Pre-Galvanized Steel Pipe and Tubing from China Suppliers and Factory - Round, Square, Rectangular Options Available
Detailed Description of Pre-Galvanized Steel Pipe
Pre-galvanized pipe, sometimes referred to as mill-galvanized or in-line galvanized pipe, utilizes a different method for zinc protection. Different from post-galvanizing (hot-dip galvanizing), pre-galvanizing uses a steel strip that has been galvanized when the strips are made into pipes in a continuous process. The steel strip is galvanized and rolled into a tube using rollers. The edges of the tube are joined together with high-frequency induction welding. After welding is done, the exterior weld seam received a coating of zinc-rich invective spray to restore corrosion resistance. This is very fast and makes very smooth and uniform pipe, making it visually pleasing for many different applications.
Key Parameters for Pre-Galvanized Steel Pipe
| Parameter | Details |
|---|---|
| Manufacturing Process | ERW process using pre-galvanized steel coils |
| Base Material Standard | ASTM A653, EN 10346 |
| Pipe Standard | EN 10219, BS 4568, JIS G3444 |
| Steel Grade | Q195, Q235, S235, DX51D |
| Size Range (OD) | 21.3mm – 165mm (1/2" – 6") |
| Wall Thickness (WT) | 0.8mm – 5.0mm |
| Zinc Coating | Typically Z80 to Z275 (80–275 g/m²) |
| Surface Finish | Bright, smooth, uniform |
| Pipe Ends | Plain End |
Frequently Asked Questions (FAQ)
❓ What is the difference between pre-galvanized and hot-dip galvanized steel pipe?
Pre-galvanized pipe is made from steel strips that are galvanized before being formed into a pipe, resulting in a smooth and uniform surface. Hot-dip galvanized pipe is dipped into molten zinc after the pipe is already formed, providing a thicker but less uniform zinc coating.
❓ What standards apply to pre-galvanized steel pipe?
Common standards include ASTM A653 and EN 10346 for the base material, and EN 10219, BS 4568, and JIS G3444 for the pipe itself, depending on the region and application.
❓ What zinc coating grades are available for pre-galvanized steel pipe?
Pre-galvanized steel pipe typically comes with zinc coating classes ranging from Z80 to Z275, which corresponds to 80–275 g/m² of zinc on the steel surface, offering varying levels of corrosion protection.
❓ What size range is available for pre-galvanized steel pipe?
Pre-galvanized steel pipe is available in outer diameters from 21.3mm to 165mm (1/2" to 6"), with wall thicknesses ranging from 0.8mm to 5.0mm, suitable for a wide variety of structural and mechanical applications.
❓ How is the weld seam protected during the manufacturing of pre-galvanized pipe?
After high-frequency induction welding, the exterior weld seam is treated with a zinc-rich spray coating to restore corrosion resistance in the area affected by the welding heat, maintaining consistent protection along the entire pipe length.
❓ What are the common applications of pre-galvanized steel pipe?
Due to its smooth, bright, and uniform surface finish, pre-galvanized steel pipe is widely used in construction frameworks, furniture, fencing, mechanical structures, and other applications where both aesthetics and corrosion resistance are important.