Except 13 is the predominant legal standard in the US. FM can do whatever they want but no where that I know of are they the legal standard.
Perhaps you said that in your 3rd paragraph but where would FM exceed 13 but only need 2" lines vs. 2.5"? Do you mean to say FM has a higher density than 13 but rounding mathematically you get 2" lines and when you recalc per 13's lower density and rounding up you end up with 2" lines? Does this actually happen? Is this just a marketing trick by FM seeming to require a higher level of protection but in reality it's the same? Cynical I guess. Chris Cahill, P.E. Fire Protection Engineer Sentry Fire Protection, Inc. 763-658-4483 763-658-4921 fax Email: [email protected] Mail: P.O. Box 69 Waverly, MN 55390 Location: 4439 Hwy 12 SW Waverly, MN 55390 -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of George Church Sent: Monday, June 29, 2009 3:39 PM To: [email protected] Subject: FM rounding and other changes Along those lines, FM Global is being very articulate about their ROUNDING being standard mathematical rounding, not NFPA #13 round UP, in # heads per line in MRA. Those who were at NFSA's convention might know that from attending a seminar on FM proposed changes; not pushing NFSA, just the chance to learn. I've not had time to look to see if AFSA has similar seminar, I'd be surprised if they didn't since FMG is trying to telegraph the large changes like grouping STORAGE heads together instead of keeping suppression heads separate from area/density or CMSA; and hose streams will be based on the number of heads operating in the remote area. Those are some big conceptual changes and if you want to know about them, go to FM Global's site, see if they have more there; find out from someone who attended the NFSA seminar on this topic, or see if the AFSA has one coming in San Diego. Contractors rounding UP per #13 can be estimating 2.5" lines all year against the little piggie that learned at convention that 2" will do fine with one less head operating per line, so assuming FM criteria exceeds code minimums and is the design criteria, the 2" lines are generally going to bring in more profitable work than saving money not going to convention and not knowing what the others do and losing bids all year. If all you do is follow what the plumbing designer drew up and try to be low on street work, ignore all the above. glc -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of [email protected] Sent: Monday, June 29, 2009 3:58 PM To: [email protected] Subject: RE: In-rack fireprotection Yup, you got it. For example if you look at Figure 12.3.2.1.2(g) if you used Curve "A" with an 8ft aisle at .39/2000 and Curve "C" with a 4ft aisle at .475/2000, a 6ft aisle would give you a density of 0.4325/2000. And I would hold that density tightly to that 0.4325, I wouldn't let any old contractor get away with only giving 0.43 when the spec says 0.4325 gpm/sq. ft. Specs is specs! ;) Craig L. Prahl, CET Fire Protection Specialist 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.ch2m.com -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Jay White Sent: Monday, June 29, 2009 3:33 PM To: [email protected] Subject: RE: In-rack fireprotection I am guessing this is a point or density between the density at 4ft. and the density of 8ft. wide aisle? Jay White Estimator/Design Manager Dynamic Fire Protection 1807 Hwy. 25 South Starkville, MS 39759 Phone: 662-324-1550 Fax: 662-324-1545 Cell: 662-312-2426 -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Jay White Sent: Monday, June 29, 2009 2:30 PM To: [email protected] Subject: In-rack fireprotection In NFPA 13 2002 edition, section 12.3.2.1.2.1; for aisle widths between 4ft and 8 ft, a direct linear interpolation between densities shall be made. Can someone explain this? Jay White Estimator/Design Manager Dynamic Fire Protection 1807 Hwy. 25 South Starkville, MS 39759 Phone: 662-324-1550 Fax: 662-324-1545 Cell: 662-312-2426 _______________________________________________ Sprinklerforum mailing list http://lists.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) _______________________________________________ Sprinklerforum mailing list http://lists.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) _______________________________________________ Sprinklerforum mailing list http://lists.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) _______________________________________________ Sprinklerforum mailing list http://lists.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) _______________________________________________ Sprinklerforum mailing list http://lists.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)
