ASTM B111 Copper Nickel Condenser Tube C70600 C71500 for Marine Engineering

1. Product Description**
This copper-nickel seamless condenser tube is manufactured to ASTM B111/B111M, covering UNS C70600 (90/10 CuNi) and C71500 (70/30 CuNi) alloys. The tube is produced as a seamless product for use in surface condensers, evaporators, and heat exchangers. The addition of nickel, iron, and manganese provides excellent resistance to seawater corrosion, erosion, and biofouling, making it a preferred material for marine engineering and offshore cooling systems.

**2. Key Specifications**

• Material: UNS C70600 (90/10 CuNi) / UNS C71500 (70/30 CuNi)
• Standard: ASTM B111/B111M
• Form: Seamless tube
• Outer Diameter: 6mm – 80mm (standard range per ASTM B111); custom sizes available
• Wall Thickness: 0.5mm – 3.0mm (depending on OD and application)
• Length: Straight lengths up to 6m, or U-bend as required
• Temper: Annealed (O61), Light-Drawn (H55), or Hard-Drawn (H80)
• Chemical Composition (C70600): Ni 9.0–11.0%, Fe 1.0–1.8%, Mn ≤1.0%, Cu balance
• Chemical Composition (C71500): Ni 29.0–33.0%, Fe 0.4–1.0%, Mn ≤1.0%, Cu balance
• Mechanical Properties (C70600 Annealed): Tensile strength ≥38 ksi (262 MPa), Yield strength ≥15 ksi (103 MPa), Elongation ≥30%

**3. Applications**

Widely used in marine engineering, shipbuilding, offshore platforms, power plant surface condensers, desalination plants, seawater cooling systems, heat exchangers, evaporators, and petrochemical cooling units. C70600 is suitable for general seawater service; C71500 is preferred for high-velocity or more aggressive seawater conditions.

**4. Product Advantages**

• Excellent resistance to seawater corrosion, erosion, and impingement attack
• Natural resistance to biofouling due to copper ion release, reducing cleaning frequency
• High thermal conductivity for efficient heat transfer
• Good mechanical strength allowing thinner wall designs
• Superior performance in thermal cycling compared to welded tubes (seamless construction)
• Long service life in marine environments, reducing downtime and maintenance costs

**5. Product Functions**

The tube serves as the heat transfer surface in shell-and-tube heat exchangers and condensers. It separates two fluid streams while conducting heat through the tube wall, enabling cooling, condensation, or heat recovery. The seamless construction ensures pressure integrity and leak-free operation under marine conditions.

**6. Instruction for Use**

• Verify tube grade (C70600 or C71500) matches the cooling medium and design velocity.
• Inspect tubes for dents, ovality, or surface defects before installation.
• Cut tubes using a rotary tube cutter or fine-tooth bandsaw; remove all burrs and clean ends to bright metal. Do not use abrasive wheels on thin-wall tubes.
• For tube sheet installation: clean tube sheet holes and tube ends; apply roller expansion per specified torque and expansion depth (typically 10–15% wall reduction).
• For welding: use GTAW (TIG) with ERCuNi filler metal, 100% argon shielding, and argon purge inside the tube. Interpass temperature must stay below 150°C. Do not use pure copper filler.
• After installation, perform hydrostatic or pneumatic testing to confirm joint integrity.

**7. Precautions**

• Do not expose tubes to ammonia, sulfides, or high organic loads without monitoring; these can attack copper alloys.
• Keep tubes away from contact with carbon steel or dissimilar metals to prevent galvanic corrosion.
• Do not exceed recommended flow velocity: C70600 typically up to 3.0–3.5 m/s in clean seawater; C71500 tolerates higher velocities.
• Avoid overheating during welding or bending; C70600 becomes brittle above 200°C interpass temperature.
• Do not use steel brushes for cleaning; use stainless steel or nylon brushes.
• Store tubes in a dry, covered area away from moisture and contaminants.
• Ensure proper water treatment and pH control in closed-loop systems.

**8. Shipping Information**

• Standard export packing: wooden cases or plywood crates with plastic end caps and moisture barrier.
• U-bend tubes are packed with supports to maintain shape.
• Dispatch within 7–15 working days for stock sizes; 20–35 days for custom specifications.
• Shipping methods: sea freight (recommended for bulk orders), air freight, or express courier for samples.
• Tracking number and packing list provided upon dispatch.

**9. Payment Terms**

• T/T (bank transfer): 30% deposit, 70% balance before shipment.
• L/C at sight accepted for orders exceeding USD 20,000.
• PayPal / Western Union for sample orders.
• All prices are quoted EXW or FOB unless otherwise specified.

**10. Packaging**

• Each tube is wrapped in plastic film or VCI paper for corrosion protection.
• Tubes are bundled and secured in wooden cases or plywood crates with iron frames for sea shipment.
• Desiccant is added to absorb moisture during transit.
• U-bend tubes are individually supported to prevent deformation.
• Custom labeling, marking, and end caps available upon request.

**11. Return & After-Sales Policy**

• 7-day return or exchange for quality defects (buyer bears return freight unless defect is verified as our responsibility).
• Custom-cut or custom-bent tubes are not eligible for return unless defective.
• Warranty period: 12 months from delivery for manufacturing defects (material composition, dimensions, and mechanical properties per ASTM B111).
• Claims for shortage or transit damage must be reported within 3 working days of receipt with photo evidence.
• Technical support available for material selection, welding procedures, expansion parameters, and installation guidance.