Question 29

The Correct Answer is C **Why option C ("To prevent flames from entering tanks") is correct:** Flame screens (more formally known as flame arresters or flame traps) are essential safety devices used in industrial and maritime settings, particularly when handling flammable liquids or gases. Their primary function is to prevent an external flame or spark from igniting a potentially explosive vapor-air mixture contained within a tank, vessel, or pipeline. They work by using small passages (often a mesh, perforated plate, or crimped metal ribbon) that allow vapor to pass through, but which rapidly absorb and dissipate the heat from the approaching flame front, effectively quenching the flame and preventing flashback into the confined space. **Why the other options are incorrect:** * **A) To protect firefighters from flames:** While firefighters use protective gear, flame screens themselves are passive, fixed safety devices designed to protect equipment and contents, not actively shield personnel from external flames. * **B) To contain flammable fumes:** The primary function of flame screens is not to *contain* the fumes (which are allowed to pass through the screen as part of normal venting), but to prevent ignition of those fumes by *external* sources. Fumes are contained by the tank or vessel itself. * **D) To keep flames and sparks from getting out of an engines exhaust system:** Devices used for this purpose are typically called spark arresters or spark shields. While they share a similar principle (quenching hot particles), a dedicated flame screen is specifically designed to stop a sustained flame front from propagating into an enclosed area, such as a fuel or cargo tank's vent line.