Oil Tank Types

In times past, Heating Oil Tanks were simply large, hollow objects which stored oil. Their basic design remained unchanged for decades. But fast forward a few years and product innovation has changed everything. Advances in modern boiler technology now allow you to choose between an outlet positioned at the top of the tank, or at the bottom. You’ve a choice of overfill prevention technology too. And of course, you can choose between an old-fashioned Single Skin, or an environmentally preferred, Bunded Tank. Double-Skinned Underground models are of course available too.

It’s important to understand the differences in storage tank technology. Installing the wrong tank in the wrong place can prove an expensive mistake. Whilst fuel spills are rare and Heating Oil is an inherently safe fuel choice, regulatory compliance makes it even safer still.

What is a Single Skin Oil Tank?

A Single Skin Tank consists of a tank which stores oil. In the event of a spill, oil will be discharged to the environment and an environmental pollution incident will occur. That’s why Single Skin tanks today should only be installed within a suitably bunded area or at the very small number of installations where a Bunded Tank is not now a legal requirement.

Installing a Single Skin Tank where a Bunded Tank is legally required is a serious offence. Before choosing or installing any Heating Oil Tank, a Risk Assessment must be completed by a competent, storage tank technician, to examine the likely impact of a spill and to determine whether a Single Skin Tank can be fitted or whether a Bunded Tank is required.

What is a Bunded Oil Tank?

Unlike Single Skin Heating Oil Tanks, a Bunded Tank consists of a ‘tank within a tank’. The inner tank is the primary storage container, whilst the outer tank or ‘bund’, acts as a failsafe and can contain 110% of the volume of the inner tank. Should a spill occur, spilt fuel will be safely and securely contained within the outer tank and an environmental pollution incident avoided.

Bunded Tanks are proven to significantly reduce the likelihood of an environmental pollution incident arising. Today, they are a legal requirement at most Heating Oil storage installations in the UK and many in the Republic of Ireland. So, if you’re considering the installation of a Single Skin Tank, beware… you could be installing the wrong tank, in the wrong place.

Do Bunded Tanks cost more than Single Skin Oil Tanks?

Yes. However, the additional cost is often a small price to pay, given that a Bunded Tank can significantly reduce the likelihood of a spill. Clean-up costs for even a small spill may run into many thousands. Furthermore, oil spills are not always covered by home insurance policies. If you’re unfortunate enough to suffer a spill, you may also incur significant legal expenses, potentially a fine and in the UK, a victim surcharge.

Even at the few installations where a Single Skin Tank may currently suffice, consideration should always be given to installing a Bunded Tank to minimise the risk of damage and loss in the event of a spill.

What is a Masonry Bund?

An alternative to purchasing a manufactured Bunded Tank is to construct a masonry bund and then install a single skin tank inside it. A masonry bund is much more however than simply laying down a concrete pad and constructing a containment wall from blocks. Instead, detailed guidelines for the construction of masonry bunds exist e.g. CIRIA Report No. 163. So, if you’re considering the construction of such a bund, you’ll need to take expert advice. Whilst masonry bunds are often found at large commercial fuel storage installations, for smaller, domestic fuel storage applications, they will frequently prove cost prohibitive.

What is a Double Skin Oil Tank?

As well as Single Skin and Bunded Heating Oil Tanks, Double Skinned tanks are also available. Typically, a Double-Skinned tank comprises a plastic inner tank with a steel or aluminium outer tank. However, unlike Bunded Tanks, the outer tank does not always contain 110% of the capacity of the inner tank. Double-Skinned tanks are therefore not always suitable for installation at premises where a Bunded Tank is required, unless placed within a suitably bunded area. Whilst common in mainland EU countries, in the UK and Republic of Ireland, Double Skin Tanks are normally only found at belowground installations and typically comprise a plastic inner tank with a GRP outer.

Can I replace an existing Single Skin Oil Tank with another Single Skin Oil Tank?

The simple answer is almost certainly not. At most oil storage installations, it will be necessary to upgrade to a Bunded Tank. The only way to be certain is to arrange for an Environmental Risk Assessment to be undertaken by a competent, professional Storage Tank Technician.

How do I know whether I need to fit a Bunded Oil Tank?

Prior to installing any Heating Oil Tank, a Risk Assessment should be completed to determine whether a Single Skin Tank can be installed, or whether a Bunded Tank is instead required. The Risk Assessment should be undertaken only by a competent, professional Storage Tank Technician. You can find out more about Environmental Risk Assessments by clicking or tapping here.   

Queries? Questions?

We recognise that choosing the ideal tank for your home, farm or business is not always simple or straightforward. That’s why our Customer Support Team is on hand to answer any queries or questions you may have. They’re available weekdays from 9am to 5pm – excluding Public Holidays. To speak with them, call us in the UK, Channel Islands and Isle of Man on 01789 632 151 and in the Republic of Ireland, you can call 01 5268 642. Alternatively, you can e-mail hello@fueltank.store