California ICC UST Inspector Practice Exam

Which type of product piping requires cathodic protection?

1. Single-walled steel

2. Single-walled fiberglass

3. Thermoplastic flex piping

4. Double-walled fiberglass

The correct answer is: Single-walled steel

Single-walled steel product piping requires cathodic protection because it is susceptible to corrosion when buried underground or exposed to moisture. Steel, being a metal, can undergo electrochemical reactions in the presence of an electrolyte, which can lead to rust and deterioration over time. Cathodic protection is a technique used to control the corrosion of metal surfaces by making them the cathode of an electrochemical cell. In the case of single-walled steel piping, this protection is essential to ensure the integrity and longevity of the piping system, especially when transporting hazardous materials. While other materials, such as fiberglass and thermoplastic, are generally more resistant to corrosion, single-walled fiberglass and double-walled fiberglass piping do not require cathodic protection as they do not corrode in the same way as steel. Similarly, thermoplastic flex piping, which is also non-metallic, does not undergo corrosion like steel does. Therefore, the requirement for cathodic protection is specifically applicable to single-walled steel piping due to its vulnerability to environmental factors that lead to corrosion.