🔍 Key Concepts

• Boiler furnace and uptake pressure and how gases try to escape high-pressure areas • Physical components that penetrate the boiler casing and separate the gas path from the fire room • What each listed item in the choices actually does in a marine boiler system

💭 Think About

• For each choice, ask: does this part form a boundary between the combustion gas path and the fire room? If it fails, would there be a direct path for hot gases into the room? • Consider whether the component normally carries steam/water, air for combustion, or is part of the gas-side path (furnace/uptake). Which one, if it leaks, would let combustion gases escape into the fire room? • Think about which part must have packing or seals that are exposed on one side to hot flue gas and on the other side to the fire room atmosphere.

✅ Before You Answer

• Identify which components actually pass through the boiler wall or casing and therefore could leak from the gas side to the fire room • Verify which item uses packing glands or seals specifically to keep gases from escaping to the atmosphere • Eliminate any items that are primarily involved with steam conditioning (temperature control) or fuel/air mixing but do not themselves form the main barrier between gas passages and the fire room