Question 35

The Correct Answer is C **Why option C is correct:** Flame screens (also known as flame arresters or flame traps) are safety devices designed to prevent a flame or explosion outside a vessel or system (like a tank, pipe, or vent) from propagating back into the contained flammable atmosphere. When used on storage tanks (especially those containing volatile, flammable liquids), they are installed on the vents. Their primary function is to allow vapor to escape or air to enter while ensuring that if the escaping vapor ignites, the flame cannot travel back through the vent opening and ignite the main contents of the tank, which could cause a catastrophic explosion. **Why the other options are incorrect:** * **A) To keep flames and sparks from getting out of an engines exhaust system:** While exhaust systems sometimes use spark arresters or mufflers to contain sparks, the term "flame screen" specifically refers to the flame-quenching devices used to prevent flame propagation into storage vessels or processes, not generally for controlling emissions from an engine exhaust. * **B) To contain flammable fumes:** Flame screens do not contain fumes; they allow fumes (vapors) to pass through. Their purpose is purely to block the heat and physical propagation of a flame front. * **D) To protect firefighters from flames:** Flame screens are passive mechanical safety devices used on industrial equipment (tanks, pipelines). They are process safety controls, not personal protective equipment (PPE) or direct safety barriers for personnel like firefighters. Firefighters use specialized gear and tactics for protection.