You've probably seen several movies where a small amount of smoke triggers the sprinklers in a building, soaking everyone and everything inside. But did you know sprinklers aren't even triggered by smoke and don't all go off immediately? So, how do automatic fire sprinklers work? Fire sprinkler systems are heat activated, one sprinkler head at a time, and most fires require only one or two sprinklers to be extinguished. These are only two of the many misconceptions regarding fire sprinkler systems. This piece will explore the details and debunk some common misconceptions about this crucial safety technology.
To better understand how the fire suppression system works as a whole, it is helpful to know the various parts that make up a fire sprinkler system:
Automatic sprinklers are the part of the fire sprinkler system you see throughout the building that disperses water onto the fire. There is a wide variety of automatic sprinkler types to suit varying needs and settings.
A component of each automatic sprinkler, the heat-sensitive element, is the all-important trigger that activates the sprinkler. The most common type of heat-sensitive element is a glass bulb filled with a kind of glycerin-based liquid that expands and bursts in response to fire-related temperatures, typically between 135-165 degrees Fahrenheit.
The pipes that run above the ceilings and behind the walls carry and hold the pressurized water that will be dispersed through the automatic sprinkler(s) in the event of a fire.
The pipes that connect the sprinkler system cross and main pipes to the domestic water supply for the building.
Gauges measure the water pressure within the sprinkler system to indicate whether or not sufficient pressure is present to efficiently send water through the system in the event of a fire.
Valves drain, test, and isolate specific sections of the fire sprinkler system.
When the switch is activated, water runs through the sprinkler system, sending an alarm to alert local authorities that the system has been triggered.
A device that sounds an alarm when water flows through the sprinkler system.
These are where the system's water can be drained and removed during maintenance or testing.
Now that the main elements of the sprinkler system have been defined, it will be easier to understand how the parts work together to make the whole system work.
Automatic sprinklers are heat-activated, not smoke-activated, and in most systems, only one automatic sprinkler is activated at a time.
In most wet and dry pipe systems, an automatic sprinkler is activated when the heat reaches fire-related temperatures, usually within the range of 135-165 degrees Fahrenheit, depending on the system.
Only the automatic sprinkler experiencing those temperatures will then be activated when the heat-sensitive glass bulb breaks in response to the heat.
Once the bulb breaks, the sprinkler system's water is released through the automatic sprinkler and flows down and out over the fire, suppressing it and stopping it from spreading and re-igniting. Because most fire sprinklers only activate at the automatic sprinklers where the fire is, a fire can often be extinguished and kept in the first room/area where it began without other automatic sprinklers needing to activate.
There is some variance among fire sprinkler systems regarding where the water is stored and how it gets to the sprinkler head upon activation.
Wet Pipe Fire Sprinklers: In a wet pipe system, the pipes are filled with slightly pressurized water. When the system is activated, the activated automated sprinkler releases the water immediately. Wet pipe systems show the fastest response time and are the easiest to install, but they may not be ideal for regions where pipes may freeze or where a leak could be devastating.
Dry Pipe Fire Sprinklers: In a dry pipe system, pressurized air fills the pipes behind the automatic sprinklers while the water is kept back behind a valve. When an automatic sprinkler is activated, the valve is lifted, and water is released to flow through the system to the activated automatic sprinkler.
All sprinkler systems, wet or dry, are connected to a domestic water supply through the system's risers, usually located in a designated riser room along with the system's gauges and controls.
Many may assume that a fire sprinkler will automatically switch off after a fire is extinguished or under control. This is certainly not the case.
Whether after a fire is extinguished, when an automatic sprinkler malfunctions, or when a pipe breaks, the system must be manually shut off so that water flow is halted and the activated or malfunctioning automatic sprinkler can be repaired/replaced before the system is reset.
This is why knowing where the system's risers are is important. On the main risers, the pipes connecting the fire sprinkler system to the water supply, as well as water control valves, allow you to turn the water flow off and on.
In the event of an actual fire, emergency responders will likely take care of this step. But in the event of a malfunctioning or damaged automatic sprinkler or pipe, it may be pertinent to know where the control valve is so that you can shut off the water and prevent needless water damage.
Manual sprinkler systems operate with manual control valves, so water must be turned on and off by hand. Automatic sprinkler systems use an electronic controller and solenoid-operated valves to turn water on and off.
Today, most property owners who are installing a new sprinkler system choose automatic systems. The costs are practically the same, and automatic systems are far more convenient. However, many older properties have older manual sprinklers, which may need to be replaced or updated.
Fire sprinkler systems are located in various buildings, from retail stores to apartment buildings. They're a crucial part of an establishment's protection system and, if maintained and checked regularly, are among the best resources for putting out a fire. With routine inspections, the systems might work properly in an emergency and be useful for lighting a fire. Ensure your business is protected by scheduling inspection and testing services with Texas Fire & Safety today.
We at Texas Fire & Safety have you covered whether you require smoke detectors, an automatic sprinkler system, or fire extinguishers installed at your property. We have been protecting properties and people from fire damage for years—and our experience is present in our excellent work! We are known for our outstanding customer service, expertise, and reliability. Please reach out to us today!