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. [1] [2] [3]
In 1812, British inventor Sir William Congreve patented a manual sprinkler system using perforated pipes along the ceiling. [4] [5] When someone noticed a fire, a valve outside the building could be opened to send water through the pipes. [6] It was not until a short time later that, as a result of a large furniture factory that repeatedly burned down, Hiram Stevens Maxim 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. [7] [8] [ clarification needed ]
In 1872, Thomas J. Martin was awarded a patent for improvement to the fire extinguisher [9] [10] [11] [12] which involved the use of pipes to carry water upwards and valves in the ceiling acting as sprinklers to extinguish fires in buildings. [13] In 1874, Henry S. Parmalee of New Haven, Connecticut, created and installed the first automatic fire sprinkler system, using solder that melted in a fire to unplug holes in the otherwise sealed water pipes. [14] He was the president of Mathusek Piano Works, and invented his sprinkler system in response to exorbitantly high insurance rates. Parmelee patented his idea and had great success with it in the U.S., calling his invention the "automatic fire extinguisher". [15] He then traveled to Europe to demonstrate his method to stop a building fire before total destruction.
Parmelee'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 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 Parmelee's early experiments. Hesketh got Parmelee 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.
Although Parmelee got two sales through its efforts, the Bolton Cotton Trades Mutual Insurance Company was not a very big company outside of its local area. Parmelee needed a wider influence. He found this influence in James North Lane, the manager of the Mutual Fire Insurance Corporation of Manchester. This company was founded in 1870 by the Textile Manufacturers' Associations of Lancashire and Yorkshire 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 Parmelee sprinkler.
Back in the U.S., Frederick Grinnell, who was manufacturing the Parmelee 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. [16] He also took his invention to Europe, where it was a much bigger success than the Parmelee version. Eventually, the Parmelee system was withdrawn, opening the path for Grinnell and his invention. [17]
Fire sprinkler application and installation guidelines, and overall fire sprinkler system design guidelines are provided by the National Fire Protection Association (NFPA) 13, (NFPA) 13D, and (NFPA) 13R and enforced by local jurisdictions.
Certain states, including California, Pennsylvania and Illinois, require sprinklers in at least some new residential construction. [18]
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. [19] [20]
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. 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). [21] [22]
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)1/2 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. [23]
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. [24]
| Quick Response per NFPA 13 RTI < 50 (ms)1/2 | Nominal Diameter in mm | Norbulb Model [25] | Operating Time in Seconds | Response Time Index (RTI) (ms)1/2 |
|---|---|---|---|---|
| Yes | 2.5 | N2.5 | 9 | 25 |
| Yes | 3 | N3 | 11.5 | 33 |
| Yes | 3.3 | N3.3 | 13.5 | 38 |
| No | 5 | NF5 | 23 | 65 |
| No | 5 | N5 | 32 | 90 |
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 such as Wood's metal [26] and other alloys with similar compositions. [27] 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.
The bulb breaks as a result of the thermal expansion of the liquid inside the bulb. [28] 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 m½s½, where a low value indicates a fast response. [29] 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. [30] The RTI can also be specified in imperial units, where 1 ft½s½ is equivalent to 0.55 m½s½. The sensitivity of a sprinkler can be negatively affected if the thermal element has been painted.
| Maximum Ceiling Temperature | Temperature Rating | Temperature Classification | Color Code (with Fusible Link) | Liquid Alcohol in Glass Bulb Color |
|---|---|---|---|---|
| 100 °F / 38 °C | 135-170 °F / 57-77 °C | Ordinary | Uncolored or Black | Orange (135 °F / 57 °C) or Red (155 °F / 68 °C) |
| 150 °F / 66 °C | 175-225 °F / 79-107 °C | Intermediate | White | Yellow (175 °F / 79 °C) or Green (200 °F / 93 °C) |
| 225 °F / 107 °C | 250-300 °F / 121-149 °C | High | Blue | |
| 300 °F / 149 °C | 325-375 °F / 163-191 °C | Extra High | Red | Purple |
| 375 °F / 191 °C | 400-475 °F / 204-246 °C | Very Extra High | Green | Black |
| 475 °F / 246 °C | 500-575 °F / 260-302 °C | Ultra High | Orange | |
| 625 °F / 329 °C | 650 °F / 343 °C | |||
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.
There are several types of sprinklers: [31]
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." [32] 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 hazards. Prior to the introduction of these sprinklers, protection systems were designed to control fires until the arrival of the fire department.
A fire sprinkler system is an active fire protection method, consisting of a water supply system providing adequate pressure and flowrate to a water distribution piping system, to which fire sprinklers are connected. Although initially used only in factories and large commercial buildings, systems for homes and small buildings are now available at a cost-effective price.
The National Fire Protection Association (NFPA) is a U.S.-based international nonprofit organization devoted to eliminating death, injury, property, and economic loss due to fire, electrical, and related hazards. As of 2023, the NFPA claims to have 50,000 members and 9,000 volunteers working with the organization through its 250 technical committees.
Fire safety is the set of practices intended to reduce 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 spread and impact of a fire.
This is a glossary of firefighting equipment.
SimplexGrinnell, a subsidiary of Johnson Controls, is an American company specializing in active fire protection systems, communication systems and testing, inspection and maintenance services. The company headquarters is in Boca Raton, Florida; corporate sales and marketing offices are in Westminster, Massachusetts, and the company has about 160 district offices throughout North America. It is currently the largest fire protection company in the world.
A fire pump usually refers to a pressure-increasing component of the water supply for fixed-place fire suppression systems such as fire sprinklers, standpipes, and foam systems. Fire pumps are also a critical component integrated into fire trucks and fire boats, and serve a similar purpose boosting water supplies for firefighting hose operations.
A heat detector is a fire alarm device designed to respond when the convected thermal energy of a fire increases the temperature of a heat sensitive element. The thermal mass and conductivity of the element regulate the rate flow of heat into the element. All heat detectors have this thermal lag. Heat detectors have two main classifications of operation, "rate-of-rise" and "fixed temperature". The heat detector is used to help in the reduction of property damage.
Fire protection is the study and practice of mitigating the unwanted effects of potentially destructive fires. It involves the study of the behaviour, compartmentalisation, suppression and investigation of fire and its related emergencies, as well as the research and development, production, testing and application of mitigating systems. In structures, be they land-based, offshore or even ships, the owners and operators are responsible to maintain their facilities in accordance with a design-basis that is rooted in laws, including the local building code and fire code, which are enforced by the authority having jurisdiction.
Fire suppression systems are used to extinguish, control, or in some cases, entirely prevent fires from spreading or occurring. Fire suppression systems have an incredibly large variety of applications, and as such, there are many different types of suppression systems for different applications being used today. Of these, there are some that are still in use but are no longer legal to manufacture and produce.
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.
A fire class is a system of categorizing fire with regard to the type of material and fuel for combustion. Class letters are often assigned to the different types of fire, but these differ between territories; there are separate standards for the United States, Europe (DIN EN2 Classification of fires ISO3941 Classification of fires, and Australia. The fire class is used to determine the types of extinguishing agents that can be used for that category.
A thermal cutoff is an electrical safety device that interrupts electric current when heated to a specific temperature. These devices may be for one-time use, or may be reset manually or automatically.
A thermal expansion valve or thermostatic expansion valve is a component in vapor-compression refrigeration and air conditioning systems that controls the amount of refrigerant released into the evaporator and is intended to regulate the superheat of the refrigerant that flows out of the evaporator to a steady value. Although often described as a "thermostatic" valve, an expansion valve is not able to regulate the evaporator's temperature to a precise value. The evaporator's temperature will vary only with the evaporating pressure, which will have to be regulated through other means.
Frederick Grinnell was a pioneer in fire safety and was the creator of the first practical automatic fire sprinkler.
Heat and smoke vents are installed in buildings as an active fire protection measure. They are openings in the roof which are intended to vent the heat and smoke developed by a fire inside the building by the action of buoyancy, such that they are known as "gravity vents".
A fire extinguisher is a handheld active fire protection device usually filled with a dry or wet chemical used to extinguish or control small fires, often in emergencies. It is not intended for use on an out-of-control fire, such as one which has reached the ceiling, endangers the user, or otherwise requires the equipment, personnel, resources or expertise of a fire brigade. Typically, a fire extinguisher consists of a hand-held cylindrical pressure vessel containing an agent that can be discharged to extinguish a fire. Fire extinguishers manufactured with non-cylindrical pressure vessels also exist, but are less common.
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 extinguished in the early stages loss of life is minimal since 93% of all fire-related deaths occur once the fire has progressed beyond the early stages.
Sprinkler fitting is a skilled trade that consists of assembling, installing, testing, repairing, inspecting, and certifying automatic fire suppression systems and their associated piping in commercial, industrial and residential buildings.
Water transportation and distribution networks require hydraulic calculations to determination the flowrate and pressure characteristics at one or several consumption points and the water supply flowrate and pressures needed to meet the design requirements.
Grinnell Mechanical Products, a brand of Tyco International Ltd., manufactures grooved piping and mechanical products. Grinnell Mechanical Products specializes in mechanical, fire, HVAC, commercial, mining, institutional and industrial applications. Grinnell grooved products are used in various industries because they are historically more efficient than flanged, welded, and threaded pipe joining methods. Key product lines include grooved couplings and fittings, G-PRESS systems, strainers, stainless steel systems, copper systems, and G-MINE PVC systems. Grinnell Mechanical Products offers mechanical services used for supporting engineering and design. These include 2D and 3D drawings for the mechanical room and design suggestions and easy to follow installation drawings with legends for each pump.
