What percentage of fuel oil tank capacity can you fill without risking overfill?

The most appropriate percentage of fuel oil tank capacity that can be filled without risking overfill is 90%. This is related to safety measures and regulatory guidelines that help prevent spills and overflows during the storage and handling of fuel oils.

Filling a tank to 90% of its capacity allows for the necessary expansion of the liquid, which can occur due to changes in temperature. As fuel oil warms up, it expands, and if the tank is filled beyond this threshold, there is a significant risk of spillage. This practice also accounts for the need for vapor space above the liquid, which is essential to prevent pressure build-up within the tank that can lead to dangerous conditions.

It's important to consider that options below 90% do contribute to safety, but they do not utilize the tank's capacity efficiently. Conversely, options above this percentage risk overfilling and the associated hazards. Thus, 90% strikes a balance between maximizing storage capacity and maintaining safety protocols.