Does Galvanized Pipe Rust?

Yes, but it is more corrosion-resistant and less prone to rust than ordinary steel pipes.

First, let’s explain what galvanized pipe is. Galvanized pipe is steel pipe coated with a layer of zinc. Currently, there are two common methods: hot-dip galvanizing and Pre-galvanized.

• Hot-dip galvanizing involves a chemical reaction between molten zinc and the steel surface of the pipe, forming a strong zinc coating.
• Pre-galvanized uses an electrolytic process to form a thin zinc coating.

The purpose of galvanized pipe is to protect the steel, making it less prone to rust and extending its service life. However, it is not completely rust-proof. Rust may occur if the zinc coating is damaged or if the corrosive environment is more severe than anticipated.
Forms of rust on galvanized pipe:
1. White rust: The zinc coating has corroded due to prolonged exposure to a damp, poorly ventilated environment.
2. Red rust: The internal steel has begun to corrode.

How can rust on galvanized steel pipes be prevented? Properly planning the thickness of the zinc coating, assessing the severity of the operating environment, and performing regular maintenance can all extend the service life of galvanized pipes and prevent rust.