Cathodic Protection System Testing

What is Cathodic Protection...

Cathodic Protection is a proven method of preventing corrosion on metal structures.

How does Cathodic Protection Work...

Imperfections in the metal alloy, differences in soil composition, aeration, and moisture combine to create electrical current flow resulting in corrosion.

A Cathodic Protection system produces electrical current that effectively reverses the corrosion causing electron flow. There are two types of Cathodic Protection systems. Sacrificial Anode systems and Impressed Current systems.

Sacrificial Anode Systems:

A protective current is created when a metal anode, made from a material more electrically active than steel, is bonded to a tank or line. However, the current produced by this type of system is generally not sufficient to protect a buried steel tank unless the tank has a protective coating from the factory.

Impressed Current Systems:

Through the use of an external power source, or rectifier, electrical current is distributed to the protected tanks through the use of properly placed anodes. The rectifier can be adjusted to produce just the right amount of current required by the existing site conditions.

Cathodic Protection System Testing...

Measuring the effectiveness of the Cathodic Protection system is required by Federal Regulations for both sacrificial and impressed currents systems. All owners and operators of UST systems required to have corrosion protection shall comply with the requirements to ensure that releases due to corrosion are prevented for as long as the UST system is used to store regulated substances.

All Cathodic Protection systems shall be tested within six months of installation and at least every three years thereafter. The criteria that is used to determine that Cathodic Protection is adequate shall be in compliance with the National Association of Corrosion Engineers (NACE).

The results of the last two Cathodic Protection system inspections by a NACE Certified Technician must be kept in your store's compliance file.