Hot-Dip Galvanized Water Tank Report Update | Verified Corrosion & Performance

When selecting water tank types and materials, users are most concerned about key parameters such as physical strength, corrosion resistance, sealing performance, and overall safety. Recently, we conducted a new round of authoritative testing on our hot-dip galvanized steel water tank products and officially released an updated inspection report.

The latest inspection was carried out by Guangdong Botong Quality Inspection Co., Ltd. (China), in accordance with multiple national standards and industry specifications. The evaluation comprehensively covered material performance, galvanizing quality, structural strength, sealing performance, and drinking water safety.

The report number is CBT10502181542, and the tested sample is a 1220 × 1220 × 1220 mm hot-dip galvanized steel water tank. The overall test results were excellent, with all items meeting the required standards. The final conclusion was Qualified.

1. Core Material and Galvanizing Quality Analysis

1.1 Base Materials and Components

• Base material: Q235B high-quality carbon structural steel
• Welding wire: ER50-6 standard welding material
• Sealing material: EPDM (Ethylene Propylene Diene Monomer rubber)
• Fasteners: 304 stainless steel (measured tensile strength: 615 MPa)

👉 Technical Note:
The overall material system meets industrial-grade requirements for water treatment and fire-fighting water supply systems, ensuring strong structural stability and corrosion resistance.

1.2 Key Galvanizing Performance Indicators (Core Highlights)

• Zinc purity: 99.996% (higher than ≥99.995% standard)
• Average coating thickness: 92 μm
• Minimum local thickness: 78 μm
• Zinc coating mass: 578.6 g/m²
• Adhesion grade: 5B (highest level)
• Salt spray test: 240 hours, no red rust, only slight white rust

👉 Technical Analysis:
The galvanizing layer thickness significantly exceeds the industry standard (≥80 μm). The product demonstrates excellent corrosion resistance under salt spray conditions, making it suitable for high-humidity, industrial, and coastal environments.

2. Structural Strength and Mechanical Performance Analysis

As a load-bearing water storage system, structural safety is critical:

• Yield strength: 265 MPa (≥235 MPa)
• Tensile strength: 415 MPa (within standard range)
• Elongation after fracture: 29.5% (better than ≥20%)
• Hardness: HBW 135
• 180° bending test: no cracking
• Full-water deformation: 2.1 mm (far below L/500 limit)

👉 Conclusion:
The structure shows excellent strength and toughness. Under full-water load conditions, deformation is minimal, indicating a well-designed framework suitable for long-term operation.

3. Sealing Performance and Welding Quality Analysis

• 24-hour full-water static test: no leakage
• Flange connection test: 0.9 MPa pressure, no leakage
• Welding inspection: 20 ultrasonic tested welds, all Grade I qualified

👉 Technical Evaluation:
The welding process is highly stable, and structural connections are reliable, effectively preventing long-term leakage risks.

4. Drinking Water Safety and Hygiene Performance

This inspection also evaluated the impact on water quality:

Key Indicators:

• Color change: <5 degrees
• Turbidity: 0.15 NTU
• pH change: 8.15 (stable)
• Oxygen consumption increase: 0.65 mg/L
• Heavy metals (Cr, Hg, Al, Ni, Cu, etc.): far below limits
• No odor, no visible impurities

👉 Professional Analysis:
All indicators comply with GB/T 17219-2025 Drinking Water Hygiene Standard, confirming that the galvanized water tank does not contaminate water during long-term storage and ensures safe potable water usage.

5. Comprehensive Conclusion

Based on the authoritative inspection results:

✔ Material system meets industrial-grade standards
✔ Galvanizing thickness and adhesion reach high-level performance
✔ Excellent structural strength and deformation control
✔ Reliable sealing performance with no leakage risk
✔ Drinking water safety indicators fully compliant

👉 Final Conclusion:
The hot-dip galvanized steel water tank demonstrates stable quality and excellent performance, fully meeting the long-term requirements of fire-fighting water supply and domestic water storage systems.

6. Technical Value Summary

This inspection fully validates the key advantages of hot-dip galvanized water tanks:

• Long-term corrosion resistance (excellent performance in 240-hour salt spray test)
• High structural safety factor
• Excellent welding and sealing technology
• Compliance with drinking water safety standards

This confirms that hot-dip galvanized water tanks are highly reliable for modern building water supply, fire protection storage, and industrial water storage applications.

About Us

As a professional manufacturer of modular water tanks and an international trading supplier, we always place product quality control as our top priority. From raw material selection to manufacturing processes and final product inspection, we strictly implement standardized quality management systems to ensure every water tank delivers stable and reliable performance.

Among our product range, hot-dip galvanized water tanks are one of our core strengths. We use high-quality steel and advanced hot-dip galvanizing technology to form a dense protective zinc layer on the steel surface, significantly enhancing corrosion resistance and service life. Even in complex water conditions or high-humidity environments, the system maintains long-term stable operation.

In addition, we conduct multiple rigorous quality tests, including structural strength testing, coating adhesion testing, and corrosion resistance verification, ensuring superior safety and durability in real-world applications.

With a mature production system and continuously optimized manufacturing technology, our modular water tanks meet the needs of building water supply, secondary water supply, and industrial storage applications, providing customers with safer, more reliable, and cost-effective water storage solutions.