Why In-Rack Sprinklers?

Tom MulterVice President, Product TechnologyThe Reliable Automatic Sprinkler Co., Inc.

As an industry, we have spent the last 30 years trying to eliminate in-rack sprinklers.

Are they coming back?

Higher buildings using automated storage and retrieval systems

More exposed plastic storage

Lower water demands by using horizontal in-rack barriers.

Using K- 360 ECs as in-rack sprinklers

.

Fire Protection Research Foundation:

Project for Rack Storage of Exposed Expanded Group A

Plastics

Outside the scope of NFPA 13

Ceiling sprinklers with vertical barriers @

4.8 m intervals

Testing carried out at Underwriters Laboratories (UL)

Standard fuel package for EEP tests using polystyrene meat trays.

Rack Storage of Exposed Expanded Group A Plastics

Ceiling Height = 12.2 mStorage Height = 10.7 m

10 mm Plywood Horizontal Barrier at 6.1 m

Ceiling Sprinklers K-16.8 (240), 100°C ESFR @ 3.4 bar

In-Rack Sprinklers K-25.2 (360)EC, 100°C Pendent @ 2.1 bar

Reliable Model

N252 EC Pendent

•K-360•UL Listed, FM approved as a ceiling

application sprinkler• 100°C version was used for all testing

Patented

The Model N252 EC Pendent Sprinkler is a component of the N-Rack-EC™ Fire Protection System – Patent Pending

Minimum:100mm clearance above commodity50mm deflector distance below beam

Target Array

Spray Pattern @ 2.1 bar

1.2 m aisle width

4.2 m

10 mm plywood

barrier at 6.1 m level

N252 EC Sprinklers Centered in Longitudinal Flue and Centered

Between Rack Uprights = 2.5 m on center.

The horizontal barrier was left open at the rack uprights and no sprinklers are installed in the transverse flue or at the face of the racks.

Opened one (1) sprinkler at the

ceiling @ 1 minute/2 seconds

3.4 bar and 830 L/pm

Opened two (2) sprinklers in the rack @ 49 and 52 seconds

2.1 bar and 520 L/pm each or 1040 L/pm total

Results:

Before

After

N-252 EC with

Horizontal Barrier

AfterK-25 ESFR

with Vertical Barriers

Proposed DesignCeiling Temp bar L/pm

per sprNo. of sprs

calculated

System Demand in

L/pm

K-16.8 ESFR 100° 3.4 450 12 5400+

In-Rack Temp bar L/pm per spr

No. of sprs

calculated

System Demand in

L/pm

N-252 EC Pendent

100° 2.1 520 3 1560+

The in-rack sprinkler demand would not be added to the ceiling demand because of the horizontal barrier. The system demand

would be the ceiling demand at 5400+ L/pm

For comparison: Actual water demands will be higher based upon hydraulic calculations.

Proposed bar L/pm per spr

No. of sprs calculated

Hose Stream in

L/pm

Total System Demand in

L/pm

K-16.8 ESFR & N252 EC In-Rack

3.4 450 12 950 6350+

FM DS 8-9 bar L/pm per spr

No. of sprs calculated

Hose Stream in

L/pm

Total System Demand in

L/pm

K-25.2 ESFR

5.2 830 20 1900 18,500+ 2 hours

Existing Ceiling Sprinkler Design (FM) for Exposed Expanded Plastics Stored in Open Racks with

12.2 m ceiling and 10.7 m of storage

For comparison: Actual water demands will be higher based upon hydraulic calculations.

Proposed bar L/pm per spr

No. of sprs calculated

Hose Stream in

L/pm

Total System Demand in

L/pm

K-16.8 ESFR & N252 EC In-Rack

3.4 520 12 950 6350+

NFPA 13 bar L/pm per spr

No. of sprs calculated

Hose Stream in

L/pm

Total System Demand in

L/pm

K-25.2 ESFR

4.1 740 15 950 12,050+

Proposed Design (NFPA 13 -2016) for Exposed Expanded Plastics Stored in Open

Racks using Vertical Barriers at 16’ Intervals 12.2 m ceiling

and 10.7 m of storage

For comparison: Actual water demands will be higher based upon hydraulic calculations.

Second Phase of TestingCartoned Unexpanded, Group A Plastics

Primary Goals:• To reduce the number of in-rack sprinklers when

compared to standard in-rack schemes and to reduce water demands.

• To have a significant reduction of water demand for buildings up to 14.6 m high that can currently be protected by ceiling-only sprinklers.

• Protect buildings higher than 14.6 m with low water demands.

• Retrofit existing facilities, where the storage commodities or methods of storage have changed, without changing the existing ceiling sprinklers and/or increasing water flows or pressures.

To Date: Four Additional Fire Tests

Test 2 with Cartoned Unexpanded Plastics

Objective:

By using a horizontal barrier at 9.1 m, the total water demand and pressure would be lower than existing ceiling-only sprinkler designs. Also to protect buildings higher than 14.6 m with one level of in-rack sprinklers.

Test 2

Ceiling Height 14.6 m

Storage Height 13.1 m on double row racks

Horizontal Barrier 1 at the 9.1 m level

Ignition Point At upright- face (aisle)

Ceiling Sprinklers N 252 EC pendent @ 18.2 m² and 2.1 barIn-Rack Sprinklers N 252 EC 100° pendent @ 2.1 bar

Ceiling Spr. Operated 1 @ 3:01 minutesIn-Rack Spr. Operated 2 - 1st @ 2:53 2nd @ 2:59Peak Steel Temp – Ceil. 67° C

Proposed Design for Cartoned Unexpanded Plastics Stored in Racks up to and potentially over 14.6 m with Horizontal Barriers

at the 9.1 m level

Ceiling bar L/pm per spr

No. of sprs .

calculated

System Demand in

L/pm

N-252 EC Pendent @ 18.2 m²/spr

2.1 520 6 3120+

The ceiling sprinkler design is based upon NFPA 13 and FM Global requirements for 9.1 m high ceilings with ceiling-only sprinkler protection.

In-Rack bar L/pm per spr

No. of sprs .

calculated

System Demand in

L/pm

N-252 EC Pendent

2.1 520 3 1560+

The in-rack sprinkler demand would not be added to the ceiling demand because of the horizontal barrier. The total system demand would be the ceiling demand at

3120+ L/pm

For comparison: Actual water demands will be higher based upon hydraulic calculations.

Current UL Listings for 14.6 m High Buildings-Class 4/Group A Plastics

K22/K 25 ESFR @ 9.3 m² Proposed Design - N252 EC @ 18.2 m²

Sprinkler demand 7550+ L/pm/8100+ L/pm 3120+ L/pm

Hose stream demand 950 L/pm 950 L/pm

Total demand 8500+ L/pm/9050+ L/pm 4070+ L/pm

Future Protection for 14.6 m+ High Buildings- Class 4/Group A PlasticsK22/K 25 ESFR Proposed Design - N252 EC

Sprinkler demand NA 3120+ L/pm

Hose stream demand NA 950 L/pm

Total demand NA 4070+ L/pm

Current UL Listings for 13.7 m High Buildings-Class 4/Group A Plastics

K22/K 25 ESFR @ 9.3 m² Proposed Design - N252 EC @ 18.2 m²

Sprinkler demand 6440+ L/pm/7240+ L/pm 3120+ L/pm

Hose stream demand 950 L/pm 950 L/pm

Total demand 8390+ L/pm/8190+ L/pm 4070+ L/pm

The Future of Storage ProtectionTests 3, 4, & 5

12.2 m/18.2 m

6.1 m/9.1 m

18.3 m/27.3 m

24.4 m/36.4 m

Test 3 with Cartoned Unexpanded Plastics

Objective:

By using multiple horizontal barriers at 6.1 m intervals, high bay buildings may be protected with fewer in-rack sprinklers. No face sprinklers and no sprinklers in transverse flues.

Test 3

Ceiling Height 14.6 m

Storage Height 13.1 m on double row racks

Horizontal Barrier 2 – 6.1 m level & 12.2 m level

Ignition Point Offset in Transverse Flue

Ceiling Sprinklers N 252 EC pendent @ 18.2 m² and 0 psiIn-Rack Sprinklers N 252 EC 100° pendent @ 2.1 bar

Ceiling Spr. Operated 3 – 1st @ 20:40 last @ 21:15 In-Rack Spr. Operated 5 - 1st @ 1:13 in 6.1 m level

1st in 12.2 m level @ 13:40Peak Steel Temp – Ceil. 235° C

Testing with a Continuous Barrier Across the Uprights

Tests 1, 2, & 3 Tests 4 & 5

Test 4 with Cartoned Unexpanded PlasticsObjective:

By using multiple continuous horizontal barriers at 6.1 intervals, high bay buildings may be protected with fewer in-rack sprinklers. No face sprinklers and no sprinklers in transverse flues. Fires may be contained between barriers with no horizontal spread.

Test 4

Ceiling Height 14.6 m

Storage Height 13.1 m on double row racks

Horizontal Barrier 2 – 6.1 m level & 12.2 m level

Ignition Point Offset in Transverse Flue

Ceiling Sprinklers N 252 EC pendent @ 18.2 m² and 0 psiIn-Rack Sprinklers N 252 EC 100° pendent @ 2.1 bar

Ceiling Spr. Operated NoneIn-Rack Spr. Operated 4 – 6.1 m level only 1st @ 1:26 4th @ 1:36

Peak Steel Temp – Ceil. 28° C

Test 5 with Cartoned Unexpanded PlasticsObjective:

By using multiple continuous horizontal barriers at 9.1 m intervals, high bay buildings may be protected with fewer in-rack sprinklers. No face sprinklers and no sprinklers in transverse flues. Fires may be contained between barriers with no horizontal spread.

Test 5

Ceiling Height 14.6 m

Storage Height 13.1 m on double row racks

Horizontal Barrier 1 – 9.1 m level

Ignition Point Offset in Transverse Flue

Ceiling Sprinklers N 252 EC pendent @ 18.2 m² and 0 psiIn-Rack Sprinklers N 252 EC 100° pendent @ 2.1 bar

Ceiling Spr. Operated NoneIn-Rack Spr. Operated 3 -9.1 m level 1st @ 1.14 3rd @ 1.15

Peak Steel Temp – Ceil. 28° C

View at 9.1 m Level Horizontal Barrier

In Conclusion:

For storage of exposed expanded plastics in double row, open framed racks:

By installing a horizontal barrier at the 6.1 m level with the Model N252 EC Pendent, used as in-rack sprinklers, buildings up to 12.2 m high will have lower water demands than using ceiling-only sprinkler protection.

For storage of cartoned unexpanded plastics in double row, open framed racks:

By installing a horizontal barrier at the 9.1 m level with the Model N252 EC Pendent, used as in-rack sprinklers, buildings up to 14.6 m high will have lower water demands than using ceiling-only sprinkler protection.

Retrofit applications where storage commodities or methods of storage have changed, adding a horizontal barrier or barriers with the Model N252 EC Pendent, used as in-rack sprinklers, may eliminate changing ceiling sprinklers or water supplies.

For storage of cartoned unexpanded plastics in double row, open framed racks:

By installing continuous horizontal barriers at 6.1 m to 9.1 m levels with the Model N252 EC Pendent, used as in-rack sprinklers, buildings over 14.6 m high may be protected while reducing the number of sprinklers required by current in-rack schemes. Fires may be contained between barriers with no horizontal spread.

Retrofit applications of high bay buildings where storage commodities or methods of storage have changed, adding continuous horizontal barriers with the Model N252 EC Pendent, used as in-rack sprinklers, may eliminate changing ceiling sprinklers or water supplies while greatly reducing the quantity of in-rack sprinklers.