🔍 Key Concepts

• Boiler refractory purpose – why it’s installed and what kinds of damage typically shorten its life (cracking, spalling, erosion) • Thermal stress – what happens to refractory when it is heated or cooled too quickly • Manufacturer’s operating recommendations – warm-up, cooldown, and firing procedures

💭 Think About

• Which option focuses on how you operate the boiler over time rather than just how you install or repair the refractory? • Think about what usually causes refractory to crack or fall out: is it steady operation, sudden changes, or something else? • Which choice would best minimize thermal shock and mechanical stress during normal boiler use?

✅ Before You Answer

• Compare each answer to common refractory failure causes: thermal shock, improper firing rates, and poor start-up/shutdown practices. • Ask: Does this option protect the refractory during everyday operation, or is it only about one-time installation or emergency repair? • Eliminate any option that could actually increase thermal stress, such as maintaining extreme temperatures or relying on frequent patching instead of proper operation.