Hot Dip Galvanized (HDG) Steel Pipe Suppliers and Factory in China | Durable Corrosion Protection
Detailed Description of Hot Dipped Galvanized Steel Pipe
Hot-dip galvanizing is an effective method of providing corrosion protection. There are three major manufacturers' processes used in the hot-dip galvanizing operation: surface preparation, galvanizing, and post-treatment. The base steel pipe starts with a thorough cleaning using a degreaser, a pickling process (to remove mill scale and rust), and fluxing. The clean pipe is then completely submerged into a kettle of molten zinc. While the pipe is submerged, molten zinc reacts with the iron in the steel to form zinc-iron alloy layers; additionally, pure zinc forms a layer after the previous zinc-iron alloy layers, resulting in a layered structure with uniform protection. This structure provides excellent abrasion resistance and cathodic (or sacrificial) protection so that if the galvanized coating is scratched, the surrounding zinc protects the exposed steel base.
Key Parameters for Hot Dipped Galvanized Steel Pipe
| Parameter | Details |
|---|---|
| Manufacturing Process | Hot-dip galvanizing of ERW or Seamless pipes |
| Galvanizing Standard | ASTM A123 ISO 1461 AS/NZS 4680 |
| Base Pipe Standard | ASTM A53 EN 10219 GB/T 3091 |
| Steel Grade | Q235, Q345, Gr.A, Gr.B, S235, S355 |
| Size Range (OD) | 21.3mm – 914.4mm (1/2" – 10") |
| Wall Thickness (WT) | 1.5mm – 10mm |
| Zinc Coating Thickness | Average ≥ 45µm, varies with steel thickness as per standard |
| Surface Finish | Bright with crystalline zinc pattern (spangle), can be smooth |
| Pipe Ends | Plain, Beveled, Threaded with Couplings |