Thanks all for your input. Best regards J.P. Merlino
----- Original Message ----- From: "Ronl.Fletcher" <[email protected]>
To: <[email protected]> Sent: Monday, December 20, 2010 8:57 PM Subject: RE: Class III Solid Pile Protection Criteria If the building is owner occupied and they are sure they will never store Class IV or plastic in the building the minimum is the way to go. If it's not owner occupied I would advise the customer to consider going with more than the minimum to allow for more flexibility in the future. It's not hard to imagine 24 ft of Class IV in racks in a 30 ft bldg. Ron Fletcher Aero Automatic Phoenix, AZ -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of ParsleyConsulting Sent: Monday, December 20, 2010 2:36 PM To: [email protected] Subject: Re: Class III Solid Pile Protection Criteria JP - I think there are a couple of things to consider, with respect to control mode density area sprinklers. First, your density for ordinary temperature sprinklers for a class III solid pile storage to 20' would be 0.285 gpm/sqft, from table 14.2.4.1 (2010 edition), and the maximum spacing would be 100 square feet each, per Table 8.6.2.2.1(d), and you would need to flow at least 20 sprinklers to attain the 2,000 sqft minimum remote area. You can reduce the density to 0.215 gpm/sqft by using high temperature sprinklers, as noted in table 14.2.4.2. Doing so will also allow you to increase the spacing of your sprinklers to 130 square feet each, based again on Table 8.6.2.2.1(d). That would require at least 16 sprinklers to attain the 2,000 sqft minimum remote area. The k-factor of the sprinkler can be as low as 8.0, for either CMDA temperature rating, as noted in section 12.6.2, as the density is greater than 0.20 gpm/sqft but not more than 0.34 gpm/sqft. I don't know the rationale behind the differences in the flows required. Consider: CMDA = 2,000 sqft x 0.215 gpm/sqft = 430 gpm + 500 hose = 930 gpm CMSA = 15 AS @25 psi = 840 gpm + 500 hose = 1,340 gpm ESFR = 12 AS @ 50 psi (14.0K) = 1,188 gpm + 250 hose = 1,438 gpm It appears that not all sprinklers are the best solution for all situations. PARSLEY CONSULTING Ken Wagoner, SET 760.745.6181 voice 760.745.0537 fax [email protected] <mailto:[email protected]>e-mail www.ParsleyConsulting.com <http://www.ParsleyConsulting.com>website On 12/20/2010 12:43 PM, J.P. Merlino/ Ing.L.Lagomarsino y Asoc. wrote:
We have doubts regarding criteria for protection of the following: Class III, solid pile Storage height: up to 20 ft Máximum building height 30 ft NFPA 13 2010 Edition As we understand, the code gives two options which are: 1) Per 14.2.4, Control Mode Density Area:Figure 14.2.4.2 With ordinary temperature, K=11,2 sprinkler we need 0,215 gpm/sq ft over 2000 sq ft. Flow rate equals 430 gpm 2) If we go to 14.3, Control Mode Specific Application, Table 14.3.1, for same conditions, we are required to have 15 sprinklers with K= 11,2 operating with a minimum discharge pressure of 25 psi. Flow rate equals 840 gpm and density is 0,43 gpm/sq.ft.
Are both cases valid for the hazard we are protecting? Why such a large difference in terms of flow and density? Best regards and thanks in advance J.P. Merlino _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [email protected] To Unsubscribe, send an email to:[email protected] (Put the word unsubscribe in the subject field)
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