Anodes for ballast and cargo tanks

The only way of preventing corrosion to steelwork in ballast and cargo tanks, when coatings become damaged or ultimately breakdown, is to apply sacrificial anodes.

Anode types

A great variety of welded and bolted ballast tank anodes are available. Customised types and shapes can be produced on request.

Regular tank anodes

A variety of sacrificial anodes are used for protection of ballast tanks. Welded or bolted anodes with different fastening device are available.

Pitguard anodes

Pitguard anodes are specially designed to prevent pitting attack on inner bottom shell plating in tanks. They provide protection of the internal steel during ballast voyages, and during cargo voyages when residual water settles in the tank bottom.

Design basis

The tank size, shape and areas to be protected should be presented to our cathodic protection designer together with coating quality/condition and ballast routines (percentage of time the tanks are filled with ballast water, duration of ballasted periods and quality of ballast water).

If not all of the above information is available, assumptions can be made based on the volume and type of tank, and information on required lifetime.

Arrangement

Anode distribution isconsidered case-by-case based on above criterias.

In the bottom area of tanks, which are seldom completely dried, sacrificial anodes should be installed as close as possible to the bottom plates. This in order to prevent or reduce pitting corrosion starting from local coating defects.

Aluminium or zinc anodes?

Aluminium anodes are generally preferred, both from a technical and economical point of view. There are, however, some regulations regarding use of aluminium alloyed anodes in ballast tanks. Read more.