Georgia Fire Inspectors Association

120-3-3-.04(6)(c)(3) modifies NFPA 13 (2002), Table 12.4.2(d), by changing the number of sprinklers in the 25.2 Nominal K-factor rows from “12 (see Note 3)” to “15 (see Note 6)” and adds the following Note 6:

“6. The design area shall consist of the hydraulically most demanding area of 15 sprinklers, consisting of five sprinklers on each of three branch lines. The design area shall include a minimum operating area of 1,200 square feet (111.5 sq m).”

The reason for this amendment is to reflect the tests using Large Drop sprinklers (which uses 15 sprinklers) in deriving the data for the tables using ESFR K25 sprinklers for tires. The 1999/2002 NFPA handbook just says the table is based upon tests conducted at FM and no actual test using ESFR for tires have ever been done, but if you go to the FMRC Data Sheet 8-3, at the bottom of Table 6 “ESFR Protection Requirements” is a note that is not so vague as the NFPA handbook (remember, most of NFPA’s stuff is ‘taken’ from FM, IRI, etc.), stating that ESFR protection of tires is based on the favorable results of two (2) large scale tests (the ‘tests’ NFPA is talking about) using large drop sprinklers- and even then it took 15, not 12 sprinklers...