🔍 Key Concepts

• Boiler superheater operation – how steam flow through the tubes removes heat from the metal • Heat transfer on the fireside – what happens if cooling on the water/steam side is reduced or stopped • Typical causes of overheating and tube failure in superheaters

💭 Think About

• Ask yourself: under what condition would the metal of a superheater tube get much hotter than normal even though the same flame is present? • Think about the role of steam flow inside the tubes: what happens to tube temperature if steam flow is greatly reduced or stopped? • Which option describes a condition that would remove effective cooling from the inside of the tube rather than just exposing it to hot gas or fuel on the outside?

✅ Before You Answer

• Be clear on what "fireside" means (gas side vs water/steam side). • Consider which options are normal design conditions (things the tubes are built to handle) versus an abnormal condition that leads to overheating. • Verify which choice directly causes loss of internal cooling of the tubes, allowing metal temperature to rise excessively.