Mounting an automatic fire extinguisher?

[rogerroger]

I bought one of those automatic fire extinguishers the other day for my engine. Where is the best place to mount it ? If it goes above the engine then surely the spray is not going to be directed at it or does this not matter ? Is the idea just to fill the compartment with CO2 (or whatever's in there!) ??



Roger Holden
www.first-magnitude.co.uk

 

[ccscott49]

You need to mount it, so it points at the engine, above is ok, but it will have to be at an angle, so the contents will fully discharge, some are designed to be mounted vertical, to discharge correctly. Try to have it not pointing at the engine intake, as you don't really want the engine to ingest the extinguishant before it's done its job. I've found the fire service really helpful, when asked about such things, especially if it means they get to come and have a look and a beer! But it's fairly simple. Above also tends to cover a bigger area.

 

[Gaffer]

I just caught a report on the news the other day which I gathered that Halon is now banned as a fire extinguishing product because it damages the ozone. Did I hear right, or was it something else altogether ??

 

[JohnR]

My Firebuoy system is mounted in just out from the corner of the engine room with its discharge rose or daisy sort of pointing diagonally across the two engines.

 

[Chris_Stannard]

YOU HEARD RIGHT! It should no longer be sold and ahould not be fitted after 1 Jan 2003 although how this will be policed is anyones guess

Chris Stannard

 

[ccscott49]

Just had mine tested and re-certed for another three years, I even bought four more, two spares for the engine room and two for inside the boat. I hope I don't need to use them. But they are still the best available or not as the case may be. IMHO

 

[Trevor_swfyc]

The fire extinguisher is set off by heat, so it should be set up above the most probable point of fire. On a diesel engine the most probable fire is failure/rupture of the injector pipe work spraying diesel onto a hot surface or an electrical fire due to a cable being chaffed by engine vibration. In any case the hottest point will be above the engine.
A gas CO2 or Halon if you can get hold of it will fill the engine bay no matter where it points, it is worth remembering not to take a look to find out why its triggered as air would get in and you could get an explossion if its a petrol fire.
If it is dry powder or water then it will only cover the area of the spray pattern.
As to whats in yours, it should be colour coded so you can tell immediatly whats in any fire extinguisher!

All the best
Trevor

 

[Chris_Robb]

Re: clour coding of fire extinguisher?

I think the colour coding went out in the last year. In the office here all the new extinguishers are red including the CO2 which was always black before.

Anyway I got all the old Halon exstingushers for nothing which is great news.

I am not very happy with the idea of an Automatic powder extingguisher as the engine should be stopped before you fire off. I am not sure that powder will be very effective as you cannot point it at the source of the fire.

 

[Guest]

If it is Halon (colour code green) direction does not matter, It is important not to ventilate the engine space for at least 20 mins after operation or reignition may occur. Also be aware that it is toxic at concentrations above 5% and should not be used in a compartment were people are present. Any equipment will not be re-certificated after next year. The same precautions should be taken with CO2 (black) which is also an asphyxiant above 10%. There are different types of powder (blue), some form a crust over burning surface(TEC) others inhibit flame development by chemical means. The latter is quite likely to allow reignition if additional cooling (water) is not applied. Powder, water or foam would not normally be used as an automatic engine extinguishing medium.

 

[Guest]

Re: clour coding of fire extinguisher?

The predominant colour of all extinguishers is now red although a small colour coded label should show the type of medium used.

 

[Guest]

Re: clour coding of fire extinguisher?

I thought Halon was banned because of it's affect on the environment. All fire extinguishers should be mainly red, as oxygen is in black cylinders, and if you put that on a fire instead of a black CO2 extinguisher, the fire would be made even worse.

Also remember that these extinguishers work by excluding oxygen, so make sure that the engine room is unoccupied before it goes off, and ventilate area well after use, before entering otherwise no one will be able to breathe.

 

[andy_wilson]

Halon Extinguishers and the environment.

I'm sure some one will put me straight here but what the hell, here goes.

1. A halon fire extinguisher does no harm to the environment (at least until set off).

2. Halon has the best fire knock-down properties of all types for engine compartment fires.

3. When you let off a halon extinguisher to fight a fire it reacts chemically and the result is not harmful to the ozone layer.

4. I fully accept that some extiguishant will 'escape'.

5. At least you may have a chance of re-starting the engine. What chance after it has taken a large gulp of dry powder?

 

[vyv_cox]

Re: Halon Extinguishers and the environment.

1. Correct
2. Correct
3. Correct
4. Correct
5. Correct.

Add to that:
Halon is not banned. It can be used legally until end 2003 but not bought new.
Halon does not work by excluding air. It reacts with the fire, changing its composition and probably rendering it less harmful or not harmful to the environment
Halon works equally well out of doors and indoors
Halon is not asphyxiating, poisonous or carcinogenic in confined spaces. It is not nice but it won't kill you as much as the fire will (would)
Amounts of Halon released to the atmosphere during fire fighting were miniscule by comparison with CFC releases from refrigeration, electronic component manufacture and fire-fighting training.
CO2 works by excluding air. In engine rooms it is OK but outside forget it.
Powder is not very effective and fires re-ignite if surfaces are hot.
Foam works well but runs off vertical and sloping surfaces

Why was Halon banned?

 

[ccscott49]

Re: Halon Extinguishers and the environment.

Because some pillock overeacted! another green cock up, like the brent spar!

 

[Trevor_swfyc]

Re: Halon Extinguishers and the environment.

Andy,
I fully agree it would appear that the Halon which was safe in fire extinguishers in companies control is now in the hands of individuals who will eventually let it off into the atmosphere to get rid of it when the containers corrode. We have a similar cock up with refridgerators which will end up being illegally dumped rather than pay for the refridgerant to be removed safely.
Halon will have a similar effect as chloroform so if it goes off in a boat do not stay in the cabin and breath it in.
In answer to Rogers question how do you mount a fire extinguisher "PUT ONE LEG EITHER SIDE"
See Ya
Trevor

 

[Guest]

Re: Halon Extinguishers and the environment.

Halon is toxic at 5% concentration- an example of halon extinguishing medium is Bromochlorodiflouromethane which reacts, amongst other things to form bromide, hydrochloric and hydroflouric acid (dsissolves skeletal tissue after absorption through skin). It is being phased out by the Montreal protocol because the vast majority of halon systems are discharged to atmosphere as part of a 10 year maintenance test.

 

[vyv_cox]

Re: Halon Extinguishers and the environment.

I have some doubts about the chemistry. Doubting Thomases love to find every remote possibility and HF is always a good one. I once saw an article suggesting that Teflon coatings on frying pans could generate HF if overheated. There is only one way to test these daft theories - how many people have died/been seriously affected by Halon gassing? I suspect the answer to be none or a very low number.

Your second point - so is banning the only option? Why is it that governments have come up with effective legislation that prevents atmospheric discharge of air conditioning and refrigeration gases but can't do the same thing for the most effective fire-fighting medium in existence? If legislation can work for toilet discharge I feel certain it can for fire extinguisher maintenance.

 

[philip_stevens]

Re: Halon Extinguishers and the environment.

You are on a rig. I was on containerships. What have they come up with as a replacement for Halon. We had CO2 flooding for the engine room, but Halon for the purifier room - more efficient.

The governments have been quick to ban it, with no effective replacement that isn't gold plated in price. When lead petrol was to be replaced, lead free was available.

So why cannot we get a Halon replacement at a reasonable price, or at least allow it for fire fighting but not for domestic refrigerators.

I suppose, if all else fails, a CO2 auto system will have to be looked at., (I am not going to install a powder auto system - ref. comments this thread ).

regards,
Philip