Halon Fire System

[86Hat41]

I just removed the old Halon system /auto shutdown etc... Out of my '86 41C. Are any parts of this system worth any money or should I just throw them out?

[Avenger]

Halon can be recycled. Is it still charged?

[86Hat41]

dead.

[Canuck Dennis]

Halon will kill an engine if used in a fire .

[Boatnut]

When would halon be used other than a fire? Why does it kill an engine?

[Genesis]

Kill = shut down.

I don't think he meant "kill" as in "destroy."

CO2, incidentally, will also shut down diesels. The newer "clean agent" Halon replacements will NOT shut diesels down with any sort of reliability, and as such you need other components so the engines are shut down if the system discharges or you risk the agent being pulled through the engines and the fire doesn't go out (or at least doesn't STAY out!)

[bobk]

dead.

Are you sure? The original Halon is a liquid and is pushed out by nitrogen pressure. You might just need more nitrogen if the bottle weight is correct. That was my case. The needle was in the red but the weight was OK. A service center simply recharged the nitrogen.... free of charge.

Bobk

[Canuck Dennis]

Based on info received from a mechanic who was rebuilding a pair of V12's in a 66 Princess due to halon discharge to put out a fire...destroyed the engines.

[Jaxfishgyd]

I set off my CO2 tank some years ago accidentally, IT IS LOUD... but as soon as I got fresh air down there...both engines and generator fired right up... Couldn't of done that had it been a halon system....

[Genesis]

Based on info received from a mechanic who was rebuilding a pair of V12's in a 66 Princess due to halon discharge to put out a fire...destroyed the engines.

Uh, I don't buy that. I'd like to know the mechanism by which the engines were destroyed, since Halon interferes chemically with fire.

The only mechanism I can come up with would be enough 1211 (which is a liquid streaming agent when discharged) ingested as a liquid (and remaining one from ingestion until it reached the cylinders) to hydrolock the cylinders. That sounds rather unlikely given how intakes and these systems are generally arranged along with the fact that 1211 vaporizes at room temperatures and pressures.

[saltshaker]

Based on info received from a mechanic who was rebuilding a pair of V12's in a 66 Princess due to halon discharge to put out a fire...destroyed the engines.Maybe the fire and smoke did the damage? I've never heard of engine damage caused by the halon itself. Seems odd that an agent that destroys the engines would be the choosen fire protection when there are other options that don't.

Then I found this bit of info. Sounds interesting and plausible.

http://www.marinefireequipment.com/Q006.html

Does halon damage my engine?

There are actually two different halon gasses used in the fire protection industry that consumers would be familiar with. The type used in portable fire extinguishers was called 1211 and was actually bromochlorodifluoromethane. It usually had a warning on the side that limited it's use to spaces over a certain cubic ft. because the agent does break down into hydrogen fluoride when exposed to temperatures above 900 degrees. These extinguishers are common in aviation applications because they are a clean agent, leaving no residue on sensitive electronic instruments. The warning is particular to it's common use in the cockpits of airplanes.

The second type of halon seen is the 1301 which is typically a system gas. It is actually monobromotrifluoromethane. Both agents were marketed as clean agents ideal for use in computer rooms, marine engine rooms and normally occupied spaces because in the proper concentration the agent itself is harmless to humans. After seeing for myself the effects of halon on the stainless steel in engine compartments after several fires, and hearing repeatedly from guys repairing engines that had ingested halon, it is true that these agents can cause damage. The salesmen of these agents use to swear it wasn't the agent itself but the "byproducts" that are produced at the high temperatures that is in fact damaging to the engine, as well as the damage seen on the surface of all unpainted metals in the engine compartments. Halon 1301 gas does break down into hydrogen fluoride and hydrogen bromides and apparently produces enough of it before the fire goes out to damage the engine. That is why it is very important to have automatic engine shut-down capability with halon systems. Under normal conditions the agent does extinguish the fire very rapidly and very little of those harmful gasses are produced.

Of note- the new agents are FM-200 which is actually heptafluoropropane (producing hydrogen fluoride at 1292 degrees F) and FE-241 which is actually chlorotetrafluorine. FE-241 is not approved as a halon alternative by the European Union. Only FM-200 is approved for occupied spaces, and is the propellant used in asthma inhalers.

Halon Alternatives Research Corporation Kyoto Protocol Info

[Seabrooke]

BromoChloroDiFlouromethane or BCF extinguishers were outlawed from use in the RAN (Royal Australian Navy) back in the late 70's or early 80's just as I was finishing my apprenticeship and joining the fleet.

At the time it was not from the environmental issues (that understanding came a few years later) but because when used on a hot liquid fire such as Oil, Diesel or Petrol (Gasoline) it gave off Phosgene gas which is REALLY FREAKING DANGEROUS to people.

On electrical fires etc. it was fine as they didn't burn that hot (being mainly solid combustible material fires) and it was very effective when used on liquid fire but there is no way you will stop people using an effective agent on a fire so they took them out of circulation.

Can you still get BCF extinguishers in the US??? They are (from memory) typically yellow cylinders.

CO2 is the go as far as I'm concerned.

[Genesis]

People don't like CO2 because the cylinders are large and heavy for the capacity required, and they also require recert (hydro) because they're a compressed gas cylinder. If they go off when you're in the space you better get out of there fast or have someone around to pull you out (before they lose consciousness too!) because CO2 will quite reliably suffocate you along with the fire.

But CO2 works exceptionally well when it comes to actually putting fires out without destroying equipment.

[Canuck Dennis]

The mechanic on the Princess indicated that the owner/skipper had replaced the spin on fuel filters in the Bahamas and not really checked if fully tightened and sealed, fuel pissed out on the exh. manifold and the fire started, rest was $$$$$$$$$$$$$$$$$$$$$

[bohans]

I have a fireboy halon system in the engine room and need to remove it. What is the procedure for removal. Thanks for any assistance. The reason for removal is for my insurance here in Aus. Not sure why.

[Canuck Dennis]

I would place the onus on whoever was going to install the replacement system, take no chances with that stuff