Galvanized Welded Tube Mills

Galvanized Welded Tube Mills from Shijiazhuang Faith Machinery Co.,Ltd address the specific requirements of producing welded tubes with pre‑galvanized or post‑galvanized coatings for corrosion resistance in outdoor structures, fencing, and furniture. These mills combine precise welding, controlled heat input, and gentle handling to preserve zinc coatings while delivering tubes with uniform geometry.

1. Processing Strategy

1. Strip Decoiling and Pre‑Treatment

• Mandrel decoilers feed zinc‑coated strip into levelers with polyurethane‑sleeved rolls that protect the coating.

2. Forming and Welding

• Forming stands shape the strip into tubular form; high‑frequency induction welding heads apply localized heat, minimizing coating burn‑off.

3. Post‑Weld Cooling and Re‑Galvanizing (Optional)

• After welding, the tube passes through cooling stations that rapidly reduce seam temperature. Optional inline re‑galvanizing brushes or spray modules can replenish any lost zinc.

4. Sizing and Bead Removal

• Sizing stands refine tube diameter. Bead scarfing tools remove weld protrusions with minimal impact on surrounding coating.

2. Coating Protection Features

• Non‑Marking Guide Rolls: All guide rolls and support stands in the slitting and forming sections use non‑abrasive sleeves to prevent scratching the galvanized surface.

• Controlled Heat Input: Welding parameters—frequency, current, and roll pressure—are optimized for minimal coating degradation, guided by real‐time pyrometer feedback.

• Zinc Replenishment: For lines handling thicker coatings or critical applications, optional electrogalvanizing units can restore uniform zinc coverage along the weld seam.

3. Line Performance

• Tube Specifications: Produces diameters from 20 mm to 114 mm with wall thicknesses from 0.8 mm to 4 mm.

• Speed and Yield: Typical line speeds reach 80 m/min for lighter gauges, with scrap rates under 1% due to precise edge alignment and tension control.

• Quality Assurance: Inline ultrasonic weld inspection and eddy‐current surface scanning detect flaws and coating discontinuities, diverting affected lengths to scrap or rework.

4. Automation and Data Management

• Central PLC Control: Manages decoiler tension, forming stand servo positions, welding power supply, and cooling flow rates.

• HMI Recipe Recall: Operators select tube size and coating thickness; the system automatically loads welding, cooling, and re‑galvanizing parameters.

• Data Logging: Records process data—weld temperature profiles, coating thickness measurements, production lengths—in a database for traceability and audit compliance.

5. Service and Support

• Turnkey Installation: Complete project execution, including civil, mechanical, and electrical works, ensures rapid start‑up.

• Operator and Maintenance Training: Focused on coating preservation techniques, welding parameter adjustment, and routine cleaning of re‑galvanizing heads.

• Spare Parts Inventory: Critical parts such as non‑marking roll sleeves, welding power electronics, and cooling nozzles are stocked to minimize line downtime.

• Remote Monitoring: Optional cloud‑based dashboard provides real‑time line status, alarm alerts, and performance metrics accessible from any location.