FIXED FIRE FIGHTING SYSTEM
CO2 FIXED FIRE FIGHTING SYSTEM
- Draw CO2 fixed system? Explain it?
-Regulation of this system
-Safety on this System? Explain about fire into E/R and P/R, -what is your action?
-Regulation Regarding CO2 Room? Safety in CO2 Room?
-Function of Master Valve
-Calculation Of CO2 bottle? What you mean by 0.56 in calculation?
-Weighting of CO2 bottle
-Maintenance on CO2 system?
-Principle of this system
SMOOTHERING and COOLING, reduceO2%
Regulation:
-First of all Solas regulation says that the ship which has MACHINARY SPACE of category A class 500m3 and above volume required additional fixed fire fighting system requirement that 85 % of the CO2 gas is released into the space within 2 min of the actuating the system release.
-bottle are SOLID DRAWN steel, hydraulically tested @ 228 bar.
-bottle should not stored where the temp exceed 55degree c.
-bottle pressure normally about 52 bar and it will varies with temp.
-bottle content are checked by RADIO ACTIVE ISOTOPE GUN level indicator or WEIGHTING.
-CO2 bottle head assembly the Bursting Disc are designed to rupture @ 177 bar produced by temp about 63 c.
-syphon tube in bottle ensure that liquid is discharged from the bottles.Without syphon tube the CO2 would evaporate from the surface giving a very slow discharge rate and taking latent heat, would cause the remaining CO2 in bottle to freeze.
-Once you CO2 is release it will reduce o2 in the space to less than 15 % to extinguish fire.
CO2 ROOM REGULATION
-The storage room should be used for no other purposes
- the storage space is located below deck, it should be located no more than one deck below the Open deck and should be directly accessible by a stairway or ladder from the open deck.
-Spaces which are located below deck or spaces where access from the open deck is not provided Should be fitted with a mechanical ventilation system designed to take exhaust air from the bottom
Of the space and should be sized to provide at least 6 air changes per hour
-Access doors should open outwards, and bulkheads and decks including doors and other means oF closing any opening therein, which form the boundaries between such rooms and adjacent enclosed spaces, should be gas tight
-Room temp should maintain below 55 degree c.
-Room should have a minimum clear height of 2.4 m to provide the mounting of manifold and weighting the cylinder
-if fixed extinguishing medium stored outside a protected space, it shall be stored in a room which is behind FWD collision bulkhead.
Safety on CO2 system
1.Trip switch: control cabinet have special trip switch for ventilation trip and sound CO2 alarm. As soon as you open cabinet it will trip ventilation and sound alarm.
2.Master valve: on main manifold line which is going to M/C space or Cargo space will have this valve.It will not allowed to release
CO2 in any of the space in case accidentally release.
3.Relief valve: it will located on at the end of manifold if manifold pressure will exceed the relief valve will lift up into ATM,
4.Safety pin : it will be provided into bottle head assembly, u can see into picture what I put just above.It will function like to dont accidental release of lever to operate and for manual operation you have to take it out to operate the lever.
5. Bursting disc: it will also into bottle head assembly .It will burst when the pressure into bottle exceed @ 177 bar along with the temp around the bottle reach 63 c.
6.Non-return check valve: as I mentioned into my CO2 line diagram, it will located between bottle and Manifold.
Function of it is act as a non return and when you blow the system along with manifold it want allow to service air will pass through it, and if u have fire in Cargo hold or any one place where u need only few bottle to extinguish the fire, so once u operate system the manifold will fully pressurized but it want allow to open the another bottle after operating pilot cylinder.
7.leak alarm : the most of the surveyor want to hear this safety from you. As I saw you in my picture. It will located on the manifold. It will work @ 4 bar pressure, it like a pressure switch, if any of the CO2 bottle will leak so pressure into the manifold will be increase and as you know CO2 is stored @ 52 bar
pressure so a small leak will also create a high pressure in to manifold once the manifold pressure will reach @ 4 bar it will sound alarm, and by this safety switch you will get to know there is a leakage from any one bottle, but you dont know which one is it.
So now you have to found the leak bottle? Now the question is how
-Simple once u got alarm at least 2 person will go to outside the
CO2 room
-Start the ventilation and stay outside for some time
-Carry proper communication equipment with you
-Now after some time the space will be properly ventilated, go inside the room.
-Now the main thing how u can identify?
-So start from the first bottle by physical touch by your hand, if any of the bottle leak the bottle is much cooler than the other.
-Mark on the bottle and check another
-After u finished all of them, u can come to know how many of them is leak pipe work solid drawn mild steel & galvanized to protect against corrosion.
Safety in CO2 room:
-Room is fully insulated
-Proper ventilation provided
-Room access door open outward
-room should not be use for any other purpose
-All near by compartment should be gas tight
Required CO2 cylinder calculation:
On my vessel I had
For E/R = 201 cylinder
For Purifier room = 7 cylinder
And Spare = 4 cylinder
SO,
Total = 212 cylinder
Cylinder pressure store = 58 bar
Approx weight = 120 kg /each cylinder and cylinder tare weight is approx= 72-80 kg
Design discharge time = 120 second
Actual discharge time = 107 s
Solas regulation to calculate no of cylinder
1.If the CO2 system is installed in the cargo spaces, the quantity of CO2 available should be sufficient enough to give at least a minimum of 30% of the total volume of the largest space that
is protected by the CO2 system.
2.40% of the total volume of the largest machinery spaces that is protected by the CO2 system.The volume should exclude that part of the casing where the horizontal area of the casing
40% or less then the horizontal area of the space taken into consideration and measured midway, between tank top and lowest part of casing).
3. 35% of the total volume of the largest machinery spaces that are protected by the CO2 system including the area covered by the casing.
It is also a requirement that 85% of the required quantity of gas should be released into the spaces within two minutes of evacuating the fire-affected space.
Formulae
WEIGHTING OF CO2 CYLINDER
1.As I shown in figure below there is beam scale assembly tool, it is a special tool for weighting
2 It contain adjustable hook, yoke, scale from 0 to 200 kg and a handle
3.And in second figure the way to take weighting of cylinder is mention.
4.First you loosen the securing strap from the cylinder as shown in fig 1.
5.Fit the yoke in the CO2 head assembly and also fit the adjustable hook on the crossbar as shown in Fig 2.
6. Now pull down the scale with the help of handle and lift the cylinder upto it will free from the Bottom contact.
7.Now slowly pull down the beam to 900 against hook and now you can take reading from the scale.
Note: ± 5 degree of beam angle is allowed for measuring the bottle.
Recharge is must necessary if there is 10% reduction in weight.
Maintenance or check on CO2 system:
Weekly:
-Inform bridge before going inside the CO2 room.
-start ventilation blowers first and room should be ventilated for some time.
-Go with a person with proper communication equipment.
-Check all cylinder are properly secured
-Check all the operating lever and there accessories are properly tight.
-Check clamping.
-Check valve actuator
-Flexible hose visually check and do leak test if required
Monthly
- Alarms, Machinery trips, Door alarm, Quick closing valves, Flaps, Skylights, Ventilation fan trips to be tested.
Yearly
- General inspection of the installation, pipe lines to be checked.
2 Yearly
- 1+
- Verify CO2 contents by mechanical advantage lever, ultrasonic liquid level measurement or radioactive liquid level measurement. Equipment for measuring CO2 content must be available on board ships. A maximum reduction of 5% in CO2 content may be allowed provided total CO2 quantity on board is not less than the required amount.
- Blow through the system with 6-7 bar air with plastic air bags at the nozzle ends.
5 Yearly
- 1+2+
- The servo cylinders and any remote controlled stop valves to be tested by opening one pilot cylinder. The main CO2 bottles must be uncoupled for this purpose.
- Spring loaded relief valves to be checked and pressure tested at 180 bar.
- Checking of HP alarms which operate with gas pressure.
- Section of CO2 which can be shut off must be tested with air at 25 bar.
10 Yearly
- 1+2+5+
- CO2 bottles to be inspected internally. Siphon tube or dip tube to be checked. Cylinders to be pressure tested at 250 bar. If permanent change in volume is observed, those cylinders to be discarded. After 20 years of installation of CO2 flooding system, these tests to be carried out every 5 years thereafter.
15 yearly and 5 year thereafter
- 1+5+
- Pressure test HP pipes, stop valves to engine room, pump room, purifier room,etc. at 190 bar (hydraulic), medium pressure pipes at 80 bar (hydraulic) and low pressure pipes at 7 bar air.
- After hydraulic pressure testing, lines to be blown through by dry air.
Working of CO2 system
-In E/R you also have hyper mist system so if you sure that it will help full to extinguish fire you can Operate it also, for that you no need to shut any system.
-so you all know that this system we can use only inside the enclosed space, in open space it will not work any more .
-So mainly it will be use in Machinery space or Engine room and Purifier room and Cargo hold.
-This system must be operated by Chief engineer or
2nd Engineer, these two person are responsible
for all operation for this system
Fire in E/R what is your action
-so you seen fire in any place in E/R, immediately rise the Fire Alarm from nearby place by breaking the glass with the use of hammer but in case if you dont found hammer what u will do? In that case remove your safety shoes and hit on the glass bcoz shoes have steel plate at fwd part so by using that u can easily break the glass.
-Now if you can able to recognized that which type of fire is there than use proper type of portable fire extinguisher ( if fire is not too big )or if u cant able to extinguish that fire than call chief engineer or any dek officer on Bridge. Inform about location and type of fire.
-Now if M/E is running than immediately slow down and stop the M/E.
-After the instruction given by C/E or Master to release
CO2 system so before you leave the E/R make Sure that all access from the E/R must be closed properly.
-Stop your running A/E and start E.G. and take on load. As you stop A/E all ventilation will also stop Just need to close flaps.
-Now all crew member except the one bridge watch keeper or any officer or master. All have to present at muster station for head counting
-After head counting done as per the muster list follow the duty.
-Regarding closing vents, doors, flaps, damper, quick closing valve for fuel line.
-Now start the Emergency Fire Pump to make boundary cooling for the E/R bulkhead continue.
-Now from the fire control station you can operate the
CO2 system.
-Make sure that all crew member are present, no one is missing.
-Open the cabinet with the help of key, as soon as you open it will cut the power supply for Ventilation fans and sound the CO2 release alarm in E/R.
-Now operate the pilot cylinder valve and master valve to release the CO2 as given
-keep continue boundary cooling and time to time check the temp of B/H.
ABOVE PICTURE WILL TELL YOU WHEN U OPEN CABINET THAN HOW THE VENTILATION SHUT AND
ALARM SOUND
Fire in PURIFIER ROOM what is your action?
-In P/R you also have hyper mist system so if you sure that it will help full to extinguish fire you can operate it also, for that you no need to shut any system. But if high then co2 to be flooded
-In this case as you found fire in P/R. immediately rise the Fire Alarm from nearby place by breaking the glass.
-Stop the purifier from outside of the room by using EMERGENCY STOP
-Now if you can able to recognized that which type of fire is there than use proper type of portable fire extinguisher ( if fire is not too big )
-close the P/R door. DoN’t forget to Close it
-If you cant able to extinguish that fire than immediately run
to inform the C/E and Deck Office on Bridge. Inform about location and type of fire.
-Shut the ventilation of the P/R from the MSB. And shut the flaps
-Shut the quick closing valve for fuel line only for the Purifier.
-Make boundary cooling for purifier room.
-C/E will be responsible to operate the CO2 system from the outside of the P/R or from Fire control Station
-Release the CO2 as per I mentioned above.
-Keep continue boundary cooling.
Prevention of Purifier Fire:
-lf the pipes leading to the separator are to be double sheathed; the reason for this is that if inner pipe leaks, then it will not spray all over the place but instead it will leak into outer pipe.
-drip trays should be provided below the purifier or separator, so that in case of oil spill the oil will wont flow and spread in the purifier room and contact with any hot material and catch fire.
-lf the pipes with flanges or connections are to be covered with anti spill tapes which can prevent spill from the flanges in case of a leakage.
-Fire fighting system such as water mist and CO2 system should be installed.
-Quick closing valves and remote stopping of pumps and purifier should be provided.
-Fire detection and alarm system are to be provided so that quick action can be taken.
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