California ICC UST Service Technician Practice Exam

Which approved cathodic protection methodologies exist?

1. Impressed current systems only

2. Sacrificial anodes only

3. Both sacrificial anodes and impressed current system

4. No approved methodologies exist

The correct answer is: Both sacrificial anodes and impressed current system

The correct answer identifies that both sacrificial anodes and impressed current systems are approved methodologies for cathodic protection. This is important because cathodic protection is a technique used to prevent corrosion on metal surfaces, particularly for underground storage tanks (USTs) and pipelines. Sacrificial anodes work by using a more reactive metal that corrodes preferentially, thereby protecting the structural steel or metal that needs safeguarding. The sacrificial anode is attached to the structure, and as it corrode, it prevents the corrosion of the metal surface. Impressed current systems, on the other hand, utilize an external power source to drive a current through the electrolyte to the metal surface. This creates a protective layer by reversing the electrochemical reactions that cause corrosion. Both methods are recognized as effective in providing cathodic protection and are integral to maintaining the structural integrity of installations subject to corrosion. The existence of these methods underscores the importance of using suitable techniques in order to ensure safety and compliance with regulatory standards.