Above ground storage tanks
1. Inner walls
- Coating degradation
- Corrosion due to water/dissolved oxygen
- insufficient/damaged cathodic protection system
- dissolved sacrificial anodes
2. Outer walls/roof
- Atmospheric corrosion
- coating degradation due to moisture + UV radiation + temperature
- Erosion and wear due to wind and dust particles
- biological growth at the bottom areas near soil
- soil corrosion near the bottom
3. Pipes
- Atmospheric corrosion
- Coating degradation
- mechanical failure
- internal corrosion due to water/dissolved oxygen
- crevice corrosion in areas facing away from atmosphere
- corrosion at welds and joints
- microbial corrosion at 6 o’ clock positions
- erosion corrosion at bends
4. Railing
- Coating degradation
- Wrong coating selection based on pure aesthetics
- coating damage at joints and bends
- corrosion at welds in the railing
- crevice corrosion at fixtures
- pitting corrosion
5. Breather valve
- uniform corrosion/pitting depending on whether it is made up of carbon steel/stainless steel
- Galvanic couple at the joining/welding point of valve to roof
- corrosion after damage of galvanized layer
6. Spray nozzle
- Crevice corrosion at orifices
- clogging
- erosion and mechanical damage at orifices and bends
- crevice corrosion at fixtures
7. Manhole
- corrosion at edges of cover
- galvanic corrosion at contact points with neighbouring parts
- pitting due to chloride ion contact
- crevice corrosion at fixtures
- pitting corrosion at welds
8. Lagging
- pitting due to chloride ion contact
- crevice corrosion at overlapping joints
- water seepage at insufficiently bonded overlaps