A firefighter or sprinkler head is a component of a fire spraying system that emits water when a fire effect has been detected, such as when a predetermined temperature has been exceeded. Sprinkler fire is widely used around the world, with over 40 million sprinkler heads installed annually. In buildings protected by well-designed fire sprinklers, more than 99% of fires are controlled by flush sprays only.
Video Fire sprinkler
Histori
In 1812, British inventor Sir William Congreve patented a manual sprinkler system using a hollow pipe along the ceiling. When one sees a fire, a valve outside the building can be opened to send water through a pipe. Not long after, as a result of the repeatedly burnt furniture factory, Hiram Stevens Maxim consulted on how to prevent recurrence and find the first automatic fire sprayer. It will extinguish the burning area and report the fire to the fire station. Maxim can not sell ideas elsewhere, even when the patent ends, the idea is used.
Henry S. Parmalee of New Haven, Connecticut invented and installed the first automatic fire sprinkler system in 1874, using a solder that melted in the fire to drain a hole in the sealed water pipe. He is president of Mathusek Piano Works, and creates his sprinkler system in response to a very high insurance rate. Parmalee patented his idea and had great success with him in the US, calling his invention "an automatic fire extinguisher." He then traveled to Europe to demonstrate his method of stopping the building fire before total destruction.
Parmalee's discovery did not get as much attention as he planned, because most people were not able to install sprinkler systems. Once he realized this, he changed his business to educate insurance companies about his system. He explained that the sprinkler system would reduce the ratio of losses, and thus save money for insurance companies. He knew that he would never manage to get a contract from a business owner to install his system unless he could ensure for them a reasonable return in the form of a premium reduction.
In this regard, he is able to attract two people, both of whom have connections in the insurance industry. The first is Major Hesketh, a cotton spinner in big business in Bolton who is also Chairman of the Mutual Insurance Company of Bolton Cotton Trades. The Board of Directors of the Company and its Secretary, Peter Kevan, took an interest in Parmalee's early experiments. Hesketh got his first order Parmalee for a sprinkler installation at a cotton spinning mill from John Stones & amp; The company, at Astley Bridge, Bolton. This was followed shortly afterwards by an order from Alexandra Mills, owned by John Butler from the same city.
Although Parmalee got two sales through his efforts, Mutual Insurance Company Bolton Cotton Trades is not a very large company outside its local area. Parmalee requires a wider influence. He found this influence at James North Lane, Manager of Mutual Fire Insurance Corporation of Manchester. The company was founded in 1870 by the Lancashire and Yorkshire Textile Manufacturers Association in protest against high insurance rates. They have policies to encourage risk management and more specifically the use of the most advanced and scientific tools to extinguish fires. Although he tried and spent a lot of time educating the masses in his sprinkler system, in 1883 only about 10 factories were protected by sprinkler Parmalee.
Back in the US, Frederick Grinnell, who manufactures sprinkler Parmalee, designs a more effective Grinnell sprinkler. He increases the sensitivity by removing the fused joint from all contact with water, and, by placing the valve at the center of the resilient diaphragm, he releases a low-sprayed joint of the water pressure strain. In this way, the valve seat is forced against the valve by water pressure, resulting in a self-closing action. The bigger the water pressure, the tighter the valve. Flexible diaphragms have further and more important functions. This causes the valve and chair to move out simultaneously until the solder joint is completely disconnected. Grinnell got a patent for his version of the sprinkler system. He also brought his invention to Europe, where it was a much greater success than the Parmalee version. Finally, the Parmalee system was withdrawn, paving the way for Grinnell and his invention.
Maps Fire sprinkler
US Rules
The fire sprinkler application and installation guidelines, and overall fire-fighting system design guidelines are provided by the 13F National Fire Protection Association (NFPA) 13, (NFPA) 13D, and (NFPA) 13R.
California, Pennsylvania and Illinois need sprinklers at least in some new residential construction.
The sprinkler may be either an automatic or open pit. Automatic fire sprayers operate at predetermined temperatures, using fusible elements, melted portions, or fragile glass bulbs that contain broken fluid, allowing the plug in the orifice to be pushed out of the hole by water pressure inside the fire. sprinkler pipe, generating water flow from hole. The water flow affects the deflector, which produces a special spray pattern designed to support the purpose of the sprinkler type (ie, control or emphasis). The modern sprinkler head is designed to direct the spray down. Spray nozzles are available to provide sprays in various directions and patterns. The majority of automatic fire sprinklers operate individually in fire. Contrary to motion picture representation, the entire sprinkler system is inactive, unless the system is a special flood type.
Open orifice sprinklers are only used in water spray systems or flood sprinklers. They are identical to the automatic sprinkler in which they are placed, with the heat sensitive operating elements removed.
Automatic fire sprinklers use frangible lights following the standard color coding conventions that indicate their operating temperatures. The activation temperature corresponds to the type of hazard protected by the sprinkler system. Occupancy occupancy is provided with a special quick response sprinkler type with the unique purpose of life safety.
Quick Response Sprinklers
The NFPA standard # 13 was revised in 1996 to require a Quick Response Sprinkler in all buildings with the classification of light hazard occupancy.
The 2002 edition of the NFPA # 13 standard, section 3.6.1 defines a quick response sprinkler as having a response time index (RTI) of 50 (meters-seconds) 1/2 or less. The term quick response refers to a whole list of sprinklers (including distance, density, and location) rather than just a rapidly responding release element. Many standard flush sprinklers, such as the usual long-distance disruption hazard (ECOH), have a rapid response (low thermal mass element) to pass their fire test. Quick response sprinklers are available with standard spray deflectors, but they are also available with expanded coverage deflectors.
Operation
Each closed sprinkler is enclosed with a heat-sensitive bulb (see below) or a two-piece metal link held together with a fused alloy such as Wood metal and other alloys with similar compositions. The light bulb or link applies pressure to the pipe cap that acts as a connector preventing water from flowing until the ambient temperature of the sprinkler reaches the activation temperature of the individual sprayer design. Since each sprinkler is actively independent when the specified heat level is reached, the number of operating sprinklers is limited to those close to fire, thus maximizing the available water pressure above the fire point.
The bulb breaks out as a result of the thermal expansion of the fluid inside the bulb. The time required before the rest of the bulb depends on the temperature. Under the temperature of the design, it does not break, and above the design temperature, breaks down, taking less time to rest as the temperature rises above the design threshold. The response time is expressed as the response time index (RTI), which typically has a value between 35 and 250 m Ã,½ s Ã,½ , where the low value indicates the response fast. Under the standard test procedure (135Ã,  ° C air at a speed of 2.5 m/s), sprinkler spindle bulb 68Ã,  ° C will break within 7 to 33 seconds, depending on RTI. RTI can also be determined in imperial units, where 1Ã, ft Ã,½ s Ã,½ is equivalent to 0.55 m Ã,½ s Ã,½ . The sensitivity of the sprinkler can be negatively affected if the thermal element has been painted.
From Table 6.2.5.1 NFPA13 2007 edition shows the maximum ceiling temperature, nominal operating temperature of sprinkler, color of bulb or link and temperature classification.
Type
There are several types of sprinklers:
- Quick responses
- Standard response
- CMSA (custom application control mode)
- Shelter
- ESFR (early prompt response)
ESFR
ESFR (rapid response to early stress) refers to the concept and type of sprinkler. "The concept is that a quick response from a sprinkler can generate a gain in fire if the response is accompanied by an effective discharge density - sprinkler sprays capable of fighting down a path through a sufficient number of igneous clumps to squeeze burning fuel packets." Sprinkler developed for this concept made for use in high shelf storage.
The ESFR sprinkler head was developed in the 1980s to utilize the latest rapid fire sprinkler technology to provide fire suppression against fire hazards with certain high-specific challenges. Prior to the introduction of these sprinklers, the protection system is designed to control fire until the arrival of the fire department.
Quick responses
The quick response sprinkler heads are usually found in the inhabited buildings, they point the water up to the ceiling thus cooling it to prevent fire from rising.
See also
References
External links
- https://archive.is/20140605201415/http://magazine.sfpe.org/sprinklers/whys-behind-fm-global-data-sheets-2-0-and-8-9 < i> The Whys Behind FM Global Data Sheets 2-0 and 8-9
- https://archive.is/20140612174945/http://magazine.sfpe.org/sprinklers/historical-perspective-evolution-storage-sprinkler-design Historical Perspective on the Evolution of the Flush Sprinkler Design
Source of the article : Wikipedia
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