In-Rack Fire Sprinkler Solutions
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 30, 2021 Edition
(See NFPA 30 Section 16.5.2.13 for complete details)
The new design criteria contained in Section 16.5.2.13 uses new Fire Protection Design Scheme “E” in Section 16.6.5. The design criteria is intended to protect Class II and Class III combustible liquids in metal containers up to 60 gallons (228 L), stored in racks up to 34 ft (10.2 m) tall, under ceilings up to 48 ft (14.4 m ) in height.
The protection scheme allows sprinkler spacing in racks up to 10 ft (3 m) apart in single‐ and double‐row racks, without the need for “face sprinklers”. The scheme is also hydraulically efficient by not requiring standard‐response ceiling‐level sprinklers to be included in the hydraulic calculations for the in‐rack sprinkler system.
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)
