What may cause galvanized iron pipe to corrode excessively?

The excessive corrosion of galvanized iron pipe is primarily influenced by its direct connection to brass and other dissimilar metal fittings. When these different metals are connected, it creates a galvanic cell where one metal (in this case, galvanized iron) may corrode at an accelerated rate compared to what would occur under normal conditions. This happens because of the electrochemical reaction where the more reactive metal (such as galvanized iron) will sacrifice itself to protect the less reactive metal, leading to increased corrosion.

This type of corrosion can be particularly problematic in plumbing systems where multiple types of metals are frequently used together. It’s important to use compatible materials to avoid these types of issues in water distribution systems.

Exposure to high temperatures, improper installation techniques, and prolonged periods of inactivity are factors that can affect pipes in general, but they are not as directly responsible for galvanic corrosion as the presence of dissimilar metals in the system.