Galvanized steel pipes were commonly used in plumbing for water supply lines and framing in outdoor and industrial applications due to their durability and resistance to rust. However, their use has declined in residential water supply systems due to the potential for corrosion and accumulation of mineral deposits inside the pipe, which can lead to reduced water flow and water quality issues. Nowadays, they are more likely to be found in older homes or for specific non-potable water applications where corrosion resistance is a priority. Best tool for cleaning & descaling Galvanized Steel Pipes: Cleaning & Descaling Galvanized Steel Pipes goes with the same recommendations as with the Cast Iron Pipes. Use Medium Duty Chain Knockers for aggressive descaling tasks and if you prefer Heavy Duty Chain Knockers, those will also work perfectly. Descaling with Light Duty Chain Knockers in Galvanized steel pipes will most likely be more time consuming, but it will eventually get the job done.