🔍 Key Concepts

• Fuel oil tank gauging methods on ships • Purpose of a sounding tube versus vent, overflow, and feed lines • Safe ways to check tank levels and prevent spills/vapor escape

💭 Think About

• Which part of the system is specifically designed for safely inserting a tape or rod to measure liquid depth in a tank? • What is the primary job of a vent or overflow line, and why would it be unsafe or impractical to use them for routine level measurement? • Among the four options, which is intended for liquid transfer, which for pressure equalization, which for excess liquid discharge, and which for measuring level?

✅ Before You Answer

• Identify which component is designed for manual level measurement (sounding) of tanks • Confirm which lines are meant for air/pressure relief and not liquid gauging • Ensure you are not choosing a line whose main function is fuel supply to machinery or emergency overflow protection