Around here, all new dry fire suppression systems must be tested for a minimum delay from when the sprinkler head is tripped to when the water starts spraying at the furthest head. This testing guarantees the system will be wet inside. Blow the lines all you want but you will never get all of the moisture out.
I suppose I should have written that the air dryers minimize the introduction of more moisture from the compressed air source. I'm curious as to how often the time to spray water has to be tested? Is it a one time certification or is it an annual test? I know the guys from the fire protection company don't want water pooling in the unheated warehouse sprinkler systems so I don't what their procedures are but I've taken automotive antifreeze and blown it through pneumatic systems that were freezing up in cold weather. If it was extremely critical, I'm sure they could blow denatured alcohol through the system to get rid of residual water like I've done on some pneumatic systems. I'll have to ask one of the guys about it. I guess a fire would melt an ice plug? :-)
TDD
Sprinkler heads go off one at a time. It's not like the movies where a fire by one head makes the whole room rain. Only the heads that get hot enough will start spraying. If that happens you'll be glad they did.
They don't trip accidentaly. BUT! They are pretty delicate when it comes to being bumped, and they dump an impressive amount of water when they go off. So you do want to be VERY careful when near them. I've seen people hang a clothes hanger on them with disastrous results, or your kids could toss a frisbee, etc. You'll be liable for the damage if you cause it.
Yes, you could certainly install a water sensing device that would kill the power to the machines, but you might want to place it as close to the spinkler head as possible.
If you placed it on the floor (where most water sensing alarms are usually placed) your systems would probably already be wet by the time the sensor sensed the water.
You could also place your equipment in racks with a "roof" to keep the water off of the equipment, but you'd have to deal with ventilation so that the roof didn't keep the heat in. That could, ironically, cause a fire! ;-)
Of course, once the fire department crashes through the window with hoses a-blazing and waters down your whole apartment, all bets are off as far as keeping your equipment dry.
All that said, if you are that concerned about your equipment, I'll assume that you already employ off site back-up storage for your data. You can try and protect the systems from water, but if the fire itself wipes out the back-up media stored in the shoe box in the hall closet, you're just as out of luck.
thanks for pointing this out. I used to wonder about that. Wondered how the other heads knew to start. Now I see that they don't.
P&?M?
No. You cannot control the sprinklers. They are controlled at a central location in the apartment building, on a floor-by-floor basis, or a building-by-building basis, depending on the size of the building.
You don't want some idiot turning off his sprinklers out of some misguided notion that his electronic toys are worth more than human lives.
That's the risk you run. Make sure you have renter's insurance that covers all your stuff. Keep important papers in a water-tight fire safe. Keep backups of your important data off site.
There are some devices designed to protect against basement flooding. However, they may not work if it's just "raining." Also, even if your computer is off, if it gets wet, you can forget about ever using it again.
Maybe if you bang the pipes, but if you hit the head there's a good chance.
I've seen it happen several times, once in a hotel room where somebody hung a clothes hanger on the head. (Doh!)
That little glass piece is fragile - it handles a good compressive load but any sideways pressure will trip it, and an impressive amount of water will come out.
@Harry K:
Definitely sounds to me like some sort of neglect on the part of the jail has gone on here... Your sprinkler system should be having at least annual flow tests -- where inspector test valves in each zone are opened to determine the responsiveness of the water flow sensors for each zone (which can go bad) as well as each supervised zone valve being exercised from fully opened to fully closed and back to open to test the tamper switches...
If your water in your sprinkler system expires and smells like sewage after only 12 months then there are local water quality issues at play -- if your sprinkler system is being fed from a potable water supply... Some regions of the country maintain a separate system for fire hydrants and sprinkler mains which is NOT potable and your system might be connected to such a water supply...
Generally even good treated water in a sprinkler main will have the manganese dioxide (fine gritty black powder) precipitate out of solution from sitting a year in the pipe... It is better to rinse any of the powder down the nearest drain with clean water than to wait and try to sweep it up once it is dry...
~~ Evan
What you are discussing in the stairwells is NOT the sprinkler riser pipe but merely the fire hose standpipe riser which is an entirely separate feed down the the fire pump room in the building (and in some buildings the riser pipes are dry and require a fire pumper truck to hook up at the external connection point after the engine has established a water supply from a fire hydrant to feed water into them) to allow the fire crews to obtain water to fight fires on the upper levels without having to drag hoses in from the ground floor...
Typical fire hose standpipe risers are 4" to 6" in size... The main sprinkler piping in a building is generally 8" (small building) or better with main supply pipes serving large sections of the building being at least 12"...
~~ Evan
+1 to what Nate said...
The expenses involved in all the additional sensors as well as the special valves that each "dry zone" needs as well as the dedicated air compressor for each zone required and emergency power to feed it are enough of a barrier to reserve the use of "dry sprinkler" systems to sections of a building where environmental concerns like freezing temperatures are a factor in the fire protection system design like loading dock areas, parking areas and entry ways and stairwells which are unheated...
~~ Evan
+1 to the fire melting the ice plug...
Although you would want to take every effort to prevent the ice plug from forming as ice is pretty strong and can do interesting things in pipes with the sprinkler heads installed facing downwards... So it is more of a maintenance issue for preventing the heads from blowing out and causing a nuisance discharge...
~~ Evan
Around here generally the floor control valves and the hose valves are tapped off the same pipe, or at least that's what I'm used to seeing.
nate
I could have sworn I've seen the sprinkler heads pointing up in a lot of warehouses and industrial buildings. It could be for protecting them from the goofy forklift driver of for making sure no residual water collects in them and freezes. Once again, I'll have to ask one of the guys from the Fire Protection company. It makes sense to do that in an unheated building and I have seen different designs for the little metal umbrella so there is probably one designed just for the upturned head.
TDD
Just once when the system is installed. After that it just has to be serviced by a licensed fire protection co.
In the 17 years I lived there both systems tripped many times due to malfunctions, accidental contact, vandalism, and car fires. Keeping the pipes dry would have been a hell of a challenge.
After a watching the fire prevention company a few times. I could pretty much have the system drained and compressor back up and running.
All they had left to do was blow out the low points one final time, shut the main valve from the city water, drain the diaphragm check valve and pressurize it from the sprinkler side, open the valve to the city water, and sign off on it.
One time the malfunction was caused by a flaw in a seam of a pipe. The pin hole got progressively bigger until the compressor could not keep up. The system tripped (naturally on the weekend). By the time the fire prevention guys got there on the Monday the small hole was about a centimetre in diameter and the water was gushing out.
Darn, defective pipe. I saw a lot of that 20 years ago when I was working for a big construction corp. when the black pipe came from third world countries because they had the best price. There were all sorts of pinholes and casting flaws in the pipe and fittings. I have to wonder how long that stuff lasted.
TDD
Get you facts straight! Dry pipe sprinklers are only used were there is a danger of freezing. They are more expensive to maintain because the condensate traps have to be drained monthly. The compressor for the piping air adds cost and the differential dry pipe valve is much more expensive than the Alarm Check Valves used on wet pipe systems. Preaction only systems are only found were the damage from water might well exceed the damage from a fire. Examples include museums, historic library collections, fur storage, paper supply storage, and similar occupancies. If you are thinking of a combination preaction dry pipe system those are extremely rare and are found only in areas exposed to freezing that are so large that an ordinary dry pipe system would take too long to deliver water to the fire.
-- Tom Horne
On Jun 25, 2:46=A0pm, "bob" wrote: snip
Yes the switch you are asking about is called a shunt trip. It's name comes from the shunting of some of a breakers current to a solenoid inside the breaker that trips the breaker to the tripped position even though the current flow has not exceeded the breaker's rating. The shunt switch can take many forms including a manually operated push button. Automatic shunt trips are now required in elevator machine rooms and shafts in order to avoid any erratic operation that might be caused by sprinkler discharge effecting the elevator controls. That is needed because indoor elevator controls are not built to be waterproof. These use a heat detector to shunt the current to the solenoid and trip the breaker. The heat detector used has a lower actuation temperature than the sprinkler heads used in those spaces.
That said I believe you would find the cost of parts and installation a large price to pay for a scenario that is not likely. Keep in mind that smoke can do as much damage to delicate electronics as water so suppressing the fire quickly; which is an automatic sprinkler systems reason for existence; will do much to raise the chance of successful salvage of the electronics you are trying to protect.
-- Tom Horne
The inspectors test on a sprinkler system only flows the same water as a single sprinkler. It is used to test the Alarm Check Valve, water motor gong, and the water flow switches that activate the buildings alarm system. It is not an effective way to flush the system. Many residential sprinkler systems do not use black iron piping and do not contaminate the water used in them. Copper tubing and plastic piping are both used in residential sprinkler systems because the piping installed in such occupancies is not as subject to physical damage as the piping that is installed in warehouses, factories, and other industrial buildings.
-- Tom Horne
I think we clarified that in later posts. I've only seen dry pipe systems in commercial/industrial settings.
TDD
I've installed a lot of shunt trip breakers and contactors that power commercial kitchen equipment located under exhaust hoods equipped with dry chemical fire suppression systems. Most folks don't know to leave the hood fan running because the whole building will get covered with white powder. :-)
TDD
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