Is the surface of hot dip galvanized pipe painted or not?

　　Generally, galvanized pipes do not need to be painted. If they need to be painted, they are usually painted with silver powder. After galvanizing, the surface of the steel pipe 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. For the coating of zinc on the surface of steel pipe, due to its strong chemical activity, a thin and dense layer of zinc carbonate will be formed in the air at room temperature to protect the zinc from further oxidation.

　　Therefore, the galvanized pipe, whether the surface zinc or the steel pipe itself has been protected, will not rust, do not need to brush antirust paint. Only when the galvanized layer is damaged (such as steel pipe welding, joint coating burned), the steel pipe is exposed to the air, and the protection of galvanized layer is lost, then it needs to be repainted with antirust paint.