ABYC Diesel Practice Exam

What is the primary advantage of using sacrificial anodes in heat exchangers?

1. They are more durable than other materials

2. They are more anodic than other alloys in the system

3. They improve the efficiency of heat transfer

4. They reduce the cost of maintenance

The correct answer is: They are more anodic than other alloys in the system

The primary advantage of using sacrificial anodes in heat exchangers lies in their ability to provide cathodic protection to the metal surfaces within the system. Sacrificial anodes are made of materials that are more anodic than the metals they are meant to protect, such as the copper or aluminum typically found in heat exchangers. When these anodes are present, they corrode preferentially, thereby protecting the underlying metal from corrosive damage. This is particularly important in systems where electrolysis can lead to significant wear and tear on metal components. Using materials with a more anodic potential helps to extend the lifespan of the heat exchanger by mitigating the effects of corrosion, which is a common issue in marine environments where saltwater can accelerate corrosion processes. The effectiveness of sacrificial anodes in providing this type of protection is crucial for maintaining the integrity and functionality of the heat exchanger over time.