First, the production process and surface treatment of TDG pipe

TDG pipe is the ordinary steel pipe soaked in the tank heating, after a series of pretreatment, the surface is plated with a layer of zinc. 

The thickness of the galvanized layer is generally 5~30μm, and it is uniform and has strong adhesion. 

TDG pipe surface smooth, strong, good corrosion resistance.

Second, the production process and surface treatment of HDG pipe

The HDG pipe is to acid clean the surface of the steel pipe, and then dip into the molten galvanized tank containing zinc salt, 

and form a zinc-iron alloy layer and pure zinc layer on the surface of the steel pipe through chemical reaction. 

The thickness of the galvanized layer of the HDG pipe is generally 35~600μm, and the surface is rougher than that of the HDG pipe, 

and the galvanized layer is not uniform.

Third, comparison of corrosion resistance of TDG pipe and HDG pipe

Because the zinc layer on the surface of the TDG pipe is relatively thin, it is easy to be damaged by machinery or exposed to the harsh environment for a long time, 

which causes the zinc layer to fall off, thus affecting its corrosion resistance. The zinc layer of HDG pipe is relatively thick, the surface is rough, and it is not easy to 

be subjected to mechanical damage and external environment erosion, and has better corrosion resistance.

 For different use scenarios, choosing the right galvanized pipe material can bring better economic benefits and use experience for users.