Copper Nickel Flange ASTM B151 UNS C70600 Heat Exchanger Application

Copper Nickel Flange ASTM B151 UNS C70600 Heat Exchanger Application

The modulus of elasticity (C71500 annealed) of the copper-nickel flange is 22,000 ksi (152 GPa). The yield strength (annealed) of the copper-nickel WNRF flanges is 15,000 psi (103 MPa).The density of ASME SA151 copper-nickel threaded flanges is 0.323 lb/in³ (8.94 g/cm3). The Poisson's ratio for copper-nickel threaded flanges (C71500 annealed) is 0.325. The pressure rating of these copper-nickel blind flanges is very important as it determines what kind of copper-nickel industrial flanges can be used, for what purpose and in which industry. Cu-Ni grade forged flanges are weldable and show resistance to scaling and very good corrosion resistance. ANSI B16.5 Cooney Ring Joint flanges show excellent resistance to corrosion (especially seawater), cavitation and erosion. Cu-Ni RTJ flanges show good weldability. ASTM A151 Cu-Ni threaded flanges are durable and, most importantly, they are inexpensive. They are used in process equipment, hydraulic lines, automotive components, underwater enclosures, marine hardware components, feedwater heaters, pump components, heating cables and air conditioning plants.

Characteristic

Copper-nickel alloys have excellent resistance to seawater corrosion, biofouling and resist attack by corrosion and erosion.

The corrosion resistance of copper-nickel alloys is due to the presence of a protective surface film of copper-nickel oxide, which is firmly bound to the metal and virtually insoluble in water. This oxide film protects the pipes from further attack. The protective oxide film takes about three months to stabilise. It is therefore recommended that newly made copper-nickel alloy pipes are not exposed to corrosive environments. The corrosion rate in static seawater is approximately 0.1 mm/year. Once a protective film has formed, the corrosion rate is reduced to 0.01 mm/year. In acidic environments (e.g. H2S) the corrosion rate increases sharply as the sulphide ions destroy the protective oxide film.
In continuous use systems, excessively high flow rates can destroy the protective film by erosion. At flow rates of approximately 3.5 m/s, the copper oxide film is destroyed by erosion. To limit the rate of erosion, copper-nickel piping systems can be larger in diameter than equivalent steel piping systems.

Chemical Composition of B151 UNS C70600

Mechanical Properties of B151 UNS C70600

Equivalent Grades

Application

Offshore fire water systems

Tubes for power plants and ships

Hear Exchanger

Condensers

Pumps, valves, sheathing and fittings for ship hulls