What is the primary purpose of cathodic readings for underground propane tanks?

What is the primary purpose of cathodic readings for underground propane tanks?

• A. Test valve integrity
• B. Assess corrosion protection
• C. Measure vapor pressure
• D. Determine gas purity

Answer: (B)

Cathodic readings are used to verify the effectiveness of the corrosion protection system for underground steel propane tanks. By measuring the tank’s electrical potential against a reference electrode in the soil, you can tell whether the protective current (from sacrificial anodes or an impressed current system) is producing a sufficiently negative potential to prevent rusting. If the reading shows the tank is adequately protected, corrosion is being inhibited. If it’s not enough, adjustments to the protection system—such as adding or reconfiguring anodes or correcting wiring—may be needed. These readings aren’t about valve leaks, vapor pressure, or gas purity, which is why they’re not used for those purposes.

Cathodic readings are used to verify the effectiveness of the corrosion protection system for underground steel propane tanks. By measuring the tank’s electrical potential against a reference electrode in the soil, you can tell whether the protective current (from sacrificial anodes or an impressed current system) is producing a sufficiently negative potential to prevent rusting. If the reading shows the tank is adequately protected, corrosion is being inhibited. If it’s not enough, adjustments to the protection system—such as adding or reconfiguring anodes or correcting wiring—may be needed. These readings aren’t about valve leaks, vapor pressure, or gas purity, which is why they’re not used for those purposes.