ASTM B171 C71500 Copper Nickel 70/30 Tube Sheet used in Heat Exchangers

What is tubesheet ?

A tube sheet is a plate which is used to support the tubes in a shell-and-tube heat exchanger. The tubes are aligned in a parallel way, and supported and held in place by tube sheets. The tube sheet is a circular plate which is perforated so that the tubes can fit through the openings.

Description

ASTM B171 is a standard specification that covers the resistance butt welding or pressure welding (flash welding) of copper and copper alloy tube sheets. However, there seems to be a mix-up with the alloy designation C71500 in your query.

C71500 refers to a specific type of copper-nickel alloy, commonly known as 90/10 Copper-Nickel (CuNi90/10). This alloy is often used in marine environments due to its excellent corrosion resistance, particularly against biofouling and seawater.

Chemical Composition

Physical Properties

Corrosion resistance of C71500 in seawater

Cu-Ni alloys show good corrosion resistance in seawater. On the one hand, it is because Cu itself has a low electrode potential and it is difficult to directly oxidize Cu in neutral seawater; on the other hand, it is also because Cu can form a protective oxidation product film in seawater to prevent further corrosion reactions. When the seawater environment remains basically unchanged, the properties of the surface film directly affect the corrosion resistance of copper-nickel alloys in seawater. This study has revealed the corrosion state and corrosion causes of copper-nickel alloys under different conditions to a certain extent, which is helpful to more accurately study the corrosion process of copper-nickel alloys and the effects of alloying elements on corrosion resistance.

C71500 is usually a copper-nickel-zinc alloy, sometimes also called nickel silver or German silver. The exact composition may vary slightly depending on the manufacturer or industry standard.

This alloy generally has good mechanical strength and wear resistance. It also has excellent corrosion resistance, especially in marine environments.

Application

• Heat Exchangers and Condensers
• Seawater Systems
• Oil and Gas Industry
• Chemical Processing
• Power Generation
• Desalination Plants
• Petrochemical Industry
• Shipbuilding