🔍 Key Concepts

• Boiler water level control during operations at sea • Purpose of a surface blow (removing impurities/foaming at the water surface) • Effect of changing water level and firing rate just before opening a surface blow valve

💭 Think About

• Think about what happens to the steam drum level and steaming conditions when you suddenly open the surface blow valve while underway. • Would a higher or lower water level before the blow-off reduce the risk of exposing tubes or causing priming/carryover? • How would securing burners or changing draft affect steam supply and boiler stability at sea just before a brief surface blow?

✅ Before You Answer

• Verify which action best keeps water level within safe limits when some water is removed via surface blow. • Check which choice avoids upsetting steam pressure and combustion conditions more than necessary. • Confirm which procedure is standard for a brief surface blow while underway, not for a full boiler shutdown or bottom blow.