I. Selection of Anti-corrosion Materials
Choosing the right coating based on the tank material and the stored medium is fundamental:
1. Metal Cans (Steel):
Outer Wall: Commonly used: Epoxy zinc-rich primer (cathodic protection) + Epoxy micaceous iron oxide intermediate coat (corrosion shielding) + Polyurethane topcoat (weather and wear resistance).
Inner Wall: If storing oil, use antistatic anti-corrosion coatings (such as epoxy glass flake coatings) to prevent static sparks.
2. Plastic Cans (HDPE): They are inherently corrosion-resistant, but UV protection is necessary. Choose coatings with anti-aging agents.
3. Special Environments: In humid or chemical environments, fluorocarbon coatings or heavy-duty anti-corrosion coatings (such as epoxy) are recommended.
II. Surface Treatment
This is crucial for successful corrosion prevention and must be thoroughly cleaned:
1. Rust Removal: Sandblast to Sa2.5 grade (ISO 8501-1), surface roughness 30-50 microns, to enhance adhesion.
2. Cleaning: Remove oil and dust, ensuring the surface is dry and free of impurities.
III. Coating Process
Proper application is essential to ensure coating quality:
1. Environment: Temperature 10-35℃, humidity <85%, no rain or fog.
2. Coating: Control the thickness and recoating interval according to the product instructions (e.g., recoat 1-2 hours after two-component paint is surface dry).
3. Ventilation: Continuous ventilation during application and curing to prevent solvent vapor buildup.
IV. Regular Inspection and Maintenance
1. Inspection: At least once a year, focusing on welds, joints, etc., and promptly repair any damage.
2. Thickness Inspection: Use a paint film thickness gauge to check the coating thickness to ensure it meets the standard (e.g., ≥400μm in strong acid environments).
3. Record Keeping: Establish maintenance files to track the corrosion protection status.
V. Other Protective Measures
1. Cathodic Protection: For buried or underwater tanks, sacrificial anode or impressed current methods can be used.
2. Environmental Control: Keep the tank area dry and well-ventilated to reduce contact with corrosive media.
