Heads up: There are no amended sections in this chapter.
Sprinklers intended to protect storage fire risks shall be permitted to be installed using water supply design criteria that are different from the design criteria specified for the sprinklers described in Chapters 12 through 20 when specifically listed for such use within the limitations described in this chapter.
The requirements of Chapters 12 through 20 shall apply unless modified by this chapter.
Sprinklers having standard coverage areas that require up to 20 sprinklers to be included in the hydraulic calculation shall be installed in accordance with 8.4.6.2, 8.4.6.3, 8.4.6.3.1 and 12.1.1.
Quick-response sprinklers shall also be installed in accordance with 8.4.6.4.1 and 8.4.6.4.2.
Sprinklers having extended coverage areas that require up to 10 sprinklers to be included in the hydraulic calculation shall be installed in accordance with 8.4.6.2, 8.4.6.3, 8.4.6.3.1 and 12.1.1.
Quick-response sprinklers shall also be installed in accordance with 8.4.6.4.1 and 8.4.6.4.2.
The in-rack protection requirements of Chapters 12 through 20 shall apply when storage racks are equipped with solid shelves and in-rack sprinklers are required per the applicable chapter.
The requirements of the applicable chapter shall apply when ceiling-only protection options are not available per this chapter.
The design criteria in this chapter shall not be used to permit a reduction in the water supply requirements for in-rack sprinkler protection.
A series of large-scale fire tests involving challenging test scenarios that address the range of variables associated with the intended application of the sprinkler shall be conducted to evaluate the ability of the sprinkler to protect storage fire risks that are representative of those described in the manufacturer's installation and design parameter instructions and referenced in the listing.
The manufacturer's installation and design parameter instructions for these sprinklers shall specify in a standardized manner the end-use limitations and sprinkler system design criteria including at least the following:
  1. Commodity or commodities to be protected
  2. Storage arrangements allowed
  3. Installation guidelines including obstruction and ceiling construction limitations
  4. Maximum ceiling and storage heights with associated minimum operating pressures and number of sprinklers required to be included in the hydraulic calculation
  5. Hose stream allowance and duration
The number of sprinklers to be used in the sprinkler system design shall be based on the worst-case result obtained from the full-scale fire test series increased by a minimum 50 percent.
Regardless of the number of sprinklers that operated during the worst-case full-scale fire test, the number in the sprinkler system demand shall be no less than one of the following:
  1. Twelve sprinklers for standard coverage sprinklers
  2. Eight sprinklers for extended-coverage sprinklers based on a spacing of 12 ft × 12 ft (3.7 × 3.7 m)
  3. Six sprinklers for extended-coverage sprinklers based on a spacing of 14 ft × 14 ft (4.3 m × 4.3 m)
Once the number of sprinklers for a demand area has been established, the minimum operating area, based on the proposed sprinkler spacing, shall not be less than 768 ft2 (71 m2).
The design area and number of sprinklers calculated on a branch line shall be in accordance with 23.4.4.2 using an area of sprinkler operation equal to the required number of operating sprinklers and the maximum allowable coverage for the specific design criteria being utilized.
Listed storage sprinklers that are not specifically referenced in Sections 21.2 and 21.3 but are tested in accordance with Chapter 21 with system design criteria based upon Sections 21.1, 21.4, and 21.5 shall be permitted to be used in accordance with their listing limitations, where approved.
Protection of palletized and solid-piled storage of Class I through Class IV and cartoned unexpanded plastic commodities shall be permitted to be protected in accordance with Table 21.2.1.

Table 21.2.1 Extended Coverage, CMSA [K-factor 25.2 (360)] Sprinkler Design Criteria for Palletized and Solid-Piled Storage of Class I Through Class IV and Cartoned Unexpanded Plastic Commodities

Storage Arrangement Commodity Class Maximum Storage Height Maximum Ceiling/Roof Height K-Factor/ Orientation Type of System Number of Design Sprinklers Minimum Operating Pressure Maximum Coverage Area
ft m ft m
Palletized and solid-piled Class I through Class IV, encapsulated and nonencapsulated, and cartoned nonexpanded plastics 20 6.1 30 9.1 25.2 (360) Upright/pendent Wet 6 30 psi
(2.1 bar)
12 ft × 12 ft (3.7 m × 3.7 m) 144 ft2 (13.4 m2)
20 6.1 30 9.1 25.2 (360) Upright/pendent Wet 6 30 psi
(2.1 bar)
14 ft × 14 ft (4.3 m × 4.3 m) 196 ft2 (18.2 m2)
25 7.6 30 9.1 25.2 (360) Upright/pendent Wet 6 30 psi
(2.1 bar)
12 ft × 12 ft (3.7 m × 3.7 m) 144 ft2 (13.4 m2)
25 7.6 30 9.1 25.2 (360) Upright/pendent Wet 6 30 psi
(2.1 bar)
14 ft × 14 ft (4.3 m × 4.3 m) 196 ft2 (18.2 m2)
25 7.6 35 11 25.2 (360) Upright/pendent Wet 8 40 psi
(2.7 bar)
12 ft × 12 ft (3.7 m × 3.7 m) 144 ft2 (13.4 m2)
25 7.6 35 11 25.2 (360) Upright Wet 8 40 psi
(2.8 bar)
14 ft × 14 ft (4.3 m × 4.3 m) 196 ft2 (18.2 m2)
30 9.1 35 11 25.2 (360) Upright/pendent Wet 8 40 psi
(2.8 bar)
12 ft × 12 ft (3.7 m × 3.7 m) 144 ft2 (13.4 m2)
30 9.1 35 11 25.2 (360) Upright Wet 8 40 psi
(2.8 bar)
14 ft × 14 ft (4.3 × 4.3 m) 196 ft2 (18.2 m2)
Protection of single-, double-, and multiple-row racks without solid shelves of Class I through Class IV and cartoned unexpanded plastic commodities shall be permitted to be protected in accordance with Table 21.3.1.

Table 21.3.1 Extended Coverage, CMSA [K-Factor 25.2 (360)] Sprinkler Design Criteria for Single-, Double-, and Multiple-Row Racks Without Solid Shelves of Class I Through Class IV and Cartoned Unexpanded Plastic Commodities

Storage Arrangement Commodity Class Maximum Storage Height Maximum Ceiling/Roof Height K-Factor/ Orientation Type of System Number of Design Sprinklers Minimum Operating Pressure Maximum Coverage Area
ft m ft m
Single-, double-, and multiple-row racks without solid shelves (no open-top containers) Class I through Class IV, encapsulated and nonencapsulated, and cartoned nonexpanded plastics 20 6.1 30 9.1 25.2 (360) Upright/pendent Wet 6 30 psi
(2.1 bar)
12 ft × 12 ft (3.7 m × 3.7 m) 144 ft2 (13.4 m2)
20 6.1 30 9.1 25.2 (360) Upright/pendent Wet 6 30 psi
(2.1 bar)
14 ft × 14 ft (4.3 m × 4.3m) 196 ft2 (18.2 m2)
25 7.6 30 9.1 25.2 (360) Upright/pendent Wet 6 30 psi
(2.1 bar)
12 ft × 12 ft (3.7 m × 3.7 m) 144 ft2 (13.4 m2)
25 7.6 30 9.1 25.2 (360) Upright/pendent Wet 6 30 psi
(2.1 bar)
14 ft × 14 ft (4.3 m × 4.3 m) 196 ft2 (18.2 m2)
25 7.6 35 11 25.2 (360) Upright/pendent Wet 8 40 psi
(2.6 bar)
12 ft × 12 ft (3.7 m × 3.7 m) 144 ft2 (13.4 m2)
25 7.6 35 11 25.2 (360) Upright Wet 8 40 psi
(2.6 bar)
14 ft × 14 ft (4.3 m × 4.3 m) 196 ft2 (18.2 m2)
30 9.1 35 11 25.2 (360) Upright/pendent Wet 8 40 psi
(2.7 bar)
12 ft × 12 ft (3.7 m × 3.7 m) 144 ft2 (13.4 m2)
30 9.1 35 11 25.2 (360) Upright Wet 8 40 psi
(2.6 bar)
14 ft × 14 ft (4.3 × 4.3 m) 196 ft2 (18.2 m2)
Protection of Class I through Class IV and cartoned unexpanded plastic commodities stored on single-, double-, or multiple-row racks without solid shelves or solid-piled, palletized storage arrangements shall be permitted to be protected in accordance with Table 21.3.2.

Table 21.3.2 CMSA K-25.2 Upright Standard Coverage Sprinkler Design Criteria for Single-, Double-, and Multiple-Row Racks Without Solid Shelves and Solid-Piled, Palletized Storage Arrangement of Class I Through IV and Cartoned Unexpanded Plastic Commodities

Storage Arrangement Commodity Class Maximum Storage Height Maximum Ceiling/Roof Height K-Factor Orientation System Type Number of Design Sprinklers Minimum Operating Pressure Sprinkler Linear Spacing Sprinkler Area Spacing
ft m ft m Min Max Min Max
Solid-piled, palletized, and single-, double-, and multiple-row racks without solid shelves (no open top containers) Class I—IV encapsulated and nonencapsulated, and cartoned nonexpanded plastics 25 7.6 30 9.1 25.2 (360) Upright Wet 12 20 psi
(1.4 bar)
8 ft (2.4m) 12 ft (3.6m) 80 ft2 (7.5m2) 100 ft2 (9.0m2)
Protection of Class I through Class IV and cartoned unexpanded plastic commodities stored on single-, double-, or multiple-row racks without solid shelves or solid-piled, palletized storage arrangements shall be permitted to be protected in accordance with Table 21.3.3.

Table 21.3.3 CMSA K-25.2 Pendent Standard Coverage Sprinkler Design Criteria for Single-, Double-, and Multiple-Row Racks Without Solid Shelves and Solid-Piled, Palletized Storage Arrangement of Class I Through IV and Cartoned Unexpanded Plastic Commodities

Storage Arrangement Commodity Class Maximum Storage Height Maximum Ceiling/Roof Height K-Factor/ Orientation Type of System Number of Design Sprinklers Minimum Operating Pressure Sprinkler Linear Spacing Sprinkler Area Spacing
ft m ft m Min Max Min Max
Solid-piled, palletized, and single-, double-, and multiple-row racks without solid shelves (no open top containers) Class I—IV encapsulated and nonencapsulated, and cartoned nonexpanded plastics 25 7.6 30 9.1 25.2 (360) Pendent wet 12 15 psi
(1.0 bar)
8 ft (2.4m) 12 ft (3.6m) 80 ft2 (7.5m2) 100 ft2 (9.0m2)
The minimum water supply requirements for a hydraulically designed occupancy hazard fire control sprinkler system shall be determined by adding the hose stream allowance from Table 21.4.1 to the water supply for sprinklers obtained from this chapter.

Table 21.4.1 Hose Stream Allowance and Water Supply Duration

Sprinkler Type Sprinkler Spacing Type Number of Sprinklers in Design Area Hose Stream Allowance Water Supply Duration (minutes)
gpm L/min
Control mode density/area and CMSA Standard Up to 12 250 950 60
Over 12 to 15 500 1900 90
Over 15 to 25 500 1900 120
Over 25 500 1900 150
Extended
coverage
Up to 6 250 950 60
Up to 8 (144 ft2) 250 950 60
Over 6 to 8 500 1900 90
Over 8 to 12 500 1900 120
Over 12 500 1900 150
ESFR Standard Up to 12 250 950 60
Over 12 to 15 500 1900 90
Over 15 to 25 500 1900 120
Over 25 500 1900 150
The water supply requirements for a hydraulically designed occupancy hazard fire control sprinkler system shall be available for the minimum duration specified in Table 21.4.1.
The installation guidelines for obstructions to ceiling-level sprinklers shall be in accordance with the requirements of Section 21.5 for sprinkler system designs obtained from this chapter.
Sprinklers having standard coverage areas requiring up to 20 sprinklers to be included in the hydraulic calculation shall be installed in accordance with the obstruction criteria described in 8.12.5, unless large-scale fire testing is conducted with a representative obstruction below the sprinkler that demonstrates equivalent performance.
Control mode density/area (CMDA) and CMSA sprinklers having standard coverage areas requiring more than 20 sprinklers in the design area shall be installed in accordance with the obstructions to sprinkler discharge criteria described in 8.11.5.
ESFR sprinklers having standard-coverage areas requiring more than 20 sprinklers in the design area shall be installed in accordance with the obstructions to sprinkler discharge criteria described in 8.12.5.
Other obstruction criteria shall be acceptable if large-scale fire testing is conducted with a representative obstruction below the sprinkler that demonstrates equivalent performance.
Sprinklers having extended coverage areas requiring up to 10 sprinklers to be included in the hydraulic calculation shall be installed in accordance with the obstruction criteria described in 8.8.5.1, 8.12.5.2, and 8.12.5.3, unless large-scale fire testing is conducted with a representative obstruction below the sprinkler that demonstrates equivalent performance.
CMDA and CMSA sprinklers having extended coverage areas requiring more than 10 sprinklers in the design area shall be installed in accordance with the obstructions to sprinkler discharge criteria described in 8.11.5 and 8.8.5.1.
ESFR sprinklers having extended coverage areas requiring more than 10 sprinklers in the design area shall be installed in accordance with the obstructions to sprinkler discharge criteria described in 8.12.5.2 and 8.12.5.3.
Other obstruction criteria shall be acceptable if large-scale fire testing is conducted with a representative obstruction below the sprinkler that demonstrates equivalent performance.
When utilizing upright CMSA, CMDA, or ESFR sprinklers, any continuous obstruction 4 in. (100 mm) or less shall be permitted to be ignored.
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