What are Advantages and Disadvantages of IG or Inert gas system?

Advantages are:

1. Inert gas in cargo tank make atmosphere non-explosive.
2. It allows high-pressure tank washing and reduces tank-cleaning time.
3. It allows COW( crude oil washing)
4. Reduces corrosion in tanks – with an efficient scrubber in the system.
5. Improves stripping efficiency and reduces discharge time.
6. Aids the safe gas freeing of tanks.
7. It is economical to operate.
8. It forms a readily available extinguishing agent for other spaces.
9. Reduces the loss of cargo through evaporation.
10. Complies with legislation and reduces insurance premiums.

Disadvantages are :

1. Additional costs for installation
2. Additional Maintenance require manpower and money.
3. Low visibility inside tanks
4. With low oxygen content, tank access is denied.
5. Could lead to contamination of high-grade products.
6. Moisture and sulphur content corrodes equipment.
7. An established reverse route for cargo to enter the engine room.
8. Oxygen content must be monitored and alarm sensed at all times.
9. Instrumentation failure could affect fail-safe devices putting the ship at risk through the IG system.
10. An additional gas generator is required in the system in the absence of waste heat products from boiler flue gases.