Debate over mandatory spriklers

[Ed Pawlowski]

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Saving lives is a big emotional issue. I think it is more about saving property, but saving lives just sounds better.

[Ed Pawlowski]

On Sep 18, 10:00 am, Eric in North TX wrote: > " The downside

The sprinklers only go off in the area of the fire, not the entire property so that is not a consideration. Homeowner should be able to turn them off, also. In commercial/industrial applications, the shut off valve is usually chained open to prevent accidental or mischievous turning off of the valve.

[Ed Pawlowski]

But they do. I've seen it on TV so I know its real.

[Ed Pawlowski]

Deluge systems "Deluge" systems are systems that have open sprinklers, i.e. the heat sensing operating element is removed or specifically designed open sprinklers, so that all sprinklers connected to the water piping system are open. These systems are used for special hazards where rapid fire spread is a concern, as they provide a simultaneous application of water over the entire hazard. They are commonly seen as preventative measures to prevent egress of fire from an external source (eg hi-rise windows, warehouse bay entries, over openings in a fire-rated wall)

Water is not present in the piping until the system operates. Because the sprinkler orifices are open, the piping is at atmospheric pressure. To prevent the water supply pressure from forcing water into the piping, a deluge valve is used in the water supply connection, which is a mechanically latched valve. It is a non-resetting valve, and stays open once tripped.

Because the heat sensing elements present in the automatic sprinklers have been removed (resulting in open sprinklers), the deluge valve must be opened as signaled by a specialized fire alarm system. The type of fire alarm initiating device is selected mainly based on the hazard (e.g., smoke detectors, heat detectors, or optical flame detectors). The initiation device signals the fire alarm panel, which in turn signals the deluge valve to open. Activation can also be manual, depending on the system goals. Manual activation is usually via an electric or pneumatic fire alarm pull station, which signals the fire alarm panel, which in turn signals the deluge valve to open.

Operation - Activation of a fire alarm initiating device, or a manual pull station, signals the fire alarm panel, which in turn signals the deluge valve to open, allowing water to enter the piping system. Water flows from all sprinklers simultaneously.

[Kurt Ullman]

As of three years ago there had NEVER been a fatality reported in a fire with a functional sprinkler system.

[Stormin Mormon]

When I took some fire protection courses, we learned about the Parmalee Perforated pipe system (it was 20 years or so ago I learned of this). Some textile mill owner put pipes overhead, with holes drilled. In case of fire, they could open the valve, and spray the entire plant. Same concept.

I doubt deluge systems will be installed in homes.

[trader4]

Actually the leading cause of home fires is smoking. I doubt sprinklers would have saved someone who died smoking in bed. But a working smoke detector probably would.

[Ed Pawlowski]

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True, but the sprinkler would possibly save the people in other rooms and save property damage to the rest of the house. Sprinklers certainly don't replace smoke detectors.

[Ed Pawlowski]

That's a good thing, but I bet the statistics on property damage are even better. If you were selling sprinkler systems, you'd get a better reaction from potential buyers when you tell them crippled granny or the new baby can be saved compared to telling them the attached garage won't get burned down.

[HeyBub]

"Deluge systems are connected to a water supply through a deluge valve that is opened by the operation of a smoke or heat detection system. The detection system is installed in the same area as the sprinklers. When the detection system is activated water discharges through all of the sprinkler heads in the system. Deluge systems are used in places that are considered high hazard areas such as power plants, aircraft hangars and chemical storage or processing facilities. Deluge systems are needed where high velocity suppression is necessary to prevent fire spread."

or

[HeyBub]

Where water pressure may be inadequate, auxillary pumps are installed as part of the system.

You probably never inspected a munitions bunker, a Minuteman Missle silo, or similar. In my town, near the ship channel, is a WW2 Ordnance Depot. It has hundreds of munition bunkers that have these overhead water pipes.

Aside: The San Jacinto Ordnance Depot was sited on 5,000 acres and is comprised of these bunkers. Each bunker is about 150' long and 50' wide, and 20' high, made of concrete with 6-ft walls in the shape of a Quonset hut. Each bunker it topped with about ten feet of dirt. Between each bunker is a mound of soil higher than the bunker.

These bunkers are arranged in rows with VERY small thick steel-doored entrances (~3x6 ft) that face each other across a "street." The "street" is more like a concrete pad with a railroad track down its center. The bunkers are on either side of this 100' wide "street."

Over the years, since 1941, the dirt and mounds between the bunkers have been overgrown with a pine forest and assorted shrubbery.

You'd think the valuable land - on the Houston Ship Channel - would have been converted to something other than storage warehouses for honey. It hasn't, and I suppose the reason is the enormous cost to demolish these bunkers. For sure you can't blow them up!

[aemeijers]

And each one of those bunkers likely has a blowout plug in the top or in the back wall, designed to be weaker than the door, and to vent the pressure wave from an explosion away from the other bunkers. Any crew in the bunker would be a writeoff, of course, but they didn't want the whole yard going up.

As to linked sprinkler heads- I'm no expert, but I thought they just linked heads within the local firewall perimeter- ie, that wing or floor or whatever. No need to flood the whole building for a small fire.

-- aem sends...

[Kurt Ullman]

The original context was how sprinkler always all came on on TV and how unlike real life that is. Unless people are having nuclear reactors or refineries or some kinds of warehouses storing highly flammable haz materials in their homes, it is still very unrealistic. Probably about as many deluge systems going off over the course of a year as cars actually blowing up.

[Kurt Ullman]

I missed those, I admit. Of course the original context of how they ALWAYS all go off on TV and how that is unlike reality (outside of maybe something they are doing on 24).

[Tom Horne]

Automatic Fire Sprinklers are always zoned. Except in some rather exotic systems, that protect risks containing flash fire or flammable liquid hazards, fire sprinkler heads; which is what the individual discharge nozzles are called; do not open until the temperature at the individual head reaches a set level and remains there long enough to melt the woods metal, or rupture the glass bulb, that hold it closed. In other words ordinary fire sprinkler heads open one at a time in response to the temperature at the head. They can be combined with a heat detector system that will shut off the water when the temperature has dropped to a safe level but such additional controls add markedly to the cost. There are even sprinkler heads that shut themselves when the temperature drops but there cost is quite high compared to the much simpler open and replace type. All fire sprinkler systems are easy to shut off but premature shut down is the primary cause of large losses in sprinklered premises. Many large cities have local laws or ordinances that forbid the closing of sprinkler valves prior to the fire department's permission.

-- Tom Horne

[Tom Horne]

Those are known as deluge sprinkler systems. The individual heads are open and only covered with a light weight dust cover to keep hte heads clear of accumulations that might interfere with the discharge pattern. Deluge systems are used to protect occupancies like cotton mills, explosives and pyrotechnic manufacturing, and aircraft hangers were there is a danger of flash fire or the ignition of spilled flammable liquids such that the fire might spread faster than individual heads would heat up and open to the point that more heads would open then the system was designed to supply. Deluge sprinklers are often supplied with foam or other water additives that make them effective against the particular hazard for which the system is installed.

-- Tom Horne

[Tom Horne]

I wish that were true but it is not. People die from fires in sprinklered buildings quite regularly. What is true is that there is no known record of a multiple fire death in a building protected by a working automatic sprinkler system. People who smoke in bed or while consuming alcohol or other intoxicants are often dead before the sprinkler can activate. There is a special smoke detector that can be fastened to a glass bulb type of sprinkler head that will break the glass bulb when it activates thus saving a person who is intimately involved with the source of ignition. They are sometimes installed over nursing home beds were the patient has previously attempted self immolation. They are also useful in the bedrooms of children who have a history of fire setting.

-- Tom Horne

[Tom Horne]

Unfortunately the smoke detectors do not save small children, the elderly and infirm, or the smoker themselves, because the smoking ignition is often coupled with the consumption of intoxicants which render the user incapable of responding effectively to the alarm. Children, and others that are incapable of self evacuation, can only be completely protected by automatic fire suppression. The office of the State Fire Marshal did a study of ten years worth of fire fatalities in the State. They concluded that about half of those deaths would have been prevented by a fire alarm system that would have automatically summon the fire department and that all except the smoking igniters; including the children and others who had died with the person who's smoking had caused the fire; would have been saved by fire sprinklers.

-- Tom Horne

[Tony Hwang]

Hmmm, One reason I have two different kind of detectors.

[HeyBub]

Uh, both World Trade towers had sprinklers.