🔍 Key Concepts

• Steam plant systems: Know the normal steam sources for auxiliary equipment like evaporators. • Pressure and cleanliness requirements for evaporator steam: why we avoid certain contaminated or low‑pressure sources. • Difference between main steam, extraction steam, and exhaust steam and how/where each is used.

💭 Think About

• Which steam source provides sufficiently high pressure, reliable flow, and relatively clean steam suitable for making distillate water? • Would an engineer normally want to take steam from a line whose pressure or flow changes with turbine load, or from a more stable, controlled source? • Think about what the air ejector exhaust and extraction lines are usually used for—would their characteristics be ideal for an evaporator’s heating steam? Why or why not?

✅ Before You Answer

• Verify which line is normally designed to supply auxiliary services such as evaporators in a marine steam plant. • Check whether the option you pick would give relatively constant pressure and availability, even when main propulsion power changes. • Ensure the steam source you choose would not normally be wet, contaminated, or too low pressure for efficient evaporator operation.