1. Galvanized steel pipe reacts molten metal with the iron matrix to produce an alloy layer, thereby combining the matrix and the coating. Hot-dip galvanizing is to pickle the steel pipe first. In order to remove the iron oxide on the surface of the steel pipe, after pickling, it is cleaned in an aqueous solution of ammonium chloride or zinc chloride or a mixed aqueous solution of ammonium chloride and zinc chloride, and then sent to in a hot dip plating tank. The advantages of galvanized pipes are: uniform coating, strong adhesion, and long service life. For hot-dip galvanizing, many companies now reduce the thickness of the galvanized layer in order to make profits. The original theoretical life span was 7-8 years, but now product quality can only be guaranteed for two to three years.
2. Fire-fighting plastic-coated steel pipes are a combination of steel pipes and plastics. They can be used for pipes of any diameter. The connection methods are not only limited to threaded connections and groove connections of galvanized pipes, but also welded connections, flange connections, and double connections. Metal welding connections, etc. The emergence of plastic-coated steel pipes solves the above problems. It has the strength of steel pipes, and the inner and outer layers of the steel pipes are anti-corrosion to make the inner and outer walls smooth without reducing the circulation diameter and improving transportation efficiency. Corrosion-resistant, strong coating adhesion, good impact resistance, adaptable to normal work in harsh natural environments. The service life is long, more than five times that of galvanized pipes.
