🔍 Key Concepts

• Wet lay-up versus dry lay-up of boilers and why oxygen control matters • The purpose of deaerated feedwater in preventing corrosion • What it means to "maintain" a boiler during a lay-up period

💭 Think About

• Which option best prevents oxygen corrosion inside a boiler that is out of service but still kept ready? • How would you keep air from entering the boiler metal surfaces during a wet lay-up? • Which choices mention a stable condition versus frequent draining and refilling, which can introduce more oxygen?

✅ Before You Answer

• Identify which options involve introducing fresh untreated water repeatedly and why that is undesirable • Check which choice mentions deaerated feedwater and think about why removing oxygen is important • Look for the option that keeps the boiler completely full and under slight positive pressure to exclude air