Sacrificial Anodes are highly active metals that are used to prevent a less active material surface from corroding. They are created from a metal alloy with a more negative electro-chemical potential than the other metal they are being used to protect. The sacrificial anode will be consumed in place of the metal it is protecting, which is why it is referred to as a "sacrificial".
If you would like to discuss any maintenance of commercial equipment such as this we are always happy talk and hopefully help you