A galvanized steel pipe is generally called a cold-plated pipe. It adopts an electroplating process and only the outer wall of the steel pipe is galvanized. The inner wall of the steel pipe is not galvanized.
Hot-dip galvanized steel pipes use a hot-dip galvanizing process, and the inner and outer walls of the steel pipes have zinc layers.

the difference:
1. The processes are different: chemical treatment and physical treatment; the hot-dip galvanized coating is firm and not easy to fall off.
2. The hot-dip galvanized coating is thick, so it has strong anti-corrosion ability. Galvanizing (electroplating) has a uniform coating and good surface quality, and the thickness of the coating is generally between a few microns and more than ten microns.
3. Hot-dip galvanizing is a chemical treatment and an electrochemical reaction. Galvanizing is a physical treatment. It just brushes a layer of zinc on the surface. There is no zinc plating inside, so the zinc layer easily falls off. Hot dip galvanizing is often used in building construction.
4. Hot-dip galvanized steel pipe reacts molten metal with the iron matrix to produce an alloy layer, thereby combining the matrix and the coating.