Make sure your tank is not an anode

Installation of different accessories and connections of electrical equipment can result in considerable risk of corrosion if not made correctly.

INSUFFICIENT ISOLATION?

Risk of corrosion attacks increase considerably by lack of isolation.

Several underground tanks are being directly connected to copper grounding systems, making the tank an anode for the copper grounding metal. Such connections are often obtained by grounding of electrical equipment installed on the tank or associated pipes, or lack of isolation joints on pipes connected to the tank. When such connections are established the steel tank will become an anode, protecting the surrounding copper grounding. This may result in accelerated corrosion on the tank surface, and may in worst case lead to leakage.

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Lack of isolation leads to stray current

Equipment grounding

What about pumps, valves, instruments, etc., connected onto the tank, shouldn’t these be grounded for safety? A solution to avoid a direct connection with the buried tank and the grounding system is to ground any equipment to the non-protected side of the isolation joint(s). You may learn more about how to test isolation joint.

On-site service

If a cathodic protection system is installed to protect a tank connected with the copper grounding system against corrosion, more current will be required in order to protect both the tank and the nearby grounding. In such cases, more frequent control and maintenance of the cathodic protection system is required to ensure the tank is properly protected. It is vital that the cathodic protection system is in continuous operation in order to avoid accelerated corrosion.