🔍 Key Concepts

• Function of a DC (de-aerating) heater in a steam plant • Typical source and pressure level of steam used for heating and stripping dissolved gases from condensate • Difference between main steam, auxiliary steam, and exhaust steam in a marine power plant

💭 Think About

• Think about which steam source is readily available and at a suitable pressure and temperature for both heating and removing dissolved gases from condensate, without wasting highest‑energy steam • Consider how steam is cascaded through the plant: which steam has already done some work but still has enough energy for heating duties? • Ask yourself which source is most economical and normally routed to feed heaters and other low‑pressure heating services on board

✅ Before You Answer

• Verify what type of steam is normally connected to low‑pressure heaters and DC heaters in standard steam plant diagrams • Check which steam source is typically used for auxiliary services versus propulsion so you don’t pick a source that’s too valuable for this duty • Confirm which option represents exhaust or lower‑pressure steam that is commonly recovered for heating, rather than being vented or wasted