surface defects at every stage of production.
