Fire Sprinkler Systems
Fires can be devastating and fatal, but they do not have to be. Fire sprinkler systems were effective at controlling the fire in 97% of home fires between Installing a fire sprinkler system is a practical way to keep people and firefighters safe from the risks of fires.
a picture of a fire sprinkler system spraying water on fire
A fire sprinkler system is a type of automatic extinguishing system (AES) that prevents fire growth and spread by releasing water through a series of sprinkler heads connected to a distribution piping system. Water is released through the sprinkler heads once the surrounding air reaches 165 degrees Fahrenheit. This is an active protection method that can contribute to the safety of firefighters and those they work to protect.
Although these systems provide protection, they are not present in every structure. Fire departments responded to an average of 51,000 structure fires per year from 2015-2019.1 Only 10% of those structures had fire sprinkler systems.1 Additionally, most structure fires and fire deaths occurred in homes, but only 7% of all home fires had sprinklers.1
Ensure buildings have functioning fire sprinkler systems
Civilian fire death and injury rates are lower when fire sprinkler systems are present compared to reported fires in structures with no AES.1 The rate of firefighter injuries was also lower when sprinklers were present.1 Commercial structures (like warehouses or office buildings) are required to have fire sprinkler systems. However, some fire sprinkler systems failed to operate, primarily due to the system being shut off.1 The NIOSH Fire Fighter Fatality Investigation and Prevention Program notes that functioning fire sprinkler systems can decrease the effect of a fire by reducing fire spread and in some instances, extinguishing a fire.
The lack of a fire sprinkler system has contributed to firefighters’ deaths. Firefighters are better protected when there is a fire sprinkler system in place to control the fire spread. Controlling fire spread allows firefighters to better perform their jobs safely because the fire is less aggressive. Property owners can be proactive by having a fire sprinkler system installed. If there is a fire, being prepared with a fire sprinkler system can help create a less severe outcome.
Require, inspect, and track
Being proactive in fire prevention is not limited to having a fire sprinkler system. The NIOSH Fire Fighter Fatality Investigation and Prevention Program recommends that municipalities, building fire code officials, and authorities having jurisdiction should consider the following actions:
These recommendations could apply to commercial and industrial structures like warehouses, strip malls, and factories as well as residential structures like apartments and single-family dwellings that are converted to multifamily dwellings. Commercial or industrial structures may have high risk high hazard inventory such as furniture, lumber, and other flammable products. The added risk highlights the importance of acting on these recommendations.
Computers: Fire Protection
Buildings housing computer centers should be of made of noncombustible construction materials to reduce the chance of fire. These facilities must be continuously monitored for temperature, humidity, water leakage, smoke, and fire. Most building codes today require that sprinkler systems be installed.
Remember that water and electrical equipment do not mix. It is preferable to install a dry pipe sprinkler rather than a wet pipe system. Dry pipe systems only allow water into the pipes after heat is sensed. This avoids potential wet pipe problems, such as leakage. In addition, fast-acting sensors can be installed to shut down electricity before water sprinklers are activated. Sprinkler heads should be individually activated to avoid widespread water damage.
Another type of fire-suppression system uses chemicals instead of water. The two approved types of chemical were Halon 1301 and
A sprinkler system consists of pipes along a ceiling that contain water under pressure, with an additional source of water for a constant flow. Attached to the pipes, automatic sprinklers are placed at select locations. When a fire occurs, a seal in the sprinkler head ruptures at a pre-established temperature, and a steady stream of water flows.
Research compiled by Hall (2011) shows that sprinklers are an effective and reliable fire suppression strategy for buildings. However, he writes that sprinklers are still rare in most places where people are most exposed to fire, including educational buildings, stores and offices, public assembly properties, and especially homes, where most fire deaths occur. Hall notes that sprinklers are 87 percent effective. When a sprinkler system fails, the most frequent reason (65%) is that the system was turned off prior to the fire. Other reasons include manual intervention that defeated the system (16%), maintenance issues (7%), and inappropriate system for the type of fire (5%).
Results and discussions
3.1 Investigation of fire safety predictors
The fire safety strategies for almost 1000 fire incidents are investigated in the BC province of Canada. Fig. 2 shows three of the investigated safety strategies for the first 25 fire incidents. In the initial detection strategies, it is found that 67% of the fire incidents were detected visually. It is followed by a smoke alarm device and smoke detector device with 15.6% and 13.9% of the fire incidents, respectively. Regarding the transmission of alarm to fire department, 57.8% of the fires had telephone tie-line to fire department; the coded signal municipal fire alarm system, including telephone and radio systems, is associated with 38.8%, as the second high, of the recorded fires in MURBs. Concerning the taken actions, it is found that around 45% of the fire incidents were extinguished by the fire department. It is followed by fires extinguished by the occupants, which were 41.8%. Approx
Koubachi  is a mobile application water sprinkler system that automatically waters plants in a garden in an optimized way. The sensor attached to the plants collects the sunlight intensity levels, water levels, moisture, and temperature information. The device controls the water valves and sprinkler system as and when required. 6LoWPAN, a wireless networking protocol, is supported by the device to connect to the gateway through the Internet. Several sensors can be added in the soil to form a mesh, which enables each device to act as a transceiver. Mobile applications are available for both Android and iOS to see the real-time data from anywhere in the world.
Table 1 shows a comparative study of various sensor kits with a few parameters.
Last updated: December 15, 2019
What Does Sprinkler System Mean?
A sprinkler system is a fire fighting device that is installed in buildings as a preventative measure. The sprinkler heads are placed in the ceilings facing toward either the floor or towards any fire hit spots. The other end of the sprinkler system is connected to a number of pipes and a high pressure water supply. A fire sprinkler system is designed to put out a fire during its infancy stage before it develops.
Safeopedia Explains Sprinkler System
Fire sprinkler systems work by way of a heat sensor bulb that is contained in the head of the system. If a fire starts, the heat from the flames will rise to heat the sprinkler sensor. When the heat exceeds a set point, the sensor bulb will break and the water will spray out onto the fire. A sprinkler system is an automatic system.
designed a sprinkler system in the 15th century. Leonardo automated his patron’s kitchen with a super-oven and a system of conveyor belts. In a comedy of errors, everything went wrong during a huge banquet, and a fire broke out. “The sprinkler system worked all too well, causing a flood that washed away all the food and a good part of the kitchen.”[better source needed]
Ambrose Godfrey created the first successful automated sprinkler system in 1723.[full citation needed] He used gunpowder to release a tank of extinguishing fluid.[full citation needed]
The world’s first modern recognizable sprinkler system was installed in the Theatre Royal, Drury Lane in the United Kingdom in 1812 by its architect, William Congreve, and was covered by patent No. 3606 dated the same year. The apparatus consisted of a cylindrical airtight reservoir of 400 hogsheads (c. 95,000 litres) fed by a 10-inch (250 mm) water main which branched to all parts of the theatre. A series of smaller pipes fed from the distribution pipe were pierced with a series of 1⁄2-inch (13 mm) holes which would pour water in the event of a fire.
Frederick Grinnell improved Henry S. Parmalee’s design and in 1881 patented the automatic sprinkler that bears his name. He continued to improve the device and in 1890 invented the glass disc sprinkler, essentially the same as that in use today.
“Until the 1940s, sprinklers were installed almost exclusively for the protection of commercial buildings, whose owners were generally able to recoup their expenses with savings in insurance costs. Over the years, fire sprinklers have become mandatory safety equipment” in some parts of North America, in certain occupancies, including, but not limited to newly constructed “hospitals, schools, hotels and other public buildings”, subject to the local building codes and enforcement. However, outside of the US and Canada, sprinklers have rarely been mandated by building codes for normal hazard occupancies which do not have large numbers of occupants (e.g. factories, process lines, retail outlets, petrol stations, etc.)
Sprinklers are now commonly installed in non-industrial buildings, including schools and residential premises. This is largely as a result of lobbying by the National Fire Sprinkler Network, the European Fire Sprinkler Network, and the British Automatic Fire Sprinkler Association.
The primary fire code writing organization is the private National Fire Protection Association or NFPA. NFPA sets the standards for technical aspects of sprinklers installed in the USA. Building codes, which specify which buildings require sprinklers are generally left to local jurisdictions. However, there are some exceptions:
In 1990 the US passed PL-101-391, better known as the Hotel and Motel Fire Safety Act of 1990. This law requires that any hotel, meeting hall, or similar institution that receives federal funds (i.e. for overnight stay, or a conference, etc.), must meet fire and other safety requirements. The most visible of these conditions is the implementation of sprinklers. As more and more hotels and other public accommodations upgraded their facilities to enable business with government visitors, this type of construction became the de facto industry norm – even when not directly mandated by any local building codes.
If building codes do not explicitly mandate the use of fire sprinklers, the code often makes it highly advantageous to install them as an optional system. Most US building codes allow for less-expensive construction materials, larger floor area limitations, longer egress paths, and fewer requirements for fire-rated construction in structures which are protected by fire sprinklers. Consequently, the total building cost is often decreased by installing a sprinkler system and saving money in the other aspects of the project, as compared to building a non-sprinklered structure.
In 2011, Pennsylvania and California became the first US states to require sprinkler systems in all new residential construction. However, Pennsylvania repealed the law later that same year. Many municipalities now require residential sprinklers, even if they are not required at the state level
n Norway as of July 2010, all new housing of more than two storeys, all new hotels, care homes, and hospitals must be sprinklered. Other Nordic countries require or soon will require sprinklers in new care homes, and in Finland as of 2010 a third of care homes were retrofitted with sprinklers. A fire in an illegal immigrant detention center at Schiphol Airport in the Netherlands on 27 October 2005 killed 11 detainees, and led to the retrofitting of sprinklers in all similarly-designed prisons in the Netherlands. A fire at Düsseldorf Airport on 11 April 1996 which killed 17 people led to sprinklers being retrofitted in all major German airports. Most European countries also require sprinklers in shopping centers, in large warehouses, and in high-rise buildings.
Renewed interest in and support for sprinkler systems in the UK has resulted in sprinkler systems being more widely installed. In schools, for example, the government has issued recommendations through Building Bulletin 100, a design guide for fire safety in schools, that most new schools, except for a few low risk schools, should be constructed with sprinkler protection. In 2011, Wales became the first country in the world where sprinklers are compulsory in all new homes. The law applies to newly built houses and blocks of flats, as well as care homes and university halls of residence. In Scotland, all new schools are sprinklered, as are new care homes, sheltered housing and high rise flats.
In the UK, since the 1990s sprinklers have gained recognition within the Building Regulations (England and Wales) and Scottish Building Standards and under certain circumstances, the presence of sprinkler systems is deemed to provide a form of alternative compliance to some parts of the codes. For example, the presence of a sprinkler system will usually permit doubling of compartment sizes and increases in travel distances (to fire exits) as well as allowing a reduction in the fire rating of internal compartment walls
Each closed-head sprinkler is held closed by either a heat-sensitive glass bulb or a two-part metal link held together with fusible alloy. The glass bulb or link hold in place a pipe cap which acts as a plug to prevent water from flowing, unless the ambient temperature around the sprinkler reaches the design activation temperature of the individual sprinkler head. In a standard wet-pipe sprinkler system, each sprinkler activates independently when the predetermined heat level is reached. Thus, only sprinklers near the heat of the fire will operate, normally just one or two. This maximizes water pressure over the point of fire origin, and minimizes water damage to the building.
A sprinkler activation will usually do less water damage than a fire department hose stream (which provide approximately 900 litres/min (250 US gallons/min). A typical sprinkler used for industrial manufacturing occupancies discharges about 75–150 litres/min (20–40 US gallons/min). However, a typical Early Suppression Fast Response (ESFR) sprinkler at a pressure of 50 psi (340 kPa) will discharge approximately 380 litres per minute (100 US gal/min).
In addition, a sprinkler will usually activate within one to four minutes of the fire’s start, whereas it typically takes at least five minutes for a fire department to register an alarm and drive to the fire site, and an additional ten minutes to set up equipment and apply hose streams to the fire. This additional time can result in a much larger fire, requiring much more water to extinguish.
By a wide margin, wet pipe sprinkler systems are installed more often than all other types of fire sprinkler systems. They also are the most reliable, because they are simple, with the only operating components being the automatic sprinklers and (commonly, but not always) the automatic alarm check valve. An automatic water supply provides water under pressure to the system piping.
Wet systems have been optionally been charged with an antifreeze chemical, for use where pipes cannot reliably be kept above 40 °F (4 °C).
While such systems were once common in cold areas, after several fires which were not controlled because of sprinkler systems filled with too high a percentage of antifreeze, the regulatory authority in the United States effectively banned new antifreeze installations. A sunset date of 2022 applies to older antifreeze systems in the US. This regulatory action has greatly increased costs and reduced options for cold weather tolerant sprinkler systems.
Dry pipe systems are the second most common sprinkler system type. Dry pipe systems are installed in spaces in which the ambient temperature may be cold enough to freeze the water in a wet pipe system, which would make the system inoperable. Dry pipe systems are most often used in unheated buildings, in parking garages, in outside canopies attached to heated buildings (within which a wet pipe system would also be provided)[further explanation needed], or in refrigerated coolers. In regions using NFPA regulations, wet pipe systems cannot be installed unless the range of ambient temperatures remains
Water is not present in the piping until the system operates; instead, the piping is filled with dry air at a pressure below the water supply pressure. To prevent the larger water supply pressure from prematurely forcing water into the piping, the design of the dry pipe valve (a specialized type of check valve) results in a greater force on top of the check valve clapper by the use of a larger valve clapper area exposed to the piping air pressure, as compared to the higher water pressure but smaller clapper surface area.
When one or more of the automatic sprinkler heads is triggered, it opens, allowing the air in the piping to vent from that sprinkler. Each sprinkler operates independently, as its temperature rises above its triggering threshold. As the air pressure in the piping drops, the pressure differential across the dry pipe valve changes, allowing water to enter the piping system. Water flow from sprinklers, needed to control the fire, is delayed until the air is vented from the sprinklers. In regions using NFPA 13 regulations, the time it takes water to reach the hydraulically remote sprinkler from the time that sprinkler is activated is limited to a maximum of 60 seconds. In industry practice, this is known as the “Maximum Time of Water Delivery”. The maximum time of water delivery may be required to be reduced, depending on the hazard classification of the area protected by the sprinkler system.
Some property owners and building occupants may view dry pipe sprinklers as advantageous for protection of valuable collections and other water-sensitive areas. This perceived benefit is due to a fear that wet system piping may slowly leak water without attracting notice, while dry pipe systems should not fail in this manner.
Disadvantages of using dry pipe fire sprinkler systems include:
“Deluge” systems are systems in which all sprinklers connected to the water piping system are open, in that the heat sensing operating element is removed, or specifically designed as such. These systems are used for special hazards where rapid fire spread is a concern, as they provide a simultaneous application of water over the entire hazard. They are sometimes installed in personnel egress paths or building openings to slow travel of fire (e.g. openings in a fire-rated wall).
Water is not present in the piping until the system operates. Because the sprinkler orifices are open, the piping is at atmospheric pressure. To prevent the water supply pressure from forcing water into the piping, a “deluge valve” (a mechanically latched valve) is used in the water supply connection. It is a non-resetting valve, and stays open once tripped.
Because the heat sensing elements normally present in automatic sprinklers have been removed (resulting in open sprinkler heads), the deluge valve is opened via a signal from the fire alarm system which utilizes fire detectors. The type of fire alarm initiating device is selected mainly based on the hazard (e.g. pilot sprinklers, smoke detectors, heat detectors, or optical flame detectors). The initiation device signals the fire alarm panel, which in turn signals the deluge valve to open. Activation can also be via an electric or pneumatic fire alarm pull station which signals the fire alarm panel to signal the deluge valve to open.
Pre-action sprinkler systems are specialized for use in locations where accidental activation is especially undesirable, such as in museums with rare art works, manuscripts, or books; and data centers, for protection of computer equipment from accidental water discharge.
Pre-action systems are hybrids of wet, dry, and deluge systems, depending on the exact system goal. There are two main sub-types of pre-action systems: single interlock, and double interlock.
The operation of single interlock systems are similar to dry systems except that these systems require that a “preceding” fire detection event, typically the activation of a heat or smoke detector takes place prior to the “action” of water introduction into the system’s piping by opening the pre-action valve which is a mechanically latched valve (i.e. similar to a deluge valve). In this way, the system is essentially converted from a dry system into a wet system. The intent is to reduce the undesirable time delay of water delivery to sprinklers that is inherent in dry systems. Prior to fire detection, if the sprinkler operates, or the piping system develops a leak, loss of air pressure in the piping will activate a trouble alarm. In this case, the pre-action valve will not open due to loss of supervisory pressure, and water will not enter the piping.
Double interlock systems require that both a “preceding” fire detection event, typically the activation of a heat or smoke detector, and an automatic sprinkler operation take place prior to the “action” of water introduction into the system’s piping. Activation of either the fire detectors alone,
or sprinklers alone, without the concurrent operation of the other will not allow water to enter the piping. Because water does not enter the piping until a sprinkler operates, double interlock systems are considered as dry systems in terms of water delivery times, and similarly require a larger design area.
Electronic sprinkler systems are systems comprising sprinklers in which the heat sensing operating element is replaced by electronic sensing and electronically triggered actuation. Sprinkler operation is often controlled via an algorithm that determines which sprinklers will operate and when. These systems are often used in scenarios that require fast response and controlled sprinkler operations, such as high-ceiling pallet racking storage with fast-burning commodities or dense storage applications.
A foam water fire sprinkler system is a special application system, discharging a mixture of water and low expansion foam concentrate, resulting in a foam spray from the sprinkler. These systems are usually used with special hazards occupancies associated with high challenge fires, such as flammable liquids, and airport hangars. Operation is as described above, depending on the system type into which the foam is injected.
“Water spray” systems are operationally identical to a deluge system, but the piping and discharge nozzle spray patterns are designed to protect a uniquely configured hazard, usually being three-dimensional components or equipment (i.e. as opposed to a deluge system, which is designed to cover the horizontal floor area of a room). The nozzles used may not be listed fire sprinklers, and are usually selected for a specific spray pattern to conform to the three-dimensional nature of the hazard (e.g. typical spray patterns being oval, fan, full circle, narrow jet). Examples of hazards protected by water spray systems are electrical transformers containing oil for cooling or turbo-generator bearings. Water spray systems can also be used externally on the surfaces of tanks containing flammable liquids or gases (such as hydrogen). Here the water spray is intended to cool the tank and its contents to prevent tank rupture/explosion (BLEVE) and fire spread.
Water mist systems are used for special hazards applications. This type of system is typically used where water damage may be a concern, or where water supplies are limited. NFPA 750 defines water mist as a water spray with a droplet size of “less than 1000 microns at the minimum operation pressure of the discharge nozzle”. The droplet size can be controlled by adjusting the discharge pressure through a nozzle of a fixed orifice size. The fire suppression mechanisms provided by water mist systems include cooling, local flame oxygen reduction, and radiation blocking.
In operation, water mist systems can operate with the same functionality as deluge, wet pipe, dry pipe, or pre-action systems. The difference is that a water mist system uses a compressed gas as an atomizing medium, which is pumped through the sprinkler pipe. Instead of compressed gas, some systems use a high-pressure pump to pressurize the water so it atomizes as it exits the sprinkler nozzle. Systems can be applied using local application method or total flooding method, similar to Clean Agent Fire Protection Systems.