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Oil Tank Guide: An Essential Guide to Fuel Tanks

All oil tank owners have a legal duty to ensure your stored fuel is safe and secure. This guide is a must for anyone who’s recently had a tank installed, moved into a property with an existing oil tank or simply needs to refresh their knowledge. We’ll take you through the regulatory requirements, including some of our most commonly asked questions and answers.

Which oil tank should you buy

Both steel and plastic fuel tanks have their own advantages, so it’s entirely up to you which type you choose. Some people prefer the non-rusting attributes of plastic tanks and others are drawn to the strength and robustness of steel.

To help you determine which fuel storage tank is best for you, we’ve put the pros and cons together of both plastic and steel tanks.

Steel tanks

Steel tanks are commonly used to store bulk fuel due to their robust characteristics when compared to plastic fuel tanks.

Advantages of steel fuel tanks

• Stronger than plastic
• Available as standard or bespoke sizes
• Fully compliant with all legislation
• Offer higher levels of security against theft
• Able to withstand larger impacts
• Can be repaired and patched, unlike plastic tanks
• Don’t require a solid platform – can be installed on piers
• Non-porous – don’t absorb any of the stored fuel
• Sturdier than plastic tanks, boasting a much longer lifespan

Disadvantages of steel fuel tanks

Steel tanks are more vulnerable to corrosion from the elements, such as heat, UV light and condensation. Over time, this reduces a tank’s integrity and ultimately penetrates the tank structure, leading to tank bottom perforation. When it goes unchecked, this corrosion can cause the tank’s contents to leak into the nearby environment, leading to pollution, high clean-up costs and voided warranties.

Plastic tanks

Plastic tanks are a popular choice as they are often cheaper and don’t rust like metal tanks. They boast a 10-15-year shelf life, but poor maintenance will significantly reduce this.

Advantages of plastic fuel tanks

• Made from polyethene, making them less prone to corrosion than steel tanks
• A lightweight solution
• A variety of off the shelf sizes and capabilities
• Easy to install and manoeuvre – can be fitted straight on a base on the ground without piers
• Plastic is an insulator, which reduces the risk of contamination
• Seamless, so deformed tanks can regain their original shape, provided there are no cracks
• Readily available fully bunded

Disadvantages of plastic fuel tanks

Once a plastic tank is damaged, there is no option but to replace it. An oil tank replacement can be expensive and inconvenient so it’s imperative that you carry out regular checks. Plastic tanks undergo a large amount of stress when located outside due to the weather and temperature fluctuations. Cold temperatures can cause them to become brittle and result in splits and cracks, endangering the environment and nearby wildlife.

Single skinned plastic tanks are also at risk from the sunlight and UV exposure which can cause whitening and discolouration. This can result in the plastic expanding, twisting and bowing which will eventually turn into cracks.

Where to locate an oil tank

Your oil tank must be located at least 10 meters away from inland or coastal water, away from areas that are at danger from flooding and 50 meters clear of a spring to reduce the risk of pipelines breaking and leading to spills and groundwater contamination.

It must also be located at ground level or underground; it should never be positioned above roof level. You must also bear in mind that it needs to be easily accessed for deliveries and regular maintenance but also away from areas that could damage the tank such as machinery and bad weather.

A single skin oil tank explained

A single skin oil tank is a container which stores fuel. There is no bund or second skin (catchment area), so if any oil spills, it would enter the environment, endangering surrounding waterways and wildlife and risking huge environmental fines.

The importance of using a bunded oil tank

A bunded tank is effectively a tank within a tank, the aim being that if the tank is overfilled or splits, any oil that escapes will be contained within the outer skin, rather than leaking onto the ground or watercourses.

The regulations surrounding installing an oil tank

There are different regulations that apply to the safe storage of fuel, depending on where you store it and how much you store.

For more information, read our dedicated Oil Tank Storage Regulations Guide.

Why plastic tanks crack

Plastic tanks can crack due to a number of factors, so it’s important to consider these when locating your tank and carrying out checks.

An uneven tank base – This can put the tank under pressure in specific areas once topped up. This will cause the plastic to stretch and eventually split. Using a professional registered OFTEC engineer will ensure your tank is installed safely and correctly.

Sun exposure – Single skinned tanks are at risk of discolouration/whitening from the sun as they don’t have an outer shell to protect it. Over time, this can weaken the tank’s body and cause cracks where fuel can escape, and water can get in.

Cold weather – Tanks can become brittle which can lead to cracks and splits. After any snowfall, it’s important to clear any snow off the top of your tank to avoid damaging the tank.

A cracked fuel tank doesn’t just put its surrounding at risk, but also makes your fuel more prone to water contamination, a serious problem with stored fuel. It can lead to diesel bug and sludge build-up which can clog filters, injectors and fuel lines. During periods of wet weather, you should ensure that your tank is sealed, lids are securely closed and there are no cracks where water could enter.

How to protect an oil tank from the sun

UV damage can be extremely harmful to an oil tank. Surrounding it with fencing or brick shed will keep the sun, wind and rain off your tank and will also hide it in your garden.

Alternatively, why not consider a subterranean location for your tank? Underground tanks are far less prone to accidental damage in high traffic areas, in addition to being protected from the elements. However, it’s important to also bear in mind that it’s much more difficult to monitor an underground tank’s condition, as well as to check for leaks and spills.

When to replace an oil tank

Oil tanks have on average a 10-15-year lifespan, provided they’re well maintained.

The problem with steel tanks is that corrosion appears from the inside out, so quite often, you will not be aware of any issues until it’s too late. That’s why it’s important to invest in regular tank inspections from a qualified engineer, so you can be confident that both your stored fuel and tank are in good condition.

The good news with plastic tanks is that any problems usually appear on the exterior first. You will usually be able to notice any cracks or discolouration during regular checks yourself, which will indicate that your tank needs replacing as soon as possible.

We recommend carrying out monthly inspections, particularly during the cold months. Things to look out for:

• Cracks in the body of your tank
• Bulges or bowing
• Discolouration of tank colour due to sun exposure
• Corrosion on the tank and pipework
• Stains or wet patches around your tank indicate a leak
• Strong smell of fuel will suggest a leak

Are you confident your fuel tank is in good shape? Speak to a fuel expert today on 0330 123 1144 to protect your costly assets. Our oil tank installations are available nationwide for both commercial and domestic customers.

Fuel tank repairs

Unfortunately, once a plastic fuel storage tank is damaged, it cannot be repaired so it needs to be replaced as soon as possible. Having your tank serviced regularly is key so you (or the engineer) notice any signs early on to avoid the fuel becoming contaminated or even worse, it leaking into the environment.

Steel tanks are more robust and can better withstand the effects from the weather. A bunded oil tank is a great investment and will help you avoid fuel leaking into the environment.

How a fuel tank level sensor works

Fuel tank level sensors work via a mobile phone signal or existing WiFi network. Or, if the signal is weak, such as where the tank is in a rural area or underground, an external antenna can be fitted. You will either have a standard sensor or a pressure sensor, depending on the tank’s dimensions and shape.

• Standard sensor – fitted at the top of a tank. A metal rod is inserted into the fuel, so when fuel levels drop the float drops too and alerts your account manager to arrange a delivery.
• Pressure sensor – fitted at the top of a tank. A metal rod is put into the fuel and electromagnetic pulses are produced when fuel levels drop, alerting your account manager to arrange a delivery.

Visit our tank telemetry page to find out more or get in touch today to find out more about our tank telemetry systems.

How to check your oil tank level

There are a number of ways to check your oil tank level. You can do this yourself by removing the cap off the top of the tank and inserting a dipstick to the bottom of the tank. When you take the stick out, the oil will have left a mark which is consistent with the level of oil in your tank.

Some tanks have a gauge (or sensor) fitted inside of the tank to tell you how much fuel you have left. This removes the need to manually dipstick your tank and avoids the need for key personnel to be onsite in your business, removing the risk of oil spilling into the environment.

How to read an oil tank gauge

Oil tanks usually have a gauge (sensor) installed at the top of the tank to make reading your fuel levels easier. It is commonly a clear cylinder which contains a float. As the float moves down, the visible disk on the top of the tank moves down correspondingly. To read the level of a float gauge, there will be tick marks on the plastic vial, which usually indicate full, ¾, ½, and ¼.

How to clean a fuel tank

If a fuel tank is not maintained properly, harmful substances such as toxins can build up and compromise the quality of its contents, making them less efficient, or even worse, unusable.

Your fuel storage tank should only ever be cleaned by a professional company. The engineer will come directly to your site or home and drain the fuel out of the tank. This ensures that the tank can be cleaned properly. There are different methods of cleaning, depending on the size and condition of the tank, such as man-entry and advanced automatic cleaning.

Once the tank is clean, the fuel will either be polished (cleaned) and returned to the tank or disposed of safely and a fresh batch delivered. Putting dirty fuel back into a clean tank would defeat the object of cleaning the tank entirely and would damage it almost instantly.

Find out more about our industrial tank cleaning service.

Oil tank costs

At Beesley Fuels, we supply Deso and Harlequin commercial and domestic fuel tanks in a wide range of sizes to suit your exact needs. All our tanks are OFTEC standard and can hold from 500 litres up to 120,000 litres of oil.

Are you confident your fuel tank is in good shape? Speak to a fuel tank expert today on 0330 123 1144 to protect your costly assets. Our oil tank installations are available nationwide for both commercial and domestic customers.