What are Automatic Fire Sprinkler Systems?
Fires can happen anywhere and anytime, putting human life and property at risk. Uncontained, they can wipe residential or office buildings from existence.
Could automatic fire sprinklers be the efficient fire control measures you need?
Fire sprinklers combat and contain the spread of fires with water. Automatic fire sprinkler systems can detect and suppress fires at any time. They’ve become some of the most reliable fire control methods in Australia, stopping slight accidents from escalating.
In this post, we cover automatic sprinkler systems, their types, inner workings, regulations and their essential fire safety maintenance. As a building owner or manager charged with building and occupant safety, you must check and ensure that your premise complies with Australian fire safety regulations.
Types of Fire Sprinkler Systems
Let’s go over the different types of fire sprinkler systems.
Wet Pipe Systems (Automatic Fire Sprinklers)
Wet pipes are the most reliable, cost-effective, and widespread sprinklers in buildings, effective on all fires caused by diverse hazards. This system is straightforward and typically composed of an automatic fire sprinkler (head), alarm check valve, pipe, stop valve, motorised alarm bell, and alarm test valve. Also, the automatic sprinkler comes with a heat bulb, fusible link, or another heat-responsive element.
In a Wet Pipe Sprinkler System, an automatic water supply fills the piping network with water under pressure. It’s then activated at a specific high temperature, releasing the flow of water over an assigned floor space.
Dry Pipe Sprinkler Systems
Dry pipe systems are excellent for water-sensitive areas, including data centres, electrical control rooms, computer equipment, and locations where you store valuables and documents.
In a dry pipe sprinkler, pressurised air or nitrogen fills the pipes, and air keeps a remote valve (the dry pipe valve) locked, blocking water until a fire activates the sprinklers (via their heat-responsive elements).
Then, the dry pipe system pressure drops, and the air is released from the sprinklers, pumping water from the dry valve into the pipe and out of the open sprinklers on the fire.
Pre-Action Sprinkler Systems
Pre-action sprinklers are designed for locations where you must avoid accidental activations at all costs, such as data centres and museums with rare books, manuscripts, and artworks. These have dry pipes with pressurised air or nitrogen that block the water flow. For water to be released, two circumstances need to occur.
Firstly, an independent fire detection system must detect a fire, activating the pre-action valve, which gets filled with water. Secondly, one or more individual sprinkler heads must get activated and release their gas to pump water.
If you’re overseeing buildings where rapid fire spread is a risk or pricey equipment needs cooling (such as tunnels and airport hangars), deluge systems give you a simultaneous application over the entire hazard. Instead of automatic sprinklers with heat-responsive elements, sprinklers are open.
However, a special deluge valve holds water back and only releases it if a separate fire detection system is activated. Then, water flows through the piping network and is discharged from all the connected sprinklers simultaneously.
Water Mist Sprinkler Systems
Water mist systems are versatile, highly effective, and efficient since they’re a mix of water-based and gas-based fire suppression methods. A water mist sprinkler stands out among other fire protection methods, thanks to its use of heat-absorbent compressed gas.
To illustrate, sprinklers don’t release regular water droplets but vaporise them to expand them by about 1,600 times. When these small droplets are released, they cover more surface area unlike a water spray.
Also, the mist turns into steam, putting out fires and preventing more oxygen from reaching the hazardous areas. Additionally, the evaporation process has a cooling effect, which prevents heat from spreading.
Foam Sprinkler System
Foam fire sprinklers are special application systems for liquid fires, making them eligible for flammable liquids, airport hangars, refineries, marine applications, and more. They release a combination of water and low-expansion foam concentrate.
Together, they create a foam that exits the sprinklers, expands, and covers the liquid on fire. Then, the foam cools it, suppresses the fire, and protects the property against fire re-ignition.
Having covered the main sprinkler systems, it’s your responsibility as a building manager to pick the appropriate one. In other words, it should be the most effective for your building type and the most suitable for your usage.
How Do Automatic Fire Sprinklers Work?
Put simply, a network of piping surges with water under pressure from a reliable water supply. The automatic sprinklers have heat-responsive elements (heat bulbs or fusible links), which break when the fire sprinklers reach or exceed a particular temperature level for enough time.
Then, the affected sprinklers are activated, and water flows from an alarm valve into the area of protection. This system is mainly composed of a:
- Fire Sprinkler Head: The component has a heat-sensitive element that activates it and opens sprinklers. You can use it to control the water flow.
- Alarm Valve: It prevents water from flowing into the sprinkler system until the water pressure on that side gets higher than on the water supply side. This way, it reduces the chances of false alarms.
- Alarm Test Valve: Typically closed, this valve can open to simulate the water flow from a single sprinkler.
- Motorised Alarm Bell: The water flow turns this mechanical device on, moving a hammer, which hits a gong and triggers a sound alarm and may also alert the fire services to send a fire brigade.
- Stop Valve: Often painted RED, this valve can stop the water flow from entering the fire sprinkler system. It’s in the OPEN position by default.
- Valve Monitor: This valve monitors the Stop Valve’s state (open/closed).
As for the compatible sprinkler heads with automatic systems, they are:
- Conventional Sprinklers
- Flush Sprinklers
- Spray Sprinklers
- Concealed Sprinklers
- Recessed Sprinklers
- Sidewall Sprinklers
- Fast Response Sprinklers
- Dry Pendant and Dry Sidewall Sprinklers
- Dry Upright Sprinklers
If a sprinkler system has heat-sensitive glass bulbs, you can consider the following colour cheat code for temperature ratings:
- Orange: Ordinary (57°C)
- Red: Ordinary (68°C)
- Yellow: Intermediate (79°C)
- Green: High (93°C)
- Blue: Extra High Hazard (141°C)
- Purple: Ultra High (182°C)
- Black: Ultra High (227/260°C)
Despite the major benefits of fire sprinkler systems, they can cause property damage through interior, inventory, or equipment water damage, such as rust and corrosion (even if the system isn’t activated).
Fire Sprinkler Systems vs. Fire Suppression Systems
Although the two systems extinguish fires when activated by heat, smoke, or both, fire sprinkler systems use water, whereas fire suppression systems use several chemical agents (liquids, gases, and foams).
Sprinklers can cause water damage and aren’t effective on some fire types. For that reason, fire suppression systems are more effective in server rooms, semiconductor manufacturing facilities, and areas with highly combustible substances, oils, and gases.
Maintenance of Automatic Fire Sprinklers
When it comes to installation and other requirements for fire sprinkler systems, your system should be up to the Australian Standards 1851 (AS 1851), which details the requirements for testing, inspecting, and maintaining fire sprinklers. It should also comply with building codes (AS 2118) regarding manufacturing, installing, and commissioning sprinklers and other fire safety equipment such as fire hose reels, and fire extinguishers.
Firstly, AS 1851 requires you to follow a four-stage approach. These four stages are equipment testing, keeping records, reporting and rectifying any failures of fire equipment, and annual condition reports.
Secondly, AS 2118 dictates that residential buildings must have residential-type fire sprinkler systems. Among other requirements, these systems should contain reliable water supplies, sprinkler heads, pipework, pumps, and control valves.
Finally, there are testing regulations for sprinkler systems. They include basic and annual system testing, including fire alarms, spring heads, control valves, and annual flow testing. Using suitable test equipment, the operation of these components is verified.
Investing in automatic fire sprinkler systems should be your priority, especially because they’re the most simple and effective fire protection systems, with the ability to detect fires, start alarms, and put them out at any time.
Data collected in the US proves that “when sprinklers are present, the chances of dying in a fire are reduced by one-half to three-fourths, and the average property loss per fire is cut by one-half to two-thirds.”
Just make sure to confirm that wet pipe systems are right for your type of property and stay one or several steps ahead of unforeseen fire emergencies with an automated, updated, and well-maintained fire sprinkler system.
Remember to also comply with Australian standards for your fire equipment, which means conducting regular fire safety inspection and fire maintenance services. This way, you can keep fire protection and the safety of your building and people a priority!