🔍 Key Concepts

• Proper warm-up procedures for an automatically fired auxiliary boiler starting from cold • Why vents/air cocks are used during initial raising of steam pressure • When it is safe to close vents and operate valves as pressure increases

💭 Think About

• Think about what happens inside the boiler drum as cold water is heated and steam first begins to form—what else is inside the drum besides water and steam? • Consider which action helps protect the boiler from damage due to trapped air or rapid pressure changes when starting from cold. • Ask yourself: at very low pressure, which fittings should be tested or moved fully open/closed, and which ones should wait until the boiler is warmed and pressure is closer to operating range?

✅ Before You Answer

• Identify which fitting is used specifically to remove air and prevent vacuum/air pockets during startup. • Decide whether it is safe or recommended to fully open the main steam stop when only initial steam is forming. • Consider whether bottom blows and safety valve tests are normally done at very low pressures right at first steam, or at a later, safer point in the warm-up.