Procedures & Alarms

Milestones

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

1. Open All Required Valves for Lineup.

 

• Assessment Phase – Operational flow and Assessment:

2. Achieved Required Temperatures On Liquid Lines.

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Actions and Process Details

Deviation From Exercise

• Once the line cooldown has started or resumed, do not open any non-required valves or close any required valves.
• If a deviation occurs, a caution message will prompt the user to undo the action.
• If the action is not undone within the given time, the exercise will be terminated.

High Crossover Pressure

• During the line cooldown, if the crossover pressure reaches 4 bar, a warning will prompt the user to open valve CL400 to reduce the pressure.
• If the pressure reaches 5 bar and CL400 is not opened, the exercise will be terminated.

Liquid Entering the Tank

• Opening valve CL400 to reduce crossover pressure will eventually result in liquid entering the tank.
• If liquid enters the tank, the user will be warned to close valve CL400.
• If valve CL400 is not closed within 1 minute of the warning, the exercise will be terminated.

Close Tank Filling Valves (CL200, CL300, CL400)

• At the 3-minute mark, the user must close the filling valves CL200, CL300, and CL400.
• Failure to close any of these valves will result in termination of the exercise.

Keep Tank Filling Valves CL100 and CL400 Open

• At the 12-minute mark, the user must keep valves CL100 and CL400 open.
• Failure to keep these valves open will result in termination of the exercise.

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Alarms & Remarks

Alarm Condition	Alarm Time	Alarm Level	Alarm Title	Alarm Description
No Conditions	3rd minute of the exercise	Caution	Close tank filling valves	Close the filling valves CL200, CL300 and CL400.
Cross Over Pressure > 4 bar	whenever pressure reaches 4 bar	Caution	High Cross Over Pressure	High cross over pressure in liquid lines, open filling valve CL400.
After Opening CL400 to reduce cross over pressure	20 Sec, After Opening the CL400.	Caution	Liquid entering the tank	Liquid entering the tank, close the filling valves of all the tanks to required percentage.
No Conditions	12th minute of the exercise	Caution	Open filling valves	Keep the filling valves CL100 and CL400 open.
When temperature reaches -106°C in liquid header aft temperature.	Approximately 15th minute of the exercise	Remark	Obtained required temperature in liquid header	Obtained required temperature in liquid header for loading,Open CL033 and close spray line valve CS031.
Deviation from the exercise	whenever a deviation is detected.	Caution	Deviation Detected	Deviation from the exercise is detected, undo your last action.

Step by step procedure:

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

1. Open All Required Valves for Lineup

• CL023 Open
• CL043 Open
• CL100 10%
• CL107 100%
• CL200 5%
• CL207 100%
• CL300 5%
• CL307 100%
• CL400 10%
• CL407 100%
• CS704 Open
• CS705 Open

 

• Assessment Phase – Operational flow and Assessment:

2. Start Line Cooldown

• After completing the valve lineup, press the “Start Line Cooldown” button to initiate the 15-minute cooldown process.
• Initially, the crossover pressure will be maintained at 2 bar, and the tank pressure will increase by 0.5 kPa every minute.

3. Actions at 3-Minute Mark

• At the 3-minute mark, the user will be warned to close the filling valves CL200, CL300, and CL400.
• Once these valves are closed, the tank pressure will decrease by 0.5 kPa every minute, while the crossover pressure will begin to rise from 2 bar to 5 bar.

4. Managing Crossover Pressure at 4 Bar

• When the crossover pressure reaches 4 bar, the user will receive a warning to open valve CL400 for 20 seconds to reduce the pressure.
• Opening CL400 will cause the tank pressure to increase by 1 kPa.
• The user will receive a warning to close valve CL400 and must do so within 30 seconds to avoid exercise termination.
• After closing CL400, the crossover pressure will rise again from 2 bar to 5 bar. If the pressure reaches 4 bar again, the user must repeat the process of opening CL400 for 20 seconds.

5. Actions at 12-Minute Mark

• At the 12-minute mark, the user must keep valves CL100 and CL400 open.
• The crossover pressure will be maintained at 2 bar, while the tank pressure will continue to increase by 0.5 kPa every minute.

6. Completion of the Exercise

• The exercise will be completed once the liquid header forward temperature reaches -100°C.
• At this point, the user must:
  1. Open liquid line valve CL033.
  2. Close spray line valve CS031.
  3. Complete the procedure.

Proper line up for line cooldown from shore: