AxelFoley85 said:
Supposedly it runs for so long until FD comes. The guy was then starting more fires to bypass.
It'll run until you cut the water off, you burn out the booster pump (if you have one), or you run the main dry. Once a head is opened, there's really no closing it.
Yeah, the guy set fires and the FD came and shut the system down. These systems are only meant to suppress small fires and keep them from spreading until the FD gets there, and they're designed to stay on and open until that happens or someone cuts them off. They may have shut down individual sections of the system, but even if sections of the system were shut down, he could've started a fire in one or multiple of those that could easily grow and become too much for the adjacent suppression system to stop by the time it reached it. Only the nearest heads would trigger, and at that point you have a full blown fire that they're not sized to put out. It would be like fighting a forest fire with a garden hose. The fire would easily jump the heads into the next section of warehouse and just keep going.
These systems also aren't sized to flow all or even most heads at once. You don't want that kind of deluge in a warehouse (or most settings) because then a small, localized fire creates a total loss from water damage. The system is sized and designed for containment, not putting out a giant blaze, and only a those heads that are heated enough to trigger should be going off. Deluge systems that activate every head when one is activated like in movies are actually atypical and found only in specific, high risk applications. Once this for got going, the sprinkler system was never going to stop it.
