Massachusetts Oil Burner License Practice Test

What are common sources of water in oil tanks?

1. Rainwater and flooding

2. Condensation and defective fittings

3. Ice and snow

4. Old oil residues

The correct answer is: Condensation and defective fittings

Common sources of water in oil tanks primarily include condensation and defective fittings. Condensation occurs when warm air inside the tank meets the cooler metal walls, causing moisture to form. This is particularly common in tanks that contain only a small amount of fuel, leading to significant temperature fluctuations. As the air inside the tank cools, the moisture condenses and drips to the bottom of the tank, where it can mix with the oil. Defective fittings, such as poor seals or corroded connections, can also allow water to enter the tank directly. If these fittings are compromised, rainwater or groundwater can seep in, leading to further contamination of the oil. While rainwater and flooding, ice and snow, and old oil residues can potentially contribute to moisture in an oil tank, they are not as common or significant as condensation and defective fittings when considering the primary sources of water contamination. These other options may contribute to water accumulation in specific scenarios, but condensation and defective fittings remain the primary concerns for maintainable oil tank systems.