🔍 Key Concepts

• Fuel oil tank venting systems and why vents are required • Purpose of a wire mesh (gauze) screen in a vent line on a tank containing flammable liquids • Fire and explosion risks associated with vapors leaving and entering fuel tanks

💭 Think About

• Ask yourself: What is the main safety hazard with fuel oil tanks – is it solids, liquids, or vapors that create the greatest risk? • Think about how a fine wire mesh behaves if a flame front tries to pass through it. What property of the mesh affects this? • Which option directly addresses the biggest danger associated with fuel vapors at an open vent?

✅ Before You Answer

• Identify the primary safety function of wire mesh in vents on tanks that hold flammable liquids, not just fuel oil tanks. • Distinguish between preventing product loss/contamination and preventing ignition of vapors. • Consider which choice most closely matches the function of a flame arrester-type screen commonly fitted on tank vents.