🔍 Key Concepts

• Flame screens purpose on tank vents • How flashback (flame traveling back into a tank) is prevented • Difference between blocking vapors and cooling or stopping a flame front

💭 Think About

• Think about what happens if there is a fire or explosion outside the tank near the vent – what risk do we most want to prevent? • Does a tank vent flame screen normally stop vapors from going out, or is the tank designed so vapors must be able to escape safely? • In order to stop a flame from entering the tank through the vent, what physical property of the flame could the device act on – the vapors themselves, or the heat/temperature of combustion?

✅ Before You Answer

• Remember that tanks must be able to vent pressure safely – so which options are compatible with letting pressure/vapors escape? • Ask whether a thin metal mesh or perforated plate could realistically absorb all vapors or completely prevent vapors from entering or leaving. • Focus on the option that involves stopping or cooling a flame front coming from outside, while still permitting gas flow through the vent.