Do galvanized steel pipes need to be painted with antirust paint?

　　After the steel pipe is galvanized, the surface is covered with a layer of zinc coating, which separates the steel pipe from the atmosphere, avoids the direct contact and corrosion of the atmosphere on the steel pipe, and is protected. However, due to the strong chemical activity of zinc, a thin and dense layer of zinc carbonate will be formed in the air at room temperature to protect zinc from being oxidized. Therefore, ASTM A53 Galvanized Steel Pipe, no matter the zinc on the surface or the steel pipe itself, is protected from rust and does not need to be painted with antirust paint. Only when the galvanized layer is damaged (such as steel pipe welding, coating burning at the joint), the steel pipe is exposed in the air, and the protection of the galvanized layer is lost, at this time, the antirust paint shall be applied again.