Procedures & Alarms

Milestones:

• Learning and Training Phase – Pre-Requisites for the start of operation:

1. Start The Portable Multi Gas Detector And Dew Point Meter.
2. Install The Spool Piece To Connect Inert Gas Line To Liquid Line.
3. Set Cargo Tank Vapour Valves.
4. Set Cargo Tank Liquid Valves.
5. Set The Vapour Line To No. 1 Vent Mast Regulating Valve.
6. Set The Inert Gas Line Valve.
7. Prepare And Start Ballast Pump 2.
8. Prepare Inert Gas Generator In Inert Gas Mode.

 

• Assessment Phase – Operational flow and Assessment:

9. Start Inert Gas Generator In Inert Gas Mode.
10. Methane Content < 2% By Volume.
11. Maintain Cargo Tanks Pressure Between 5 kPa And 7 kPa.
12. Check The Sampling Point On Vapour Line In All Cargo Tanks.
13. When All Of The Cargo Tanks And Piping Are Inerted, Stop The Supply Of Inert Gas.

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Actions During Exercise:

1. Deviation From Exercise:
   • After starting gassing up, the user must not open non-required valves or close required ones. If this occurs, a caution message will appear, instructing the user to undo the action. Failure to correct it will terminate the exercise.
2. Not Maintaining IGG Outlet Flow:
   • During inerting, maintain IGG outlet flow and flow to the atmosphere between 15,500 kg/h and 16,500 kg/h. Failure to do so will trigger a high-priority alarm. If the flow is not corrected within 1 minute, the exercise will terminate.

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Alarms & Remarks

Alarm Condition	Alarm Time	Alarm Level	Alarm Title	Alarm Description	Action
		remark	Inerting Of Cargo Tanks Started	Inerting of the cargo tanks has started.
		remark	Inerting Of Tanks Completed	Inerting of cargo tanks is completed, stop the delivery of inert gas.
		remark	Check The Sampling Point On Vapour Line	Check the sampling point on vapour line for dry air properties, in all cargo tanks.
		remark	Close Valve CG702	Inerting of tanks is stopped, close the valve CG702.
		remark	Open Valve CG702	Open the valve CG702 to vent out the warm vapour.
		caution	Maintain IGG Outlet Flow And Outlet Flow To Atmosphere	Maintain IGG outlet flow and outlet flow to atmosphere between 15,500 kg/h to 16,500 kg/h.
		caution	Deviation Detected	Deviation from the exercise is detected, undo your last action.

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Step By Step Procedure

• Learning and Training Phase – Pre-Requisites for the start of operation:

1. Start The Portable Multi Gas Detector And Dew Point Meter

Steps:

• • Navigate to the “MISCELLANEOUS EQUIPMENT” page.
  • Press and hold the power button on the Portable Multi Gas Detector and Dew Point Meter for 5 seconds to start the instruments.
  • Verify both devices are operational to complete this milestone.

 

2. Install The Spool Piece

• • Connect the spool piece above valve CL701, linking the IGG outlet to the cargo tank’s liquid lines.

 

3. Set Cargo Tank Vapour Valves

Valve	Status
CG100	Open
CG101	Open
CG200	Open
CG201	Open
CG300	Open
CG301	Open
CG400	Open
CG401	Open

Once these valves are set, the milestone is complete.

 

4. Set Cargo Tank Liquid Valves

Valve	Status
CL100	100%
CL107	100%
CL200	100%
CL207	100%
CL300	100%
CL307	100%
CL400	100%
CL407	100%

 

5. Set Vapour Line To No. 1 Vent Mast Regulating Valve

Valve	Status
CG701	Open

 

 

6. Set Inert Gas Line Valve

Valve	Status
CL701	Open

 

7. Prepare And Start Ballast Pump 2

Steps:

• • Navigate to the Ballast System or Ballast Water Treatment System page.
  • Ensure at least two generators are operational:
    • Navigate to the “PMS” page and activate another generator.
  • Configure the ballast pump:
    • Open BA010F (15%)
    • Open BA006F
    • Close BA005F (if open)
    • Open BA026F
  • Start the ballast pump to complete this milestone.

 

8. Prepare Inert Gas Generator In Inert Gas Mode

Steps:

• • Set Generator Mode to “Inert Gas”.
  • Adjust Operating Percentage to “100%”.
  • Turn Fuel Pump to “On”.
  • Activate IG Chiller Unit.

• Assessment Phase – Operational flow and Assessment:

9. Start Inert Gas Generator In Inert Gas Mode

Steps:

• • Wait for the IG chiller outlet temperature to drop to 3°C or below.
  • Click “Start” on the IGG system to initiate inert gas production.
  • Ensure the oxygen analyzer shows <2% oxygen before starting delivery.

 

10. Cargo Tank Dew Point < -40°C

• • Use the Dew Point Meter to confirm the dew point is below -40°C.

 

11. Cargo Tank Methane Content < 2%

• • Use the Portable Multi Gas Detector to confirm methane content is <2% by volume.

 

12. Maintain Cargo Tanks Pressure Between 5 kPa And 7 kPa

• • Regulate the vent mast valves to maintain pressure within the specified range.

 

13. Check Sampling Points

• • Verify vapor line sampling points for the following:
    • CH₄: 0% LEL
    • O₂: 1% vol
    • CO: 100 ppm
    • CO₂: 14% vol
    • Dew Point: -45°C

 

14. Stop Inert Gas Supply

• • Once all tanks achieve a dew point of -45°C, stop the IGG delivery.
  • Close CG702 to finalize the operation.
  • A confirmation remark will indicate completion.

Proper line up for inerting: