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 And Open Required Valves To Connect Inert Gas Line To Vapour Header Line.
3. Install The Spectacle Flange On The Emergency Vent Line To No.1 Vent Must.
4. Set The Cargo Tank Vapour Valves.
5. Set Cargo Tank Liquid Valves.
6. Set The Vapour Line To No. 1 Vent Mast Regulating Valve.
7. Prepare Inert Gas Generator In Dry Air Mode.

 

• Assessment Phase – Operational flow and Assessment:

8. Start Inert Gas Generator In Dry Air Mode.
9. Oxygen Content > 20% By Volume.
10. Cargo Tank Carbon Dioxide Content < 0.5% By Volume.
11. Cargo Tank Carbon Monoxide Content < 0.50ppm.
12. Maintain Cargo Tanks Pressure Between 5kPa And 7kPa.
13. Check The Sampling Point On Liquid Line In All Cargo Tanks.

When The Required Dew Point Has Been Reached For All Cargo Tanks And Piping , Stop The Dry Air Supply.

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Actions During the Exercise

Deviation From Exercise

• Restriction: After starting the aeration process, the user must not open non-required valves or close required ones.
• Consequence: A caution message will instruct the user to undo the action. Failure to correct it will result in exercise termination.

Not Maintaining IGG Outlet Flow and Flow to Atmosphere

• Requirement: Maintain inert gas generator outlet flow and flow to atmosphere between 15,500 kg/h and 16,500 kg/h.
• Consequence: If a high-priority alarm is triggered and the user fails to maintain the flow within 1 minute, the exercise will be terminated.

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Alarms & Remarks

Alarm Condition	Alarm Time	Alarm Level	Alarm Title	Alarm Description	Action
		remark	Aeration Of Cargo Tanks Started	Aeration of the cargo tanks has started.
		remark	Aeration Of Tanks Completed	Aeration of cargo tanks is completed, stop the delivery of dry air.
		remark	Check The Sampling Point On Liquid Line	Check the sampling point on liquid line for dry air properties, in all cargo tanks.
		remark	Close Valve CG702	Aeration of tanks is stopped, close the valve CG702.
		remark	Open Valve CG702	Open the valve CG702 to vent out the inert gas.
		caution	Maintain IGG Outlet Flow And Outlet Flow To Atmosphere	Maintain IGG outlet flow and outlet flow to the 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

1. 1. Navigate to the “Miscellaneous Equipment” page through the side navigation menu.
   2. On the page, press and hold the power button for “Portable Multi Gas Detector” and “Dew Point Meter” for 2 seconds.
   3. Once both devices are started, this milestone is complete.

2. Install the Spool Piece and Open Required Valves

• • Connect the spool piece above valve CL701 to connect the IGG outlet and vapor header.

Valve	Action
CG704	Open
CG705	Open

3. Install the Spectacle Flange on the Emergency Vent Line

• • Connect the spool piece below valve CL700 to connect the liquid line and No. 1 vent mast.

4. Set Cargo Tank Vapor Valves

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

5. Set Cargo Tank Liquid Valves

Valve	Action
CL100	100% Open
CL107	100% Open
CL200	100% Open
CL207	100% Open
CL300	100% Open
CL307	100% Open
CL400	100% Open
CL407	100% Open

6. Set the Vapor Line to No. 1 Vent Mast Regulating Valve

Valve	Action
CL700	Open

7. Prepare the Inert Gas Generator in Dry Air Mode

1. 1. Set Generator Mode to “Dry Air” by clicking the label or dragging the lever to the right.
   2. Set Operating Percentage to “100%” by clicking the label or dragging the lever to the left.
   3. Set Fuel Pump to “Off” by clicking the label or dragging the lever to the right.
   4. Set IG Chiller Unit to “On” by clicking the label or dragging the lever to the left.
   5. Once these settings are achieved, this milestone is complete.

• Assessment Phase – Operational flow and Assessment:

 

8. Start the Inert Gas Generator in Dry Air Mode

1. 1. Wait until the IG chiller unit outlet temperature drops to 3°C or below.
   2. Click the “Start” button to activate both air blower units and open the air delivery valves.
   3. The drying process begins as the inert gas flows through the cargo tanks.

9. Achieve Cargo Tank Oxygen Content > 20% by Volume

• • Observe the oxygen content using the Portable Multi Gas Detector at the vapor line sampling point. Once it exceeds 20%, this milestone is complete.

10. Achieve Cargo Tank Carbon Dioxide Content < 0.5% by Volume

• • Observe the carbon dioxide content using the Portable Multi Gas Detector at the vapor line sampling point. Once it is below 0.5%, this milestone is complete.

11. Achieve Cargo Tank Carbon Monoxide Content < 0.50 ppm

• • Observe the carbon monoxide content using the Portable Multi Gas Detector at the vapor line sampling point. Once it is below 0.50 ppm, this milestone is complete.

12. Maintain Cargo Tank Pressure Between 5 kPa and 7 kPa

• • Regulate the vent mast valves to ensure the tank pressure remains between 5 kPa and 7 kPa during the aeration process.

13. Check the Sampling Point on Liquid Line in All Cargo Tanks

• • During or after aeration, check the liquid line sampling points for dry air properties using the Portable Multi Gas Detector and Dew Point Meter.

 

14. Stop the Supply of Dry Air

1. 1. Navigate to the IGG System Page.
   2. Click “STOP” under the Delivery section.
   3. Close the vent mast regulating valve (CG702).
   4. A remark will be displayed indicating the completion of aeration.

Proper line up for aeration: