Total CO2 Flooding System

Total CO2 Flooding System

This CO2 system is called total flooding system because once it is initiated, all CO2 bottle connected to this system is discharged at once. Therefore is may also termed as one shot system!

This system is provided for Main engine or auxiliary engines whose total power is 746kW or more

NOTE : The first and the foremost thing before using this system is to ensure that Engine room or Pump room is evacuated and all people are accounted for in muster.

Working

1) In case of fire, if Fire team is unable to extinguish the fire, this message is given to the Master/Captain of the vessel and captain decide weather to release CO2 or not, and Chief engineer is the one who is appointed to initiate the release.
2) Ensure that space to be flooded is evacuated of the personals and is sealed off.
3) All Machinery should be stopped.
4) When control box is opened, an alarm sound in the engine room, ventilation stop, all the damper get closed.
5) First pull the starting bottle handle, second, pull the master valve handle.

Total CO2 Flooding System

Maintenance

1) Pressure testing is done annually
2) Cables are made up of phosphorus bronze which are rust/dust proof and does not require extensive maintenance, but we check and apply grease to wire and pulley.
3) CO2 line has to be blow through annually with compressed air.
4) Check the bottles, weighing of bottle every 4 months.
5) Use Radio isotopes
6)Check the entire pipeline, lines are made up of mild steel, sometime CO2 line will be Galvanized (Zinc Coated)

Precaution

1) Ensure that fans are shut off.
2) Ensure that skylight is closed.
3) Funnel flap should be shut.
4) To make sure that, all fuel handling machine are off. In modern vessel it can be done from fire control station.
5) Ensure all personnel are evacuated.
6) Normal bottle pressure is about 52Bar (Varies with ambient temperature), CO2 bottle room  temperature should not exceed 55C, Bursting disk rupture at 117Bar (At 63C).

What if there's a fire in CO2 battery room or starting bottles room ?
CO2 battery bottles have seals that act as Self Rupturing of bursting disk when there's a fire in CO2 room. in starting bottle pipeline pressure transducer detect the leakage and give the alarm of leakage, relief valve is provided to avoid pressurization of the pipeline and to release the CO@ in CO2 room and extinguish fire.

Testing

Test A) 1) The master lines end at Nozzles that are situated at deck head, is is threaded.
2) Remove nozzle head, put plug in nozzle, start the pressure testing.
3) See the pressure gauge and when it is at 7BAr, close the valve and check weather there's a drop, identify the leakage if any.
4) This testing should be carried out annually, but as it is time consuming, risk is taken and is done at every dry-dock.

Test B) Bottles are of solid drawn manganese steel hydraulically tested at 228Bar

Test C) Recharging of bottle is necessary if more than 10% of weight loss


Note:
Quantity of CO2 is calculated from gross volume of the largest machinery compartment or cargo-space.
85% of total CO2 should be released within 2 minutes of initiation of the system (After the time delay of 60 to 90 second)
Pilot line and safety valves are similar to Master valve and main line.

The article and images Included in the article cannot be reproduced, copied, shared or used in any form without the prior permission of the author and Ship Diggers.