ASTM B111 C68700 Aluminium Brass Tubes

GNEE is a renowned manufacturer and exporter of high-quality ASTM B111 C68700 aluminum brass tubing. Utilizing cutting-edge technology and premium raw materials, we produce a wide range of products that adhere to global quality standards while remaining competitively priced.

ASTM B111 C68700 aluminum brass tubes are highly sought-after components in various industries due to their superior corrosion resistance, thermal conductivity, and workability. Made from an ideal blend of aluminum and copper alloy, they boast unique properties which make them suitable for a range of demanding applications.

Exceptional Corrosion Resistance

One of the primary advantages of ASTM B111 C68700 tubes is their exceptional corrosion resistance, making them particularly ideal for environments exposed to moisture, saltwater, or corrosive chemicals – including:

Marine engineering

Offshore oil & gas platforms

Chemical processing industries

These tubes help ensure long-term performance under difficult circumstances.

Outstanding Thermal Conductivity

ASTM B111 C68700 tubes offer outstanding thermal conductivity, making them integral components in heat exchangers and HVAC systems. Their ability to transfer heat efficiently allows for optimum performance and energy efficiency in various heating/cooling applications – be they industrial heat exchangers or residential air conditioning units.

Excellent Workability

ASTM B111 C68700 tubes provide more than just corrosion resistance and thermal conductivity; their workability allows for effortless fabrication and installation. We can shape these tubes to meet specific design requirements easily, providing seamless integration into various systems and equipment. Due to this versatility, engineers and designers often turn to C68700 tubing when seeking reliable solutions for their projects.

ASTM B111 C68700 tubes find use across numerous industries:

1. Why is UNS C68700 aluminium brass tubing preferred for offshore oil and gas platforms?

UNS C68700 aluminium brass tubing is preferred for offshore oil and gas platforms because of its exceptional resistance to saltwater corrosion and impingement attack from high-velocity waves and pumping systems. Unlike standard copper tubes, C68700 contains 1.8-2.5% aluminium, which forms a protective oxide film that self-heals in seawater, ensuring long-term reliability in harsh marine environments.

2. Can BS CZ110 aluminium brass tubes be used in chemical processing plants with acidic environments?

BS CZ110 (UNS C68700) aluminium brass tubes are suitable for mildly acidic environments but are not recommended for strong acids like sulfuric or hydrochloric acid. For chemical processing applications, C68700 performs best in neutral to slightly alkaline conditions and environments with ammonia-free exposure. For strongly acidic service, GNEE recommends stainless steel or copper-nickel alloys instead.

3. What makes EN CW702R (CuZn20Al2) tubes easier to fabricate than other copper alloys for HVAC systems?

EN CW702R (CuZn20Al2) tubes offer superior workability due to their optimized aluminium content (1.8-2.3%) and arsenic addition (0.02-0.06%) , which together prevent work hardening during bending and forming. For HVAC system fabrication, CW702R can be bent, flared, and swaged without cracking – a distinct advantage over harder copper-nickel alloys like C70600.

4. What quality tests does ASTM B111 require for C68700 heat exchanger tubes before shipment?

ASTM B111 requires the following tests for C68700 heat exchanger tubes: hydrostatic test (to verify leak-tightness), expansion test (to assess ductility), flattening test (to evaluate deformation resistance), nondestructive eddy current test (for surface defects), residual stress test (mercury nitrate test for dezincification susceptibility), and grain size analysis (0.010-0.045 mm requirement).

5. What is the typical lead time for custom-length DIN 2.0460 aluminium brass condenser tubes from GNEE?

For DIN 2.0460 aluminium brass condenser tubes in custom lengths (non-standard sizes), GNEE typically requires 3-4 weeks for manufacturing, including melting, extrusion, drawing, annealing, cutting, and inspection. For standard sizes (e.g., 19mm OD x 1.5mm wall x 6m length), lead time is 7-10 working days from order confirmation.

6. How does the arsenic (As) content in JIS C6870 T tubes prevent premature failure in seawater distillers?

The 0.02-0.06% arsenic (As) in JIS C6870 T tubes acts as an inhibitor against dezincification – a selective corrosion process where zinc leaches out of the brass alloy, leaving porous copper behind. In seawater distillers, without arsenic, aluminium brass tubes could fail within 6-12 months. With arsenic, service life extends to 10+ years in the same environment.

7. What is the maximum allowable velocity for seawater flowing through ASTM B111 C68700 tubes in power plant condensers?

ASTM B111 C68700 tubes can handle seawater velocities up to 3.0 m/s (10 ft/s) without significant impingement attack. For comparison, Admiralty brass (C44300) is limited to 2.0 m/s, and copper-nickel (C70600) can handle up to 3.5-4.0 m/s. For power plant condensers with velocities exceeding 3.0 m/s, GNEE recommends C70600 copper-nickel instead of C68700.

8. Does GNEE offer third-party inspection for CuZn20Al2 heat exchanger tubes before export?

Yes, GNEE can arrange third-party inspections for CuZn20Al2 (C68700) heat exchanger tubes from recognized agencies including BV (Bureau Veritas), SGS, TUV, DNV, Lloyds, and ABS. Inspection can cover chemical composition analysis, mechanical property testing, dimensional verification, hydrostatic testing, and eddy current examination. Additional charges and lead time (typically +5-7 days) apply.

9. What is the difference in thermal conductivity between C68700 aluminium brass and pure copper for HVAC condenser coils?

C68700 aluminium brass has a thermal conductivity of 58.0 BTU·in/hr·ft²·°F (100.4 W/m·K) , while pure copper (C11000) has 226 BTU·in/hr·ft²·°F (391 W/m·K) . However, for HVAC condenser coils, the 20-30% lower conductivity of C68700 is offset by its far superior seawater corrosion resistance – in marine HVAC systems, pure copper would corrode within months, while C68700 lasts for decades.

10. What are the standard packaging methods for ASTM B111 C68700 seamless tubes for export?

GNEE packages ASTM B111 C68700 seamless tubes using the following methods: plastic end caps (to protect ends and threads), individual polybag wrapping (to prevent moisture contact), wooden crates or steel bundles (for structural protection), waterproof paper (outer layer for container shipment), and labeled with grade, size, heat number, and quantity. Packaging complies with export standards for sea or air freight.

11. What is the minimum wall thickness available for UNS C68700 hydraulic tubing from GNEE?

GNEE offers UNS C68700 hydraulic tubing with minimum wall thickness of 0.25mm (0.010 inches) for small-diameter tubes (4-10mm OD). For larger diameters (up to 150mm OD), the minimum wall thickness is 0.5mm (0.020 inches) . Thinner walls are available upon special request, subject to minimum order quantity and additional manufacturing lead time.

12. How does GNEE ensure on-time delivery for large orders of C68700 condenser tubes?

GNEE ensures on-time delivery for large orders of C68700 condenser tubes through: dedicated production lines for high-volume orders, strategic raw material inventory (copper, aluminium, zinc in stock), automated drawing and cutting equipment (reducing processing time), real-time order tracking systems, and multiple shipping partners (air, sea, rail) to meet committed deadlines.

13. What is the difference between seamless and welded ASTM B111 C68700 tubes for refrigeration applications?

Seamless ASTM B111 C68700 tubes are cold drawn from solid billets with no weld seam, making them ideal for refrigeration applications requiring high pressure integrity (up to 60,000 psi) and corrosion uniformity. Welded C68700 tubes are not commonly produced because the aluminium content makes welding difficult and creates a heat-affected zone prone to preferential corrosion. GNEE supplies only seamless C68700 for refrigeration.

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.

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