Definition - What does Ballast mean?
A ballast is a heavy or high-density solid material used to support the fixture of roof membranes steadfastly in place by providing stability and control. Tanks used as a ballast can experience corrosion due to micro blistering and electroendosmotic blistering, which lead to cracking corrosion.
Corrosionpedia explains Ballast
A ballast tank that is prone to corrosion can be protected via the separations of water, the examination of design integrity and oxygen purging.