Fire sprinklers are lifesavers in fire situations. The fire sprinkler in a building helps to reduce the effect of fire outbreaks. Making it possible for residents to escape to safety in time. There are different types of sprinklers for different types of buildings. There are standard response and quick response sprinklers. But what are the differences between these two sprinkler types?
The major difference between the standard response sprinkler and the quick response sprinkler is the time of activation and the manner of sprinkling. The quick response sprinkler activates a bit faster than the standard response sprinkler.
The differences between these two sprinklers are the basis for knowing where each is needed. Read on to find out the peculiarities of these response sprinklers. Where each of them is best suited for and much more information.
What is a Fire Sprinkler
A fire sprinkler is a device that sprinkles water during a fire accident. It is meant to put the fire under check until the arrival of the fire servicemen. The fire sprinkler allows people in a fire-gutted building to escape by reducing the potency of the fire.
There are four basic types of fire sprinklers. The Pendent, Sidewall. Upright and Concealed are the four types. The fire sprinkler system is composed of a water source connected to a sprinkler head. It is the sprinkler head that ejects the water when the fire breaks.
There are two types of sprinkler heads, quick response, and standard response. They are used for specific buildings and situations. The sprinkler heads are majorly made of the same components.
How does the fire sprinkler head work?
The fire sprinkler head is the most active part of the fire sprinkler system. The head is fitted with a sensitive system that activates it at a particular temperature. There are four main parts of a sprinkler head. The first one is the plug or the sealing assembly.
The plug prevents water from coming out of the head until it is activated. The second part is the deflector, which helps in the efficient distribution of water once the sprinkler is activated. The frame is the mechanical part that holds all components together. The final part is the heat-sensitive glass bulb or fusible link.
When there is a fire outbreak, the air temperature increases. This increase in temperature is what the glass bulb or fusible link detects to set off the sprinkling. The glass bulb contains glycerin which expands as the air temperature around it increases.
Once the temperature reaches between 68C and 93C, the glycerin will reach its boiling point. This will cause the tube to break. Consequently, it will release the water to the deflectors which then spreads the water around. The fusible link has a metal component. The metal is attached to the sprinkler via a heat-sensitive alloy.
On the increase of temperature, the alloy melts and releases the metal component. This leads to the release of the water in the bulb. And it is dispersed by the deflector. Modern fire sprinklers are fitted with glass bulb detectors rather than the alloy-metal type. Based on the time of activation, there are two sprinkler heads.
What is a standard response sprinkler?
A standard response sprinkler head works to spray water to the areas surrounding the fire. It takes a little longer to activate than the quick response sprinkler. This type of sprinkler head is best suited for commercial buildings and warehouses.
The sprinkler is not suited for a place that has many people. It focuses on reducing the spread of fire to give time for the firemen. The focus here is to secure the building and its content from being engulfed by the fire.
The glass bulb in the standard response sprinkler is 5 mm in diameter. This is bigger than the bulb in the quick response sprinkler. This increased diameter is accountable for the slight delay in the time of activation of the standard sprinkler.
What is a quick response sprinkler?
This sprinkler head activates faster than the standard response sprinkler. It is majorly used for locations with a high population of people. Places like dormitories, hospitals, schools, and offices.
This works to reduce the fire severity so that people can escape to safety. The sprinkler sprays the upper parts of the building, the ceilings, and the walls precisely. This helps in keeping the severity of the fire effect minimal
The quick response sprinkler specifically works to delay flashovers. Flashover is a chain reaction resulting from the fire. It leads to a shortage of oxygen and extreme heat. This can lead to the death of the occupants of a fire engulfed room. Delaying this allows the people to evacuate in time.
The quick activation of the quick response sprinkler is aided by the diameter of its glass bulb. The glass bulb is 3 mm in diameter. This makes it more sensitive to heat than the standard response sprinkler.
What is the difference between a quick and a standard response sprinkler?
The major distinguishing property between the quick and standard response sprinkler is the time of activation. The quick fire head sprinkler activates at a slightly faster time than standard one. The quick response sprinkler activates at a lower temperature than the standard sprinkler.
Another difference between these two types of fire sprinklers is the diameter of the glass bulb. This difference is also what accounts for the difference in temperature sensitivity of these two sprinklers.The standard response sprinkler has a glass bulb with 5mm diameter while the quick response sprinkler has a 3mm diameter bulb.
Due to the difference in their temperature sensitivity, these two sprinklers are used in different places. Majorly, the quick response sprinkler is used in a light-hazard environment such as schools, offices and others. The standard response sprinkler on the other hand is used for places like warehouses, industrial buildings and stores.
Finally, there is a difference in the mode of operation of these two sprinklers. The quick response sprinkler aims at buying time for people to evacuate the site of the fire outbreak. This is why the sprinkler sprays water high-up the building. It wets the walls and ceilings to reduce the fire severity.
The standard response sprinkler on the other hand works to curb the spread of fire. SInce it is usually in places that do not have a high population of people. The sprinkler targets the fire source and thus sprinkles the lower parts of the building.
In warehouses, standard sprinklers wet cartons and any other material that can be a fuel to the fire. Thereby cutting off the spread of the fire. Below is a table to summarize the differences between a standard and a quick response sprinkler.
Differences between Standard and Quick Response Sprinklers
| Differences | Standard Response Sprinkler | Quick Response Sprinkler |
|---|---|---|
| Time of Activation | Fast | Slightly faster |
| Glass Bulb | 5 mm in diameter | 3 mm in diameter |
| Place of Usage | Warehouses and industrial buildings | Schools, hospitals, hostels, and other places with people |
| Target of sprinkling | Reduce fire spread to save products. | Reduce fire severity to allow for escape of people |
When did quick response sprinklers come out?
The origin of fire sprinklers dates back to 1812. The first one was made by Architect Willian Congreve at the Theatre Royal, Drury Lane, London. It was until 1870 that the first automatic fire sprinkler was made by Philip Pratt.
The automatic sprinkler made by Pratt was modified by two other men. The first was by Henry Parmalee and later worked on by Federick Grinnel all in the 1890s. It was precisely in 1881 that Grineel introduced an upright sprinkler with deflectors. It has an orifice size of 12mm and was able to deflect water to the upper parts of the building.
This was the start of the quick response sprinklers. In the 1950s, standard response sprinklers were made. The design featured a sprinkler deflector that was able to direct the water downwards away from the sprinkler. It featured parabolic spraying of water in what was called the sprinkler’s umbrella pattern.
What is the K-Factor for Sprinklers?
The K-factor of a sprinkler is its discharge coefficient. It is related in simple terms to the amount of water that is let out by the sprinkler. The coefficient is dependent on the orifice diameter of the sprinkler. The bigger the K-factor, the bigger the sprinkler orifice.
A big orifice means there will be more water discharged by the sprinkler under low pressure. The increased water aids in a better effect in reducing the fire spread and severity. The two most common sprinklers have K-factors of 5.6k and 8.0k.
The National Fire Protection Association (NFPA) mandated in NFPA 557 (2020) that buildings with high fire loads must use fire sprinklers with high K-factor. High fire load buildings are defined as those with a large number of combustible materials. Such buildings include warehouses and stores.
Light-hazard environments like schools, hospitals, churches, and apartments need fire sprinklers that produce up to one-tenth of a gallon per minute per square foot. In an ordinary hazard setting, the fire sprinkler must deliver up to two-tenth of a gallon per minute per square foot.
High hazard places such as warehouses require a fire sprinkler with a capacity to deliver up to four-tenth of a gallon per minute per square foot. The more the hazard, the more the water delivery that is expected. This is corresponding to the K-factor of each fire sprinkler.
What are the different Sprinkler bulb temperature ratings?
Modern fire sprinkler heads now feature glass bulbs as the temperature-sensitive component. Different sprinkler heads have glass bulbs of different temperature ratings. This is an advancement to the specificity of sprinkler heads to different environments.
Based on the fire codes and hazard level of a location, a sprinkler head with appropriate temperature sensitivity will be used. The varying temperature ratings of glass bulbs have been organized into a color code. Each color represents a particular temperature range.
These temperature ratings are the boiling points of the glycerin contained in these tubes. At that temperature, the glass bulb breaks to activate the sprinkler. Below is a table that shows the different sprinkler bulb temperature ratings:
| Maximum Ceiling Temperature | Temperature Rating | Temperature Classification | Color Code | Glass Bulb Color | ||
|---|---|---|---|---|---|---|
| F | C | F | C | |||
| 100 | 30 | 135 – 170 | 57 – 77 | Ordinary | Uncolored | Orange/ Red |
| 150 | 66 | 175 – 225 | 79 – 107 | Intermediate | White | Yellow/Green |
| 225 | 107 | 250 – 300 | 121 – 149 | High | Blue | Blue |
| 300 | 149 | 325 – 375 | 163 – 191 | Extra-High | Red | Purple |
| 375 | 191 | 400 – 475 | 204 – 246 | Very extra high | Green | Black |
| 475 | 246 | 500 – 575 | 260 – 302 | Ultra-high | Orange | Black |
| 625 | 329 | 650 | 343 | Ultra-high | Orange | Black |
Source: NFPA 13 (2019 Edition)
Use of a Fire Sprinkler
Originally, fire sprinklers were designed to contain the fire until the fire authority came to extinguish it. In some cases, the fire sprinklers are enough to put out a fire. But in many other cases, the sprinklers buy time for people to evacuate a fire-ridden building or to reduce the spread of fire in a warehouse.
Recently, fire sprinkler systems are integrated with the fire alarm panels. This has resulted in a more rapid response to fire outbreaks. There has also been a great reduction in the amount of property damage and losses due to fire outbreaks with the use of fire sprinklers.
What are the different sprinkler head designs?
The classification of fire sprinkler heads into standard and quick response is based on the time of activation. There are different designs of sprinkler heads irrespective of the response time. Fire sprinkler heads can be grouped based on design as Pendent, Upright sprinkler head, Sidewall Sprinkler head, and Concealed sprinkler head.
Pendent Sprinkler Head
This fire sprinkler features a design where the head hangs from the ceiling. It dispenses water in a conical manner because it has a convex deflector. The head of the pendent sprinkler is visible as against that of a concealed sprinkler after installation.
Pendent fire sprinkler heads have both standard and quick response sprinkler types. This means that they can be used in a wide range of places irrespective of the hazard ratings. This fire sprinkler design comes with different K-factors and orifices.
The most common pendent fire sprinkler head has a K-factor of 5.6 and 12.7mm thread connection. This design of sprinklers has enviable aesthetics. They have escutcheons which are decorative covers or rings. The ring is to cover holes at the point of entry.
Though decorative, the escutcheons aid in the gathering of heat around the sprinkler head. WIthout the decorative ring, the bulb may be delayed in its sensitivity to the rising heat around the sprinkler head. Each pendent sprinkler head has a fitting escutcheon.
Upright Sprinkler Head
This design of fire sprinkler has a concave deflector. The deflector shape makes it spray water in a dome-shaped manner. The Upright sprinkler head is commonly found in open ceiling buildings and warehouses.
Upright fire sprinkler heads are best suited for industrial buildings and dry-pipe systems. These sprinklers usually have K-factors of about 8.0 and up to 19.5 mm thread connection. This shows that they usually deliver a high amount of water when activated.
To allow space for the spray pattern, this sprinkler must be installed in a specific way. Because it is upright, it must be installed with the arm parallel to the water pipe. This will allow it to maintain its upright orientation and for the water to be dispensed in its expected dome-shaped pattern.
Sidewall Sprinkler Head
The sidewall fire sprinkler heads are installed on walls as the name implied. This head is used when there are no ceiling pipes available for the other sprinkler head types. It could also be used due to structural designs that will not allow other installations.
Sidewall heads produce a crescent-shaped sprinkling pattern. This is made possible by their semi-circular deflectors. They are well suited for lobbies, small rooms, hallways and closets. They are used in churches, restaurants, and hotels.
Most sidewall fire sprinkler heads have a K-factor of 5.6 and a 12.7mm thread connection.
Concealed Sprinkler Head
A concealed fire sprinkler head can be anyone of the pendent or sidewall type. This type of sprinkler head is covered with a cover plate. The cover plate is usually with high heat sensitivity. This sensitivity allows it to detach from the sprinkler at about 15-20 degrees below the sprinkler bulb’s temperature rating.
Once the cover detaches, the bulb is able to read the temperature around it efficiently. Most concealed sprinklers have 5.6 K-factor and a 12.7mm thread connection. The fire sprinkler cover plates come in varying colors and shapes.
The concealed sprinklers offer aesthetics with the fire protection. Since they come in different colors and shapes, they can even be ordered with some customization.
In the End
There is no superior type of fire sprinkler. Each type is suitable for a specific place and situation. The choice of sprinkler is dependent on the hazard rating and the need of each building. It is important to understand the place to have each of the types.
A quick response fire sprinkler is best for a place where there are people in numbers. It is good for places like schools, dormitories, hospitals, and offices. The standard response sprinkler on the other hand is suited for warehouses and industrial buildings.
For a place where the priority is to buy time for people to evacuate, a quick response sprinkler is best. When this is not the case, a standard response sprinkler is good.
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