🔍 Key Concepts

• Gravity lube oil tank function and purpose in a steam plant system • How an overflow or spill‑back line from a tank is shown on a piping diagram • Difference between a level-indicating device (like a gauge glass or switch) and an actual overflow discharge point

💭 Think About

• On the diagram, trace the piping from the gravity lube oil tank upwards and outwards: where would oil go if the tank kept filling past its normal level? • Which labeled item connects to the top of the gravity tank and leads to a safe discharge location (such as a sump or drain), instead of back into the operating part of the system? • Of the answer letters, which symbol represents a point where you could physically observe liquid flowing when the tank is completely full?

✅ Before You Answer

• Verify which labeled item is tied directly to the top of the gravity tank rather than to its suction or discharge lines. • Confirm that the selected item leads to a drain, sump, or return line that would carry away overflowing oil. • Make sure you are not choosing a level switch or gauge that only indicates level electrically, but a point where you could actually see overflow occurring.