Fuel Oil Tank Pressure: Full Tank, High Pressure?

A full fuel oil tank does create pressure, and this pressure can be dangerous. Fuel tanks are designed to store fuel and release it into an engine. They are usually made of metal or plastic and can range in size from small plastic tanks in a butane lighter to large multi-chambered cryogenic tanks. Fuel tanks must be filled securely and without sparks, and they must also have a way to determine the level of fuel in the tank.

Fuel tanks are pressurised during the filling process, and this pressure can cause leaks. If a tank is not adequately vented, the pressure can be substantial. This is because the vapours in the tank create more pressure than the liquid fuel. The pressure in the tank is also affected by temperature; higher temperatures increase pressure.

Condensation is the biggest threat to any home oil tank. Keeping the tank as full as possible is the best way to avoid condensation, which can cause bacteria and other microorganisms to grow, compromising the efficiency of heating systems and potentially leading to failure.

Condensation in an empty oil tank can cause sediment that clogs fuel lines and reduces heating efficiency

Condensation in an empty oil tank can cause serious problems for your heating system. As oil tanks are usually made of metal, condensation can lead to rust inside the tank, which can cause your heating system to fail. This rust can also mix with the heating oil to create sediment. This sediment can clog your fuel lines and reduce the efficiency of your heating system. If the clog becomes severe enough, your heating system will shut down.

To prevent this, it is recommended to keep your tank at least half-full during the warmer months. This is because condensation is more common during the summer. Hot, humid days and cool nights create the perfect conditions for condensation to build up inside your tank. If your tank is above ground, outdoors, and in an unshaded area, it is even more prone to condensation.

Filling your tank before the summer can also save you money. Demand for heating oil is typically low during this time, so prices are usually lower than during the peak heating season. By filling your tank when demand is low, you can avoid the inconvenience and higher cost of an emergency fuel delivery when the cold weather arrives.

Condensation can also cause premature rusting from the inside out

Condensation can cause premature rusting in fuel oil tanks, which can lead to serious problems with the tank and the heating system. The more space there is in the tank, the more room there is for condensation to form during the summer months. This moisture settles at the bottom of the tank, causing rusting that can, over time, lead to the metal deteriorating and the potential threat of leaking oil.

This rust sediment gets mixed in with the heating oil and, when the heat is turned on, gets pulled into the heating equipment. This can cause a complete breakdown of the heating system, erratic or unpredictable operation, blocking and erosion of burner tips and mechanical parts, and loss of heat release.

The oxidation of hydrocarbon ingredients increases when corrosion occurs, degrading the quality of the contents and leading to sludge build-up. This can reduce fuel lubrication and obstruct the operation of release detection, eventually leading to equipment and machinery failure.

To prevent condensation, it is important to keep fuel tanks topped up, especially during the summer months. This leaves less space for air and, therefore, less chance of humidity and condensation. It is also recommended to get fuel and tanks checked every six months, as corrosion forms from the inside of a tank and is not visible by exterior examination.

A full tank ensures you always have fuel when you need it

However, there are some cons to keeping your tank full. Firstly, it can be expensive, especially if you have a large car. Secondly, more fuel equals added weight, which may cause a slight dip in fuel economy.

There are also potential safety issues with full tanks. For example, if a tank is not vented properly, the pressure can build up to dangerous levels. Additionally, if a tank is overfilled, there is a risk of spillage.

To ensure your safety and maintain your vehicle, it is important to monitor your fuel levels and fill up when necessary. This will help you avoid running out of fuel and keep your tank in good condition.

A full tank lets you schedule deliveries at your convenience

If you wait until the last minute to order fuel, you may have to pay an emergency delivery surcharge. By keeping your tank full, you can avoid this extra cost and ensure you always have fuel on hand when you need it.

Heating oil can sit for years without degradation, so there is no risk in buying and topping off when prices are at their seasonal low points. This can save you money on fuel as the less fuel you need, the less you will be affected by periodic shifts in heating oil pricing.

A full tank can save you money on fuel

A full tank of fuel can save you money, but it may not be for the reasons you think.

Firstly, a common misconception is that a full tank of fuel weighs significantly more than a half-full tank, and therefore a car with a full tank will use more fuel to move. While this is true, the difference in weight is minimal—a full tank of fuel only accounts for around 5% of a car's total weight. Reducing the tank to half its maximum level will only save around 2.5% in total vehicle weight, which will have a negligible effect on fuel economy.

However, filling up your tank does have other benefits. A full tank reduces the space for condensation to form, so you are less likely to have issues with water in the fuel tank, which can cause performance issues and reduce fuel efficiency. Additionally, filling up your tank means fewer visits to the petrol station, which essentially results in fewer miles driven. This can save money, especially for businesses with fleets of vehicles, as their drivers will be making fewer trips and therefore driving less.

There are other ways to save on fuel costs that will have a greater impact than a full tank. These include:

• Checking tyre pressure regularly—underinflated tyres can reduce fuel economy by up to 2.5%.
• Removing excess weight from the vehicle, such as unnecessary tools, equipment, or passengers.
• Reducing the use of air conditioning, heated windscreens, and other electrical systems.
• Driving efficiently by accelerating and braking gently and changing gears early.
• Anticipating road conditions and keeping moving where possible to avoid coming to a complete stop.
• Turning off the engine when waiting for extended periods, such as in traffic.
• Carpooling or sharing fuel costs with colleagues.

Frequently asked questions