![Fire sprinkler roof mount side view](https://upload.wikimedia.org/wikipedia/commons/7/76/Fire_sprinkler_roof_mount_side_view.jpg)
A fire sprinkler or sprinkler head is the component of a
fire sprinkler system that discharges water when the effects of a fire have been detected, such as when a predetermined temperature has been exceeded. Fire sprinklers are extensively used worldwide, with over 40 million sprinkler heads fitted each year. In buildings protected by properly designed and maintained fire sprinklers, over 99% of fires were controlled by fire sprinklers alone.
History
In 1812, British inventor
Sir William Congreve
Lieutenant General Sir William Congreve, 1st Baronet (4 July 1742 – 30 April 1814) was a British military officer who improved artillery strength through gunpowder experiments.
Personal life
William Congreve was born in Stafford on 4 July 1 ...
patented a manual sprinkler system using perforated pipes along the ceiling. When someone noticed a fire, a valve outside the building could be opened to send water through the pipes. It was not until a short time later that, as a result of a large furniture factory that repeatedly burned down,
Hiram Stevens Maxim
Sir Hiram Stevens Maxim (5 February 1840 – 24 November 1916) was an American- British inventor
An invention is a unique or novel device, method, composition, idea or process. An invention may be an improvement upon a machine, product, ...
was consulted on how to prevent a recurrence and invented the first automatic fire sprinkler. It would douse the areas that were on fire and report the fire to the fire station. Maxim was unable to sell the idea elsewhere, though when the patent expired, the idea was used.
Henry S. Parmalee of
New Haven, Connecticut
New Haven is a city in the U.S. state of Connecticut. It is located on New Haven Harbor on the northern shore of Long Island Sound in New Haven County, Connecticut and is part of the New York City metropolitan area. With a population of 134,02 ...
created and installed the first automatic
fire sprinkler system in 1874, using
solder
Solder (; NA: ) is a fusible metal alloy used to create a permanent bond between metal workpieces. Solder is melted in order to wet the parts of the joint, where it adheres to and connects the pieces after cooling. Metals or alloys suitable ...
that melted in a fire to unplug holes in the otherwise sealed water pipes. He was the president of Mathusek Piano Works, and invented his sprinkler system in response to exorbitantly high insurance rates. Parmalee patented his idea and had great success with it in the U.S., calling his invention the "automatic fire extinguisher". He then traveled to Europe to demonstrate his method to stop a building fire before total destruction.
Parmalee's invention did not get as much attention as he had planned, as most people could not afford to install a sprinkler system. Once he realized this, he turned his efforts to educating insurance companies about his system. He explained that the sprinkler system would reduce the loss ratio, and thus save money for the insurance companies. He knew that he could never succeed in obtaining contracts from the business owners to install his system unless he could ensure for them a reasonable return in the form of reduced premiums.
In this connection, he was able to enlist the interest of two men, who both had connections in the insurance industry. The first of was Major Hesketh, a cotton spinner in a large business in
Bolton
Bolton (, locally ) is a large town in Greater Manchester in North West England, formerly a part of Lancashire. A former mill town, Bolton has been a production centre for textiles since Flemish people, Flemish weavers settled in the area i ...
who was also chairman of the Bolton Cotton Trades Mutual Insurance Company. The directors of this company and its secretary, Peter Kevan, took an interest in Parmalee's early experiments. Hesketh got Parmalee his first order for sprinkler installations in the cotton spinning mills of John Stones & Company, at Astley Bridge, Bolton. This was followed soon afterwards by an order from the Alexandra Mills, owned by John Butler of the same town.
![Grinnell automatic sprinkler advertisement](https://upload.wikimedia.org/wikipedia/commons/6/6f/Grinnell_automatic_sprinkler_advertisement.png)
Although Parmalee got two sales through its efforts, the Bolton Cotton Trades Mutual Insurance Company was not a very big company outside of its local area. Parmalee needed a wider influence. He found this influence in James North Lane, the manager of the Mutual Fire Insurance Corporation of
Manchester
Manchester () is a city in Greater Manchester, England. It had a population of 552,000 in 2021. It is bordered by the Cheshire Plain to the south, the Pennines to the north and east, and the neighbouring city of Salford to the west. The t ...
. This company was founded in 1870 by the Textile Manufacturers' Associations of
Lancashire
Lancashire ( , ; abbreviated Lancs) is the name of a historic county, ceremonial county, and non-metropolitan county in North West England. The boundaries of these three areas differ significantly.
The non-metropolitan county of Lancashi ...
and
Yorkshire
Yorkshire ( ; abbreviated Yorks), formally known as the County of York, is a Historic counties of England, historic county in northern England and by far the largest in the United Kingdom. Because of its large area in comparison with other Eng ...
as a protest against high insurance rates. They had a policy of encouraging risk management and more particularly the use of the most up-to-date and scientific apparatus for extinguishing fires. Even though he put tremendous effort and time into educating the masses on his sprinkler system, by 1883 only about 10 factories were protected by the Parmalee sprinkler.
Back in the U.S.,
Frederick Grinnell
Frederick Grinnell (August 14, 1836 – October 21, 1905) was a pioneer in fire safety and was the creator of the first practical automatic fire sprinkler.
Early life and education
He was born in New Bedford, Massachusetts. In 1855, he graduated ...
, who was manufacturing the Parmalee sprinkler, designed the more effective Grinnell sprinkler. He increased sensitivity by removing the fusible joint from all contact with the water, and, by seating a valve in the center of a flexible
diaphragm, he relieved the low-fusing soldered joint of the strain of water pressure. By this means, the valve seat was forced against the valve by the water pressure, producing a self-closing action. The greater the water pressure, the tighter the valve. The flexible diaphragm had a further and more important function. It caused the valve and its seat to move outwards simultaneously until the solder joint was completely severed. Grinnell got a patent for his version of the sprinkler system. He also took his invention to Europe, where it was a much bigger success than the Parmalee version. Eventually, the Parmalee system was withdrawn, opening the path for Grinnell and his invention.
US regulations
Fire sprinkler application and installation guidelines, and overall fire sprinkler system design guidelines are provided by the
National Fire Protection Association
The National Fire Protection Association (NFPA) is an international nonprofit organization devoted to eliminating death, injury, property and economic loss due to fire, electrical and related hazards. As of 2018, the NFPA claims to have 50,000 mem ...
(NFPA) 13, (NFPA) 13D, and (NFPA) 13R and enforced by local jurisdictions.
Certain states, including
California
California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...
,
Pennsylvania
Pennsylvania (; ( Pennsylvania Dutch: )), officially the Commonwealth of Pennsylvania, is a state spanning the Mid-Atlantic, Northeastern, Appalachian, and Great Lakes regions of the United States. It borders Delaware to its southeast, ...
and
Illinois
Illinois ( ) is a U.S. state, state in the Midwestern United States, Midwestern United States. Its largest metropolitan areas include the Chicago metropolitan area, and the Metro East section, of Greater St. Louis. Other smaller metropolita ...
require sprinklers in at least some new residential construction.
Fire sprinklers can be automatic or open orifice. Automatic fire sprinklers use a fusible element that activates at a predetermined temperature. The fusible element either melts or has a frangible liquid-containing glass bulb that breaks, causing the water pressure in the fire sprinkler piping to push a plug out of the sprinkler orifice, resulting in water spraying from the orifice. The water stream strikes a deflector that forms the water into a spray pattern designed in support of the goals of the sprinkler type (i.e., control or suppression). Modern sprinkler heads are designed to direct spray downwards. Spray nozzles are available to provide spray in various directions and patterns. The majority of automatic fire sprinklers operate individually in a fire. Contrary to motion picture representation, the entire sprinkler system does not activate at the same time, unless the system is a special deluge type.
Open orifice sprinklers are only used in water spray systems or deluge sprinklers systems. They are identical to the automatic sprinkler on which they are based, with the heat-sensitive operating element removed.
Automatic fire sprinklers utilizing frangible bulbs follow a standardized color-coding convention indicating their
operating temperature
An operating temperature is the allowable temperature range of the local ambient environment at which an electrical or mechanical device operates. The device will operate effectively within a specified temperature range which varies based on the de ...
. Activation temperatures correspond to the type of hazard against which the sprinkler system protects. Residential occupancies are provided with a special type of fast response sprinkler with the unique goal of life safety (a residential sprinkler has a higher discharge pattern than that of a standard spray sprinkler and they also have been specifically developed for discharging water higher on the walls in order to keep ceiling gas temperatures lower).
Quick Response Sprinklers
The 2002 edition of the NFPA #13 standard, section 3.6.1 defines quick response sprinklers as having a response time index (RTI) of 50 (meter-seconds) or less. RTI is a measure of how thermally responsive the heat-responsive element of the sprinkler is, measured as the time needed to raise the temperature of the sprinkler bulb to 63% of the temperature of the hot air stream times the square root of the velocity of the air stream.
The term quick response refers to the listing of the entire sprinkler (including spacing, density and location) not just the fast responding releasing element. Many standard response sprinklers, such as extended coverage ordinary hazard (ECOH) sprinklers, have fast responding (low thermal mass elements) in order to pass their fire tests. Quick response sprinklers are available with standard spray deflectors, but they are also available with extended coverage deflectors.
Operation
![TYCO-Standard-Spray-Sprinkler-head-141-degree-celsius-01](https://upload.wikimedia.org/wikipedia/commons/b/b5/TYCO-Standard-Spray-Sprinkler-head-141-degree-celsius-01.jpg)
Each closed-head sprinkler is held closed by either a heat-sensitive glass bulb (see below) or a two-part metal link held together with a
fusible alloy A fusible alloy is a metal alloy capable of being easily fused, i.e. easily meltable, at relatively low temperatures. Fusible alloys are commonly, but not necessarily, eutectic alloys.
Sometimes the term "fusible alloy" is used to describe alloys ...
such as
Wood's metal
Wood's metal, also known as Lipowitz's alloy or by the commercial names Cerrobend, Bendalloy, Pewtalloy and MCP 158, is a metal alloy that is useful for soldering and making custom metal parts, but which is toxic to touch or breathe vapors from. ...
and other alloys with similar compositions. The glass bulb or link applies pressure to a pipe cap which acts as a plug which prevents water from flowing until the ambient temperature around the sprinkler reaches the design activation temperature of the individual sprinkler. Because each sprinkler activates independently when the predetermined heat level is reached, the number of sprinklers that operate is limited to only those near the fire, thereby maximizing the available water pressure over the point of fire origin.
![Sprinkler ampuller temp](https://upload.wikimedia.org/wikipedia/commons/4/47/Sprinkler_ampuller_temp.jpg)
The bulb breaks as a result of the
thermal expansion
Thermal expansion is the tendency of matter to change its shape, area, volume, and density in response to a change in temperature, usually not including phase transitions.
Temperature is a monotonic function of the average molecular kinetic ...
of the liquid inside the bulb. The time it takes before a bulb breaks is dependent on the temperature. Below the design temperature, it does not break, and above the design temperature, it breaks, taking less time to break as temperature increases above the design threshold. The response time is expressed as a response time index (RTI), which typically has values between 35 and 250 m
½s
½, where a low value indicates a fast response. Under standard testing procedures (135 °C air at a velocity of 2.5 m/s), a 68 °C sprinkler bulb will break within 7 to 33 seconds, depending on the RTI. The RTI can also be specified in imperial units, where 1 ft
½s
½ is equivalent to 0.55
m
½s
½. The sensitivity of a sprinkler can be negatively affected if the thermal element has been painted.
From Table 6.2.5.1
NFPA13 2007 Edition indicates the maximum ceiling temperature, nominal operating temperature of the sprinkler, color of the bulb or link and the temperature classification.
Types
There are several types of sprinklers:
* Quick response
* Standard response
* CMSA (control mode specific application)
* Residential
* ESFR (early suppression fast response)
ESFR
ESFR (early suppression fast response) refers to both a concept and a type of sprinkler. "The concept is that fast response of sprinklers can produce an advantage in a fire if the response is accompanied by an effective discharge density — that is, a sprinkler spray capable of fighting its way down through the fire plume in sufficient quantities to suppress the burning fuel package."
The sprinkler that was developed for this concept was created for use in high rack storage.
ESFR sprinkler heads were developed in the 1980s to take advantage of the latest fast-response fire sprinkler technology to provide fire suppression of specific high-challenge
fire hazard
Fire safety is the set of practices intended to reduce the destruction caused by fire. Fire safety measures include those that are intended to prevent the ignition of an uncontrolled fire and those that are used to limit the development and ef ...
s. Prior to the introduction of these sprinklers, protection systems were designed to control fires until the arrival of the
fire department.
See also
*
Active fire protection
Active fire protection (AFP) is an integral part of fire protection. AFP is characterized by items and/or systems, which require a certain amount of motion and response in order to work, contrary to passive fire protection.
Categories of active fi ...
*
Automatic fire suppression
Automatic fire suppression systems control and extinguish fires without human intervention. Examples of automatic systems include fire sprinkler system, gaseous fire suppression, and condensed aerosol fire suppression. When fires are extinguishe ...
*
Building code
A building code (also building control or building regulations) is a set of rules that specify the standards for constructed objects such as buildings and non-building structures. Buildings must conform to the code to obtain planning permiss ...
*
Fire Safety Evaluation System
*
Hydraulic calculation
*
K-factor (fire protection) In fire protection engineering, the K-factor formula is used to calculate the volumetric flow rate rate from a nozzle. Spray nozzles can for example be fire sprinklers or water mist nozzles, hose reel nozzles, water monitors and deluge fire system ...
*
Piping
Within industry, piping is a system of pipes used to convey fluids (liquids and gases) from one location to another. The engineering discipline of piping design studies the efficient transport of fluid.
Industrial process piping (and accompan ...
*
Tyco International
Tyco International plc was a security systems company incorporated in the Republic of Ireland, with operational headquarters in Princeton, New Jersey, United States (Tyco International (US) Inc.). Tyco International was composed of two major b ...
*
Victaulic
Victaulic is a developer and manufacturer of mechanical pipe joining systems, and the originator of the grooved pipe couplings joining system. The firm is a global company with 15 major manufacturing facilities, 28 branches, and over 3600 emplo ...
References
External links
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{{Fire protection
Firefighting equipment
Fire suppression
Active fire protection
American inventions