Heads up: There are no amended sections in this chapter.
This chapter shall apply to storage of plastic and rubber commodities stored in racks. The requirements of Chapter 12 shall apply unless modified by this chapter. (See Section C.9.)
This chapter also shall be used to determine protection for commodities that are not entirely Group A plastics but contain such quantities and arrangements of Group A plastics that they are deemed more hazardous than Class IV commodities.
Plastic commodities shall be protected in accordance with Figure 17.1.2.1. (See Section C.21.)

Note: Cartons that contain Group A plastic material can be treated as Class IV commodities under the following conditions:

(1) There shall be multiple layers of corrugation or equivalent outer material that would significantly delay fire involvement of the Group A plastic.

(2) The amount and arrangement of Group A plastic material within an ordinary carton would not be expected to significantly increase the fire hazard.

FIGURE 17.1.2.1 Decision Tree.

The design criteria of Chapter 17 for single- and double-row rack storage of plastic commodities shall be applicable where aisles are 3.5 ft (1.07 m) or greater in width.
Storage with aisles less than 3.5 ft (1.07 m) shall be protected as multiple-row rack storage.
Group B plastics and free-flowing Group A plastics shall be protected the same as Class IV commodities.
Group C plastics shall be protected the same as Class III commodities.
Sprinkler protection criteria for the storage of materials on racks shall be in accordance with Section 17.2 for storage up to 25 ft (7.6 m) and Section 17.3 for storage over 25 ft (7.6 m).
Protection criteria for Group A plastics shall be permitted for the protection of the same storage height and configuration of Class I, II, III, and TV commodities.
Rack storage in movable racks shall be protected in the same manner as multiple-row racks.
Where fireproofing of building columns is not provided and storage heights are in excess of 15 ft (4.6 m), protection of building columns within the rack structure or vertical rack members supporting the building shall be protected in accordance with one of the following:
  1. In-rack sprinklers
  2. Sidewall sprinklers at the 15 ft (4.6 m) elevation, pointed toward one side of the steel column
  3. Provision of ceiling sprinkler density for a minimum of 2000 ft2 (186 m2) with ordinary temperature- or high temperature-rated sprinklers as shown in Table 17.1.4.1 for storage heights above 15 ft (4.6 m) up to and including 20 ft (6.1 m)
  4. Provision of CMSA or ESFR ceiling sprinkler protection

Table 17.1.4.1 Ceiling Sprinkler Densities for Protection of Steel Building Columns

Commodity Classification Aisle Width
4 ft (1.2 m) 8 ft (2.4 m)
gpm/ft2 (L/min)/m2 gpm/ft2 (L/min)/m2
Plastics 0.68 27.7 0.57 23.2
The flow from a column sprinkler(s) shall be permitted to be omitted from the sprinkler system hydraulic calculations.
Where solid shelving in single-, double-, and multiple-row racks exceeds 20 ft2 (1.86 m2) but does not exceed 64 ft2 (5.95 m2) in area, sprinklers shall not be required below every shelf, but shall be installed at the ceiling and below shelves at intermediate levels not more than 6 ft (2 m) apart vertically. (See Section C.11.)
Where solid shelving in single-, double-, and multiple-row racks exceeds 64 ft2 (5.95 m2) in area or where the levels of storage exceed 6 ft (2 m), sprinklers shall be installed at the ceiling and below each level of shelving.
Where multiple-row racks of any height have no longitudinal flue or where double-row racks with storage up 25 ft (7.6 m) in height have no longitudinal flue, the situation shall not be considered solid shelves where transverse flues exist at maximum 5 ft (1.5 m) intervals and additional in-rack sprinklers shall not be required in accordance with 17.1.5.1 and 17.1.5.2.
The maximum horizontal spacing between in-rack sprinklers shall be 5 ft (1.5 m).
Design criteria for combined ceiling and in-rack sprinklers shall be used for the storage configurations in 17.1.5.1 and 17.1.5.2.
Where the criteria in 17.1.5.7 are not met, the water demand for the in-rack sprinklers shall be based on a minimum flow of 30 gpm (114 L/min) discharging from the following number of sprinklers balanced to the ceiling sprinkler demand in accordance with Section 23.8:
  1. Eight sprinklers where only one level of in-rack sprinklers is installed
  2. Fourteen sprinklers (seven on each of the top two levels) when more than one level of in-rack sprinklers is installed
The water demand for in-rack sprinklers shall not be required to be balanced to the ceiling sprinkler demand where additional face sprinklers are installed under each solid shelf at rack uprights and the in-rack sprinklers are calculated to discharge at least 60 gpm (227 L/min) from eight sprinklers.
The protection of open-top containers is outside the scope of Chapter 17. (See Section C.12.)
The number of sprinklers and the pipe sizing on a line of sprinklers in racks shall be restricted only by hydraulic calculations and not by any piping schedule.
When in-rack sprinklers are necessary to protect a higher hazard commodity that occupies only a portion of the length of a rack, in-rack sprinklers shall be extended a minimum of 8 ft (2.4 m) or one bay, whichever is greater, in each direction along the rack on either side of the higher hazard.
The in-rack sprinklers protecting the higher hazard shall not be required to be extended across the aisle.
Where a storage rack, due to its length, requires less than the number of in-rack sprinklers specified, only those in-rack sprinklers in a single rack need to be included in the calculation.
In-rack sprinklers shall be located at an intersection of transverse and longitudinal flues while not exceeding the maximum spacing rules.
Where distances between transverse flues exceed the maximum allowable distances, sprinklers shall be installed at the intersection of the transverse and longitudinal flues, and additional sprinklers shall be installed between transverse flues to meet the maximum distance rules.
Where no transverse flues exist, in-rack sprinklers shall not exceed the maximum spacing rules.
Horizontal barriers used in conjunction with in-rack sprinklers to impede vertical fire development shall be constructed of sheet metal, wood, or similar material and shall extend the full length and depth of the rack.
Barriers shall be fitted within 2 in. (51 mm) horizontally around rack uprights.
In double- and multiple-row racks without solid shelves, a longitudinal (back-to-back clearance between loads) flue space shall not be required.
Nominal 6 in. (152 mm) transverse flue spaces between loads and at rack uprights shall be maintained in single-, double-, and multiple-row racks.
Random variations in the width of flue spaces or in their vertical alignment shall be permitted.
Nominal 6 in. (152 mm) longitudinal flue spaces shall be provided in double-row racks.
Nominal 6 in. (152 mm) transverse flue spaces between loads and at rack uprights shall be maintained in single-, double-, and multiple-row racks.
Random variations in the width of the flue spaces or in their vertical alignment shall be permitted.
In single-, double-, or multiple-row racks, a minimum 6 in. (152 mm) vertical clear space shall be maintained between the in-rack sprinkler deflectors and the top of a tier of storage.
Face sprinklers in such racks shall be located within the rack a minimum of 3 in. (76 mm) from rack uprights and no more than 18 in. (460 mm) from the aisle face of storage.
Longitudinal flue in-rack sprinklers shall be located at the intersection with the transverse flue space and with the deflector located at or below the bottom of horizontal load beams or above or below other adjacent horizontal rack members.
Such in-rack sprinklers shall be a minimum of 3 in. (76 mm) radially from the side of the rack uprights.
For the storage of Group A plastics stored 5 ft (1.5 m) or less in height, the sprinkler design criteria for miscellaneous storage specified in Chapter 13 shall be used.
For Group A plastic commodities in cartons, encapsulated or nonencapsulated in single-, double-, and multiple- row racks, ceiling sprinkler water demand in terms of density [gpm/ft2 (mm/min)] and area of operation [ft2 (m2)] shall be selected from Figure 17.2.1.2.1(a) through Figure 17.2.1.2.1(f).

Note: Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately 18 in. (0.5 m) up to 10 ft (3.1 m). Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.1 m) apart vertically.

FIGURE 17.2.1.2.1(a) Storage 5 ft to 10 ft (1.5 m to 3.1 m) in Height with Up to 10 ft (3.1 m) Clearance to Ceiling.

Notes:

  1. Single level of in-rack sprinklers [1/2 in. or 17/32 in. (12.7 mm or 13.5 mm) operating at 15 psi (1.03 bar) minimum] installed as indicated in the transverse flue spaces.
  2. Where sprinklers listed for storage use are installed at the ceiling only and the ceiling height in the protected area does not exceed 22 ft (6.7 m) and a minimum clearance of 5 ft (1.5 m) and the storage height does not exceed 15 ft (4.6 m), the ceiling sprinkler discharge criteria shall be permitted to be reduced to 0.45 gpm/ft2 per 2000 ft2 (18.3 mm/min per 186 m2).
  3. Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately 18 in. (0.5 m) up to 10 ft (3.1 m). Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.1 m) apart vertically.

FIGURE 17.2.1.2.1(b) Storage 15 ft (4.6 m) in Height with Up to 10 ft (3.1 m) Clearance to Ceiling.

Notes:

  1. Single level of in-rack sprinklers [1/2 in. or 17/32 in. (12.7 mm or 13.5 mm) operating at 15 psi (1.03 bar) minimum] installed as indicated in the transverse flue spaces.
  2. Ceiling-only protection is not permitted for this storage configuration except where K-11.2 or larger spray sprinklers listed for storage use are installed. In-rack sprinklers are not required, provided the ceiling sprinkler discharge criterion is increased to 0.6 gpm/ft2 (24 mm/min) over 2000 ft2 (186 m2).
  3. Single level of in-rack sprinklers [17/32 in. (13.5 mm) operating at 15 psi (1.03 bar) minimum or 1/2 in. (12.7 mm) operating at 30 psi (2.07 bar) minimum] installed on 4 ft to 5 ft (1.2 m to 1.5 m) spacings located, as indicated, in the longitudinal flue space at the intersection of every transverse flue space.
  4. Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately

FIGURE 17.2.1.2.1(c) Storage 20 ft (6.1 m) in Height with <5 ft (1.5 m) Clearance to Ceiling.

Notes:

  1. Single level of in-rack sprinklers [1/2 in. or 17/32 in. (12.7 mm or 13.5 mm) operating at 15 psi (1.03 bar) minimum] installed as indicated in the transverse flue spaces.
  2. Ceiling-only protection shall not be permitted for this storage configuration except where K-11.2 or larger orifice spray sprinklers listed for storage use are installed. In-rack sprinklers shall not be required, provided the ceiling sprinkler discharge criterion is increased to 0.6 gpm/ft2 (24 mm/min) over 2000 ft2 (186 m2) and the ceiling height in the protected area does not exceed 27 ft (8.2 m).
  3. Two levels of in-rack sprinklers [1/2 in. or 17/32 in. (12.7 mm or 13.5 mm) operating at 15 psi (1.03 bar) minimum] installed as indicated and staggered in the transverse flue space.
  4. Single level of in-rack sprinklers [17/32 in. (13.5 mm) operating at 15 psi (1.03 bar) or 1/2 in. (12.7 mm) operating at 30 psi (2.07 bar) minimum] installed on 4 ft to 5 ft (1.2 m to 1.5 m) spacings located, as indicated, in the longitudinal flue space at the intersection of every transverse flue space.
  5. Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately 18 in. (0.5 m) up to 10 ft (3.1 m). Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.1 m) apart vertically.

FIGURE 17.2.1.2.1(d) Storage 20 ft (6.1 m) in Height with 5 ft to 10 ft (1.5 m to 3.1 m) Clearance to Ceiling.

Notes:

  1. Single level of in-rack sprinklers [17/32 in. (13.5 mm) operating at 15 psi (1.03 bar) minimum or 1/2 in. (12.7 mm) operating at 30 psi (2.07 bar) minimum] installed on 4 ft to 5 ft (1.2 m to 1.5 m) spacings located, as indicated, in the longitudinal flue space at the intersection of every transverse flue space.
  2. Ceiling-only protection shall not be permitted for this storage configuration except where K-16.8 spray sprinklers listed for storage use are installed. In-rack sprinklers shall not be required, provided the ceiling sprinkler discharge criterion is increased to 0.8 gpm/ft2 (32.6 mm/min) over 2000 ft2 (186 m2) for wet systems and 4500 ft2 (418 m2) for dry systems and the ceiling height in the protected area does not exceed 30 ft (9.1 m).
  3. Two levels of in-rack sprinklers [1/2 in. or 17/32 in. (12.7 mm or 13.5 mm) operating at 15 psi (1.03 bar) minimum] installed as indicated and staggered in the transverse flue space.
  4. Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately 18 in. (0.5 m) up to 10 ft (3.1 m). Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.1 m) apart vertically.

FIGURE 17.2.1.2.1(e) Storage 25 ft (7.6 m) in Height with <5 ft (1.5 m) Clearance to Ceiling. (See Note 2.)

Notes:

  1. Two levels of in-rack sprinklers [1/2 in. or 17/32 in. (12.7 mm or 13.5 mm) operating at 15 psi (1.03 bar) minimum] installed on 8 ft to 10 ft (2.4 m to 3.1 m) spacings located as indicated and staggered in the transverse flue space.
  2. Ceiling-only protection shall not be permitted for this storage configuration except where K-16.8 spray sprinklers listed for storage use are installed. In-rack sprinklers shall not be required, provided the ceiling sprinkler discharge criterion is increased to 0.8 gpm/ft2 (32.6 mm/min) over 2000 ft2 (186 m2) for wet systems and 4500 ft2 (418 m2) for dry systems and the ceiling height in the protected area does not exceed 30 ft (9.1 m).
  3. Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately 18 in. (0.5 m) up to 10 ft (3.1 m). Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.1 m) apart vertically.

FIGURE 17.2.1.2.1(f) Storage 25 ft (7.6 m) in Height with 5 ft to 10 ft (1.5 m to 3.1 m) Clearance to Ceiling. (See Note 2.)

Linear interpolation of design densities and areas of application shall be permitted between storage heights with the same clearance to ceiling.
No interpolation between clearance to ceiling shall be permitted.
An option shall be selected from the appropriate Figure 17.2.1.2.1(a) through Figure 17.2.1.2.1(f) given the storage height and clearance being protected. The density/area criteria at the top of each option shall be applied to the ceiling sprinklers and the in-rack sprinklers shown in the option (if any) shall be provided. Options that do not show multiple-row racks in the figures shall not be permitted to protect multiple-row rack storage. Notes in each figure shall be permitted to clarify options or to present additional options not shown in the figures.
For storage of Group A plastics between 5 ft and 12 ft (1.5 m and 3.7 m) in height, the installation requirements for extra hazard systems shall apply.
Exposed unexpanded Group A plastics protected with control mode density/area sprinklers shall be protected in accordance with one of the following:
  1. Maximum 10 ft (3 m) storage in a maximum 20 ft (6.1 m) high building with ceiling sprinklers designed for a minimum 0.8 gpm/ft2 (32.6 mm/min) density over 2500 ft2 (232 m2) and no in-rack sprinklers required as shown in Figure 17.2.1.4(a)
  2. Maximum 10 ft (3 m) storage in a maximum 20 ft (6.1 m) high building with ceiling sprinklers designed for a minimum 0.45 gpm/ft2 (18.3 mm/min) density over 2000 ft2 (186 m2) and one level of in-rack sprinklers required at alternate transverse flues as shown in Figure 17.2.1.4(b)
  3. Maximum 10 ft storage in a maximum 20 ft high building with ceiling sprinklers designed for a minimum 0.3 gpm/ft2 density over 2000 ft2 and one level of in-rack sprinklers required in every transverse flue as shown in Figure 17.2.1.4(c)
  4. Maximum 15 ft storage in a maximum 25 ft high building with ceiling sprinklers designed for a minimum 0.45 gpm/ft2 density over 2000 ft2 and one level of in-rack sprinklers required at alternate transverse flues as shown in Figure 17.2.1.4(d)
  5. Maximum 15 ft storage in a maximum 25 ft high building with ceiling sprinklers designed for a minimum 0.3 gpm/ft2 density over 2000 ft2 and one level of in-rack sprinklers required in every transverse flue as shown in Figure 17.2.1.4(e)
  6. Maximum 20 ft storage in a maximum 25 ft high building with ceiling sprinklers designed for a minimum 0.6 gpm/ft2 density over 2000 ft2 and one level of in-rack sprinklers required at alternate transverse flues as shown in Figure 17.2.1.4(f)
  7. Maximum 20 ft storage in a maximum 25 ft high building with ceiling sprinklers designed for a minimum 0.45 gpm/ft2 density over 2000 ft2 and one level of in-rack sprinklers required in every transverse flue as shown in Figure 17.2.1.4(g)
  8. Maximum 20 ft storage in a maximum 30 ft high building with ceiling sprinklers designed for a minimum 0.8 gpm/ft2 density over 1500 ft2 and one level of in-rack sprinklers required at alternate transverse flues as shown in Figure 17.2.1.4(h)
  9. Maximum 20 ft storage in a maximum 30 ft high building with ceiling sprinklers designed for a minimum 0.6 gpm/ft2 density over 1500 ft2 and one level of in-rack sprinklers required in every transverse flue as shown in Figure 17.2.1.4(i)
  10. Maximum 20 ft storage in a maximum 30 ft high building with ceiling sprinklers designed for a minimum 0.3 gpm/ft2 density over 2000 ft2 and two levels of in-rack sprinklers required in every transverse flue as shown in Figure 17.2.1.4(j)
  11. Maximum 25 ft storage in a maximum 35 ft high building with ceiling sprinklers designed for a minimum 0.8 gpm/ft2 density over 1500 ft2 and one level of in-rack sprinklers required in every transverse flue as shown in Figure 17.2.1.4(k)
  12. Maximum 25 ft storage in a maximum 35 ft high building with ceiling sprinklers designed for a minimum 0.3 gpm/ft2 density over 2000 ft2 and two levels of in-rack sprinklers required in every transverse flue as shown in Figure 17.2.1.4(1)

Note: Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately 18 in. to 10 ft (0.5 m to 3.1 m). Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.1 m) apart vertically.

FIGURE 17.2.1.4(a) Exposed Nonexpanded Plastics up to 10 ft in Height in up to a 20 ft High Building with No In-Rack Sprinklers.

Note: Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately 18 in. to 10 ft (0.5 m to 3.1 m). Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.1 m) apart vertically.

FIGURE 17.2.1.4(b) Exposed Nonexpanded Plastics up to 10 ft in Height in up to a 20 ft High Building with One Level of In-Rack Sprinklers.

Note: Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately 18 in. to 10 ft (0.5 m to 3.1 m). Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.1 m) apart vertically.

FIGURE 17.2.1.4(c) Exposed Nonexpanded Plastics up to 10 ft in Height in up to a 20 ft High Building with One Level of Closely Spaced In-Rack Sprinklers.

Note: Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately 18 in. to 10 ft (0.5 m to 3.1 m). Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.1 m) apart vertically.

FIGURE 17.2.1.4(d) Exposed Nonexpanded Plastics up to 15 ft in Height in up to a 25 ft High Building with One Level of In-Rack Sprinklers.

Note: Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately 18 in. to 10 ft (0.5 m to 3.1 m). Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.1 m) apart vertically.

FIGURE 17.2.1.4(e) Exposed Nonexpanded Plastics up to 15 ft in Height in up to a 25 ft High Building with One Level of Closely Spaced In-Rack Sprinklers.

Note: Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately 18 in. to 10 ft (0.5 m to 3.1 m). Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.1 m) apart vertically.

FIGURE 17.2.1.4(f) Exposed Nonexpanded Plastics up to 20 ft in Height in up to a 25 ft High Building with One Level of In-Rack Sprinklers.

Note: Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately 18 in. to 10 ft (0.5 m to 3.1 m). Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.1 m) apart vertically.

FIGURE 17.2.1.4(g) Exposed Nonexpanded Plastics up to 20 ft in Height in up to a 25 ft High Building with One Level of Closely Spaced In-Rack Sprinklers.

Note: Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately 18 in. to 10 ft (0.5 m to 3.1 m). Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.1 m) apart vertically.

FIGURE 17.2.1.4(h) Exposed Nonexpanded Plastics up to 20 ft in Height in up to a 30 ft High Building with One Level of In-Rack Sprinklers.

Note: Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately 18 in. to 10 ft (0.5 m to 3.1 m). Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.1 m) apart vertically.

FIGURE 17.2.1.4(i) Exposed Nonexpanded Plastics up to 20 ft in Height in up to a 30 ft High Building with One Level of Closely Spaced In-Rack Sprinklers.

Note: Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately 18 in. to 10 ft (0.5 m to 3.1 m). Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.1 m) apart vertically.

FIGURE 17.2.1.4(j) Exposed Nonexpanded Plastics up to 20 ft in Height in up to a 30 ft High Building with Two Levels of Closely Spaced In-Rack Sprinklers.

Note: Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately 18 in. to 10 ft (0.5 m to 3.1 m). Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.1 m) apart vertically.

FIGURE 17.2.1.4(k) Exposed Nonexpanded Plastics up to 25 ft in Height in up to a 35 ft High Building with One Level of Closely Spaced In-Rack Sprinklers.

Note: Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately 18 in. to 10 ft (0.5 m to 3.1 m). Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.1 m) apart vertically.

FIGURE 17.2.1.4(l) Exposed Nonexpanded Plastics up to 25 ft in Height in up to a 35 ft High Building with Two Levels of Closely Spaced In-Rack Sprinklers.

The minimum of 6 in. (152 mm) vertical clear space shall be maintained between the sprinkler deflectors and the top of a tier of storage.
The spacing of in-rack sprinklers shall be in accordance with Figure 17.2.1.2.1(a) through Figure 17.2.1.2.1(f).
In-rack sprinklers shall be located at an intersection of transverse and longitudinal flues while not exceeding the maximum spacing rules.
Where distances between transverse flues exceed the maximum allowable distances, sprinklers shall be installed at the intersection of the transverse and longitudinal flues, and additional sprinklers shall be installed between transverse flues to meet the maximum distance rules.
Where no transverse flues exist, in-rack sprinklers shall not exceed the maximum spacing rules.
The water demand for sprinklers installed in racks shall be based on simultaneous operation of the most hydraulically remote sprinklers as follows:
  1. Eight sprinklers where only one level is installed in racks
  2. Fourteen sprinklers (seven on each top two levels) where more than one level is installed in racks
Sprinklers in racks shall discharge at not less than 15 psi (1 bar) for all classes of commodities. (See Section C.19.)
Protection of single-, double-, and multiple-row rack storage without solid shelves for unexpanded plastic commodities shall be in accordance with Table 17.2.2.1.

Table 17.2.2.1 CMSA Sprinkler Design Criteria for Single-, Double-, and Multiple-Row Racks Without Solid Shelves of Plastics Commodities Stored Up and Including 25 ft (7.6 m) in Height

Storage Arrangement Commodity Class Maximum Storage Height Maximum Ceiling/Roof Height K-Factor/Orientation Type of System Number of Design Sprinklers Minimum Operating Pressure
ft m ft m psi bar
Single-, double-, and multiple-row racks without solid shelves (no open-top containers) Cartoned nonexpanded plastics 20 6.1 25 7.6 11.2 (160) Upright Wet 15 50 3.5
16.8 (240) Upright Wet 15 22 1.5
19.6 (280) Pendent Wet 15 16 1.1
30 9.1 11.2 (160) Upright Wet 30 50 3.5
Wet 20 75 5.2
16.8 (240) Upright Wet 15* 22 1.5
19.6 (280) Pendent Wet 15 16 1.1
25 7.6 30 9.1 11.2 (160) Upright Wet 15 + 1 level of in-rack 50 3.5
16.8 (240) Upright Wet 15* 22 1.5
19.6 (280) Pendent Wet 15 16 1.1
25 7.6 35 10.6 11.2 (160) Upright Wet 30 + 1 level of in-rack 50 3.5
Wet 20 + 1 level of in-rack 75 5.2
16.8 (240) Upright Wet 30 + 1 level of in-rack 22 1.5
Wet 20 + 1 level of in-rack 35 2.4
19.6 (280) Pendent Wet 15 25 1.7
Exposed nonexpanded plastics 20 6.1 25 7.6 11.2 (160) Upright Wet 15 50 3.5
16.8 (240) Upright Wet 15 22 1.5
20 6.1 30 9.1 11.2 (160) Upright Wet 30 50 3.5
Wet 20 75 5.2
16.8 (240) Upright Wet 15* 22 1.5
25 7.6 30 9.1 11.2 (160) Upright Wet 15 + 1 level of in-rack 50 3.5
16.8 (240) Upright Wet 15* 22 1.5
25 7.6 35 10.6 11.2 (160) Upright Wet 30 + 1 level of in-rack 50 3.5
Wet 20 + 1 level of in-rack 75 5.2
16.8 (240) Upright Wet 30 + 1 level of in-rack 22 1.5
Wet 20 + 1 level of in-rack 35 2.4
*Minimum 8 ft (2.4 m) aisle.
Protection shall be provided as specified in Table 17.2.2.1 or appropriate NFPA standards in terms of minimum operating pressure and the number of sprinklers to be included in the design area.
Where CMSA sprinklers are installed under open wood joist construction, firestopping in accordance with 17.2.2.3.2 shall be provided or the minimum operating pressure of the sprinklers shall be 50 psi (3.4 bar) for a K-11.2 (160) sprinkler or 22 psi (1.5 bar) for a K-16.8 (240) sprinkler.
Where each joist channel of open wood joist construction is fully firestopped to its full depth at intervals not exceeding 20 ft (6.1 m), the lower pressures specified in Table 17.2.2.1 shall be permitted to be used.
For the purpose of using Table 17.2.2.1, preaction systems shall be classified as dry pipe systems.
Building steel shall not require special protection where Table 17.2.2.1 is applied as appropriate for the storage configuration.
In-rack sprinklers shall be installed at the first tier level at or above one-half of the storage height.
The minimum of 6 in. (152 mm) vertical clear space shall be maintained between the sprinkler deflectors and the top of a tier of storage.
In-rack sprinklers shall be located at an intersection of transverse and longitudinal flues.
The maximum horizontal distance between in-rack sprinklers shall be 5 ft (1.5 m).
Where distances between transverse flues exceed the maximum allowable distances, sprinklers shall be installed at the intersection of the transverse and longitudinal flues, and additional sprinklers shall be installed between transverse flues to meet the maximum distance rules.
Where no transverse flues exist, in-rack sprinklers shall not exceed the maximum spacing rules.
The water demand for sprinklers installed in racks shall be based on simultaneous operation of the most hydraulically remote eight sprinklers.
Sprinklers in racks shall discharge at not less than 15 psi (1 bar) for all classes of commodities. (See Section C.19.)
Protection of single-, double-, and multiple-row rack storage of cartoned or exposed nonexpanded plastic and cartoned expanded plastic shall be in accordance with Table 17.2.3.1.

Table 17.2.3.1 ESFR Protection of Rack Storage Without Solid Shelves of Plastics Commodities Stored Up to and Including 25 ft (7.6 m) in Height

Storage Arrangement Commodity Maximum Storage Height Maximum Ceiling/Roof Height Nominal K-Factor Orientation Minimum Operating Pressure In-Rack Sprinkler Requirements
ft m ft m psi bar
Single-, double-, and multiple-row racks (no open-top containers) Cartoned nonexpanded 20 6.1 25 7.6 14.0
(200)
Upright/pendent 50 3.4 No
16.8
(240)
Upright/pendent 35 2.4 No
22.4
(320)
Pendent 25 1.7 No
25.2
(360)
Pendent 15 1.0 No
30 9.1 14.0
(200)
Upright/pendent 50 3.4 No
16.8
(240)
Upright/pendent 35 2.4 No
22.4
(320)
Pendent 25 1.7 No
25.2
(360)
Pendent 15 1.0 No
35 10.7 14.0
(200)
Upright/pendent 75 5.2 No
16.8
(240)
Upright/pendent 52 3.6 No
22.4
(320)
Pendent 35 2.4 No
25.2
(360)
Pendent 20 1.4 No
40 12.2 16.8
(240)
Pendent 52 3.6 No
22.4
(320)
Pendent 40 2.8 No
25.2
(360)
Pendent 25 1.7 No
45 13.7 14.0
(200)
Pendent 90 6.2 Yes
16.8
(240)
Pendent 63 4.3 Yes
22.4
(320)
Pendent 40 2.8 No
25.2
(360)
Pendent 40 2.8 No
25 7.6 30 9.1 14.0
(200)
Upright/pendent 50 3.4 No
16.8
(240)
Upright/pendent 35 2.4 No
22.4
(320)
Pendent 25 1.7 No
25.2
(360)
Pendent 15 1.0 No
32 9.8 14.0
(200)
Upright/pendent 60 4.1 No
16.8
(240)
Upright/pendent 42 2.9 No
35 10.7 14.0
(200)
Upright/pendent 75 5.2 No
16.8
(240)
Upright/pendent 52 3.6 No
22.4
(320)
Pendent 35 2.4 No
25.2
(360)
Pendent 20 1.4 No
40 12.2 16.8
(240)
Pendent 52 3.6 No
22.4
(320)
Pendent 40 2.8 No
25.2
(360)
Pendent 25 1.7 No
45 13.7 14.0
(200)
Pendent 90 6.2 Yes
16.8
(240)
Pendent 63 4.3 Yes
22.4
(320)
Pendent 40 2.8 No
25.2
(360)
Pendent 40 2.8 No
Exposed nonexpanded 20 6.1 25 7.6 14.0
(200)
Pendent 50 3.4 No
16.8
(240)
Pendent 35 2.4 No
30 9.1 14.0
(200)
Pendent 50 3.4 No
16.8
(240)
Pendent 35 2.4 No
35 10.7 14.0
(200)
Pendent 75 5.2 No
16.8
(240)
Pendent 52 3.6 No
40 12.2 16.8
(240)
Pendent 52 3.6 No
45 13.7 14.0
(200)
Pendent 90 6.2 Yes
16.8
(240)
Pendent 63 4.3 Yes
25 7.6 30 9.1 14.0
(200)
Pendent 50 3.4 No
16.8
(240)
Pendent 35 2.4 No
32 9.8 14.0
(200)
Pendent 60 4.1 No
16.8
(240)
Pendent 42 2.9 No
35 10.7 14.0
(200)
Pendent 75 5.2 No
16.8
(240)
Pendent 52 3.6 No
40 12.2 16.8
(240)
Pendent 52 3.6 No
22.4
(320)
Pendent 50 3.4 No
25.2
(360)
Pendent 50 3.4 No
45 13.7 14.0
(200)
Pendent 90 6.2 Yes
16.8
(240)
Pendent 63 4.3 Yes
Cartoned expanded 20 6.1 25 7.6 14.0
(200)
Upright/pendent 50 3.4 No
16.8
(240)
Upright/pendent 35 2.4 No
30 9.1 14.0
(200)
Upright/pendent 50 3.4 No
16.8
(240)
Upright/pendent 35 2.4 No
25 7.6 30 9.1 14.0
(200)
Upright/pendent 50 3.4 No
16.8
(240)
Upright/pendent 35 2.4 No
32 9.8 14.0
(200)
Pendent 60 4.1 No
16.8
(240)
Upright/pendent 42 2.9 No
ESFR protection as defined shall not apply to the following:
  1. Rack storage involving solid shelves
  2. Rack storage involving combustible, open-top cartons or containers
ESFR sprinkler systems shall be designed such that the minimum operating pressure is not less than that indicated in Table 17.2.3.1 for type of storage, commodity, storage height, and building height involved.
The design area shall consist of the most hydraulically demanding area of 12 sprinklers, consisting of four sprinklers on each of three branch lines.
Where required by Table 17.2.3.1, in-rack sprinklers shall be installed at the first tier level at or above one-half of the storage height.
In-rack sprinklers shall be K-8.0 (115) or K-11.2 (160) quick-response, ordinary-temperature sprinklers.
The minimum of 6 in. (152.4 mm) vertical clear space shall be maintained between the sprinkler deflectors and the top of a tier of storage.
The maximum horizontal distance between in-rack sprinklers shall be 5 ft (1.5 m).
In-rack sprinklers shall be located at an intersection of transverse and longitudinal flues while not exceeding the maximum spacing rules.
Where distances between transverse flues exceed the maximum allowable distances, sprinklers shall be installed at the intersection of the transverse and longitudinal flues, and additional sprinklers shall be installed between transverse flues to meet the maximum distance rules.
Where no transverse flues exist, in-rack sprinklers shall not exceed the maximum spacing rules.
The water demand for sprinklers installed in racks shall be based on simultaneous operation of the most hydraulically remote eight sprinklers.
Each of the in-rack sprinklers described in 17.2.3.4.8 shall discharge at a minimum of 60 gpm (227 L/min).
Slatted rack shelves shall be considered equivalent to solid rack shelves where the shelving is not considered open rack shelving or where the requirements of 17.2.4.1 are not met. (See Section C.20.)
A wet pipe system that is designed to provide a minimum of 0.6 gpm/ft2 (24.5 mm/min) density over a minimum area of 2000 ft2 (186 m2) or K-14.0 (200) ESFR sprinklers operating at a minimum of 50 psi (3.5 bar), K-16.8 (240) sprinklers operating at a minimum of 32 psi (1.7 bar), or K-25.2 (360) ESFR sprinklers operating at a minimum of 15 psi (1.0 bar) shall be permitted to protect single- and double-row racks with slatted rack shelving racks where all of the following conditions are met:
  1. Sprinklers shall be K-11.2 (160), K-14.0 (200), or K-16.8 (240) orifice spray sprinklers with a temperature rating of ordinary, intermediate, or high and shall be listed for storage occupancies or shall be K-14.0 (200), K-16.8 (240), or K-25.2 (360) ESFR.
  2. The protected commodities shall be limited to Class I through Class IV, Group B plastics, Group C plastics, cartoned (expanded and nonexpanded) Group A plastics, and exposed (nonexpanded) Group A plastics.
  3. Slats in slatted rack shelving shall be a minimum nominal 2 in. (51 mm) thick by maximum nominal 6 in. (152 mm) wide with the slats held in place by spacers that maintain a minimum 2 in. (51 mm) opening between each slat.
  4. Where K-11.2 (160), K-14.0 (200), or K-16.8 (240) orifice sprinklers are used, there shall be no slatted shelf levels in the rack above 12 ft (3.7 m). Open rack shelving using wire mesh shall be permitted for shelf levels above 12 ft (3.7 m).
  5. Transverse flue spaces at least 3 in. (76 mm) wide shall be provided at least every 10 ft (3.1 m) horizontally.
  6. Longitudinal flue spaces at least 6 in. (152 mm) wide shall be provided for double-row racks. Longitudinal flue spaces shall not be required when ESFR sprinklers are used.
  7. The aisle widths shall be at least 7% ft (2.3 m).
  8. The maximum roof height shall be 27 ft (8.2 m) or 30 ft (9.1 m) where ESFR sprinklers are used.
  9. The maximum storage height shall be 20 ft (6.1 m).
  10. Solid plywood or similar materials shall not be placed on the slatted shelves so that they block the 2 in. (51 mm) spaces between slats, nor shall they be placed on the wire mesh shelves.
Protection of Group A plastics in cartons, expanded or nonexpanded, whether encapsulated or nonencapsulated, shall be permitted using control mode density/area sprinklers in accordance with 17.3.1.
Protection of Group A plastics that are exposed and nonexpanded, whether encapsulated or nonencapsulated, shall be permitted only using in-rack sprinkler arrangements that are specifically permitted to be used with exposed nonexpanded plastics.
For Group A plastic commodities, encapsulated or nonencapsulated, ceiling sprinkler water demand in terms of density [gpm/ft2 (mm/min) ] and area of operation [ft2 (m2) ] shall be selected from Table 17.3.1.3.

Table 17.3.1.3 Control Mode Density/Area Sprinkler Discharge Criteria for Single-, Double-, and Multiple-Row Racks of Plastics Commodities with Storage Over 25 ft (7.6 m) in Height

Storage Height Above Top Level In-Rack Sprinklers Ceiling Sprinklers Density
ft m gpm/ft2 over ft2 mm/min over m2
5 or less 1.5 or less 0.30/2000 12.2/186
Over 5 up to 10 Over 1.5 up to 3.05 0.45/2000 18.3/186
For protection of cartoned storage of Group A plastics, expanded or nonexpanded, whether encapsulated or nonencapsulated, on single-row racks, in-rack sprinklers shall be arranged in accordance with one of the options in Figure 17.3.1.4(a) through Figure 17.3.1.4(c) or Figure 17.3.1.7. The highest level of in-rack sprinklers shall be not more than 10 ft (3.1 m) below the top of storage.

Note: Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately 18 in. (0.5 m) up to 10 ft (3.1 m). Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.1 m) apart vertically.

FIGURE 17.3.1.4(a) In-Rack Sprinkler Arrangement, Group A Plastic Commodities, Single Row Racks, Storage Height Over 25 ft (7.6 m) — Option 1.

Note: Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately 18 in. (0.5 m) up to 10 ft (3.1 m). Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.1 m) apart vertically.

FIGURE 17.3.1.4(b) In-Rack Sprinkler Arrangement, Group A Plastic Commodities, Single-Row Racks, Storage Height Over 25 ft (7.6 m) — Option 2.

Note: Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately 18 in. (0.5 m) up to 10 ft (3.1 m).Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.1 m) apart vertically.

FIGURE 17.3.1.4(c) In-Rack Sprinkler Arrangement, Group A Plastic Commodities, Single-Row Racks, Storage Height Over 25 ft (7.6 m) — Option 3.

For protection of cartoned storage of Group A plastics, expanded or nonexpanded, whether encapsulated or nonencapsulated, on double-row racks, in-rack sprinklers shall be arranged in accordance with one of the double-row rack options in Figure 17.3.1.5(a), Figure 17.3.1.5(b), or Figure 17.3.1.7. The highest level of in-rack sprinklers shall be not more than 10 ft (3.1 m) below the top of storage.

Notes:

  1. Sprinklers and barriers labeled 1 shall be required where loads labeled A or B represent top of storage.
  2. Sprinklers labeled 1 and 2 and barriers labeled 1 shall be required where loads labeled C represent top of storage.
  3. Sprinklers and barriers labeled 1 and 3 shall be required where loads labeled D or E represent top of storage.
  4. For storage higher than represented by loads labeled E, the cycle defined by Notes 2 and 3 is repeated.
  5. Symbol Δ or x indicates face sprinklers on vertical or horizontal stagger.
  6. Symbol o indicates longitudinal flue space sprinklers.
  7. Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately 18 in. (0.5 m) up to 10 ft (3.1 m). Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.1 m) apart vertically.

FIGURE 17.3.1.5(a) In-Rack Sprinkler Arrangement, Group A Plastic Commodities, Storage Height Over 25 ft (7.6 m) — Option 1.

Notes:

  1. Sprinklers labeled 1 shall be required where loads labeled A or B represent top of storage.
  2. Sprinklers labeled 1 and 2 shall be required where loads labeled C represent top of storage.
  3. Sprinklers labeled 1 and 3 shall be required where loads labeled D or E represent top of storage.
  4. For storage higher than loads labeled F, the cycle defined by Notes 2 and 3 is repeated.
  5. Symbol x indicates face and in-rack sprinklers.
  6. Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately 18 in. (0.5 m) up to 10 ft (3.1 m). Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.1 m) apart vertically.

FIGURE 17.3.1.5(b) In-Rack Sprinkler Arrangement, Group A Plastic Commodities, Storage Height Over 25 ft (7.6 m) — Option 2.

Where a single-row rack of cartoned plastic storage is mixed with double-row racks of cartoned plastic storage, either Figure 17.3.1.5(a) or Figure 17.3.1.5(b) shall be permitted to be used in accordance with the corresponding storage height. The highest level of in-rack sprinklers shall be not more than 10 ft (3.1 m) below the top of storage.
For protection of storage of exposed nonexpanded Group A plastics, whether encapsulated or nonencapsulated, on single- racks or double-row racks, in-rack sprinklers shall be arranged in accordance with Figure 17.3.1.7. The highest level of in-rack sprinklers shall be not more than 10 ft (3.1 m) below the top of storage. Where this figure is used, aisles shall be at least 4 ft (1.2 m) wide and the ceiling sprinklers shall be designed for a minimum discharge density of 0.45 gpm/ft2 over 2000 ft2 (18.3 mm/min over 186 m2).

FIGURE 17.3.1.7 In-Rack Sprinkler Arrangement, Cartoned Expanded and Nonexpanded Plastic and Exposed Nonexpanded Plastic Commodities, Single- and Double-Row Racks, Storage Height Over 25 ft (7.6 m).

For protection of storage of exposed nonexpanded Group A plastics, whether encapsulated or nonencapsulated, or cartoned Group A plastics, expanded or nonexpanded, whether encapsulated or nonencapsulated, on multiple-row racks, in-rack sprinklers shall be arranged in accordance with one of the options in Figure 17.3.1.8(a) through Figure 17.3.1.8(f). The highest level of in-rack sprinklers shall be not more than 10 ft (3.1 m) below the top of storage.

Note: Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately 18 in. (0.5 m) up to 10 ft (3.1 m). Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.1 m) apart vertically.

FIGURE 17.3.1.8(a) In-Rack Sprinkler Arrangement, Cartoned Plastic and Exposed Nonexpanded Plastic, Multiple-Row Racks, Storage Height Over 25 ft (7.6 m) — Option 1 [10 ft (3.1 m) Maximum Spacing].

Note: Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately 18 in. (0.5 m) up to 10 ft (3.1 m). Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.1 m) apart vertically.

FIGURE 17.3.1.8(b) In-Rack Sprinkler Arrangement, Cartoned Plastic and Exposed Nonexpanded Plastic, Multiple-Row Racks, Storage Height Over 25 ft (7.6 m) — Option 2 [10 ft (3.1 m) Maximum Spacing].

Note: Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately 18 in. (0.5 m) up to 10 ft (3.1 m). Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.1 m) apart vertically.

FIGURE 17.3.1.8(c) In-Rack Sprinkler Arrangement, Cartoned Plastic and Exposed Nonexpanded Plastic, Multiple-Row Racks, Storage Height Over 25 ft (7.6 m) — Option 1 [5 ft (1.5 m) Maximum Spacing],

Note: Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately 18 in. (0.5 m) up to 10 ft (3.1 m). Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.1 m) apart vertically.

FIGURE 17.3.1.8(d) In-Rack Sprinkler Arrangement, Cartoned Plastic and Uncartoned Unexpanded Plastic, Multiple-Row Racks, Storage Height Over 25 ft (7.6 m) — Option 2 [5 ft (1.5 m) Maximum Spacing].

Note: Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately 18 in. (0.5 m) up to 10 ft (3.1 m). Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.1 m) apart vertically.

FIGURE 17.3.1.8(e) In-Rack Sprinkler Arrangement, Cartoned Plastic and Exposed Nonexpanded Plastic, Multiple-Row Racks, Storage Height Over 25 ft (7.6 m) — Option 3 [5 ft (1.5 m) Maximum Spacing].

Note: Each square represents a storage cube measuring 4 ft to 5 ft (1.2 m to 1.5 m) on a side. Actual load heights can vary from approximately 18 in. (0.5 m) up to 10 ft (3.1 m). Therefore, there could be as few as one load or as many as six or seven loads between in-rack sprinklers that are spaced 10 ft (3.1 m) apart vertically.

FIGURE 17.3.1.8(f) In-Rack Sprinkler Arrangement, Cartoned Plastic and Exposed Nonexpanded Plastic, Multiple-Row Racks, Storage Height Over 25 ft (7.6 m) — Option 4 [5 ft (1.5 m) Maximum Spacing].

The minimum of 6 in. (152 mm) vertical clear space shall be maintained between the in-rack sprinkler deflectors and the top of a tier of storage.
In-rack sprinklers shall be located at an intersection of transverse and longitudinal flues while not exceeding the maximum spacing rules.
Where distances between transverse flues exceed the maximum allowable distances, sprinklers shall be installed at the intersection of the transverse and longitudinal flues, and additional sprinklers shall be installed between transverse flues to meet the maximum distance rules.
Where no transverse flues exist, in-rack sprinklers shall not exceed the maximum spacing rules.
The water demand for sprinklers installed in racks shall be based on simultaneous operation of the most hydraulically remote sprinklers as follows:
  1. Eight sprinklers where only one level is installed in racks
  2. Fourteen sprinklers (seven on each top two levels) where more than one level is installed in racks
Sprinklers in racks shall discharge at not less than 30 gpm (113.6 L/min).
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 17.3.1.15 to the water supply for sprinklers determined in Section 17.3.

Table 17.3.1.15 Hose Stream Allowance and Water Supply Duration Requirements for Rack Storage of Plastics Commodities Stored Over 25 ft (7.6 m) in Height

Commodity Classification Storage Height Inside Hose Total Combined Inside and Outside Hose Duration (minutes)
ft m gpm L/min gpm L/min
Plastic >25 >7.6 0, 50, or 100 0, 190, or 380 500 1900 120
Protection of single-, double-, and multiple-row rack storage without solid shelves for cartoned, nonexpanded plastic commodities shall be in accordance with Table 17.3.2.1.

Table 17.3.2.1 CMSA Sprinkler Design Criteria for Single-, Double-, and Multiple-Row Racks Without Solid Shelves of Plastics Commodities Stored Over 25 ft (7.6 m) in Height

Storage Arrangement Commodity Class Maximum Storage Height Maximum Ceiling/Roof Height K-Factor/Orientation Type of System Number of Design Sprinklers Minimum Operating Pressure
ft m ft m psi bar
Single-, double-, and multiple-row racks without solid shelves (no open-top containers) Cartoned, nonexpanded plastics 30 9.1 35 10.6 19.6 (280) Pendent Wet 15 25 1.7
35 10.6 40 12.1 19.6 (280) Pendent Wet 15 30 2.1
Protection shall be provided as specified in Table 17.3.2.1 or appropriate NFPA standards in terms of minimum operating pressure and the number of sprinklers to be included in the design area.
The design area shall be a rectangular area having a dimension parallel to the branch lines at least 1.2 times the square root of the area protected by the number of sprinklers to be included in the design area. Any fractional sprinkler shall be included in the design area.
Building steel shall not require special protection where Table 17.3.2.1 is applied as appropriate for the storage configuration.
Protection of single-, double-, and multiple-row rack storage of cartoned or exposed, nonexpanded plastic shall be in accordance with Table 17.3.3.1.

Table 17.3.3.1 ESFR Protection of Rack Storage Without Solid Shelves of Plastics Commodities Stored Over 25 ft (7.6 m) in Height

Storage Arrangement Commodity Maximum Storage Height Maximum Ceiling/Roof Height Nominal K-Factor Orientation Minimum Operating Pressure In-Rack Sprinkler Requirements
ft m ft m psi bar
Single-, double-, and multiple-row racks (no open-top containers) Cartoned nonexpanded 30 9.1 35 10.7 14.0 (200) Upright/pendent 75 5.2 No
16.8(240) Upright/pendent 52 3.6 No
22.4(320) Pendent 35 2.4 No
25.2(360) Pendent 20 1.4 No
40 12.2 16.8(240) Pendent 52 3.6 No
22.4(320) Pendent 40 2.8 No
25.2(360) Pendent 25 1.7 No
45 13.7 14.0(200) Pendent 90 6.2 Yes
16.8(240) Pendent 63 4.3 Yes
22.4(320) Pendent 40 2.8 No
25.2(360) Pendent 40 2.8 No
35 10.7 40 12.2 16.8(240) Pendent 52 3.6 No
25.2(360) Pendent 25 1.7 No
45 13.7 14.0(200) Pendent 90 6.2 Yes
16.8(240) Pendent 63 4.3 Yes
22.4(320) Pendent 40 2.8 No
25.2(320) Pendent 40 2.8 No
40 12.2 45 13.7 14.0(200) Pendent 90 6.2 Yes
16.8(240) Pendent 63 4.3 Yes
22.4(320) Pendent 40 2.8 No
25.2(320) Pendent 40 2.8 No
Exposed nonexpanded 30 9.1 35 10.7 14.0(200) Pendent 75 5.2 No
16.8(240) Pendent 52 3.6 No
40 12.2 16.8(240) Pendent 52 3.6 No
22.4(320) Pendent 50 3.4 No
25.2(320) Pendent 50 3.4 No
45 13.7 14.0(200) Pendent 90 6.2 Yes
16.8(240) Pendent 63 4.3 Yes
35 10.7 40 12.2 16.8(240) Pendent 52 3.6 No
22.4(320) Pendent 50 3.4 No
25.2(320) Pendent 50 3.4 No
45 13.7 14.0(200) Pendent 90 6.2 Yes
16.8(240) Pendent 63 4.3 Yes
40 12.2 45 13.7 14.0(200) Pendent 90 6.2 Yes
16.8(240) Pendent 63 4.3 Yes
ESFR sprinklers shall not be permitted to protect storage on solid shelf racks unless the solid shelf racks are protected with in-rack sprinklers in accordance with 17.1.5.
ESFR sprinklers shall not be permitted to protect storage with open-top containers.
ESFR sprinkler systems shall be designed such that the minimum operating pressure is not less than that indicated in Table 17.3.3.1 for type of storage, commodity, storage height, and building height involved.
The design area shall consist of the most hydraulically demanding area of 12 sprinklers, consisting of four sprinklers on each of three branch lines.
Where required by Table 17.3.3.1, one level of K-8.0 (115) or K-11.2 (160) quick-response, ordinary-temperature in-rack sprinklers shall be installed at the tier level closest to but not exceeding one-half of the maximum storage height.
In-rack sprinkler hydraulic design criteria shall be the most hydraulically remote eight sprinklers at 60 gpm (227 L/min).
In-rack sprinklers shall be located at the intersection of the longitudinal and transverse flue space.
Horizontal spacing shall not be permitted to exceed 5 ft (1.5 m) intervals.
The minimum of 6 in. (152 mm) vertical clear space shall be maintained between the sprinkler deflectors and the top of a tier of storage.
In-rack sprinklers shall be located at an intersection of transverse and longitudinal flues while not exceeding the maximum spacing rules.
Where distances between transverse flues exceed the maximum allowable distances, sprinklers shall be installed at the intersection of the transverse and longitudinal flues, and additional sprinklers shall be installed between transverse flues to meet the maximum distance rules.
Where no transverse flues exist, in-rack sprinklers shall not exceed the maximum spacing rules.
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