In my case the rack uprights were 10' 4" but with only two pallet loads. It caused the addition of an extra sprinkler even after much writing and attempted explaining of the rack uprights being the transverse flue. I don't think this was the intent but it sure is written this way. It's an unusual looking in-rack arrangement.
Bill Brooks William N. Brooks, P.E. Brooks Fire Protection Engineering Inc. 372 Wilett Drive Severna Park, MD 21146-1904 410-544-3620 410-544-3032 FAX 412-400-6528 Cell -----Original Message----- From: sprinklerforum-boun...@firesprinkler.org [mailto:sprinklerforum-boun...@firesprinkler.org] On Behalf Of å... .... Sent: Tuesday, January 15, 2013 1:38 PM To: SprinklerFORUM@firesprinkler.org Subject: Maximum in-rack sprinkler spacing - plastic over 25ft Wayne: You make a good point. Per NFPA 13 in-rack sprinkler layouts, I don't perceive that a gap between pallets constitutes a formal transverse flue. I think the transverse flue is formed by the steel column of the racking structure. Wayne, you are correct in that 2007 NPFA 13 Figure 17.3.1.2(a) includes the exception-to-the-rule of having in-rack sprinklers in each transverse flue (TF) for plastic storage in open racks two-or-more-bays deep, [1] that stores commodities at heights 25+ ft.. NFPA 13 however, mitigates the reduction of in-rack sprinklers (particularly, but not exclusively) at every transverse flue. For the case of Figure 17.3.1.2(a), this mitigation calls for horizontal barriers above each level of in-rack sprinkler *with face-sprinklers*. Does our situation you are describing contain such horizontal barriers in the racking scheme? One *could* assume (at least I do) that the horizontal spacing between in rack sprinklers in Figure 17.3.1.2(a) is not to exceed 10 ft, as this is maximum width of two pallets mentioned in Note 7 of this Figure. This maximum horizontal spacing between in-rack sprinklers is enforced even if metal racking support columns are spaced greater than 10 ft apart. [1] new criteria added to this comment. scot deal Excelsior Fire On Tue, Jan 15, 2013 at 4:03 PM, Dewayn e Martinez <deway...@dbfp.net> wrote: > Thanks Scot, > What is confusing is that you are allowed to have more loads in the > vertical as long as you don't go past 10ft spacing but nothing is > mentioned for the horizontal spacing. > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://fireball.firesprinkler.org/mailman/private/sprinklerforum/attachment s/20130115/33812f1b/attachment.html> _______________________________________________ Sprinklerforum mailing list Sprinklerforum@firesprinkler.org http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum _______________________________________________ Sprinklerforum mailing list Sprinklerforum@firesprinkler.org http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum
