ASTM B111 C68700 Aluminum Brass Tube for Heat Exchanger and Condenser

ASTM B111 C68700 aluminum brass tube is a seamless copper alloy tube designed for heat exchangers and condensers. C68700 tubes are especially adapted to resist corrosion by both salt and brackish waters.

We can supply tubes in copper and copper alloys for many applications:

Seamless tubes for heat exchanger and condensers

Seamless copper tubes for water and gas in sanitary and heating applications

Seamless copper tubes for air conditioning and refrigeration

Seamless round tubes for general purpose

We successfully supplied ASTM B111 C68700 aluminum brass tubes to a customer in India for shell & tube condenser applications. During the project, the customer visited our facility for production inspection and quality verification. All tubes were manufactured in accordance with ASTM B111 requirements and delivered with complete Material Test Certificates (MTC), ensuring full heat number traceability and verified chemical and mechanical properties.

Discuss Your Project Requirements

Q1: What is the difference between C68700 and C70600 for seawater condensers?

A: C68700 is for high-velocity seawater. C70600 is for more aggressive conditions. C68700 (aluminum brass) resists impingement attack at velocities >2m/s. C70600 (90/10 copper nickel) has better overall corrosion resistance but costs about 40% more. Choose C68700 for cost-effective seawater cooling. Choose C70600 for very aggressive seawater or service life >20 years.

Q2: What is the European equivalent grade for ASTM B111 C68700?

A: EN 12451 CuZn20Al2As is the European equivalent for C68700. This standard covers seamless tubes for heat exchangers and condensers. When ordering in Europe, specify either ASTM B111 C68700 or EN 12451 CuZn20Al2As.

Q3: What is the minimum order quantity for ASTM B111 C68700 tubes?

A: MOQ is typically 500 kg for standard sizes. Common dimensions like OD 19mm or 25.4mm with 1.2-2.0mm wall thickness may be available in smaller quantities. Contact supplier for specific MOQ.

Q4: Can C68700 be used for both saltwater and brackish water?

A: Yes, C68700 is especially adapted to resist corrosion by both salt and brackish waters. The aluminum content forms a protective oxide film. The arsenic inhibitor prevents dezincification. This makes C68700 suitable for coastal power plants, desalination plants, and marine condensers.

Q5: What is the lead time for ASTM B111 C68700 seamless tubes?

A: Standard sizes: 20-30 days. Special sizes: 35-45 days. Common sizes (OD 19mm, 25.4mm, 31.8mm; WT 1.2mm, 1.5mm, 2.0mm) are often in stock. Contact supplier for current availability.

Q6: What is the maximum operating temperature for C68700?

A: Continuous service up to 300°C. Above this temperature, dezincification accelerates and mechanical properties decrease. For high-temperature applications above 300°C, C71500 (70/30 copper nickel) is recommended as noted on the source page.

Q7: What test reports are provided for ASTM B111 C68700 tubes?

A: EN 10204 3.1 mill test certificates are standard. Reports include chemical composition, tensile strength, yield strength, elongation, flaring test, flattening test, and eddy current test. Third-party inspection (SGS, BV, TUV) is available at extra cost.

Q8: Can non-standard C68700 products be supplied?

A: Yes, non-standard C68700 products can be supplied on customer request. Custom options include: outer diameter outside 3-70mm range, wall thickness outside 0.2-5mm range, special lengths beyond 12m, non-standard tolerances, and custom tube forms (square, rectangular, hydraulic). MOQ for non-standard products is typically higher than standard sizes. Contact supplier with your specific drawing or specification for a custom quote.

Q9: How does C68700 compare to C44300 for condenser tubes?

A: C68700 has better resistance to high-velocity seawater. C44300 is for moderate conditions. C68700 (aluminum brass) contains aluminum and arsenic for impingement resistance. C44300 (admiralty brass) contains tin and is suited for lower velocities and moderate temperatures.

Q10: What is the difference between seamless and welded C68700 tube?

A: Seamless has no longitudinal weld seam and handles higher pressure. For ASTM B111 heat exchanger and condenser applications, seamless tubes are standard. Welded tubes have a seam that can corrode in seawater and are not recommended for critical service.

Every tube in this lot has passed third-party witnessed inspection per ASTM B111 standard for C68700 alloy. Below are actual photos from customer-onsite inspection, including eddy current testing and dimensional verification.

Inspection items verified:
• Eddy current testing (ECT) – no through-wall defects
• Outer diameter & wall thickness – within ±0.02mm tolerance
• Surface finish & temper (O61) – conforms to ASTM
• Hardness & chemical composition – certified.

After passing inspection, all tubes are packed according to export standards and customer-specific requirements. The packing process is documented below to ensure traceability and damage-free delivery.

Packing steps shown in video & images:
1. Tube cleaning & drying
2. Plastic end caps on both ends
3. VCI anti-rust paper wrapping
4. Bundle strapping with moisture barrier film
5. Plywood wooden case (ISPM-15 compliant) with foam padding
6. Labeling with ASTM grade, lot number, and inspection stamp

All ASTM C68700 tubes are produced and inspected on our in-house equipment, allowing full process control from billet casting to final packing.

Key equipment used for this lot:
• Induction melting furnace – precise alloying (Cu + Zn + Al + As)
• Horizontal continuous casting – uniform billet structure
• Extrusion press (800T / 1630T) – seamless tube forming
• Cold drawing bench (5–40m) – dimensional accuracy to ±0.02mm
• Online eddy current tester (FOERSTER / MAC) – 100% NDT
• Ultrasonic wall thickness gauge – real-time monitoring
• Annealing furnace (controlled atmosphere) – temper O61

In-house metrology: Micrometers, pin gauges, optical comparator, hardness tester (HV/HRB)

All equipment is calibrated quarterly. Production records are traceable by lot number.

Check Today's Stock & Lead Time