ASTM B111 C68700 Copper Nickel Tube for Condenser Heat Exchanger

ASTM B111 C68700 Copper Nickel Tube for Condenser, Heat Exchanger Application

ASTM B111 is a standard developed by the American Society for Testing and Materials, officially known as the "Standard Specification for Copper and Copper Aluminum Seamless Condenser Tubes and Ferrule Stock". The products under its standards are mainly copper and copper nickel seamless tubes used for condensers, heat exchangers, and their accessories (such as ring materials). C68700 is a specific copper nickel grade under this standard, belonging to the aluminum brass family.

Why is ASTM B111 C68700 copper nickel tube widely used in the heat exchange industry? 

• Good corrosion resistance: It has good resistance to corrosive media such as seawater, salt solutions, and acid solutions. In seawater environment, a dense protective oxide layer will form on the surface of the material, which can effectively resist the erosion of seawater and is suitable for equipment such as seawater desalination plants, heat exchangers, condensers, and subsea pipelines on offshore platforms.
• High strength: The tensile strength of C68700 copper nickel tube is between 360MPa and 600MPa, and the yield strength is between 80MPa and 540MPa. It has good bearing capacity and is suitable for working conditions under certain pressure and load.
• Good processing performance: It is easy to perform cold processing and can be processed into various shapes of tube fittings, such as straight tubes, bend tubes, etc., to meet the needs of different application scenarios. At the same time, its welding performance is also good, and various welding methods such as gas welding and argon arc welding can be used.
• Good thermal and electrical conductivity: This makes C68700 copper nickel tubes have good application prospects in equipment such as heat exchangers and condensers that require thermal and electrical conductivity.

ASTM B111 C68700 Copper Nickel Tube Chemical Composition

C68700 belongs to brass, specifically aluminum brass. The two most critical elements in its chemical composition are aluminum (about 1.8% - 2.5%) and arsenic (about 0.02% - 0.10%). The core function of aluminum is to form a dense, high-strength and highly adhesive aluminum oxide protective film on the surface of C68700. This protective film can significantly improve the erosion corrosion resistance and fatigue corrosion resistance of C68700 tubes in flowing seawater, brackish water and other media. At the same time, the addition of aluminum can effectively prevent the selective dissolution of zinc in environments containing chloride ions, low pH values, and high temperatures, greatly inhibit dezincification corrosion, and enhance the strength and hardness of C68700; arsenic is added specifically to inhibit dezincification corrosion, because no matter how much arsenic is present, it can form a protective barrier layer on the metal surface, further enhancing the resistance to dezincification corrosion, which makes C68700 widely applicable to seawater environments.

What applications are ASTM B111 C68700 Copper Nickel Tubes mainly used in?

• Condenser and evaporator: ASTM B111 C68700 copper nickel tubes are commonly used as fittings for condensers and evaporators due to their excellent thermal conductivity and corrosion resistance. In these devices, the tubes need to withstand the flow of high-temperature and high-pressure refrigerant, while also resisting the corrosive effects of the refrigerant. Therefore, the performance characteristics of ASTM B111 C68700 copper nickel tubes make them an ideal choice.
• Heat exchanger: In the chemical industry, heat exchanger is one of the common equipment. ASTM B111 C68700 copper nickel tubes are commonly used as fittings for heat exchangers due to their high strength and good corrosion resistance. These tube fittings need to withstand the flow of high-temperature and high-pressure chemical media, as well as resist the corrosive effects of the media. Therefore, the performance characteristics of ASTM B111 C68700 copper nickel tubes make them the preferred material in the chemical industry.
• Seawater desalination plant: In the process of seawater desalination, a large number of heat exchangers and condensers are required to remove salt from seawater. ASTM B111 C68700 copper nickel tubes are often used as fittings for these devices due to their good resistance to corrosive media such as seawater. The protective oxide layer formed on its surface can effectively resist the erosion of seawater, thereby extending the service life of the equipment.
• Marine platform: In marine platforms, various equipment and pipelines need to withstand the corrosive effects of the marine environment. ASTM B111 C68700 copper nickel tubes are commonly used as fittings for heat exchangers, condensers, and subsea pipelines in offshore platforms due to their excellent corrosion resistance
• Distiller pipeline: During the distillation process, pipelines are required to transport steam and condensate. ASTM B111 C68700 copper nickel tubes are commonly used as fittings for distiller pipelines due to their excellent thermal conductivity and corrosion resistance.
• Other occasions that require corrosion-resistant and high-strength materials: Due to the excellent corrosion resistance and high-strength characteristics of ASTM B111 C68700 copper nickel tubes, they can also be applied to other occasions that require these properties, such as heat exchangers and condenser equipment in industries such as food processing and pharmaceuticals.