Copper nickel is mainly composed of copper and nickel, and contains small amounts of other elements. It has beautiful yellow appearance because of the large amount of copper. The most popular copper nickel are UNS C70600 and C71500. UNS C70600 Flanges contains 90% copper and 10% nickel, so it's also called Cu-Ni 90/10 flange. C71500 flange is 70/30 copper nickel flange.

The UNS C71500 is mainly used for military submarine services due to its higher strength, maximum allowable flow rate, and low magnetic permeability. However, due to the high cost of materials, this alloy has to some extent limited its wider commercial applications. Therefore, the 'main force' is UNS C70600 (CuNi 90/10, cupronickel). This alloy exhibits a well balanced combination of characteristics, allowing for its widespread and economical use.

ASME B16.5 C70600 flanges are mainly used on the oil field. There are 5 main flange types as below:

1. Copper Nickel Weld Neck Flanges
2. Copper Nickel Slip On Flanges
3. Copper Nickel Socket Weld Flanges
4. Copper Nickel Threaded Flanges
5. Copper Nickel Blind Flanges

Advantages of UNS C70600 Flange:

ASTM B466 UNS C70600 Flange is stable and reliable at any temperature. It has good strength at moderate and elevate temperatures. At low temperatures, it maintains good mechanical properties, weld ability and high resistance to hydrogen. The great resistance to stress and erosion, excellent fabrication, high tensile strength, accurate dimensions make it largely used in seawater, aerospace, oil, chemical and gas industries.