I couldn't find any exception to the minimum 7 psi EHP (22.4.4.10.1). So unless there's an exception I didn't find, there would be no case where in OH1 that the EHP would be permitted to be less than 7 psi.
The wording in 8.3.4 specifically mentions LH, it doesn't give any indication expressed or implied that it applies to any other occupancy. The commentary backs up that assumption. Tyco's data sheet makes sense if you take it that the 2.8 and 4.2 are for LH as allowed by 13. The wording could use a little work to make it clearer. 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 Fletcher, Ron Sent: Tuesday, December 01, 2009 9:21 AM To: [email protected] Subject: RE: Calcs-How much margin If the heads "are not as effective in controlling a fire" then how do they get UL Listed? If it is Listed and I would assume tested it should be okay to use. If it is OH-I and the spacing requires an EHP less than 7 psi why not use the UL listed 4.2k head? Ron Fletcher Aero Automatic Phoenix, AZ -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Ben Young Sent: Tuesday, December 01, 2009 7:03 AM To: [email protected] Subject: Re: Calcs-How much margin I know it isn't enforceable code, but the handbook explanitory text clearly states (and explains why) that small orifice heads are for light hazard use only. This is from the 2007 handbook, and if after 8.3.4.1(2) "Restrictions on small orifice sprinklers are found in 8.3.4.1(1) and (2). Small orifice sprinklers are restricted to light hazard occupancies, because they are not as effective in controlling a fire as are sprinklers with a nominal K-factor and also do not pass the same fire tests that K-5.6 and larger sprinklers do. Small orifice sprinklers are restricted to wet systems because...." And it goes on to talk about the other restrictions on small orifice heads. On Tue, Dec 1, 2009 at 8:41 AM, Fletcher, Ron <[email protected]>wrote: > 8.3.4 doesn't say for light hazard "only" and it doesn't prohibit the > use of small orifice sprinklers in OH. The Tyco TY-FRB is UL Listed in > 2.8k,4.2k, 5.6k and 8k for light and ordinary hazard. If it's Listed for > OH why couldn't it be used? > > I would probably call the company that submitted the plans and ask for > supporting information like an area water main map with elevations > etc... With the right information the validity of the flow test could be > determined. It isn't unusual for a building to be near completion before > the extended water system is in place and ready to be tested. > > Ron Fletcher > Aero Automatic > Phoenix, AZ > > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of Chris > Cahill > Sent: Monday, November 30, 2009 3:46 PM > To: [email protected] > Subject: RE: Calcs-How much margin > > Not talking about Craig specifics. All John/NFPA provides is great > except it should be in AWWA standards not NFPA standards. These > people forget > the > water system originally was a fire protection function to keep the town > from > burning down. Even today its flows are FP based not domestic. Ask a > water guy anything about anything other than GPD and you get a lot of > blank stares. You can't adjust if the water utility doesn't know any > of the stipulated information. > > 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 John > Drucker > Sent: Monday, November 30, 2009 4:22 PM > To: [email protected] > Subject: RE: Calcs-How much margin > > Craig, > > You've received plenty of comment. Travis and John found the first > problem with the design, the code section is 2007 NFPA-13-8.3.4. > Before one can > decide if the water supply is adequate the system demand must be > validated. > 22.2.1 provides the required information for water supply, 22.3.5.4 for > supply analysis and 23.2.1.2 for determination. > > 23.2.1.2 provides the answer; "The volume and pressure of a public water > supply shall be determined from waterflow test data. An ADJUSTMENT TO > THE WATERFLOW TEST DATA TO ACCOUNT FOR daily and seasonal > fluctuations, possible interruption by flood or ice conditions, large > simultaneous industrial use, future demand on the water supply system, > OR ANY OTHER CONDITION THAT COULD AFFECT THE WATER SUPPLY SHALL BE > MADE AS APPROPRIATE. > > As for a prescribed absolute, my understanding pursuant to the standard > is > supply (properly determined) and demand can match, thus nothing > implicitly saying "adjust by 10%". > > The annex of NFPA-13 does provide insight; A.23.2.1 "Care should be > taken in making water tests to be used in designing or evaluating the > capability of sprinkler systems. The water supply tested should be > representative of the supply that might be available at the time of a > fire. For example, testing of public water supplies should be done at > times of normal demand on the system. Public water supplies are likely > to fluctuate widely from season to season and even within a 24-hour > period. Allowance should be made for > seasonal or daily fluctuations, for drought conditions, for possibility > of > interruption by flood, or for ice conditions in winter. Testing of water > supplies also normally used for industrial use should be done while > water is being drawn for industrial use. The range of industrial-use > demand should be taken into account. In special situations where the > domestic water demand could significantly reduce the sprinkler water > supply,an increase in the > size of the pipe supplying both the domestic and sprinkler water can be > justified. Future changes in water supplies should be considered. For > example, a large, established, urban supply is not likely to change > greatly within a few years. However, the supply in a growing suburban industrial > park might deteriorate quite rapidly as greater numbers of plants draw > more water. > > Testing of Water Supply. To determine the value of public water as a > supply for automatic sprinkler systems, it is generally necessary to > make a flow test to determine how much water can be discharged at a > residual pressure at a rate sufficient to give the required residual > pressure under the roof > (with the volume flow hydraulically translated to the base of the riser) > - > that is, a pressure head represented by the height of the building plus > the > required residual pressure. The proper method of conducting this test is > to > use two hydrants in the vicinity of the property. The static pressure > should be measured on the hydrant in front of or nearest to the > property and the water allowed to flow from the hydrant next nearest > the property, preferably the one farthest from the source of supply if > the main is fed only one way. > > For further information on water supply testing, see NFPA-291, > Recommended Practice for Fire Flow Testing and Marking of Hydrants. > Keep in mind that while NFPA-291 is recommended practice and not a > standard it nonetheless > has > bearing in jurisdictions that include language such; "Any requirement > essential for structural, fire or sanitary safety of a building or > structure, or essential for the safety of the occupants thereof, and > which is not specifically covered by the regulations, shall be > determined by the construction official, and appropriate subcode > official" (NJAC > 5:23-2.2(c)) > > With that you have more than enough justification to reject this > application, as I would. > > Hope that helps, > > John Drucker, CET > Fire Protection Subcode Official > Fire/Building/Electrical Inspector > Fire Marshals Office > Borough of Red Bank, NJ > > PS. It's too late once the fire starts. > > > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of > [email protected] > Sent: Monday, November 30, 2009 3:11 PM > To: [email protected] > Subject: Calcs-How much margin > > I've got a calc I'm reviewing, after all said and done, 3.63 psi margin > between demand and available. Designer used 4.2K heads to get the flow > exactly to the decimal of the required flow. This is an industrial type > project. With a .15 gpm/sf density at 92 sf per head, the flow would be > 13.8 gpm and he's dead on the money. The concern would be that over the > years if there was any change in the water supply or decay of the > piping, that the operation of half the design area would be > questionable. > > Would you approve or reject this design? Is this cutting it just a bit > close? > > > > > 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 > > _______________________________________________ > 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]<to%3ASprinklerforum-request@ firesprinkler.org> > (Put the word unsubscribe in the subject field) > > > _______________________________________________ > 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]<to%3ASprinklerforum-request@ firesprinkler.org> > (Put the word unsubscribe in the subject field) > > _______________________________________________ > 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]<to%3ASprinklerforum-request@ firesprinkler.org> > (Put the word unsubscribe in the subject field) > > _______________________________________________ > 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]<to%3ASprinklerforum-request@ firesprinkler.org> > (Put the word unsubscribe in the subject field) > _______________________________________________ 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) _______________________________________________ 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) _______________________________________________ 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)
