🔍 Key Concepts

• Boiler priming and what actually carries over with the steam when priming occurs • Where downcomers are located and what their function is in a "D" type propulsion boiler • How moisture or water carryover from a boiler can affect high‑speed rotating machinery like main steam turbines and reduction gears

💭 Think About

• Think about whether priming mainly affects internal water‑circulation components in the boiler or external steam‑using machinery in the propulsion train • Ask yourself: if a slug of water or very wet steam leaves the boiler, which listed items would actually be in the path of that flow? • Consider which item is more likely to suffer from erosion, water hammer, or mechanical shock versus problems like circulation or overheating inside the boiler

✅ Before You Answer

• Verify what downcomers do (do they carry steam, water, or a mixture, and are they on the water side or steam side?) • Confirm what components the main steam line feeds directly after the boiler in a propulsion plant (turbines and then reduction gears). • Check whether typical texts warn about priming damage mainly in the boiler internals or in turbines/reduction gears downstream.