In a recent project we had an existing bldg. which had 28ft high double-row racks in a 35ft high bldg. I don't know what they stored on the racks when the bldg. was occupied but anyway, the bldg did have ESFR, K14's in it. Our new client was going to be dividing up the bldg with one half being a production area and the other half (separated by a wall) being rack storage. We directed the contractor to remove the ESFR's in the production area (and due to various circumstances we completely demo'ed the whse area). What was odd was that the Underwriter's Rep. told us that we could have left the ESFR's in there within the production area. His rational was that the amount of water discharged from the ESFR's was far greater than the required discharge from the control mode sprinklers, so more water wouldn't hurt anything. It was kind of surprising and in light of this topic thread somewhat confusing.
Craig L. Prahl, CET Fire Protection Group Mechanical Department CH2MHILL Lockwood Greene 1500 International Drive PO Box 491, Spartanburg, SC 29304-0491 Direct - 864.599.4102 Fax - 864.599.8439 [EMAIL PROTECTED] http://www.lg.com -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Joe Hankins Sent: Wednesday, December 20, 2006 10:08 AM To: [email protected] Subject: Re: ESFR in production areas Ron, I should never have used the term "density" in describing the discharge from an ESFR as it gives the false impression that density is a direct measure of sprinkler performance, which it most certainly is not. I should have said that you can't design K14 ESFRs with an operating pressure less than roughly 25 psi.and expect an effective discharge pattern. It may be fine if the fire starts directly under a sprinkler, but not if the fire starts right in the middle between two sprinklers. You are assuming that there is a direct relationship between discharge density and area of operation in a fire. For many fires (flammable liquids, shielded combustibles etc), that is not a valid assumption. The best example I can give is a test run several years age with 4 ft. wide solid shelf racks 12 ft.high protected by K11.2 sprinklers operating at 50 psi.(80 gpm per sprinkler) The fire spread to the ends of the test array and jumped a 4 ft. aisle. A lot more than 12 sprinklers operated. The real message here is that mixing suppression and control concepts to come up with a conclusion that something "should work" is dangerous. It's easy to "solve" a problem if you start with the answer you want and then work backwards by selecting the data that supports it. The problem is that you can change the answer, and "prove" that one, too. Joe Fletcher, Ron wrote: >Is the .8 based on 64 sqft, 80sqft, or 100 sqft? Or is it 80 gpm >minimum? Seems like .8 x 1500 (1200 gpm) should be able to control most >OH Grp II hazards even if the discharge patter is a little weak. > >Ron > >-----Original Message----- >From: [EMAIL PROTECTED] >[mailto:[EMAIL PROTECTED] On Behalf Of Joe >Hankins >Sent: Tuesday, December 19, 2006 11:59 AM >To: [email protected] >Subject: Re: ESFR in production areas > >You can't calculate and ESFR for a density less than about 0.80 because >they will not develop an effective distribution patern at those low >pressures. That's why Tyco reacted to your suggestion the way they did. > >Joe > >Fletcher, Ron wrote: > > > >>We have run into the problem of ESFR's in production areas many times >>but mostly due to the obstruction rules. I haven't had an AHJ try to >>apply area/density criteria to ESFR's. >> >>Offer to calc a full RA at "X" density to prove the system exceeds >>that >> >> > > > >>prescribed for the hazard. There is no precedence for treating ESFR's >>as area/density but if the AHJ wants a full size remote "area" then >>they should be willing to allow a "density" calc in lieu of the ESFR >>discharge criteria. (In for a penny in for a pound.) >> >>The Tyco guys once asked me if I had any ideas for new products. I >>suggested they cross list ESFR's for area/density. They looked at me >>like I had two heads so I wouldn't look for any changes from the OEM. >> >>Ron Fletcher >>Aero Automatic >>Phoenix, AZ >> >> >> >> >> >>-----Original Message----- >>From: [EMAIL PROTECTED] >>[mailto:[EMAIL PROTECTED] On Behalf Of John >>Powell >>Sent: Monday, December 18, 2006 3:25 PM >>To: [email protected] >>Subject: ESFR in production areas >> >>We have an issue with ESFR in a rack storage area interspersed with >>componant assembly. The assembly process does not involve flamable >>liquids or hydraulic equipment. There are no shielded hazards and the >>storage complies with the ESFR listing. Our AHJ requires that the >>limited assembly/process hazard be listed for QR sprinklers, which it >>is, and the number of ESFR sprinklers calculated for the usual OH area >>of operation discharging at the listed pressure for the storage and >>building height involved. Seems excessive to me. Have the forum >>members had any similar ruling? >>John Powell - New Zealand >> >>_______________________________________________ >>Sprinklerforum mailing list >>[email protected] >>http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum >>_______________________________________________ >>Sprinklerforum mailing list >>[email protected] >>http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum >> >> >> >> >> > >_______________________________________________ >Sprinklerforum mailing list >[email protected] >http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum >_______________________________________________ >Sprinklerforum mailing list >[email protected] >http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum > > > _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum
