Small diameter copper tubes that can withstand the pressure of refrigerant R-744
New refrigerants like R-774 (carbon dioxide), characterized by low GWP (Global Warming Potential) have a significant drawback. The operating pressure in the system is significantly higher than the operating pressure of similar refrigerants that do not meet “green” standards.
Copper coils should have increased strength, which naturally requires thickening of the walls of copper tubes. However, there is a technology to increase the level of burst pressure without increasing the wall thickness. For this purpose, high-strength copper alloys are used.
Such alloys have already appeared on the market. They are distinguished by high corrosion resistance, good thermal conductivity and soldering.
One of these materials is C12200, which is almost pure copper (99.9%) with a low percentage of phosphorus. This material has almost the same mechanical properties as, for example, high-purity alloys C11000.
The production of copper tubes is regulated by the standard ASTM B359 “Standard specifications for seamless tubes with cast ribs of copper and copper alloys for condensers and heat exchangers”. The standard is developed by the American Society for Testing Materials (ASTM) and contains the characteristics of the material of the brand C12200.
A more modern and technological analogue C12200 is low-alloyed copper, with a small percentage of nickel, iron, tin, and other metals. These additives improve material characteristics such as; strength and resistance to deformation due to the fact that the density of particles in the microstructure is higher, and the size of the particles themselves is less.
With this technology, it is possible to improve the performance of cooling and air-conditioning systems, while at the same time reducing copper consumption.
The development and implementation of technology is supported by ICA, headquartered in New York (USA), and has offices in more than 60 countries around the world.