🔍 Key Concepts

• Boiler drum level "shrink and swell" behavior when steam demand or feedwater rate changes • What happens to steam bubbles inside the water when load or pressure conditions change • Difference between a real change in water mass and an apparent level change on the gauge glass

💭 Think About

• Think about what would make the water in the drum look LOWER on the gauge glass even if you did NOT suddenly remove a lot of water. • When steam demand drops and pressure rises, what happens to the size and number of steam bubbles in the water? Does that make the level seem to go up or down? • Which option describes a change that directly affects the steam bubbles themselves, rather than just changing flow rates or pressures indirectly?

✅ Before You Answer

• Identify which choice is about bubble behavior inside the water rather than outside system changes like pressure or feed flow. • Ask: "Does this option explain an effect that would make the bubbles take up less space in the drum water?" • Eliminate any choices that would more likely cause more steam volume in the water (which is associated with swell, not shrink).