Self Bunded Fuel Tanks
Double-walled self bunded fuel tanks with 110% integrated containment, built to AS1940 and supplied Australia-wide from 1,000L to 100,000L+.
Definition
What is a self bunded fuel tank?
A self bunded tank is a double-walled steel tank: the fuel sits in an inner primary tank, and a fully welded outer skin forms the bund around it. If the primary tank is ever breached, the fuel is caught in the space between the two walls rather than reaching the ground. It is the reason the design is often described as a tank within a tank.
The space between those walls is sized at 110% of the primary tank, which is the containment Australian Standard AS1940 requires for flammable and combustible liquids. A bunded fuel tank built this way arrives compliant: there is no concrete bund to pour, no excavation, and no separate containment structure to certify alongside it.
That matters beyond the paperwork. A single-wall tank needs an external bund built and maintained around it, and an underground tank needs excavation and a much heavier regulatory burden. A self bunded diesel tank is craned into position on a prepared surface, connected, and can be relocated when the site changes.
Sizing
Capacities and what they suit
Every size carries the same 110% containment, so the decision is about throughput and the footprint you have, not about compliance - that part does not change with capacity.
Sizes below are the standard build. Custom fabrication is available at any point on the range, and anything above 75,000L is engineered to the site.
| Capacity | Typically specified for |
|---|---|
| 1,000 - 5,000L | Small and medium operations, workshops and single-plant refuelling |
| 10,000 - 25,000L | Construction depots and transport fleets running daily |
| 30,000 - 50,000L | Heavy-duty mining and industrial sites |
| 75,000L+ | Bulk storage, engineered to the site with custom fabrication |
Construction
How it is built
Every tank is manufactured to exceed Australian regulatory requirements, and the certification process covers environmental protection, workplace safety and dangerous goods storage.
| Primary tank | High-grade steel with internal coating |
| Secondary bund | Fully welded steel at 110% of primary capacity |
| Coatings | Corrosion-resistant, specified for Australian UV and weather |
| Access | Lockable fill points and gauge access |
| Dispensing | Multiple pump and dispenser configurations, NMI-certified metering where fuel is sold or recharged |
| Power | Electric, diesel, generator and solar options |
| Monitoring | Optional fuel management systems and tank alarms |
Comparison
Self bunded against the alternatives
The three ways to store bulk fuel on a site are a self bunded tank, a single-wall tank inside a built bund, or an underground tank. They differ most in what you have to build around them.
| Self bunded | Single-wall + built bund | Underground | |
|---|---|---|---|
| Containment | 110%, welded into the tank | Built separately on site | Below ground |
| Site works | Prepared surface only | Bund construction | Excavation |
| Compliance | AS1940 from the factory | Bund certified separately | Heavier regulatory burden |
| Maintenance access | Full external access | External, around the bund | Specialised equipment |
| Relocatable | Yes, craned out | No, bund is fixed | No |
Process
Installation and ongoing support
Our engineers start by evaluating your site conditions and requirements, then the tank specification is drawn to those exact needs. Certified installers handle the setup, and the tank is fully tested and commissioned before handover.
Every installation is handed over with complete compliance certificates and operating manuals, which is what keeps the site audit-ready and the fuel storage insurance-compliant. Professional engineering certification is available where a site or an insurer asks for it.
After handover we run annual compliance inspections, preventive maintenance programmes, emergency repairs, and upgrade or modification work, through an Australia-wide service network.
Applications
Where it is used
Self bunded tanks are the default for permanent bulk storage because the containment travels with the tank. These are the sectors we supply most.
