When building a costly industrial facility, a major consideration is enduring that the facility’s design life is attained. Corrosion can weaken improperly protected structures prematurely, making expensive repairs or replacement necessary. Zinc’s corrosion rate is only a small fraction of that of steel because of the protective corrosion product layer, which forms on the zinc surface. This allows a thin coating of zinc to last for the life of a facility with little or no maintenance requirements. Hot dip galvanized coatings are typically 4 to 8 mils thick and provide long-term corrosion protection even in aggressive atmospheric environments.
In certain situations, it may be necessary for galvanized steel to be immersed in liquids. Galvanizing is suitable for these applications when the liquid’s pH is between 6 and 12.5 and the temperature does not exceed 55 degrees C (130 degrees F). Operating under these conditions allows a stable, protective film to form on the zinc surface.