Whether we realize it or not, we encounter fire sprinklers almost every time we leave the house. Schools, restaurants, malls, offices; they’re everywhere. While they’re at all these places and more, most people don’t know their components and how they truly operate. Since sprinklers controlled 97% of fire incidents where they were present from 2017 to 2021, understanding what a sprinkler is and its overall importance is necessary.
Main Components of a Fire Sprinkler
Fire sprinklers may seem simple at first glance, but their compact design conceals a sophisticated assembly of parts, with each component equally important during an emergency. Having a clear understanding of these components helps highlight why fire sprinklers are so effective at protecting lives and property.
The frame is responsible for providing structural support for all the internal components. By having one, the sprinkler will stay properly mounted and functional over time. Judging from Tyco’s catalog, sprinkler head frames typically consist of brass. A small percentage of them are still stainless steel, but brass is often the primary choice due to its corrosion resistance, durability, and processing properties.
Another main component of a sprinkler system isn’t physical, but a number that helps to calculate the discharge rate from the heads. In the United States, the k-factor measure is calculated in imperial units by using the flow in gallons per minute (gpm) and the pressure in PSI. AGF Manufacturing considers the k-factor to be the needed orifice size for a specific pressure and flow. On the one hand, low k-factors have a smaller diameter, which restricts the flow, while on the other hand, larger k-factors have a larger diameter, allowing for more flow.
For fire sprinklers to function correctly, they rely on sensitive thermal elements to detect heat and activate the system. Double D Piping describes the two main types: the glass bulb, which contains a heat-sensitive liquid, and the fusible link, which melts at a specific temperature. When exposed to temperatures ranging from 135°F to 165°F, the glass bulb expands and bursts, or the fusible link melts, releasing the seal and causing water to flow through the sprinkler head to suppress flames.
Without a frame-mounted deflector, the sprinkler system won’t disperse water efficiently over the designated area. Research from the University of Illinois at Urbana-Champaign explains that their purpose is to “break up the water stream discharging from the orifice into a more efficient extinguishing pattern.” There are sprinkler mounting options to accommodate the deflector style, including upright, sidewall, and pendent. These varying shapes and configurations compensate for different room layouts and coverage needs.
Spray Patterns
Once a sprinkler is activated by heat, the plug releases water at the designated flow and pressure. As the pressurized water exits, it hits the deflector, dispersing the water into a spray pattern that maximizes coverage and effectiveness. The National Fire Protection Association (NFPA) states that water distribution can occur in one of three ways:
- Standard Spray: The most common type, installed in pendent, upright, or sidewall positions to ensure adequate coverage and adaptable discharge for various fire risks.
- Extended Coverage: Suitable for larger areas with fewer sprinkler heads, this option reduces installation costs but requires higher water pressure for effective fire protection.
- Old Type: Now rare, these distribute water both up and down, suitable for specialized needs like fur vaults, and can be mounted pendent or upright.
The correct spray pattern is crucial for safeguarding lives and property from fire, but so is the selection of the right sprinkler head. Becoming knowledgeable of the two response types can help facility managers, building owners, and safety professionals ensure the most effective method is used to protect their unique environments.
Response Types
According to the NFPA, standard response sprinklers operate by cooling and saturating the areas surrounding the flames, thereby cutting off the fuel source. However, this type of sprinkler will only activate individually. Essentially, they only discharge water when they’re above a fire, which is known as targeted fire suppression. This is designed to minimize water damage and is often found in industrial and commercial environments, such as factories, warehouses, and offices, for this reason.
The second type, quick-response sprinklers, is suitable for light-hazard settings due to their rapid response to heat and ability to reach high ceilings. Cooling down the ceiling in this manner prevents the fire from rising and deters flashover. This also allows sufficient time to ensure a safe evacuation for building occupants. These sprinklers are typically found in highly populated buildings, such as schools and office buildings, where occupant safety and rapid containment are most necessary.
Conclusion
Having a solid understanding of fire sprinklers is essential for preventing the loss of life and property. Each component plays a significant role in the system’s overall effectiveness during an emergency. To keep these systems at peak performance, NFPA recommends conducting quarterly mechanical and alarm device checks, in addition to annual tests for the main drain, water flow, and fire pump. By staying informed and proactive, building owners and facility managers alike can have peace of mind, knowing they have maximum protection and minimal fire-related risks. For more information on the hidden costs of neglecting fire safety, click here.
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