In rack Design and Storage Height Limitation. 2

[NJ1]

Ok. I went to job site today and this if what I found.

Hydraulic Name Plate Info. (Each Hydraulic Plate)

Number of Sprinklers 320
Density .6 gpm sq ft
Design Area of Coverage 2500 sq ft

System Demand
GPM Discharge 1563 GPM
Residual Pressure at base of riser 115 psi

Static pressure at riser is 140 psi
1500 gpm fire pump
6" Mains w/ 2" branch lines gridded systems
3/4" sprinkler uprights 286 degrees
10 risers

One entire sprinkler system covers the portion of rack storage without In-Rack sprinklers.
Deck is about 30'
Storage height is about 27'
Product stored is textiles (clothes in boxes)palletized

Adequate or not?

 

[stookeyfpe]

Natural fibers or synthetic fibers in the boxes?
Wood or plastic pallets?
Encapsulated?
Double-row or multiple row racks?
Aisle width?
Wet or dry pipe?
Roof slope < 2:12 pitch?
3/4 inch sprinklers. Are they K = 11.2 sprinklers?

 

[NJ1]

Natural fibers or synthetic fibers in the boxes? Mixed
Wood or plastic pallets? Wood
Encapsulated? No
Double-row or multiple row racks? Multiple row
Aisle width? 8'
Wet or dry pipe? wet
Roof slope < 2:12 pitch? Flat or maybe 2:12 pitch
3/4 inch sprinklers. Are they K = 11.2 sprinklers? yes 11.2

To clarify not the entire portion of that particular sprinkler system (riser) is in rack. Maybe only about 30%-40%

 

[stookeyfpe]

You have the required information. Go forth and calculate the design and confirm the system's adequacy.

 

[NJ1]

Yeah. One Engineer did that and he claims to be adequate. I am just looking for second opinion.

 

[stookeyfpe]

Based on the height of storage, the sprinklers being control mode density/area, and treating the stored commodity as a unexpanded, cartoned Group A plastic, my opinion is the design doesn't comply with NFPA 13 (2010 ed.), Section 17.3.1.2. From your explanation, it appears that in-rack sprinklers or in-rack sprinklers and horizontal barriers are required, depending on the design option selected. See Figures 17.3.1.2(a) or (b).

 

[NJ1]

OK so I punched the numbers myself and this is what I got.

If they are 286 degree heads (which they are), they need 0.345gpm / 2500 sq. ft. for 20’ of storage. At 25’ it’s 0.345 x 1.75 = 0.60 / 2500. (Refer to hydro plate)
This put their system design at the edge with no safety margin. Pretty much at the risk line.
If they are 155/165 heads it doesn’t work.
Their storage needs to be at 23' to maintain a small safety margin at least.

 

[TravisMack]

Unless you are using heads with a special application, I believe that all multi-row over 25' will require some level of in-rack sprinklers.

2500 sq ft design areas are typically seen with extra hazard and solid piled plastics. Rack design areas are typically 2000 sq ft. Something does not seem right in all of this.

Travis Mack
MFP Design, LLC

http://www.mfpdesign.com

 

[NJ1]

That is the whole whole point. At 25' with 155-165 degree heads it wont work at all. If he can bring that elevation down to 23' it could work with 286 degree heads. 155-165 degree heads will not work period.

Can anyone please disagree.
Take also in consideration that the existing hydraulic data is about 15-20 years old. That could bring this down to 20' height easily granted pump still delivers same output since that date.

 

[LCREP]

See below , I think it is a class IV commodity not Group A Plastic, see below

NFPA 13, 2010, Table A.5.6.3

Cloth
Cartoned and not cartoned
- Natural fiber, viscose Class III

- Syntheticd Class IV

BUT even if class IV, still inadequate without in-racks. See table
Table 16.3.1.2 Multiple-Row Racks of Class I Through Class IV Commodities Stored Over 25 ft (7.6 m) in Height

The 2500 design area gave it away, AND no in-racks. Does not sunrise me many warehouse designs are wrong, in particular when they that old and the occupancy has changed many times.

****************************************
Fire Sprinklers Save Firefighters’ Lives Too!

 

[stookeyfpe]

LCREP (Tom):

I ask a different question and that is, how much of this commodity is not plastic? I bought a Carhart hooded jacket last summer for the nasty Texas winter weather (sarcasm alert). It's essentially 90% synthetics and checking on the materials, they are all Spandex derivative materials.

Now my one jacket does not make for a prudent commodity classification. However, I sincerely disagree with the NFPA 13 TC and there nonmandatory Annex. I find more problems in NFPA 13 Chapter 5 Annex A than solutions. In my world, it's safer to assume the warehouse will store plastics rather than assume it's a lower class commodity.

NJ1 asked for an opinion (from an engineer no less) and I offered mine. His building has got issues or is one pallet load away from becoming noncompliant depending how the answer is presented.

 

[LCREP]

Stookey (Scott)

I looked at this from an insurance point of view, so I reviewed NFPA 13, our internal commodity list and FM Data Sheet 8-1 COMMODITY CLASSIFICATION, for synthetic fabric or clothing it is classified a class IV. Does this make it the correct call, perhaps not, but I would be OK with it AND would pay the loss if a fire happen.

What gets me NJ1 indicates he had an engineer look at it and they said it was OK. I wonder what they used as the commodity and protection criteria??


Bottom line even if this was a class one commodity , metal in a cardboard box on a wood pallet, without in-racks as per NFPA 13 Table 16.3.1.2 the protection is not adequate.




****************************************
Fire Sprinklers Save Firefighters’ Lives Too!

 

[LCREP]

Stookey (Scott)

I looked at this from an insurance point of view, so I reviewed NFPA 13, our internal commodity list and FM Data Sheet 8-1 COMMODITY CLASSIFICATION, for synthetic fabric or clothing it is classified a class IV. Does this make it the correct call, perhaps not, but I would be OK with it AND would pay the loss if a fire happen.

What gets me NJ1 indicates he had an engineer look at it and they said it was OK. I wonder what they used as the commodity and protection criteria??


Bottom line even if this was a class one commodity , metal in a cardboard box on a wood pallet, without in-racks as per NFPA 13 Table 16.3.1.2 the protection is not adequate.

****************************************
Fire Sprinklers Save Firefighters’ Lives Too!

 

[SprinklerDesigner2]

All other issues aside temperature doesn't matter.

NJ1
7 Mar 12 19:49
That is the whole whole point. At 25' with 155-165 degree heads it wont work at all. If he can bring that elevation down to 23' it could work with 286 degree heads. 155-165 degree heads will not work period.

From NFPA #13 2002 Edition

12.2.2.1.7 Ordinary- and intermediate-temperature sprinklers with K-factors of 11.2 or larger, where listed for storage, shall be permitted to use the densities from the high temperature curves of Figure 12.2.2.1.5.2.

 

[SprinklerDesigner2]

All other issues aside temperature doesn't matter.

NJ1
7 Mar 12 19:49
That is the whole whole point. At 25' with 155-165 degree heads it wont work at all. If he can bring that elevation down to 23' it could work with 286 degree heads. 155-165 degree heads will not work period.

From NFPA #13 2002 Edition

12.2.2.1.7 Ordinary- and intermediate-temperature sprinklers with K-factors of 11.2 or larger, where listed for storage, shall be permitted to use the densities from the high temperature curves of Figure 12.2.2.1.5.2.

 

[NJ1]

My only problem is that these hydraulic plates are over 15 years.
Another engineer looked at is and said same thing. It works with 285 sprinkler heads if kept lower than 23'

The only problem is that relying on data 15-20 years old could be problematic. Does the fore pump still performs at 150% ? I dont know.

We will see. I open some boxes they are mixed textiles. In other words it falls under fabrics.
I read NFPA 13-Storage Chapter yesterday about 3 times. I think it could work at 23' height or lower. Lets see. This right here is not my strong side of the field

 

[TravisMack]

Per Table 16.2.1.3.3.1 Multiple-Row Racks — Rack Depth Up to and Including 16 ft (4.9 m), Aisles 8 ft (2.4 m) or Wider, Storage
Height Over 12 ft (3.7 m) Up to 25 ft (7.6 m), you need in-rack sprinklers for anything over 15'.

So, if this is multiple row racks like you state, without in-racks, it is non compliant, unless you are using a specific application sprinkler. But, based on the age of the system, I doubt the specific application sprinkler was available at the time.

Travis Mack
MFP Design, LLC

http://www.mfpdesign.com

 

[LCREP]

NJ1

If you are in NJ check out training at

http://www.chubb.com/lcu,

they have a 2 day warehouse seminar which covers NFPA 13 and storage.

****************************************
Fire Sprinklers Save Firefighters’ Lives Too!

 

[NJ1]

Yes I have heard of chubb. Let me tell you about chubb. The guy that teaches inspection, testing and maintenance does not ever have a certification. So why would I even want to do that. I just going to get more opinions since this is based on old data. I will keep you guys posted.

 

[LCREP]

NJ1

I understand Chubb provides CEU seminars for NJ inspectors for the Division of Fire Safety and the Building Department, see brochure from the DCA below. I would think if the 2 organizations that regulate fire safety and building construction in NJ uses Chubb to train their inspectors they must know what they are doing.

http://www.state.nj.us/dca/divisions/codes/forms/pdf_licensing/ucc_spring_2011_brochure.pdf

****************************************
Fire Sprinklers Save Firefighters’ Lives Too!