Sketch a line diagram of a typical inert gas system for oil tanker cargo tanks, label the parts, describe the system, and state the expected oxygen content in flue gases with good combustion?

flowchart LR
    A[Propulsion\nsystem exhaust] --> B[Inert gas plant]
    B --> C[Inert gas\ndistribution]
    C --> D[Cargo tanks]
    E[Two non-return\nvalves and\nautomatic\nstop valve] -.-> B
    F[Fixed and\nportable\nmeasuring\ninstruments] -.-> C

• Purpose: inert gas displaces air in cargo tanks to keep the atmosphere non-flammable
• Source: treated flue gas from propulsion system exhaust
• Oxygen in flue gas (good combustion): ≤ 5 % by volume
• Oxygen in inert gas supply main: ≤ 5 % by volume
• Oxygen in cargo tanks: ≤ 8 % by volume, positive pressure at all times
• Governing instrument: SOLAS chapter II-2, FSS Code chapter 15
• Key components: propulsion system exhaust, inert gas plant, inert gas distribution, two non-return valves and automatic stop valve, fixed and portable measuring instruments
• CL4 scope: operate and monitor the system, verify readings, report faults, maintain log book