Galvanized greenhouse pipes are first subjected to acid pickling to remove the iron oxide from the surface of the steel pipes. After pickling, they are cleaned in a槽 containing an ammonium chloride or zinc chloride aqueous solution, or a mixture of both. Then, they are sent to a hot-dip galvanizing tank. Hot-dip galvanizing offers advantages such as even coating, strong adhesion, and long service life. The base steel of hot-dip galvanized pipes undergoes complex physical and chemical reactions with the molten galvanizing liquid, forming a tightly structured, corrosion-resistant zinc-iron alloy layer. This alloy layer merges with the pure zinc layer and the base steel of the pipe, resulting in excellent corrosion resistance.