Fire Safety

[donald w. miller]

Justin,

I can't speak for others, but I enjoy most anything coming across this
forum with technical content.

If you don't get comment about a technical post, it might be because your
logic is so flawless even the quibblers can't find anything to quibble with
and you answered all the questions anyone might have.

I made note of your post, a couple by Marcus, and several others including
that sensational uproar brought about by the purchase of a Halon
extinguisher awhile back.

Twenty five years ago I had a carburetor fire in an almost new car. Maybe I
was just unlucky, but they will have a hard time convincing me it rarely
happens to well maintained vehicles. Your vehicle can be well maintained
when you leave your driveway and not so well maintained by the time you get
to the post office.

Anyway, I was on a large parking lot and several good old boys came running
with extinguishers. My sons ran into a nearby store. They and the manager
came out with several more extinguishers. It was incredible how much dry
chemical it took to finally control it.

I want to do all I can to keep our GMCMH from burning up. I think
prevention is far better than cure so I am taking a number of steps aimed
toward preventing a fire from ever starting. I think I have the prevention
part pretty well worked out.

In case a fire does start, a built in system such as yours would be a
wonderful investment.

I have been thinking about getting my fresh water system into the act. It
would seem misting or spraying 35 gallons of water onto an engine would be a
move in the right direction.

Did Arch or someone already mention doing this ?

Perhaps a chemical such as Fyrfighter could be mixed with the water down
line from the pump ?

Anyone know if water works OK when applied simultaneous with CO2, Halon, dry
chemical, or whatever else you might care to spread on the flames ?

Glenn suggests temperature warning sensors above the engine. Allied catalog
lists thermal switches that close at different temperatures. Any one know
typical and maximum under hood temperatures for a GMCMH ?

It seems motor home fires are happening too frequently to be ignored.

Don Miller
75 Glennbrook
Shenandoah Valley of Virginia

>
>Heinz, you know I have an engine compartment fire extinguisher system which
I
>can activate from inside. I posted about it quite some time ago but no one
>seemed to be interested. I had it designed by a friend who was in the
>sprinkler and fire extinguisher business. I have a 5 lb co2 bottle mounted
>behind the left front wheel well liner. I ran metal 1/2 inch lines from it
up
>to the underside of the floor. I have one sprinkler head on each side of
the
>opening. One is aimed at the carbureator and left side of engine, and the
>other to take care of the right side in case of oil line leak/fire. I have
a
>control inside to pull and it releases the whole extinguisher contents. I
feel
>confident it will work because a couple years ago the pin I was using
was
>made of metal that was too soft and it broke, letting it go off. My
reaction
>was that I had a bad puncture from the hissing noise. I stopped and dirt
was
>blowing up all around the front of the coach from the ground. It had that
>much pressure.My friend steered me away from Halon because of price and
future
>availability. CO2 does the job and doesn't leave a mess.
>
>Justin
>

 

[arild jensen]

>I have been thinking about getting my fresh water system into the act. It
>would seem misting or spraying 35 gallons of water onto an engine would be a
>move in the right direction.

>Anyone know if water works OK when applied simultaneous with CO2, Halon, dry
>chemical, or whatever else you might care to spread on the flames ?

Arild replies:
I would not recommend simultaneous application of both powder and water as
spray or mist.
The water would tend to clump the powder and defeat its function.
CO2 would likely freeze the mist, possibly clogging the nozzles.

No reaction with Halon that I know of.
I once had to set up a computer room system in a factory I was building and
the original building had sprinklers while we installed Halon in the
dropped ceiling of the computer room.
Mind you the water would have ruined the whole computer complex worth a
bout $1 million.
The idea was the Halon would take care of any small electrical fires inside
the computer room before the water sprinkler system cut in.

I would recommend that you consider the same idea for your coach.
First the non messy CO2 or the Halon; or if you prefer the foam or
dry chem.
Hold the water mist in reserve to cool down the engine block to prevent a
reignition.
To that end have an outside accessible release grip a littel ways away
from the engine compartment. I have seen that used on some aircrafts.

We regularly hold fire drills for our students. We use a mix of gasoline
and engine oil in a big pan set on the ground. We only use about a quart
for each ignition. It is amazing how often the fire seems to die out as
the fire extinguisher is exhausted only to flare up again about fifteen
to thirty seconds later.

Cheers

Arild

>Glenn suggests temperature warning sensors above the engine. Allied catalog
>lists thermal switches that close at different temperatures. Any one know
>typical and maximum under hood temperatures for a GMCMH ?
>
>It seems motor home fires are happening too frequently to be ignored.
>
>
>Don Miller
>75 Glennbrook
>Shenandoah Valley of Virginia
>
>
>
>>
>>Heinz, you know I have an engine compartment fire extinguisher system which
>I
>>can activate from inside. I posted about it quite some time ago but no one
>>seemed to be interested. I had it designed by a friend who was in the
>>sprinkler and fire extinguisher business. I have a 5 lb co2 bottle mounted
>>behind the left front wheel well liner. I ran metal 1/2 inch lines from it
>up
>>to the underside of the floor. I have one sprinkler head on each side of
>the
>>opening. One is aimed at the carbureator and left side of engine, and the
>>other to take care of the right side in case of oil line leak/fire. I have
>a
>>control inside to pull and it releases the whole extinguisher contents. I
>feel
>>confident it will work because a couple years ago the pin I was using
>was
>>made of metal that was too soft and it broke, letting it go off. My
>reaction
>>was that I had a bad puncture from the hissing noise. I stopped and dirt
>was
>>blowing up all around the front of the coach from the ground. It had that
>>much pressure.My friend steered me away from Halon because of price and
>future
>>availability. CO2 does the job and doesn't leave a mess.
>>
>>Justin
>>
>
>
>
>
>
>
>
>
>
>
>
>
>

 

[darren paget]

Whenever we respond to a car fire, we, as a dept, use dry chem extinguishers. It
is a little messier than a Halon system but a refill is cheep and you can buy it
any where. It may make more of a mess than Halon but if it is a choice between a
fire and a mess in my coach, I'll take the mess any day. The dry-chem agent just
washes off with water. Darren Full time firefighter in Calgary.

> In a message dated 3/8/99 9:55:38 PM Central Standard Time, millerdw

>
> I have been thinking about getting my fresh water system into the act. It
> would seem misting or spraying 35 gallons of water onto an engine would be a
> move in the right direction.
> >>
> I know that water is bad for certain types of fires. I think any with oil
> involved. I suggest you drop by your friendly neighborhood fire station and
> talk with them about the best agent to use to extinguish an engine compartment
> fire.
> Justin

 

[donald w. miller]

Pouring water on an oil fire has never been recommended but recently I came
upon these water mist systems which look interesting. I will usually have
some water aboard along with our air tank although more air might be needed.

This system might be in the running for me although it might be simpler just
to install a Halon or CO2 system.

I am thinking with most systems you get one short shot. With this system
you turn on the switch and let it run until all your water is used.
Hopefully the fire is out and everything is cooled so re-ignition won't
occur.

If it falsely triggers there is no long lasting effects or expense.

Don

*************************************************************************
Water Mist Fire Suppression Systems

Fine water mist systems extinguish fires primarily by removing heat from the
materials involved in the combustion process. Water is applied to the fire
in very fine droplets which appear to the observer as a dense fog. The ratio
of droplet surface area to water volume is large and conversion to steam
occurs very efficiently. The latent heat of vaporization, which is a
physical phenomena associated with the change of state of water to a gas
(steam), removes many BTUs of heat from the fire and the steam produced also
helps to smother the fire by displacing oxygen in the vicinity of the fire.

****************************************************************************
****
Water Mist Fire Suppression System General Theory of Operation

When water mist droplets contact the surface of hot or burning substances,
the water droplet changes from a liquid to a gas (steam). This
transformation absorbs tremendous energy from the surface of the cumbusting
material. Water expanding into steam increases in volume 1,760 times. The
expansion removes heat from the burning fuel so as to lower its temperature
below the ignition threshold. This is the heart of the theory of fire
suppression by fine water mist.

Further, the droplets and steam impinge on the surface of the fire to create
blanket in which the fire quickly depletes its supply of oxygen.

The key to the success of a fine water spray fire suppression system is the
ability to generate a directional mist or fog of fine water drops through
the nozzles. The nozzle design must produce a small droplet with an orifice
sufficiently large to avoid clogging from suspended particulates that may be
present in the water stream.

Securiplex, the modern leader in the current generation of fine water mist
fire suppression systems, solved the problem with the patented twin fluid
chamber nozzle. Liquid water and pressurized air are mixed in a turbulent
motion in the mixing chamber to produce and deliver a spray of water mist.

The optimum water droplet size ranges from 80-200 microns of mean diameter.
The droplets must be small enough to penetrate all areas behind
obstructions, yet large enough to penetrate to the surface of the combusting
fuel.

Supplies of Air and Water for Water Mist Fire Suppression Systems
In most cases air or nitrogen and water are supplied from dedicated storage
vessels equipped with the necessary controls.

Only very small amounts of water and air are needed to extinguish even the
most intense fires (including gasoline fires) because a small amount of
water is effectively spread into fine water droplets covering a large area.

Many industrial plants have pre-piped supplies of compressed air throughout
the facility. In these cases plant air is substituted for compressed air
stored in dedicated cylinders.

The water contained in the storage vessel can be de-ionized and treated to
comply with current health requirements and can be pre-mixed with
commercial-grade foaming agents to provide even greater class B fire
extinguishment.

In certain applications water mist compares favorably to other fire
suppression systems.

Traditional Sprinkler Systems Fine water spray fire suppression systems
extinguish fires more effectively and in scenarios exceeding by far the
capability of traditional sprinkler systems.

Water deluge systems demand high water supply rates and are associated with
fixed large bore pipe networks around the protected area.

Unlike deluge systems, fine water spray fire extinguishing systems use very
small amounts of water and therefore only require small bore pipe networks.

Note, however, water mist fire suppression systems are not listed under NFPA
#13 as a replacement for conventional sprinkler systems

Unlike Carbon Dioxide, water mist does not remove excessive amounts of
Oxygen from the protected area, nor is it toxic upon inhalation.

Unlike Halon 1301, water mist is not a controlled substance with known Ozone
depleting properties. The recharge of a water mist system is inexpensive
compared to Halon 1301. Room sealants are not as much a concern with water
mist systems.

However, water mist does leave a residue and lacks the equipment enclosure
penetration capability of Halon 1301 and other gaseous suppression system
agents.

Fireline does not recommend the installation of water mist systems in data
processing rooms or facilities where water and dissolved salts can cause
significant problems.

Inergen and FM-200. Neither of these agents pose environmental dangers and
both offer substantial advantages when protecting data processing,
telecommunications, and other electronic equipment facilities.

Water mist does feature the ability to provide local application protection
where total flooding is not possible because of structural configurations.

Typical applications include:
Flammable Liquid Storage
Machinery Rooms (such as elevator equipment rooms)
Incinerator Installations
Emergency Generator Rooms
Switch Gear Rooms
Engine Rooms

 

[mr.c]

I would be interested in knowing more about the water mist system. We do carry
lots of water. I know of one GMC owner that sprays water in a mist to his
radiator to keep it cool. He put in some misters directly when his temp goes
up. Just has a separate pump for the radiator.
Al Chenoff
77 Eleganza II

> Pouring water on an oil fire has never been recommended but recently I came
> upon these water mist systems which look interesting. I will usually have
> some water aboard along with our air tank although more air might be needed.
>
> This system might be in the running for me although it might be simpler just
> to install a Halon or CO2 system.
>
> I am thinking with most systems you get one short shot. With this system
> you turn on the switch and let it run until all your water is used.
> Hopefully the fire is out and everything is cooled so re-ignition won't
> occur.
>
> If it falsely triggers there is no long lasting effects or expense.
>
> Don
>
> *************************************************************************
> Water Mist Fire Suppression Systems
>
> Fine water mist systems extinguish fires primarily by removing heat from the
> materials involved in the combustion process. Water is applied to the fire
> in very fine droplets which appear to the observer as a dense fog. The ratio
> of droplet surface area to water volume is large and conversion to steam
> occurs very efficiently. The latent heat of vaporization, which is a
> physical phenomena associated with the change of state of water to a gas
> (steam), removes many BTUs of heat from the fire and the steam produced also
> helps to smother the fire by displacing oxygen in the vicinity of the fire.
>
> ****************************************************************************
> ****
> Water Mist Fire Suppression System General Theory of Operation
>
> When water mist droplets contact the surface of hot or burning substances,
> the water droplet changes from a liquid to a gas (steam). This
> transformation absorbs tremendous energy from the surface of the cumbusting
> material. Water expanding into steam increases in volume 1,760 times. The
> expansion removes heat from the burning fuel so as to lower its temperature
> below the ignition threshold. This is the heart of the theory of fire
> suppression by fine water mist.
>
> Further, the droplets and steam impinge on the surface of the fire to create
> blanket in which the fire quickly depletes its supply of oxygen.
>
> The key to the success of a fine water spray fire suppression system is the
> ability to generate a directional mist or fog of fine water drops through
> the nozzles. The nozzle design must produce a small droplet with an orifice
> sufficiently large to avoid clogging from suspended particulates that may be
> present in the water stream.
>
> Securiplex, the modern leader in the current generation of fine water mist
> fire suppression systems, solved the problem with the patented twin fluid
> chamber nozzle. Liquid water and pressurized air are mixed in a turbulent
> motion in the mixing chamber to produce and deliver a spray of water mist.
>
> The optimum water droplet size ranges from 80-200 microns of mean diameter.
> The droplets must be small enough to penetrate all areas behind
> obstructions, yet large enough to penetrate to the surface of the combusting
> fuel.
>
> Supplies of Air and Water for Water Mist Fire Suppression Systems
> In most cases air or nitrogen and water are supplied from dedicated storage
> vessels equipped with the necessary controls.
>
> Only very small amounts of water and air are needed to extinguish even the
> most intense fires (including gasoline fires) because a small amount of
> water is effectively spread into fine water droplets covering a large area.
>
> Many industrial plants have pre-piped supplies of compressed air throughout
> the facility. In these cases plant air is substituted for compressed air
> stored in dedicated cylinders.
>
> The water contained in the storage vessel can be de-ionized and treated to
> comply with current health requirements and can be pre-mixed with
> commercial-grade foaming agents to provide even greater class B fire
> extinguishment.
>
> In certain applications water mist compares favorably to other fire
> suppression systems.
>
> Traditional Sprinkler Systems Fine water spray fire suppression systems
> extinguish fires more effectively and in scenarios exceeding by far the
> capability of traditional sprinkler systems.
>
> Water deluge systems demand high water supply rates and are associated with
> fixed large bore pipe networks around the protected area.
>
> Unlike deluge systems, fine water spray fire extinguishing systems use very
> small amounts of water and therefore only require small bore pipe networks.
>
> Note, however, water mist fire suppression systems are not listed under NFPA
> #13 as a replacement for conventional sprinkler systems
>
> Unlike Carbon Dioxide, water mist does not remove excessive amounts of
> Oxygen from the protected area, nor is it toxic upon inhalation.
>
> Unlike Halon 1301, water mist is not a controlled substance with known Ozone
> depleting properties. The recharge of a water mist system is inexpensive
> compared to Halon 1301. Room sealants are not as much a concern with water
> mist systems.
>
> However, water mist does leave a residue and lacks the equipment enclosure
> penetration capability of Halon 1301 and other gaseous suppression system
> agents.
>
> Fireline does not recommend the installation of water mist systems in data
> processing rooms or facilities where water and dissolved salts can cause
> significant problems.
>
> Inergen and FM-200. Neither of these agents pose environmental dangers and
> both offer substantial advantages when protecting data processing,
> telecommunications, and other electronic equipment facilities.
>
> Water mist does feature the ability to provide local application protection
> where total flooding is not possible because of structural configurations.
>
> Typical applications include:
> Flammable Liquid Storage
> Machinery Rooms (such as elevator equipment rooms)
> Incinerator Installations
> Emergency Generator Rooms
> Switch Gear Rooms
> Engine Rooms