Advanced Anti-Corrosion Protection for Self-Bunded Fuel Tanks
Material Selection
The foundation of corrosion resistance begins with strategic material choices for different tank components:
High-grade Carbon Steel Aluminum Alloys Galvanized Steel Fiberglass-Reinforced Plastic (FRP)
- Inner tanks prioritize chemical resistance and structural integrity
- Outer bunds focus on weather resistance and impact protection
- Material combinations are selected based on stored fuel type and environmental exposure
Surface Preparation
Meticulous surface treatment ensures optimal coating adhesion and longevity:
- Abrasive blasting (shot/sand) to SA 2.5 cleanliness standard
- Chemical treatments like phosphatization for steel substrates
- Profile creation (40-80 microns) for mechanical coating adhesion
- Contamination testing before coating application
Protective Coating Systems
Multi-layer protection tailored to specific exposure risks:
Epoxy base coats (chemical resistance) + Polyurethane topcoats (UV protection) + Optional ceramic/zinc-rich primers
- 2-3 coat systems with minimum DFT (Dry Film Thickness) of 250-300μm
- Zinc-rich primers provide cathodic protection (sacrificial anode effect)
- Elastomeric coatings for areas with thermal expansion/contraction
- FDA-compliant coatings for tanks storing edible oils or sensitive fuels
Electrochemical Protection
Advanced systems to neutralize corrosive reactions:
- Galvanic Anodes: Magnesium/zinc blocks (3-15 year lifespan)
- Impressed Current: External power source with inert anodes
- Potential monitoring with reference electrodes
- Current density typically 10-20 mA/m² for buried tanks
Critical Area Protection
- Seam sealing with fuel-resistant elastomers (EPDM, Fluorosilicone)
- Weld zone post-treatment including grinding and re-coating
- Extra thickness coating at water collection points
- Stainless steel fasteners in high-corrosion areas
Maintenance Protocol: Biannual coating inspections with holiday detection testing. Anode replacement when depleted to 30% mass. Immediate repair of coating defects >5mm diameter.