Zinc-Alum coating (Zn 85%-Al 15%)
According to some researches, aluminum metal creates a passive effect on surface of Iron and Zinc metal provides galvanic protection on Iron surface.
Zinc-Alum coating with combination of 85% zinc and 15% aluminum as a proper coating on ductile iron pipe has a good performance in different condition of soils and environmental circumstances.
Being together (zinc and aluminum) and Combining the advantages of bothmetals as an alloy, eventually led to the creation of a good and proper corrosion-resistant coating.
However, you should consider that according to the EN 545 in order to maintain protective properties, the Zn-Al coating thickness must beapplied at least 400 grams per square meters.