Cotton storage definition of "tiered" storage and older #231 standards

[SprinklerDesigner2]

From 2002 12.5.2.1 "For tiered or rack storage up to a nominal 15 ft (4.6 m) in height, sprinkler discharge densities and areas of application shall be in accordance with Table 12.5.2.1."

That is the only place I see the word "tiered" and it isn't in the definitions.

Is "tiered" just another way of saying "stacked"? I am pretty sure it is but would feel better with confirmation.

A picture being worth a thousand words is the cotton in this warehouse "tiered"?

http://img94.imageshack.us/img94/2259/tieredcotton.jpg

From the "Origin and Development of NFPA 13"

The 1999 edition encompassed a major reorganization of NFPA’s Sprinkler Project that included the establishment of a Technical Correlating Committee on Automatic Sprinkler Systems and four new sprinkler systems technical committees, the consolidation of NFPA’s sprinkler system design and installation requirements, and the implementation of numerous technical changes.

The scope of NFPA 13 was expanded to address all sprinkler system applications. The 1999 edition contained information on the installation of underground pipe from NFPA 24 and sprinkler system discharge criteria for on-floor and rack storage of Class I, II, III, IV, and plastic commodities, rubber tires, baled cotton, and roll paper that were previously located in NFPA 231, 231C, 231D, 231E, and 231F.

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I thought I had an older copy (1980's) of #231, can't find it, but wasn't it pretty specific the 231 standard only covered storage above 12' even if it was cotton or was cotton storage even separately addressed?

The reason I ask is we've been asked to work up a price for an expansion on an dry system covering an existing warehouse built in 1988 fed from city water. I haven't bothered running a hydrant flow test, because with a 2" main drain test of 50 psi static and 40 psi residual on an 8" manifolded riser, I just see it as a waste of time and energy. No way you are going to get .25 gpm over 3.900 W/ 500 gpm hose.

So I guess what I am asking is was there an opening in the 1986 standard that would have allowed the use of an Ordinary Hazard pipe schedule system as long as storage didn't exceed 12'?

It is noted there were hydraulic calculations involved with pipe schedule systems and the requirements for Ord Haz Group II were pretty high. I seem to remember 15 psi plus the height with 1,200 gpm at the base of the riser but it's been a long time.

I seem to remember Ord III being up to the authority having jurisdiction.

 

[LCREP]

NFPA 13, 2010 ed

3.9.6.2* Tiered Storage. An arrangement in which bales are
stored directly on the floor, two or more bales high.

That is what you have.

A.3.9.6.2 Tiered Storage. Untiered storage limits storage to
the height of one bale, on side or on end. Sprinkler protection
designed on this basis would likely prohibit future tiering without redesign of the sprinkler system.

So I guess what I am asking is was there an opening in the 1986 standard that would have allowed the use of an Ordinary Hazard pipe schedule system as long as storage didn't exceed 12'?

IF it is class I-V commodity OR Grp A Platic, YES the 12' rule applies. BUT since NFPA has specific requirements for cotton storage, it does not apply.



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Fire Sprinklers Save Firefighters’ Lives Too!

 

[SprinklerDesigner2]

I see, they added the definition in the 2010 edition which I suppose I should get. Georgia is still on the 2002.

"IF it is class I-V commodity OR Grp A Platic, YES the 12' rule applies. BUT since NFPA has specific requirements for cotton storage, it does not apply."

Of course it does but what I was asking was what did the #231 standard read in 1986? I could be wrong, I was in the north midwest so I never had to deal with cotton issues, but I don't remember seeing baled cotton as a separate issue in the 1986 edition.

 

[stookeyfpe]

SD2:

A change was made to the 2006 IFC to address the storage of compressed cotton bales for the purpose of classifying the bales as combustible fibers. I recall that the cotton ginners were not big on providing sprinkler protection and that some fire testing confirmed that densely packed cotton bales represent a fairly limited fire risk.

Does this information help and do you need more data? Sounds like your totally focused on the adequacy of the automatic sprinkler system.

 

[SprinklerDesigner2]

Stookey,

There's something about cotton storage that fascinates me but I am not sure what it is.

Maybe it is the amount of money a gin can put in a single storage facility. NFPA #13 claims the bales weigh in at 500 lbs but what I learned is at some gins these same size bales weigh in at anywhere from 800 to 1,000 lbs and it you try to punch your fist into one you learn they are very much compressed and dense. It isn't cotton it almost feels like concrete.

It's awe inspiring to be out in the middle of nowhere (there are places so far removed they have yet to get word they lost the civil war) and find a ready to fall down warehouse with 75,000 bales of cotton when cotton is selling for $1.18/lb.

The gin people, seems like they come from generations of ginning families, tell me you can't put a fire out inside a bale of cotton you have to remove it from the building and allow it to burn itself out. I am told the fire doesn't get hot enough to activate sprinklers they simply smolder until everything is consumed.

I am told the process of ginning itself starts a lot of fires in what they call "hot bales". They used to use probes in the search for hot bales but now I understand they have new laser tools to find them but I have no idea how they work. I am told you can have a fire inside a bale, sit on the bale to eat your lunch and never have a clue there's a smoldering fire a few inches away from your butt.

I learned you'll never put sprinklers in a cotton seed warehouse. An unbelievable amount of money in cotton seed and they would rather deal with fire than water damage.

I am a sprinkler technician and the only thing I know is to follow the standard which is pretty easy in the case of cotton. .25/3,900 +500 hose is about as easy as it gets. I always use 286 heads because the metal buildings used are the cheapest possible and do not have insulation. Lacking insulation you better use high temperature sprinklers in the deep south where it does get warm in the summer. That all said if you can point me to some data I would appreciate it just for my own knowledge.

 

[SprinklerDesigner2]

"Does this information help and do you need more data? Sounds like your totally focused on the adequacy of the automatic sprinkler system."

This is for the engineers and not me. I found this but on page 5 of the pdf there is this:

Recommendations for New Warehouse Construction, Significant Modification, or Redesignation of Warehouse Space
1. Identify and contact local code enforcing officials who can help you determine which codes are in affect for your area.
2. Before construction begins, confirm what code requirements and limitations will be placed on your construction project; and
3. Contact your Insurance Carrier to see if they have any special requirements that are not covered by existing codes.
The requirements for storage of baled cotton that the insurance companies have used for the past 25 years and more will not be changed by these actions.

http://www.cotton.org/beltwide/proceedings/2005-2010/data/conferences/2006/pdfs/689-693.pdf