What causes storage tanks to fail?

Storage tank Inspection

At Format NDT Ltd we support clients who use above-ground storage tanks for various purposes. We understand how important they are for storing everything from water to oil and chemicals. However, they need proper maintenance to reduce the risk of failure. A key part of this is storage tank inspection. We can provide this service and report any indications that there could be an issue.

Over the years we have seen storage tanks fail for lots of different reasons. Read on to learn more about some of the most common ones.

Construction issues

Tanks that are designed incorrectly are more likely to fail and can do so quite spectacularly. Any issue with the construction, including the welding, the integrity of the shell, the stability of the roof, or the seams, can cause leaks and failure. To avoid this every tank should comply with the relevant standards. There should also be testing to ensure everything is in order before the tank goes into service.


The fact tanks are above ground and often outside means the weather is a major hazard. Failures can occur because of different natural elements. For example, heavy, sustained rain can cause big problems for floating roof tanks. They are designed to hold the weight of several millimetres of water but can fail if it exceeds this.

Lightning is also a huge concern. It can strike tanks directly or hit anywhere near them and cause a tank failure. Depending on the contents, the tank could catch fire or even explode. As a result it is important to ground the tanks effectively.

High winds can be a problem too. They can put a huge amount of additional load on the tanks. Depending on the height or shape, this could become sufficient to cause a failure.

Pitting and corrosion

Once tanks are operational it is important to monitor them with regular storage tank inspection services. This should check for signs of wear, especially things like pitting and corrosion. Both of these can be major causes of failures, particularly if you do not take preventative or corrective action.

Ground movement

While earthquakes are rare in the UK, they can happen. This can cause trouble for lots of structures, including tanks. A bigger and more common concern though is ground movement because of water and the freeze/thaw cycle. It is important to think about this, designing the tanks so they can withstand ground movement.

Operational accidents

Sadly some tank failures can happen because of a mistake on the operator’s part. It could be something like welding or using other cutting tools too close to a tank. Or it could be a vehicular accident.


Designers create storage tanks with specific pressures in mind. There will be an upper limit here that should not be exceeded. However, operators could do this by overfilling a tank or blocking vents. Or, it could occur because the resources in the tank heat up or cool down. For example, volatile liquids tend to have a lower evaporation point. So, if there has been a period of hot weather they could evaporate, produce vapours, and increase the pressure. Excessive pressure can cause a tank to rupture or even explode.

Arrange storage tank inspection

Format NDT Ltd is one of the best companies in our industry in the UK. We set high standards and prioritise safety. We can arrange to provide inspections as frequently as clients need us to, whether it is yearly or more often. Each inspection can include visual checks as well as various forms of non-destructive testing. The aim is to give you the most comprehensive service.

So, if you want to work with a professional team with years of experience, contact us. Our storage tank inspection services are suitable for any kinds of above ground tanks. We will do our best to inspect them with minimal disruption.