🔍 Key Concepts

• boiler water chemistry and how improper chemical treatment affects different parts of the system • where carbon dioxide is most likely to dissolve and form carbonic acid in a steam/condensate system • the difference between high‑temperature dry steam areas and low‑temperature, water-carrying return lines

💭 Think About

• Trace the path: feedwater is heated, turned to steam, expanded in the plant, then condenses and returns. At which stage is CO₂ most likely to be in contact with liquid water for long periods? • Ask yourself: does CO₂ attack metal more in hot, dry steam spaces or in cooler, wet piping where condensate is present? • Which of the listed components routinely carries relatively cool condensate water that can absorb CO₂ and become acidic?

✅ Before You Answer

• Identify which option refers specifically to piping that carries condensate/return water, not steam • Consider where carbonic acid (CO₂ + H₂O) would realistically form and remain in contact with metal surfaces • Eliminate any answers that are primarily high‑temperature, dry steam paths with minimal standing water