The pre-galvanized welded steel pipe refers to welded tube which undergoes decreasing, rust removal, phosphorization, and drying processes before galvanization.The treatments before galvanization allow the product to be conveniently plated with a zinc coating and also ensure uniform coating thickness, strong coating adhesion, and improved corrosion resistance

Hot-dip galvanizing (HDG), as referenced in the process of dipping fabricated steel into a kettle or vat of molten zinc. While the steel is in the kettle, the iron metallurgically reacts with the molten zinc to form a tightly-bonded alloy coating that provides superior corrosion protection to the steel.