Modern oil storage tanks come in all shapes and sizes and can be made from plastic or steel. The size and type that your OFTEC Registered Technician recommends will depend on your individual requirements. OFTEC has created a set of standards which the tanks should meet.
To minimise the risk of pollution from an oil spill, non-domestic oil storage tanks exceeding 200 litres must be provided with secondary containment (bunding). This can be achieved by installing an integrally bunded tank or by constructing a concrete or masonry bund, to CIRIA Report 163, around a single skinned tank. The bund must capable of containing at least 110% of the oil storage tank’s capacity.
Bunding will in some circumstances also be required for domestic installations. The installation engineer will conduct a risk assessment to determine if one is required, typically in premises close to a river, well or controlled water source.
The oil tank must have a base that is suitable throughout the year. The base must be adequate for the weight of the tank, non-combustible, imperforte and level. It should be constructed of concrete, paving stones or stonework and extend at least 300mm beyond all sides of the tank.
Location – Fire Separation Distances
Although it is unlikely that a fire could be started by stored oil in a tank, when siting your tank, you are required to comply with fire separation distances.
For domestic premises the separation distances are:
- 1.8m away from non-fire rated eaves of a building;
- 1.8m away from a non-fire building or structure (e.g. garden sheds);
- 1.8m away from openings (such as doors or windows) in a fire rated building or structure (e.g. brick built house/garage);
- 1.8m away from oil fired appliance flue terminals;
- 760mm away from a non-fire rated boundary such as a wooden boundary fence;
- 600mm away from screening (e.g. trellis and foliage) that does not form part of the boundary
- Additionally, where a tank contains more than 3500 litres any openings in the walls between 1.8 and 6m away from the tank should be fitted with 1hour fire resisting glazing or 1hour fire resisting self-closing doors.
If these distances cannot be complied with then a fire protection barrier with at least a 30 minute rating must be provided with a minimum separation distance of 100mm between the tank and the fire rated barrier (or such greater distance as the manufacture of the tank may specify).
Source: The Health & Safety Consultancy