Modern In-rack Sprinkler Systems

With taller storage buildings and a greater recognition of high hazard commodities, a new generation of in-rack sprinkler systems have been developed. Reliable developed the N-RACK-EC® Extended Coverage In-rack Sprinkler System to substantially reduce the number of in-rack sprinklers required while maintaining a low water demand. In-rack sprinkler systems using min. K8.0 quick-response sprinklers with horizontal barriers or ESFR sprinklers as in-rack sprinklers are also available.

The “Virtual Floor”

Several modern in-rack sprinkler systems are now available that use a “Virtual Floor” concept. These in-rack sprinkler systems are designed to protect commodity stored in racks without assistance from the ceiling sprinkler system. This allows the ceiling sprinkler system to be designed independently of the in-rack sprinkler system by considering the highest level of in-rack sprinklers as a “virtual floor”. See the specific criteria in NFPA 13, 2019 edition, Section 25.8 and FM Data Sheet 8-9 Section 2.3.6 for complete details and limitations.

N-RACK-EC® in NFPA 13, 2019 Edition

(See NFPA 13 Section 25.8.3 for complete details)

Rack Types

Single-, Double-, and Multiple-row racks up to 15′ 6″ (4.7m) deep

Ceiling/Storage Height

Unlimited

Commodities

• Class I-IV
• Group A plastic commodity (Cartoned, Exposed, Expanded, and Nonexpanded)

Ceiling Sprinklers

Based only on commodity not protected by in-rack sprinkler system

In-rack Sprinklers

K25.2 Intermediate Temperature Extended Coverage Pendent Sprinklers: Reliable Model N252EC 212°F (100°C)

Max. Vertical Spacing of In-rack Levels

• 20′ (6.1m) for non-cartoned Group A plastic commodity
• 30′ (9.1m) for Class I-IV and cartoned Group A plastic commodity
• Horizontal barriers above in-rack levels

Max. Horizontal Spacing of In-rack Sprinklers

10′ (3.1m)

Use NFPA 13 Example Double-row Rack Layout Figure (attached)

N-RACK-EC® in FM Data Sheet 8-9

(See FM Data Sheet 8-9 Section 2.3.6.8 for complete details)

Rack Types

Open Frame Single-, Double-, and Multiple-row racks

Ceiling/Storage Height

Unlimited

Commodities

• Class I-IV
• Cartoned Unexpanded Group A plastic commodity

Ceiling Sprinklers

Based on distance from highest in-rack level to ceiling (“Virtual Floor”)

In-rack Sprinklers

Quick-response K25.2EC Pendent Storage Sprinklers: Reliable Model N252EC

Max. Vertical Spacing of In-rack Levels

• 30′ (9.0m)
• Horizontal barriers above in-rack levels

Max. Horizontal Spacing of In-rack Sprinklers

8′ 3″ (2.5m)

Use FM Data Sheet 8-9 Example Double-row Rack Layout Figure (attached)