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 the Inert Gas Line to the Liquid Line
3. Set the Cargo Tank Vapour Valves
4. Set the Cargo Tank Liquid Valves
5. Set the Vapour Line to No. 1 Vent Mast Regulating Valve
6. Connect the Dry Air Line to the Liquid Line by Opening CL701.
7. Prepare the Inert Gas Generator (IGG) in Dry Air Mode

• Assessment Phase – Operational flow and Assessment:

8. Start the Inert Gas Generator (IGG) in Dry Air Mode
9. Achieve a Cargo Tank Dew Point Below -20°C
10. Maintain Cargo Tank Pressure Between 5 kPa and 7 kPa
11. Check All Vapour Sampling Points for Dew Point in All Tanks
12. Stop the Dry Air Supply Upon Reaching the Required Dew Point

Exercise Actions and Warnings:

1. Deviation from Exercise Steps:
   • Avoid opening unnecessary valves or closing required ones after starting the drying process.
   • If such actions occur, a caution message will instruct you to undo the previous action.
   • Failure to correct the deviation will terminate the exercise.
2. Maintaining IGG Outlet Flow:
   • Keep the IGG outlet flow and flow to the atmosphere between 15,500 kg/h and 16,500 kg/h.
   • If a high-priority alarm is triggered, restore the flow within 1 minute, or the exercise will fail and terminate.

Alarms & Remarks:

Alarm Condition	Alarm Time	Alarm Level	Alarm Title	Alarm Description	Action
	Supply Started	Remark	Drying Of Cargo Tanks Started	Drying of the cargo tanks has started.
	On Drying completed	Remark	Drying of tanks completed	Drying of cargo tanks is completed, stop the deivery of inert gas.
	started delivery of Dry Air	Remark	Open Valve CG702	Open the valve CG702, To vent out the Normal air.
	Stopped delivery of Dry Air	Remark	Close Valve CG702	Drying of tanks is stopped, close the valve CG702.
	started delivery of Dry Air	Remark	Maintain IGG Oulet Flow And Outlet Flow To Atmosphere	Maintain IGG outlet flow and outlet flow to atmosphere between 15500 kg/h to 16500 kg/h.
when un necessary valve opened or required valve closed		Caution	Deviation Detected	Deviation from the exercise is detected, undo your last action.	Fails if that valve is not closed or opened within 1 minute

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:
   • Navigate to MENU > Miscellaneous Equipment.
   • Press and hold the power button for 2 seconds on both the Portable Multi-Gas Detector and Dew Point Meter until they start operating.
2. Install the Spool Piece to Connect the Inert Gas Line to the Liquid Line:
   • Navigate to MENU > Cargo System.
   • Click to connect the spool piece located above valve CL701, linking the IGG outlet and the cargo tank’s liquid lines.
3. Set the Cargo Tank Vapour Valves:
   • Open the following valves:
     CG100, CG101, CG200, CG201, CG300, CG301, CG400, CG401.
4. Set the Cargo Tank Liquid Valves:
   • Open the following valves 100%:
     CL100, CL107, CL200, CL207, CL300, CL307, CL400, CL407.
5. Set the Vapour Line to No. 1 Vent Mast Regulating Valve:
   • Open valve CG701.
6. Connect the Dry Air Line to the Liquid Line:
   • Open valve CL701.
7. Prepare the Inert Gas Generator in Dry Air Mode:
   • Navigate to MENU > IGG System.
   • Configure the following settings:
     • Generator Mode: Set to “Dry Air.”
     • Operating Percentage: Set to “100%.”
     • Fuel Pump: Set to “Off.”
     • IG Chiller Unit: Set to “On.”

• Assessment Phase – Operational flow and Assessment:

8. Start the Inert Gas Generator in Dry Air Mode:

1. 1. • Wait until the outlet temperature of the IG Chiller Unit is between 2°C and 3°C.
      • Click Start to activate the IGG.
      • Once started, air flows through the Demister Vessel and the dryer unit, reducing the dew point to below -30°C.

1. 1. 9. Cargo Tank Dew Point < -20°C:
         • Monitor the dew point using the Dew Point Meter.
           • Once the dew point reaches below -20°C at the vapour line sampling point, this milestone is completed.

1. Maintain Cargo Tank Pressure Between 5 kPa and 7 kPa:
   • Adjust the tank pressure by regulating the vent mast valves.
2. Check All Vapour Sampling Points for Dew Point in All Tanks:
   • Open the vapour line sampling points for all tanks and confirm the dew point is -25°C or lower.
3. Stop the Dry Air Supply:
   • Once all tanks reach a dew point of -25°C, stop the IGG delivery by clicking STOP under the delivery option on the IGG System page.
   • Close the vent mast regulating valve CG702.

 

Gas Properties Display on the Detector:

1. Dry Air Properties:
   • CH₄: 0% LEL
   • O₂: 20.9% vol

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 the Inert Gas Line to the Liquid Line
3. Set the Cargo Tank Vapour Valves
4. Set the Cargo Tank Liquid Valves
5. Set the Vapour Line to No. 1 Vent Mast Regulating Valve
6. Connect the Dry Air Line to the Liquid Line by Opening CL701.
7. Prepare the Inert Gas Generator (IGG) in Dry Air Mode

• Assessment Phase – Operational flow and Assessment:

8. Start the Inert Gas Generator (IGG) in Dry Air Mode
9. Achieve a Cargo Tank Dew Point Below -20°C
10. Maintain Cargo Tank Pressure Between 5 kPa and 7 kPa
11. Check All Vapour Sampling Points for Dew Point in All Tanks
12. Stop the Dry Air Supply Upon Reaching the Required Dew Point

Exercise Actions and Warnings:

1. Deviation from Exercise Steps:
   • Avoid opening unnecessary valves or closing required ones after starting the drying process.
   • If such actions occur, a caution message will instruct you to undo the previous action.
   • Failure to correct the deviation will terminate the exercise.
2. Maintaining IGG Outlet Flow:
   • Keep the IGG outlet flow and flow to the atmosphere between 15,500 kg/h and 16,500 kg/h.
   • If a high-priority alarm is triggered, restore the flow within 1 minute, or the exercise will fail and terminate.

Alarms & Remarks:

Alarm Condition	Alarm Time	Alarm Level	Alarm Title	Alarm Description	Action
	Supply Started	Remark	Drying Of Cargo Tanks Started	Drying of the cargo tanks has started.
	On Drying completed	Remark	Drying of tanks completed	Drying of cargo tanks is completed, stop the deivery of inert gas.
	started delivery of Dry Air	Remark	Open Valve CG702	Open the valve CG702, To vent out the Normal air.
	Stopped delivery of Dry Air	Remark	Close Valve CG702	Drying of tanks is stopped, close the valve CG702.
	started delivery of Dry Air	Remark	Maintain IGG Oulet Flow And Outlet Flow To Atmosphere	Maintain IGG outlet flow and outlet flow to atmosphere between 15500 kg/h to 16500 kg/h.
when un necessary valve opened or required valve closed		Caution	Deviation Detected	Deviation from the exercise is detected, undo your last action.	Fails if that valve is not closed or opened within 1 minute

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:
   • Navigate to MENU > Miscellaneous Equipment.
   • Press and hold the power button for 2 seconds on both the Portable Multi-Gas Detector and Dew Point Meter until they start operating.
2. Install the Spool Piece to Connect the Inert Gas Line to the Liquid Line:
   • Navigate to MENU > Cargo System.
   • Click to connect the spool piece located above valve CL701, linking the IGG outlet and the cargo tank’s liquid lines.
3. Set the Cargo Tank Vapour Valves:
   • Open the following valves:
     CG100, CG101, CG200, CG201, CG300, CG301, CG400, CG401.
4. Set the Cargo Tank Liquid Valves:
   • Open the following valves 100%:
     CL100, CL107, CL200, CL207, CL300, CL307, CL400, CL407.
5. Set the Vapour Line to No. 1 Vent Mast Regulating Valve:
   • Open valve CG701.
6. Connect the Dry Air Line to the Liquid Line:
   • Open valve CL701.
7. Prepare the Inert Gas Generator in Dry Air Mode:
   • Navigate to MENU > IGG System.
   • Configure the following settings:
     • Generator Mode: Set to “Dry Air.”
     • Operating Percentage: Set to “100%.”
     • Fuel Pump: Set to “Off.”
     • IG Chiller Unit: Set to “On.”

 

• Assessment Phase – Operational flow and Assessment:

8. Start the Inert Gas Generator in Dry Air Mode:

• • Wait until the outlet temperature of the IG Chiller Unit is between 2°C and 3°C.
  • Click Start to activate the IGG.
  • Once started, air flows through the Demister Vessel and the dryer unit, reducing the dew point to below -30°C.

9. Cargo Tank Dew Point < -20°C:
   • Monitor the dew point using the Dew Point Meter.
     • Once the dew point reaches below -20°C at the vapour line sampling point, this milestone is completed.
10. Maintain Cargo Tank Pressure Between 5 kPa and 7 kPa:
    • Adjust the tank pressure by regulating the vent mast valves.
11. Check All Vapour Sampling Points for Dew Point in All Tanks:
    • Open the vapour line sampling points for all tanks and confirm the dew point is -25°C or lower.
12. Stop the Dry Air Supply:
    • Once all tanks reach a dew point of -25°C, stop the IGG delivery by clicking STOP under the delivery option on the IGG System page.
    • Close the vent mast regulating valve CG702.

 

Gas Properties Display on the Detector:

1. Dry Air Properties:
   • CH₄: 0% LEL
   • O₂: 20.9% vol
   • CO: 0 ppm
   • CO₂: 0% vol
   • Dew Point: -25°C
   • Air Temperature: -25°C
   • Relative Humidity: 0%
2. Warm Vapour Properties:
   • CH₄: 0% LEL
   • O₂: 20.9% vol
   • CO: 0 ppm
   • CO₂: 0% vol
   • Dew Point: 18°C
   • Air Temperature: 30°C
   • Relative Humidity: 39%
3. Mixed Gas Properties:
   • Values will vary between the ranges above, depending on the proportions of dry air and normal air.

Proper Line Up For Drying: