California ICC UST Service Technician Practice Exam

What is one component that contributes to corrosion protection of underground metal piping?

1. Cathodic protection

2. Ultrasonic testing

3. Chemical coating

4. Thermal insulation

The correct answer is: Cathodic protection

Cathodic protection is a crucial component in preventing corrosion of underground metal piping, particularly for systems involving potentially corrosive environments, such as those found with underground storage tanks. This technique works by converting the underground metal structure into a cathode of an electrochemical cell. Essentially, it involves the installation of anodes which corrode instead of the metal piping, thus extending the lifespan of the piping significantly. The entire principle behind cathodic protection lies in its ability to mitigate the electrical currents that can lead to corrosion. By providing a sacrificial anode, which is a more reactive metal, cathodic protection efficiently protects the metal piping from corrosion through the ongoing cathodic reaction. This is especially important because underground metal piping is vulnerable to corrosive soil conditions, moisture, and environmental factors that lead to deterioration. While other methods like chemical coatings and ultrasonic testing may play roles in the maintenance and inspection of underground piping systems, they do not specifically address the ongoing electrochemical processes that lead to corrosion. Thermal insulation, too, primarily serves to manage temperature and does not provide active corrosion protection. Therefore, cathodic protection stands out as the dedicated method directly aimed at preventing corrosion in underground metal piping systems.