What material is used to protect galvanized steel pipe from corrosion?

Galvanized steel pipe is coated with a layer of zinc to protect it from corrosion. This process involves dipping the steel in molten zinc, which creates a barrier between the steel and the environment. Zinc is particularly effective because, even if the coating gets scratched, it can still provide protection through a process called galvanic protection—where the zinc sacrifices itself to prevent the underlying steel from corroding. This makes zinc a common and effective material for corrosion resistance in steel piping systems used in various plumbing applications. The other materials listed do not serve this specific protective purpose for galvanized steel pipe, which is why zinc is the correct choice.