What must cast iron fittings, up to two inches in size, be when used with potable water piping?

When dealing with cast iron fittings that are up to two inches in size and intended for use with potable water piping, the requirement for these fittings to be galvanized is crucial for ensuring the safety and longevity of the plumbing system. Galvanization involves applying a protective zinc coating to the cast iron, which helps prevent corrosion and rust that could leach into the potable water supply. This coating is especially important in preventing the deterioration of the fittings when they are exposed to moisture over time.

Galvanized cast iron fittings also contribute to maintaining the integrity of the water quality by providing a barrier against the elements and reducing the risk of contaminants from the fittings themselves. In contrast, uncoated cast iron is prone to oxidation and microbial growth, which can compromise water quality. While painting and wrapping in insulation provide some level of protection, they do not effectively prevent corrosion as galvanized coatings do. Thus, for potable water systems, the use of galvanized fittings is essential to adhere to safety standards and industry regulations.