QUESTION 8.3.3

Flue-gas inert-gas system

Oil, ChemicalEngine Room, Engine Control Room

What is being checked

The inspector is checking whether the flue-gas inert-gas system matches the approved arrangement, is physically ready, is tested through its complete operating path and is understood by responsible personnel.

Ready onboard

0/6 complete

APPROVED BASISPlans, manuals and certificates identify boiler uptake source, isolating valve, scrubber, blowers, recirculation, oxygen analyser, deck supply and non-return protection.PHYSICAL CONDITIONInspection confirms the fitted arrangement is complete, labelled and accessible, with none of these defects or unsafe conditions: uptake leakage, scrubber corrosion, low water flow, high oxygen, blower failure or soot contamination.FUNCTION TESTThe approved test method proves uptake isolation, scrubber level and flow, blower trip, oxygen alarm, deck pressure and automatic shutdown.ALARM AND INDICATIONLocal and remote indications, alarms, trips, interlocks and power supplies agree with the actual equipment condition.MAINTENANCEPMS tasks, calibration, service limits, defects and authorised repairs are traceable to the specific equipment.USER KNOWLEDGEResponsible personnel can locate the controls and explain boiler uptake source, isolating valve, scrubber, blowers, recirculation, oxygen analyser, deck supply and non-return protection, limitations and failure response.

Practice questions

Answer aloud, then open the preparation point.

1What is the purpose and operating limit of the flue-gas inert-gas system?

Explain the protection provided by boiler uptake source, isolating valve, scrubber, blowers, recirculation, oxygen analyser, deck supply and non-return protection, including the condition that requires intervention.

2How is the complete operating path tested?

Use the approved safe test method to prove uptake isolation, scrubber level and flow, blower trip, oxygen alarm, deck pressure and automatic shutdown, including the final alarm, trip, movement or indication.

3What happens if the equipment is unavailable?

Notify the Master and terminal as applicable, stop or restrict the affected operation, establish approved compensating controls and obtain repair or formal authority.

4Show the latest maintenance and defect history.

Match the physical identity to PMS, calibration or service records and verify that any temporary control has been closed.

5Which indication proves the equipment is in its safe condition?

Identify the local and remote indication, its source, alarm set point and how a false or frozen signal would be detected.

Where an observation may arise

ARRANGEMENT CONFLICT

The fitted system, drawing, manual or certificate did not agree.

PHYSICAL DEFECT

Inspection identified uptake leakage, scrubber corrosion, low water flow, high oxygen, blower failure or soot contamination.

INCOMPLETE TEST

Records did not prove uptake isolation, scrubber level and flow, blower trip, oxygen alarm, deck pressure and automatic shutdown through the complete operating path.

ALARM DEFECT

An alarm, trip, interlock or indication was isolated, incorrect, overdue for test or not understood.

MAINTENANCE GAP

PMS, calibration, service or repair evidence was missing, overdue or not traceable to the item.

KNOWLEDGE GAP

Responsible personnel could not explain boiler uptake source, isolating valve, scrubber, blowers, recirculation, oxygen analyser, deck supply and non-return protection, operating limitations or failure response.

Master's practical note

Trace one signal or flow path from the field device to the CCR or ECR and back to the final protective action. A successful local test alone may not prove the full system.

Questions reported during inspections

Anonymised user reports, not official OCIMF questions or a prediction of what an inspector will ask.

HardwareReported inspection question

The Low Low IG pressure trip caused the Cargo pumps to trip during the inspection. Upon restarting it was traced to a fault was due to a terminal relay in the circuit. Further as per consultation between Operator's representatives, Loading Master and Shipboard management team it was concluded that the IG system was operational and normal. A thorough risk assessment was carried out. The COP interlock for Low low pressure on CCR panel was canceled and operation resumed. IG pressure was being continually monitored as part of the risk assessment. Observation category: Human (Positive) Inspector’s comment: The OP very quickly assessed the Cargo pump trip issue. He was able to understand the gravity of the situation and carried out the necessary action to ensure safe operation with minimum downtime. A risk assessment was carried out to continually monitor and record the IG pressure using all other digital and analogue methods and the instructions were accordingly sent out. He also maintained excellent closed loop communication with the Ship and Shore management team.

Oil tanker · Deck · Cargo control room · January 2026

Equipment boundary and references

Equipment boundary: Use approved test modes and maker instructions. Do not bypass an interlock, release cargo or defeat protection merely to satisfy an inspection demonstration.

References

OCIMF SIRE 2.0 Question Library Part 2, Version 1.0, Question 8.3.3
SOLAS Chapter II-2 regulation 4.5.5
IMO FSS Code Chapter 15

Last reviewed: 2026-09-14