🔍 Key Concepts

• Flammable vapors vs. liquid fuel in tanks • Effect of tank fullness (ullage space) on vapor formation • Differences between diesel, lube oil, and hydraulic oil in terms of volatility

💭 Think About

• Which condition in a tank creates the most space for a flammable vapor/air mixture to form? • How does a liquid’s flash point and volatility affect its tendency to form ignitable vapors? • Compare a completely full tank to a partially full tank: in which case is there more oxygen available for combustion in the tank?

✅ Before You Answer

• Identify which products listed are more volatile and more likely to produce flammable vapors • Consider that explosions require a correct fuel-vapor/air mix, not just a large volume of liquid • Think about which option combines a more volatile product with ample air space (ullage) in the tank