Tank Maintenance
Most tanks fail from the inside out, slowly, and the warning signs are visible long before there is a leak. Maintenance is almost always cheaper than replacement.
What maintenance covers
- Inspection and condition reporting
- Cleaning, sludge removal and disinfection
- Blast cleaning to Sa 2½ to remove rust and old coating
- Protective coating, inside and out
- Repair of leaks, damaged welds and corroded plate
- Hydrostatic and pressure testing
- Calibration and calibration charts
- Repair or replacement of ladders, handrails and access platforms
Why preparation decides how long a coating lasts
A coating is only as good as the surface under it. Paint applied over rust or over a failing old coating will lift again within a year or two, however good the product is. Blast cleaning back to bare steel is the part of the job that decides whether the coating lasts, and it is the part most often skipped by a cheaper quote.
The grade to look for is Sa 2½, or an equivalent named blast cleaning grade. At that grade almost all mill scale, rust and old coating is removed and the steel shows a uniform metallic appearance with no more than very light staining. It is what most protective coating systems are designed to go over. We prepare to that grade and we write it on the quotation. If another quotation does not name a preparation grade at all, it is worth asking why.
A reasonable maintenance routine
There is no single correct interval, because it depends on what the tank holds, how fast it turns over, how old it is and how exposed it stands. What follows is a sensible starting routine for a steel tank in the Maldives. Most of it your own team can do. After an inspection we will set the intervals properly against your tanks rather than against a general table.
| How often | What to do | Who |
|---|---|---|
| Monthly | Walk round the tank. Look for wet patches, staining and rust streaks, especially where the tank meets its base. Check the vent is clear and the manhole and nozzle bolts are tight. | Your team |
| Monthly | On a fuel tank, draw water off the drain point until clean fuel runs. In a humid climate water condenses into the tank continuously. | Your team |
| Every three months | Check the level gauge against a dip reading, so you know the gauge is still telling the truth. Check the bund or the containment space is empty and dry. | Your team |
| Yearly | A proper external condition survey. Coating condition, corrosion, the base and supports, ladders and platforms, earthing on a fuel tank. | Us, or your engineer |
| Yearly, fuel tanks | Check the sludge depth and decide whether the tank needs cleaning before the next season. | Us, or your engineer |
| Every few years, as condition dictates | Internal inspection with the tank emptied and ventilated. This is when recoating, plate repair and retesting get planned. | Us |
Keep a simple written record of what was checked and when. It costs nothing, it tells you whether a problem is getting worse or holding steady, and it is the first thing anyone asks for when something goes wrong.
Signs a tank needs attention now
- A wet patch, a stain or a smell of fuel anywhere around the base
- Rust streaks running down from a weld, a nozzle or the roof
- Coating blistering, flaking or lifting in sheets
- Water or sludge coming off the drain point in quantity
- The level reading not matching what you know went in
- A vent that is blocked, painted over or missing
- A ladder, platform or handrail that is no longer safe to stand on
Any of these is worth an inspection. None of them means the tank has to be replaced — most are far cheaper to put right than to leave.
Warranty
We offer a one to two year warranty on the services we provide, covering defects in materials and workmanship, leaks and structural integrity, and coating performance. Keeping it valid depends on following the maintenance guidance we hand over with the work.
Common questions
How do we know whether a tank needs recoating or replacing?
An inspection tells us. We will give you an honest view, including when a tank is worth replacing rather than repairing.
What preparation grade do you work to?
Sa 2½ or an equivalent named blast cleaning grade, stated on the quotation. Preparation is what decides how long the coating lasts.
How often should a tank be inspected?
As a starting point, your own team monthly and a proper survey once a year. After an inspection we will set intervals that suit your tanks rather than a general rule.
Can you work while the tank stays in service?
Some external work, yes. Internal work needs the tank emptied and ventilated. We plan the timing with you.
Do you work on island sites?
Yes. We mobilise with our own crew, tools and materials to island sites across the atolls.