Steel pipes are classified according to plating characteristics

According to the surface coating characteristics of the steel pipe can be divided into: black tube (not coated) and coated tube.
The coated pipes are galvanized pipes, aluminized pipes, chromium-plated pipes, aluminized pipes and other alloy layers of steel pipes.
The coated tube has an outer coated tube, an inner coated tube and an inner and outer coated tube. Commonly used coatings are plastic, epoxy resin, coal tar epoxy resin and various glass type anticorrosive coatings.
Galvanized pipe is divided into: KBG pipe, JDG pipe, threaded pipe and so on.