Tank Fabrication

We build new steel storage tanks in our own workshop and deliver them to site anywhere in the Maldives. Diesel, petrol and water. Above ground or underground, single skin or bunded, mild steel or stainless.

There is no fixed size limit. We size the tank to the space and the need. The largest tanks we have worked on hold 200,000 litres each.

What we can build

Most enquiries start with a capacity and a corner of a plant room. These are the choices that turn that into a tank. If you are not sure which column applies to you, say so in your enquiry and we will advise.

Choice	What we build
Shape	Horizontal cylinder, vertical cylinder or rectangular. Rectangular suits a tight plant room; a cylinder is stronger for the same thickness of plate.
Mounting	Skid mounted as standard, so the tank arrives on its own steel frame and can be lifted and set in one piece. Fixed and saddle mounted also available.
Location	Above ground or underground.
Walls	Single skin, or bunded and double wall where a spill has to be contained.
Material	Mild steel, coated inside and out, or stainless steel where the contents or the exposure call for it.

Skid mounted as standard

A skid mounted tank is built onto its own steel base frame in the workshop. It travels as one unit, gets lifted into position in one lift, and sits level without a separate steel stand being built on site. On island jobs that usually saves a day of work and a crane visit, which is why we build this way unless there is a reason not to.

Bunded and double wall tanks

A bunded tank is a tank inside a second outer shell. If the inner tank leaks, the fuel is caught in the space between the two instead of reaching the floor, the ground or the lagoon. It is the single most useful thing you can specify on a fuel tank in the Maldives, where groundwater sits close to the surface and a spill is very difficult to recover.

The alternative is a concrete bund wall built around a single skin tank. Both work, and we build both, so the choice is about your site rather than about who does the work. A bunded tank costs more in steel but takes less floor space and needs no concrete, so on a plant room retrofit it is often the cheaper route overall. A concrete bund is usually better value where there is room for it. We will price both and tell you which we would choose.

Underground tanks

We build and install underground tanks. Buried steel is attacked from the outside as well as the inside, so the external coating specification matters far more than it does on an above ground tank, and we treat it accordingly.

Two things decide whether an underground tank is the right answer on your site. The first is groundwater: an empty or part empty buried tank wants to float, so it has to be held down, usually with a concrete slab and straps. The second is access, because once the tank is buried, inspecting and maintaining it is harder and more expensive than reaching one that sits in the open. We will give you a straight view on which suits your site rather than simply quoting what you asked for.

Mild steel or stainless steel

We fabricate in both. Mild steel with a protective coating inside and out is the normal choice and it is what the great majority of fuel and water tanks in the Maldives are made of. Stainless costs considerably more and is worth it in specific cases: potable water where you would rather not depend on an internal coating, exposure to salt spray with no shelter, or contents that would attack a coated surface. Tell us what the tank will hold and where it will stand and we will tell you honestly whether stainless earns its cost on your job.

The parts of a tank

Quotations and drawings use these words. Here is what they mean, so you can read a quotation — ours or anyone else’s — and know what is in it and what has been left out.

Part	What it does
Shell	The curved or flat sides of the tank. The main body.
Ends or heads	The two closing ends of a cylindrical tank. Dished ends are stronger than flat ones.
Baffles	Internal plates that stop the contents surging when the tank is part full or being moved.
Manhole	The bolted access opening. How a person gets inside to clean, inspect or recoat.
Nozzles	The welded connection points for fill, outlet, drain, vent and instruments.
Vent	Lets the tank breathe as the level rises and falls. A sealed tank will buckle or split.
Flame arrestor	Fitted in the vent on a petrol tank. Stops a flame travelling back inside.
Drain or sump	The low point where water and sludge collect, so they can be drawn off.
Dip point	Where a measuring stick goes in. Read against a calibration chart.
Level gauge	Shows the contents without opening the tank. Mechanical, or digital monitoring.
Bund	The outer shell or the wall that catches a leak.
Skid	The steel base frame the tank is built onto.
Saddles	The curved supports a horizontal tank rests on.

How a new tank is built

Every tank follows the same order of work. You see the drawing and agree it before we build anything.

• Site survey. We visit, measure the space and check how the tank will be delivered and placed.
• Sizing. We advise what capacity suits the use and the space available.
• Drawings. We prepare a drawing set and send it to you for approval. Nothing is cut until you are happy with it.
• Steel. We select and source the plate. In the Maldives 6 mm plate is commonly stocked. Thicker plate is limited here, so when a tank needs it we source from Malé suppliers or from abroad, and we tell you the lead time honestly.
• Fabrication. Cutting, rolling and welding in our workshop. Shell, ends, base, skid, baffles, manhole and nozzles.
• Surface preparation. Blast cleaning back to bare steel, to Sa 2½ or an equivalent grade.
• Coating. Internal and external protective coating, chosen for what the tank will hold.
• Testing. Hydrostatic or pressure testing before the tank leaves the workshop.
• Calibration. We prepare a calibration chart so a dip reading tells you the volume in litres.
• Foundation. We build the plinth or the bund if you want it in the same contract, or we give your own contractor the loads and fixing positions.
• Delivery and placement. Transport to the island and setting the tank on its foundation.
• Fittings and connection. Vents, fill point, outlet, level gauge and manhole fitted and connected.
• Handover. You receive the drawings, the calibration chart and the warranty.

Surface preparation to Sa 2½

Sa 2½ is a named grade of blast cleaning. At that grade the steel is cleaned until almost all of the mill scale, rust and old coating is gone and the surface shows a uniform metallic appearance, with no more than very light staining left. It is the grade most protective coating systems are designed to be applied over, and the figure to look for on a quotation.

We prepare to Sa 2½ or an equivalent named grade and we write it on the quotation. If a cheaper quotation does not say what grade the steel will be prepared to, that is usually because it is being wire brushed, and the coating will lift within a year or two whatever product goes on top.

The foundation

We build foundations ourselves. Construction and civil works are one of our own divisions, so on most tank jobs the foundation, the bund and the tank are a single contract with one company responsible for all of it. That matters more than it sounds: when the steel and the concrete are quoted by two different firms, the gap between them is where the delays and the arguments live.

If your own contractor is building the foundation instead, that is no problem at all. We give them the loaded weight, the footprint and the fixing positions from the approved drawings in good time. Either way, this is what the tank needs.

• Level and flat. A tank sitting on an uneven base carries its load on a few points instead of across the whole base. That is where the plate distorts and the welds start to work.
• Sized for the tank full of liquid, not empty. Water is a tonne per cubic metre and diesel is a little less, so a 20,000 litre tank is around 20 tonnes of contents on top of its own steel.
• Draining away from the tank. Standing water against the base is where above ground tanks rot first.
• Reachable all round where possible. Leaving room to walk around the tank is what makes inspection, coating and repair affordable later.
• Hold down provision for an underground tank. A buried tank that is empty will try to float. That needs a slab and straps, designed for the site.
• Bund capacity if a concrete bund is being used. A bund wall is only useful if it can hold the full contents of the tank.

Work out a capacity

If you know the space you have but not the size of tank it will take, or you know the capacity you want but not whether it will fit, this works it out both ways.

What to send with your enquiry

None of this is compulsory. The more of it you can send, the closer the first quotation will be to the final price, and the less likely it is that we have to come back to you with questions.

• What the tank will hold. Diesel, petrol, drinking water, irrigation water, or something else.
• The capacity you need, or the space you have available, in metres.
• Where it will stand. Plant room, open yard, roof, underground.
• Photographs. The space, the access route from the jetty or gate, and the existing tank if there is one.
• Access. Door and gate widths, ceiling height, and whether a crane or forklift can reach the position.
• The island. Which atoll and island, since transport is a real part of the cost.
• Connections. Pipe sizes and positions if the tank is joining an existing system.
• Generator details, if it is a day tank or a fuel system.
• Any drawings or specifications you already have, even rough ones.
• When you need it. So we can tell you straight away if the steel lead time is a problem.

Being straight about what we hold

We do not hold welder qualifications or coating applicator certification, and we do not claim compliance with any published tank standard. We would rather tell you that here than have you find out later. What we offer is the work itself, the drawings, the preparation grade written down, the test, the calibration chart and a warranty on what we have done.

What we can also do, which most tank fabricators here cannot, is the civil work. Foundations, plinths and concrete bund walls are our own trade, so the tank and the base it stands on come from one company under one contract.

Request a tank fabrication quotation