Automatic fire sprinklers, systems and methods for suppression fire protection of high hazard commodities including commodities stored in rack arrangements beneath ceilings of up to fifty-five feet in height

Abstract

System and methods to provide ceiling-only suppression fire protection of up to fifty feet (50 ft.) of rack storage of cartoned unexpanded plastic commodities and less hazardous commodities, such as for example, Class 1, Class 2, Class 3, Class 4 and/or combinations thereof beneath a ceiling having a maximum ceiling height up to fifty-five feet (55 ft.).

Claims

1. A ceiling-only storage occupancy fire protection system comprises: a grid of pendent fire protection sprinklers defining a sprinkler-to-sprinkler spacing ranging from eight feet to ten feet (8 ft.-10 ft.), each pendent sprinkler being a quick response storage sprinkler, each sprinkler including: a sprinkler body having an inlet and an outlet with a passageway disposed therebetween along a sprinkler axis and a nominal K-factor of 22.4 [GPM/(psi).sup.1/2] to 36.4 [GPM/(psi).sup.1/2]; a closure assembly including a plug; a thermally responsive trigger assembly to support the closure assembly adjacent the outlet of the sprinkler body, the trigger assembly having a temperature rating in the range of 155° F. to 210° F.; and a deflector coupled to the body and spaced from the outlet; and a network of pipes including at least one main pipe and a plurality of spaced apart branch lines interconnecting and locating the grid of pendent sprinklers beneath a ceiling having a ceiling height greater than 35 feet, the network of pipes being filled with a firefighting fluid and locating the grid of sprinklers relative to a source of the firefighting fluid in which a number of hydraulically most remote sprinklers in the grid of sprinklers define a hydraulic design area of the system, the network of pipes delivering to each sprinkler in the hydraulic design area at least a minimum flowing pressure upon sprinkler actuation in order to provide suppression protection of at least one commodity consisting of one of Class 1, Class 2, Class 3, Class 4 and cartoned unexpanded plastic commodities and combinations thereof, stored beneath the ceiling, the at least one commodity having a maximum storage height, the storage consists of a configuration of rack storage, the rack storage being any one of single-row, double-row, and multi-row rack storage; wherein the number of hydraulically most remote sprinklers defining the hydraulic design area consists of nine or ten (9 or 10) and the ceiling has a maximum ceiling height of up to fifty-five feet (55 ft.) and the at least one commodity has a maximum storage height of up to fifty feet (50 ft.); wherein the hydraulically most remote sprinklers defining the hydraulic design area consists of a plurality of groups of sprinklers, each group being on a separate branch line of four or less of the plurality of spaced apart branch lines, at least one group of the plurality of groups of sprinklers having a number of hydraulically most remote sprinklers unequal to a number of hydraulically most remote sprinklers of the other groups of the plurality of groups of sprinklers.

2. The ceiling-only storage occupancy fire protection system of claim 1, wherein the thermally responsive trigger assembly of each sprinkler includes a strut lever arrangement with a fusible link, and wherein the fusible links of the sprinklers have a consistent operability.

3. A method of providing a ceiling-only storage occupancy fire protection system, the method comprising: installing a grid of pendent sprinklers in a network of pipes, the network of pipes including at least one main pipe and a plurality of spaced apart branch lines, the sprinklers defining a sprinkler-to-sprinkler spacing ranging from eight feet to ten feet (8 ft.-10 ft.) within two feet of a ceiling, each sprinkler including: a sprinkler body having an orifice with an inlet and an outlet with a passageway disposed therebetween along a sprinkler axis, the orifice defining a nominal K-factor of 22.4 [GPM/(psi).sup.1/2] to 36.4 [GPM/(psi).sup.1/2], a closure assembly including a plug; a thermally rated trigger assembly to support the closure assembly adjacent the outlet of the sprinkler body, the trigger assembly having a temperature rating in the range of 155° F. to 210° F., and a deflector coupled to the body and spaced from the outlet; and coupling the network of pipes to a source of a firefighting fluid in which hydraulically remote sprinklers in the grid of sprinklers define a hydraulic design area of the system, the network of pipes configured to supply to the hydraulic design area a minimum flow of less than 2500 gallons per minute (GPM) upon sprinkler actuation to provide suppression protection of at least one commodity consisting of any one of Class 1, Class 2, Class 3, Class 4 and cartoned unexpanded plastic commodities and combinations thereof stored beneath the ceiling having a ceiling height greater than 35 feet, the at least one commodity having a maximum storage height, the storage consisting of a configuration of rack storage, the rack storage being any one of single-row, double-row, and multi-row rack storage, and the ceiling has a maximum ceiling height of up to fifty-five feet (55 ft.) and the storage commodity has a maximum storage height of fifty feet (50 ft.); wherein the number of hydraulically remote sprinklers defining the hydraulic design area consists of nine or ten (9 or 10); and wherein the hydraulically most remote sprinklers defining the hydraulic design area consists of a plurality of groups of sprinklers, each group being on a separate branch line of four or less of the plurality of spaced apart branch lines, at least one group of the plurality of groups of sprinklers having a number of hydraulically most remote sprinklers unequal to a number of hydraulically most remote sprinklers of the other groups of the plurality of groups of sprinklers.

4. The ceiling-only storage occupancy fire protection system of claim 1, wherein the hydraulically most remote sprinklers defining the hydraulic design area comprise a first group of sprinklers on a first branch line, a second group of sprinklers on a second branch line, a third group of sprinklers on a third branch line, and a fourth group of sprinklers on a fourth branch line, the first, second, third, and fourth branch lines being separate branch lines of the plurality of spaced apart branch lines.

5. The ceiling-only storage occupancy fire protection system of claim 4, wherein the hydraulically most remote sprinklers defining the hydraulic design area comprise at least the first group of sprinklers consisting of three sprinklers on the first branch line, the second group of sprinklers consisting of three sprinklers on the second branch line, the third group of sprinklers consisting of three sprinklers on the third branch line.

6. The ceiling-only storage occupancy fire protection system of claim 5, wherein the number of hydraulically most remote sprinklers defining the hydraulic design area is ten (10); and wherein the first group of sprinklers consists of the three sprinklers on the first branch line, the second group of sprinklers consists of the three sprinklers on the second branch line, the third group of sprinklers consists of the three sprinklers on the third branch line, and the fourth group of sprinklers consists of one sprinkler on the fourth branch line.

7. The ceiling-only storage occupancy fire protection system of claim 6, wherein the nominal K-factor comprises 22.4 [GPM/(psi).sup.1/2], and the network of pipes is configured to supply to each sprinkler in the hydraulic design area with a minimum flowing pressure of sixty-three pounds per square inch (63 psi.).

8. The ceiling-only storage occupancy fire protection system of claim 7, wherein the deflector of each sprinkler in the grid of pendent quick response storage sprinklers is located up to fourteen inches (14″) below the ceiling and wherein the rack storage has an aisle width that ranges from 4-8 ft.

9. The ceiling-only storage occupancy fire protection system of claim 6, wherein the nominal K-factor comprises 25.2 [GPM/(psi).sup.1/2], and the network of pipes is configured to supply to each sprinkler in the hydraulic design area with a minimum flowing pressure of fifty pounds per square inch (50 psi.).

10. A ceiling-only storage occupancy fire protection system of claim 9, wherein the deflector of each sprinkler in the grid of pendent quick response storage sprinklers is located up to fourteen inches (14″) below the ceiling and wherein the rack storage has an aisle width that ranges from 4-8 ft.

11. The ceiling-only storage occupancy fire protection system of claim 6, wherein the nominal K-factor comprises 25.2 [GPM/(psi).sup.1/2], and the network of pipes is configured to supply to each sprinkler in the hydraulic design area with a minimum flowing pressure of fifty pounds per square inch (50 psi.).

12. The ceiling-only storage occupancy fire protection system of claim 11, wherein the deflector of each sprinkler in the grid of pendent quick response storage sprinklers is located up to eighteen inches (18″) below the ceiling and wherein the rack storage has an aisle width that ranges from 4-8 ft.

13. The ceiling-only storage occupancy fire protection system of claim 6, wherein the nominal K-factor comprises 28.0 [GPM/(psi).sup.1/2], and the network of pipes is configured to supply to each sprinkler in the hydraulic design area with a minimum flowing pressure of forty pounds per square inch (40 psi.).

14. The ceiling-only storage occupancy fire protection system of claim 13, wherein the deflector of each sprinkler in the grid of pendent quick response storage sprinklers is located up to fourteen inches (14″) below the ceiling and wherein the rack storage has an aisle width that ranges from 4-8 ft.

15. The ceiling-only storage occupancy fire protection system of claim 1, wherein the hydraulically most remote sprinklers defining the hydraulic design area comprise a first group of sprinklers on a first branch line, a second group of sprinklers on a second branch line, and a third group of sprinklers on a third branch line, the first, second, and third branch lines being separate branch lines of the plurality of spaced apart branch lines.

16. The ceiling-only storage occupancy fire protection system of claim 15, wherein the hydraulically most remote sprinklers defining the hydraulic design area comprise at least the first group of sprinklers consisting of four sprinklers on the first branch line and the second group of sprinklers consisting of four sprinklers on the second branch line.

17. A ceiling-only storage occupancy fire protection system of claim 16, wherein the number of hydraulically most remote sprinklers defining the hydraulic design area is ten (10); and wherein the first group of sprinklers consists of the four sprinklers on the first branch line, the second group of sprinklers consists of the four sprinklers on the second branch line, and the third group sprinklers consists of two sprinklers on the third branch line.

18. A ceiling-only storage occupancy fire protection system of claim 17, wherein the nominal K-factor comprises 22.4 [GPM/(psi).sup.1/2], and the network of pipes is configured to supply to each sprinkler in the hydraulic design area with a minimum flowing pressure of sixty-three pounds per square inch (63 psi.).

19. A ceiling-only storage occupancy fire protection system of claim 18, wherein the deflector of each sprinkler in the grid of pendent quick response storage sprinklers is located up to fourteen inches (14″) below the ceiling and wherein the rack storage has an aisle width that ranges from 4-8 ft.

20. A ceiling-only storage occupancy fire protection system of claim 17, wherein the nominal K-factor comprises 25.2 [GPM/(psi).sup.1/2], and the network of pipes is configured to supply to each sprinkler in the hydraulic design area with a minimum flowing pressure of fifty pounds per square inch (50 psi.).

21. A ceiling-only storage occupancy fire protection system of claim 20, wherein the deflector of each sprinkler in the grid of pendent quick response storage sprinklers is located up to fourteen inches (14″) below the ceiling and wherein the rack storage has an aisle width that ranges from 4-8 ft.

22. A ceiling-only storage occupancy fire protection system of claim 17, wherein the nominal K-factor comprises 25.2 [GPM/(psi).sup.1/2], and the network of pipes is configured to supply to each sprinkler in the hydraulic design area with a minimum flowing pressure of fifty pounds per square inch (50 psi.).

23. A ceiling-only storage occupancy fire protection system of claim 22, wherein the deflector of each sprinkler in the grid of pendent quick response storage sprinklers is located up to eighteen inches (18″) below the ceiling and wherein the rack storage has an aisle width that ranges from 4-8 ft.

24. A ceiling-only storage occupancy fire protection system of claim 17, wherein the nominal K-factor comprises 28.0 [GPM/(psi).sup.1/2], and the connecting the network of pipes is configured to supply to each sprinkler in the hydraulic design area with a minimum flowing pressure of forty pounds per square inch (40 psi).

25. A ceiling-only storage occupancy fire protection system of claim 24, wherein the deflector of each sprinkler in the grid of pendent quick response storage sprinklers is located up to fourteen inches (14″) below the ceiling and wherein the rack storage has an aisle width that ranges from 4-8 ft.

26. A ceiling-only storage occupancy fire protection system of claim 16, wherein the number of hydraulically most remote sprinklers defining the hydraulic design area is nine (9), and wherein the first group of sprinklers consists of the four sprinklers on the first branch line, the second group of sprinklers consists of the four sprinklers on the second branch line, and the third group of sprinklers consists of one sprinkler on the third branch line.

27. A method of supplying a ceiling-only storage occupancy fire protection system, the method comprising: obtaining a plurality of pendent sprinklers, each sprinkler including: a sprinkler body having an orifice with an inlet and an outlet with a passageway disposed therebetween along a sprinkler axis, the orifice defining a nominal K-factor in a range of 22.4 [GPM/(psi).sup.1/2] to 36.4 [GPM/(psi).sup.1/2], a closure assembly including a plug; a thermally rated trigger assembly to support the closure assembly adjacent the outlet of the sprinkler body, the trigger assembly having a temperature rating in a range of 155° F. to 210° F., and a deflector coupled to the body and spaced from the outlet; and providing the plurality of sprinklers for installation in a grid of sprinklers located relative to a source of firefighting fluid via a network of pipes, the network of pipes including at least one main and a plurality of spaced apart branch lines, in which hydraulically remote sprinklers in the grid of sprinklers define a hydraulic design area of the system consist of nine (9) or ten (10) sprinklers with each sprinkler in the grid of sprinklers being provided with at least a minimum flowing pressure upon sprinkler actuation to provide suppression fire protection of high-piled storage including at least one commodity consisting of one of Class 1, Class 2, Class 3, Class 4 and cartoned unexpanded plastic and combinations thereof stored beneath a ceiling having a ceiling height greater than 35 feet, the at least one commodity having a maximum storage height, the storage consists of a configuration of at least rack storage, the rack storage being any one of single-row, double-row, and multi-row rack storage; wherein the ceiling has a maximum ceiling height of up to fifty-five feet (55 ft.) and the at least one commodity has a maximum storage height of up to fifty feet (50 ft.); and wherein the hydraulically most remote sprinklers defining the hydraulic design area consists of a plurality of groups of sprinklers, each group being on a separate branch line of four or less of the plurality of spaced apart branch lines, at least one group of the plurality of groups of sprinklers having a number of hydraulically most remote sprinklers unequal to a number of hydraulically most remote sprinklers of the other groups of the plurality of groups of sprinklers.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) The accompanying drawings, which are incorporated herein and constitute part of this specification, illustrate exemplary embodiments of the invention, and together, with the general description given above and the detailed description given below, serve to explain the features of the invention. It should be understood that the preferred embodiments are some examples of the invention as provided by the appended claims.

(2) FIG. 1 is a schematic perspective view of a preferred embodiment of a storage fire protection system.

(3) FIG. 2 is illustrative side elevation view of a storage arrangement protected by the storage fire protection system of FIG. 1.

(4) FIG. 2A is illustrative end elevation view of the storage arrangement of FIG. 2.

(5) FIGS. 3-3B are schematic views of various preferred embodiments of a hydraulic design area for use in the system of FIG. 1

(6) FIG. 4 is perspective illustrative view of a preferred sprinkler for use in the system of FIG. 1.

(7) FIG. 4A is a cross-sectional view of the sprinkler of FIG. 4A.

(8) FIG. 5 is a preferred fluid deflector for use in the sprinkler of FIG. 4.

(9) FIGS. 6, 6A, and 6B are schematic views of a full-scale fire test setup for a sprinkler for use in the system of FIG. 1.

(10) FIG. 7 is a schematic view of a collection pan array for testing a sprinkler for use in the system of FIG. 1.

MODE(S) FOR CARRYING OUT THE INVENTION

(11) Shown in FIG. 1 is an illustrative schematic view of a preferred embodiment of a fire protection sprinkler system 10 for protection of a storage occupancy 12 with only ceiling-level sprinklers (“ceiling-only”) to distribute firefighting fluid for addressing a fire in the occupancy. More specifically, the system 10 is preferably a suppression-mode ceiling-only storage occupancy fire protection system that provides fire protection for high hazard commodities in a rack storage arrangement as schematically shown in FIGS. 2 and 2A. Accordingly, the preferred embodiments of systems and methods described herein can provide suppression fire protection of cartoned unexpanded plastic commodities, as defined by industry accepted standards such as FM 8-1 and NFPA 13, and less hazardous commodities, such as for example, Class 1, Class 2, Class 3, Class 4 and/or combinations thereof. As further illustrated in FIGS. 2 and 2A, the preferred embodiments of the systems and methods can provide ceiling-only suppression performance protection beneath a ceiling CLG having a maximum ceiling height H of up to fifty-five feet above a floor FLR for rack storage having a maximum storage height SH of up to fifty feet. It is believed that the present invention provides for fire protection using only ceiling-level suppression performance sprinklers for the protection of high hazard commodities at heights not previously provided for commercially or under known industry standards. FIGS. 2 and 2A illustratively show a double row rack arrangement that consists of metal rack structure with flue spaces and open shelves covered by the stored commodity. Although a double row rack arrangement is shown, it should be understood that the preferred systems described herein can be configured for protection of single row, double row or multi-row rack storage arrangements.

(12) In the illustrated embodiments, system 10 includes a grid of fire protection sprinklers 20 coupled to a network of pipes 13 that includes one or more main pipes 14 from which a plurality of spaced apart branch lines 15 extend. The main pipe 14 is coupled to a source of firefighting fluid FS, such as a water supply main. The sprinklers 20 are coupled to the branch lines and spaced from one another and located relative to the fluid source. Moreover, the network of pipes locate the sprinklers 20 beneath the ceiling CLG preferably within two feet of the ceiling. The sprinklers 20 are preferably of the pendent type with its fluid deflector located arranged at a preferred distance of up to eighteen inches (18 in.) below the ceiling CLG and is even more preferably no more than fourteen inches (14 in.) below the ceiling 22. The sprinklers 20 are preferably located from one another by a sprinkler-to-sprinkler spacing which ranges from eight to as great as twelve feet (8-12 ft.).

(13) With reference to FIG. 1, in any type of a gridded fire protection system there is a group of design sprinklers whose sprinkler-to-sprinkler spacing define a hydraulic design area 16 of the system 10. In order to place a system into service, the design sprinklers of the hydraulic design area are those sprinklers that are to be hydraulically shown to an AHJ as being be provided with at least a minimum flowing pressure to produce a minimum fluid flow for effectively addressing a fire with a desired level of protection, i.e., suppression protection. Accordingly, the sprinklers of the preferred systems have to be capable of providing the desired suppression protection and more preferably are qualified for providing suppression protection. As is described herein, preferred embodiments of the sprinkler 20 have demonstrated such capability through appropriate water distribution and fire testing.

(14) In the preferred system 10 and its preferred method of suppression-mode protection, the preferred sprinklers are installed in a gridded arrangement and coupled to a fluid source to implement the preferred hydraulic design. The hydraulically remote design sprinklers are each preferably provided with a minimum flowing pressure of less than one hundred pounds per square inch (100 psi.) of firefighting fluid, e.g., water. In some preferred embodiments, the minimum flowing pressure provided to the design sprinklers is eighty pounds per square inch (80 psi.). Schematically shown in FIGS. 3-3B are preferred embodiments of the hydraulic design area 16 of the system 10 defined by a preferred number of design sprinklers 22, which are hydraulically located most remotely from the fluid source FS. For each preferred hydraulic design area 16, the number of design sprinklers preferably ranges from five to twelve (5-12) design sprinklers 22. The design sprinklers are preferably arranged or identified in groupings coupled to two or more branch pipes 15.

(15) For example, as seen in FIG. 3, is a first preferred embodiment of the hydraulic design area 16a there are ten and preferably no more than twelve (10-12) most hydraulically remote sprinklers. The hydraulically remote sprinklers of the design area 16a are preferably divided into three groups 22a, 22b, 22c coupled to three branch lines 15a, 15b, 15c. Alternatively, the hydraulically remote sprinklers of the design area 16a′ are preferably divided into four groups 22a, 22b, 22c, 22d coupled to four branch lines 15a, 15b, 15c, 15d. Preferably, the number of design sprinklers are equally divided among the branch lines. Alternatively, where the design sprinklers cannot be equally grouped, the largest group of sprinklers is preferably located on the most hydraulically remote branch line.

(16) Shown in FIG. 3A, is an alternate embodiment of the hydraulic design area 16b in which there are five to fewer than ten hydraulically remote design sprinklers. In one preferred embodiment shown there are a total of nine (9) design sprinklers, which are preferably divided into three groups 22a, 22b, 22c and coupled to three branch lines 15a, 15b, 15c. In an alternate embodiment of the hydraulic design area 16b′, the design area is defined by no more than eight (8) hydraulically remote sprinklers which are preferably divided into unequal groups located on three spaced apart branch lines 15a, 15b, 15c.

(17) In another alternate embodiment, the hydraulic design sprinklers are located on only two spaced apart branch lines. For example, as shown in FIG. 3B, is an alternate embodiment of the hydraulic design area 16c in which the eight (8) hydraulically remote sprinklers which are preferably divided into two equal groups located on two spaced apart branch lines 15a, 15b. In an alternate embodiment of the hydraulic design area 16c′, the design area is defined by a preferred six (6) hydraulically remote sprinklers which are preferably divided into equal groups located on the two branch lines 15a, 15b. The preferred ceiling-only systems described herein provide that rack storage suppression type fire protection with hydraulic design areas defined by as few as five most hydraulically remote design sprinklers. Illustrated in FIG. 3C is a preferred hydraulic design area 16d with no more than five design sprinklers divided into the two groups 22a, 22b preferably disposed on only two branch lines 15a, 15b.

(18) An illustrative embodiment of a suppression fire protection sprinkler 20 for use in the system 10 is shown in FIGS. 4 and 4A. The sprinkler 20 is preferably embodied as an automatic sprinkler having a body 24 with an internal passageway having a fluid inlet 26 and an outlet 28 spaced apart from one another and axially aligned along a sprinkler axis A-A to define the sprinkler orifice and its discharge characteristics. Generally, the discharge characteristics of the sprinkler body define a preferred nominal K-factor in a range of 11 [GPM/(psi).sup.1/2] to 50 [GPM/(psi).sup.1/2]. More particularly, preferred embodiments of the sprinkler and sprinkler body for use in the system 10 defines a nominal K-factor which range from 25.2 [GPM/(psi).sup.1/2] to 36.4 [GPM/(psi).sup.1/2] and are yet even more preferably any one of 25.2; 28.0; 33.6 or 36.4 [GPM/(psi).sup.1/2].

(19) A closure assembly 30 and a thermally responsive or heat sensitive trigger 32 maintains the outlet 28 sealed in an unactuated state of the sprinkler. The trigger 32 can be configured as a frangible glass bulb or a fusible link arrangement. The actuation, operation or thermal responsiveness of the sprinkler to fire or sufficient level of heat is preferably faster than standard response, e.g., quick response, fast response or early fast response, with a preferred response time index (RTI) of 50 (m*s).sup.1/2 [100 (ft.*s).sup.1/2] or less, preferably no more than 36 (m*s).sup.1/2, [65 (ft.*s).sup.1/2], and even more preferably 19 to 36 (m*s).sup.1/2 [35-65 (ft.*s).sup.1/2]. Accordingly, the sprinkler 20 is preferably a quick response storage sprinkler as understood from the FM standards. The thermally responsive triggers of the sprinklers are preferably thermally rated in a range of 155° F. to 210° F. and more preferably ranges from 164° F. to 205° F. and are preferably thermally rated at 165° F.

(20) The preferred thermally or heat responsive trigger assembly 32 is preferably disposed between the body 14 and the deflector 20 to maintain the closure assembly 30 in the outlet 28 sealed in an unactuated state of the sprinkler. As shown in FIG. 4A, the closure assembly 30 preferably includes a plug disposed in the outlet 28. The thermally responsive trigger assembly 32 preferably includes a strut 33, a lever 34 with a preferred fusible temperature-reactive link 35 coupling the strut 32 and lever 34 together in an actuatable position between the body 14 and the deflector 20 to support the seal assembly 40 within the outlet 18. The thermally responsive trigger assembly 32 transfers a compressive force of a load member 36, such as for example a threaded screw member, acting on the strut lever arrangement to the closure assembly 30. The preferred thermally responsive link 35 is preferably constructed to provide a consistent operability not available in prior fusible links. As used herein, “consistent operability” means that the fusible link is constructed to have an RTI that is within a preferred standard deviation of a mean value of a preferred RTI range. The preferred RTI range can be, for example, a full range characterizing the trigger, e.g., Quick Response RTI of 19 to 36 (m-s).sup.1/2 or any subrange thereof. More particularly, preferred fusible links are constructed to provide for an actual RTI value that falls within a standard deviation of 6-7 of a preferred RTI mean, more preferably with a standard deviation of less than 6 of the preferred RTI mean and more preferably within a standard deviation of 2-3 of the preferred RTI mean. By providing sprinklers with the preferred fusible links of consistent operability, a plurality of sprinklers can be provided with low variance in the thermal sensitivity and/or operational characteristics between sprinklers.

(21) Generally, the preferred fusible link 35 includes a first plate member and a second plate member joined to one another by a solder joint. Each plate member is preferably formed from beryllium nickel, such as for example, UNS-N03360 beryllium nickel. Alternatively, the plates may be formed from aluminum, steel, or copper, for example, or any other metallic material. A preferred applied solder is a eutectic solder to define a preferred temperature rating of 165° F. (74° C.) or 205° F. (96° C.) or alternatively a non-eutectic solder is applied for defining a preferred temperature rating of 161° F. (72° C.). In order to ensure a preferred adherence of the finishing coat to the soldered plates, the surfaces of the soldered elements are prepared with a surface treatment or preparation sufficient to sufficiently adhere a protective or finishing coating. Preferred embodiments of the link assembly 35 include one or more finishing coatings of an enamel paint. U.S. Provisional Application No. 62/745,800 is incorporated herein by reference as showing and describing a preferred embodiment of the fusible link 35 and its assembly.

(22) Referring again to FIGS. 4 and 4A, a preferred embodiment of the suppression sprinkler 20 includes a nominal K-factor of 28.0 [GPM/(psi).sup.1/2], a thermal sensitivity defined by an RTI of 50 (m*s).sup.1/2 [100 (ft.*s).sup.1/2] or less and a deflector 40. A preferred sprinkler is shown and described in U.S. Patent Application No. 62/745,800, which is incorporated by reference in its entirety. The sprinkler 20 is preferably configured for installation in a pendent type orientation with the fluid distribution deflector 40 coupled to the body 24 of the sprinkler 20 and spaced from the outlet 28 at fixed distance by a pair of frame arms 29. The distribution of fluid discharged from the sprinkler body defines a preferred spray pattern and coverage of the sprinkler which defines the preferred sprinkler spacing of the sprinkler. As previously noted, the sprinklers of the system 10 preferably define a preferred sprinkler-to-sprinkler spacing of eight to twelve feet (8-12 ft.) and more preferably a sprinkler-to-sprinkler spacing of eight to ten feet (8-10 ft.). A preferred sprinkler fluid distribution deflector 40 is shown in FIG. 5 centered along the sprinkler axis A-A. The preferred deflector 40 has a perimeter 42 and a central portion 44 with the deflector including a plurality of spaced apart tines defining a plurality of opposed slot pairs 46a, 46b, 46c, 46d, and 46e slot between adjacent tines. Each slot has a first width at the perimeter 42 of the deflector and radiused portion between the first width and the central portion 44 of the deflector. The spaced apart terminal ends of each tine define the perimeter 42. The perimeter 42 preferably includes a first perimeter 42a on a first circle concentric to the sprinkler axis defining a first diameter D1. The perimeter 42 includes a second perimeter portion 42b on a second circle concentric to the sprinkler axis defining a second diameter D2 less than the first diameter D1. Accordingly, there are at least a first plurality of tines located on or terminating at the first circle and at least a second plurality of tines located on or terminating at the second circle. Notably, for at least one pair of opposed slots 46e, the tine on one side of the slot terminates at the first circle and the tine on the other side of the slot terminates on the second circle. In a preferred embodiment, the diameters define a preferred first-to-second diameter ratio that ranges from 1.1:1 to 1.2:1. In an alternate embodiment, the tines can terminate on or define different perimeter geometries for example different first and second rectangles to provide a perimeter of varying the widths.

(23) The five different opposed slot pairs 46a, 46b, 46c, 46d, and 46e are differentiated by their location and geometry including their radial lengths and widths. The first group of opposed slot pairs 46a includes a first opposed pair that terminate at the first circle and aligned along a first bisecting plane P1. The second group of opposed slot pairs 46b includes a first opposed pair that terminate at the second circle and aligned along a second bisecting plane P2. In the sprinkler assembly, the second group of opposed slot pairs 46b and the second bisecting plane P2 are preferably aligned with the frame arms 25. The third group of slots 46c is preferably disposed between the first and second group of opposed pair of slots 46a, 46b and preferably equiangularly disposed between the first and second group of opposed pair of slots 46a, 46b. Accordingly, the third group of slots 46c preferably include two pairs of opposed slots disposed at a 45 degree angle between the first and second bisecting planes. In another preferred aspect, a fourth group of opposed slot pairs 42d is preferably disposed between the first and third group of slots 42a, 42c. A fifth group of opposed slot pairs 46e is preferably disposed between the second and third group of slots 42b, 42c.

(24) As shown the shortest slots are the second opposed pair 46b with the longest opposed pair being the fourth opposed pair 46d. In defining the slot lengths of the various slot groups, the radiused portions of each slot is tangent to a concentric circle circumscribed about the center C. Each of the second and third group of slots 46b, 46c are tangent to circle having a first radius R1 about the deflector center that is the largest for all slot groups and the fifth group of slots 46e is tangent to a circle having a second radius R2 about the deflector center that is the smallest for all slot groups. The radius portions of the first and fourth slots are preferably tangent to different circles having respective radii R3, R4 between the largest and smallest concentric circles. The terminal widths of three slot groups 46a, 46c and 46d are the same at the perimeter of the deflector. Each of the second and fifth slot groups 46b, 46e are different from one another and the other three slot groups.

(25) Further variations in the slot features or variations in the combination of like slot features can define alternate embodiments of the deflector that are suitable for providing a suppression-like spray pattern for use in the system 10. For example, all the slot groups can have a common slot width at the perimeter with the second group of slots 46b being the longest slots and the fifth group of slots being the shortest. To vary the lengths of the slots, the concentric circles can define alternative radii from the deflector center to which one or more radiused slot portions run tangent.

(26) As described above, the total fluid flow from a sprinkler is a function of the discharge coefficient and fluid pressure provided to the sprinkler. The fluid flow from the sprinkler in combination with the spray pattern defined by the deflector 40 can define the performance for the preferred ceiling-level sprinkler over a range of heights and commodities. The inventors have discovered a preferred range of fluid pressure for operation of the preferred sprinkler 20 to produce suppression performance in addressing a fire size indicative of a high hazard commodity fire from a vertical distance of fifty-five feet. Thus, the inventors have discovered the operational combination of sprinkler and minimum operating pressure for use in the system 10 for the protection of high hazard commodities in rack storage beneath a ceiling that is fifty-five feet (55 ft.) in height. The preferred fluid pressure is less than 100 psi., preferably ranging from 35-100 psi., more preferably ranging from 50-100 psi., even more preferably ranging from 60-100 psi., yet even more preferably ranging from 75-100 psi. and is more preferably 80 psi. For the design sprinklers and design areas of the previously described ceiling-only systems that are provided within the preferred range, a minimum volume of fluid flows therefrom which defines the preferred hydraulic demand of the ceiling-only systems to deliver suppression protection beneath a peak ceiling height of fifty-five feet (55 ft.). Thus, for the preferred five to twelve (5-12) hydraulically remote sprinklers defining the hydraulic design area of the system, the total required minimum flow is preferably less than 3000 gallons per minute (GPM), more preferably less than 2500 GPM, and yet even more preferably approximately 2000 GPM.

(27) Preferred embodiments of the sprinkler are qualified for suppression. The preferred embodiments haven subjected to full scale fire tests were conducted under the worst-case scenario for which the preferred systems are to be used. Shown in FIGS. 6, 6A and 6B are illustrative schematics of a fire-test set up for use in three full-scale fire tests. Installed beneath a ceiling located 55 ft. above the floor are a grid of thirty-six (36) of the preferred K 28.0 suppression pendent-type sprinklers at a linear sprinkler spacing at one of an 8 ft.×8 ft. spacing or a 10 ft.×10 ft. spacing. The sprinklers were supplied with the preferred 80 psi. of fluid pressure through a looped piping system of 2½ inch diameter branch lines to provide for a preferred discharge flow rate of 250 GPM from any actuated sprinkler. The sprinklers were located beneath the ceiling with their deflectors at a ceiling-to-deflector distance that ranges from 1-2 ft.

(28) Located below the sprinkler grid is the test commodity of cartoned unexpanded plastic commodity preferably embodied as single wall corrugated cardboard cartons measuring a nominal 21 in.×21 in.×20 in. containing 125 crystalline polystyrene empty 16. oz. cups in separate compartments within the carton. Each pallet load is supported by a two-way 42 in.×42 in.×5 in. slatted deck hardwood pallet. A main array 100 of industrialized racks is arranged as a double-row rack arrangement of the test commodity having a storage height of forty-five to fifty feet (45-50 ft.) with 36 in. wide rack members. The double-row main rack array 100 includes four 8 ft. across with 9-10 tiers. For the fire tests, the geometric center of the main array 100 is centered between four central sprinklers or alternatively centered between two central sprinklers.

(29) Two target arrays 100a, 100b of stored commodity forty-five to fifty feet (45-50 ft.) in height are disposed to each side of the main array 100 to define an aisle width of four to eight feet (4-8 ft.). Each target array 100a, 100b is a single row measures 4 ft. across with 9-10 tiers. The target arrays 100a, 100b were spaced about the main array to define an aisle width that ranged from 4-8 ft. Three to four fire tests were conducted with a single fire located and ignited at the floor. In each test, the fire was located at a preferred off-set distance of two feet (2 ft.) east of the centroid of the double row rack main array. In one test, the test fire is located between two sprinklers, in another test the test fire is located between four sprinklers and in the remaining test, the test fire is centered beneath a single sprinkler.

(30) For each test following ignition of the test fire, the total number of sprinkler activations was counted and the time of each sprinkler activation was recorded. Additionally, the maximum 1-minute average gas temperature above the ignition site and the maximum 1-minute average steel temperature above the ignition site was determined using appropriate sensors. At the conclusion of each fire test, the damage to the main array and target arrays, if any, is evaluated. From the test results, the performance of the sprinkler under the worst-case scenarios is determined.

(31) In each of the fire test, no more than five sprinklers operated. The maximum 1-minute average gas temperature above the ignition site was no more than 1000° F. and the maximum 1-minute average steel temperature above the ignition site remained below 200° F. In each test, the fire remained contained to the main array and did not spread to the ends of the main array. Accordingly, in each of the fire tests, the fire never crossed the aisle to impact the target array. Based upon the test results, the preferred test sprinklers, when supplied with the minimum fluid pressure of 80 psi., can qualify for suppression performance sufficient to protect cartoned unexpanded plastic or lesser hazards in a rack storage arrangement to a storage height of fifty feet beneath a maximum ceiling height of 55 ft. The test results thereby support the preferred hydraulic design criteria for ceiling-only protection previously described and shown in FIGS. 3, 3A and 3B. In particular, a ceiling-only system using the preferred sprinklers can provide for suppression performance based upon at least five design sprinklers being provided with a minimum fluid pressure of 80 psi. Moreover, by applying a safety factor of no more than 2.4, the desired suppression performance can be realized with no more than twelve (12) sprinklers.

(32) Preferred embodiments of the sprinkler were subjected to actual delivery density (ADD) testing. Shown in FIG. 7 is a forty-two collection pan set up over which two or more of the preferred sprinklers were installed and coupled to a fluid source. A series of tests were conducted in which water was distributed from the one or more sprinklers into the collection pans. From the collected volume, the actual delivered density ADD was determined for each pan. Collection pans were grouped together according to their pan location and the density values summarized. The collection pans were grouped as follows: (i) four center core pan groups (201,202,205,206); (203,204,207,208); (209,210, 213,214); (211,212,215,216); (ii) four flue pans (217, 218, 219, 220) which are centered between the four center core pans; (iii) eleven north pre-wetting pans (221, 222, 225, 226); (223, 224, 227, 228); (237, 238, 239); and (iii) eleven south pre-wetting pans (221, 222, 225, 226); (231, 232, 235, 236); (240, 241, 242). In one embodiment, the center core pans are centered beneath two sprinklers spaced apart at ten feet (10 ft.). In another embodiment, the center core pans are centered beneath four sprinklers with two sprinklers spaced apart by ten feet on a first pipe line and a two sprinklers spaced apart by ten feet on a second pipe line spaced at ten feet from the first pipe. Additional details of the ADD test are described below. ADD tests were conducted without a fire and also conducted in the presence of a fire of a known size. In order to compare the ADD, a known burning fuel package can be ignited beneath the collection pans for which the required discharge density RDD is known for suppressing the fire. If the ADD from the thermally actuated sprinkler(s) rapidly extinguishes the fire, the ADD can be concluded to have exceeded the RDD of the fire to verify that the sprinklers provides suppression performance.

(33) In one preferred set up, the collection pans were located six feet beneath a ceiling with two open sprinklers located such that the deflector was about 17 inches below the ceiling. Water was delivered to the sprinklers at 80 psi. and discharged from the open sprinklers for 8-15 minutes and no fuel package was burned. Three test runs were conducted. The ADD results were summarized as follows:

(34) Test 1

(35) TABLE-US-00001 Center Core Central Flue North Pre- South Pre- Pans Pans Wetting Pans Wetting Pans Average ADD 1.085 2.193 0.186 0.252 (GPM/SQ. FT.)

(36) Test 2

(37) TABLE-US-00002 Center Core Central Flue North Pre- South Pre- Pans Pans Wetting Pans Wetting Pans Average ADD 1.135 2.115 0.199 0.271 (GPM/SQ. FT.)

(38) Test 3

(39) TABLE-US-00003 Center Core Central Flue North Pre- South Pre- Pans Pans Wetting Pans Wetting Pans Average ADD 1.079 3.029 0.231 0.281 (GPM/SQ. FT.)

(40) In another preferred set up, the collection pans were located six feet beneath a ceiling with four open sprinklers located such that the deflector was about 17 inches below the ceiling. Water was delivered to the sprinklers at 80 psi. and discharged from the open sprinklers for 8-15 minutes and no fuel package was burned. Two test runs were conducted. The ADD results were summarized as follows:

(41) Test 4

(42) TABLE-US-00004 Center Core Central Flue North Pre- South Pre- Pans Pans Wetting Pans Wetting Pans Average ADD 0.872 1.021 1.804 1.989 (GPM/SQ. FT.)

(43) Test 5

(44) TABLE-US-00005 Center Core Central Flue North Pre- South Pre- Pans Pans Wetting Pans Wetting Pans Average ADD 0.845 1.108 1.821 1.962 (GPM/SQ. FT.)

(45) Test 6

(46) TABLE-US-00006 Center Core Central Flue North Pre- South Pre- Pans Pans Wetting Pans Wetting Pans Average ADD 0.887 1.036 1.755 2.053 (GPM/SQ. FT.)

(47) In another preferred ADD test, the collection pans were located six feet beneath a ceiling with two sprinklers located such that the deflector was about 17 inches below the ceiling and a 2600 kW heptane fire ignited beneath the collection pans. Water was delivered to the sprinklers at 80 psi. and discharged from the thermally actuated sprinkler for 8-12. Three test runs were conducted. The ADD results were summarized as follows:

(48) Test 7

(49) TABLE-US-00007 Center Core Central Flue North Pre- South Pre- Pans Pans Wetting Pans Wetting Pans Average ADD 1.09 2.98 0.387 0.436 (GPM/SQ. FT.)

(50) Test 8

(51) TABLE-US-00008 Center Core Central Flue North Pre- South Pre- Pans Pans Wetting Pans Wetting Pans Average ADD 1.094 2.983 0.38 0.452 (GPM/SQ. FT.)

(52) Test 9

(53) TABLE-US-00009 Center Core Central Flue North Pre- South Pre- Pans Pans Wetting Pans Wetting Pans Average ADD 1.089 3.361 0.494 0.435 (GPM/SQ. FT.)

(54) In another ADD test with burning fuel, the collection pans were located six feet beneath a ceiling with four sprinklers located such that the deflector was about 17 inches below the ceiling and a 3000 kW heptane fire ignited beneath the collection pans. Water was delivered to the sprinklers at 80 psi. and discharged from the thermally actuated sprinkler for 7-15 minutes. Four test runs were conducted. The ADD results were summarized as follows:

(55) Test 10

(56) TABLE-US-00010 Center Core Central Flue North Pre- South Pre- Pans Pans Wetting Pans Wetting Pans Average ADD 0.838 1.06 1.984 2.099 (GPM/SQ. FT.)

(57) Test 11

(58) TABLE-US-00011 Center Core Central Flue North Pre- South Pre- Pans Pans Wetting Pans Wetting Pans Average ADD 0.872 1.025 1.917 2.042 (GPM/SQ. FT.)

(59) Test 12

(60) TABLE-US-00012 Center Core Central Flue North Pre- South Pre- Pans Pans Wetting Pans Wetting Pans Average ADD 0.86 1.101 1.757 2.019 (GPM/SQ. FT.)

(61) Test 13

(62) TABLE-US-00013 Center Core Central Flue North Pre- South Pre- Pans Pans Wetting Pans Wetting Pans Average ADD 0.9 1.122 1.909 1.974 (GPM/SQ. FT.)

(63) In each of the distribution tests in the presence of a test fire, the fire was extinguished within a test duration ranging from 5-10 minutes. It was therefore concluded that the test sprinklers demonstrably provided an ADD greater than the required delivery density (RDD) necessary to suppress the test fire.

(64) Having identified and verified a preferred sprinkler, its minimum operating pressure and associated hydraulic design criteria for protection of high hazard commodities beneath a peak ceiling height of fifty-five feet (55 ft.), a method of obtaining and providing a sprinkler of high hazard commodities for ceiling and storage heights under 55 ft. are provided. Obtaining a preferred sprinkler can include any one of manufacturing or acquiring the preferred sprinklers; and providing can include any one of selling, specifying, or supplying the preferred sprinkler. For example, one preferred method of supplying a suppression-mode ceiling-only storage occupancy fire protection system includes obtaining a plurality of pendent sprinklers. Each sprinkler preferably including: a sprinkler body defining a nominal K-factor of any one of 28.0 and 36.4, a closure assembly and a thermally rated trigger assembly having a response time index (RTI) of 50 (m*s).sup.1/2 [100 (ft.*s).sup.1/2] or less, preferably no more than 36 (m*s).sup.1/2, [65 (ft.*s).sup.1/2], and even more preferably 19 to 36 (m*s).sup.1/2 [35-65 (ft.*s).sup.1/2]. The preferred method also preferably includes providing the plurality of sprinklers for installation in a grid of sprinklers in which hydraulically remote sprinklers in the grid of sprinklers define a hydraulic design area of the system of five to no more than ten (5-10) sprinklers to provide a suppression fire protection of at least one commodity of one of Class 1, Class 2, Class 3, Class 4/cartoned unexpanded plastic and combinations thereof. In the preferred method, the sprinklers are preferably installed beneath a ceiling having a maximum ceiling height of fifty-five feet (55 ft.) with the stored commodity having a maximum storage height of up to fifty feet (50 ft.) in a rack storage arrangement being any one of single-row, double-row, and multi-row rack storage to define a clearance distance between the commodity and the ceiling of at least five feet (5 ft.).

(65) While the present invention has been disclosed with reference to certain embodiments, numerous modifications, alterations, and changes to the described embodiments are possible without departing from the sphere and scope of the present invention, as defined in the appended claims. Accordingly, it is intended that the present invention not be limited to the described embodiments, but that it has the full scope defined by the language of the following claims, and equivalents thereof.