🔍 Key Concepts

• Boiler construction – where tubes, water wall headers, and hand holes are located relative to the boiler casing • Steam leaks vs. water leaks – what you are most likely to SEE as steam escaping from outside the pressure parts • Common failure points on a fired boiler that could allow steam to reach the casing area

💭 Think About

• Think about which components actually contain steam at boiler operating pressure and are close enough to the casing that a leak could show up as escaping steam. • Consider whether a leak in ANY one of the listed items could cause steam to be seen at the casing, or whether only one (or some) of them realistically would. • Ask yourself: if you were tracing a steam leak around the outside of the furnace/boiler, what internal parts failures would you suspect first and why?

✅ Before You Answer

• Be clear on what the boiler casing is (outer enclosure) versus pressure parts (where steam/water are under pressure). • For each option, ask: Does this part, if leaking, reasonably allow steam to reach the casing area and be visible externally? • Check whether the wording "individually correct" in choice D changes how you interpret the other three options.