What is the galvanized coating on steel and iron pipes made out of?

The galvanized coating on steel and iron pipes is primarily made out of zinc. This coating is applied to provide a protective layer that helps prevent corrosion and rusting of the underlying metal. Zinc is chosen for its ability to provide cathodic protection, meaning that when the galvanized pipe is exposed to moisture, the zinc will corrode preferentially over the steel or iron, extending the lifespan of the pipes significantly.

This process of galvanization not only enhances the durability of pipes used in water distribution systems but also maintains the integrity of the water quality by preventing contamination that can arise from rust and corrosion. Other materials mentioned, such as aluminum, copper, and lead, do not serve the same purpose or possess the same protective qualities as zinc does in this context.