Inert Gas Generator, Model No.; KGG-500

Common issues

• Scrubber tower spray nozzle fouling or blockage, reducing gas cooling and cleaning efficiency
• Deck water seal running low or its drain blocked, risking backflow of flammable gas toward the machinery space
• O2 analyzer drift or fouling giving inaccurate oxygen readings
• Combustion chamber/burner fouling or fuel nozzle wear on the generator unit
• Blower bearing wear or vibration
• Non-return/deck isolating valve failing to seal properly, and PV breaker fouling or icing in cold conditions
• Corrosion of the scrubber and ducting from wet, acidic exhaust gas conditions

Inspection checklist

• Check deck water seal water level and drain function
• Test the O2 analyzer against a calibration gas or an approved wet-chemical check
• Inspect scrubber tower spray nozzles and demister for fouling
• Check the combustion chamber/burner and fuel supply on the generator unit
• Inspect the inert gas blower for vibration, noise, and bearing condition
• Check the non-return valve and PV breaker for correct operation and freedom from fouling or ice
• Verify inert gas main pressure and O2 content at the point of use against the required tank atmosphere
• Check alarm and shutdown functions - high O2, low water seal level, high gas temperature, power failure
• Inspect ducting and scrubber shell for corrosion

Service intervals

Typical wear limits

Ranges are typical for this design class. Always confirm against the manufacturer documentation for your serial number.

Critical spares

• O2 analyzer cell/sensor
• Scrubber spray nozzles
• Burner/fuel nozzle for the generator unit
• Non-return valve seal/disc
• Deck water seal level sensor or float
• Blower bearing set

Safety

• Inert gas is an asphyxiation hazard - low-oxygen atmosphere risk in enclosed and tank spaces
• Failure of the deck water seal or non-return valve can allow flammable cargo vapour to migrate back toward the machinery space - a fire/explosion hazard
• Hot exhaust and combustion chamber surfaces
• Toxic combustion by-products (CO, SO2) if the system malfunctions
• Cargo tank atmosphere work requires proper gas-freeing and enclosed-space entry procedures independent of the IG system itself

Class survey

Inert gas systems on tankers and bulk liquid carriers are surveyed against SOLAS II-2 and the IGS Code, or equivalent flag requirements. Annual testing of the O2 analyzer, deck water seal, non-return valve, and alarm/shutdown functions is typically required and recorded, and class attends to verify the system can maintain cargo tank atmosphere within the required oxygen content during cargo operations.