And herein lies the rub for their always excessive fire sprinkler tap fees (apart from just out and out being able to get them) is that they tend to think sprinkler water is constantly in use. I once had a water department expert tell me that the phenomena we were both watching on her by-pass detector (spin rapidly ahead, then slowly back) couldn't mean the 3/4" check valve (Nippon Kan Theater for Rich) feeding the wet standpipe was bad and could ONLY indicate a leak. Now mind you that this "leak" on a class one, wet standpipe was to the tune of 90 gallons a day as extrapolated through this detector. We put a 250# hydro on the standpipe back to the main and by-pass for 24 hours and she still insisted that the standpipe feed was leaking. Finally convinced her boss that replacing the check valve was cheaper than digging up the fire line and that if it didn't fix the problem the owner would pay the city back for their try and proceed with the excavation. To everyone's astonishment the meter stopped recording after the check was replaced. Six months later the same problem and same woman but this time the entire feed line to the sprinklers was exposed in the basement of the building (FX Mcrory's Rich) and once again she insisted on either a leak or that someone had tapped a plumbing fixture off the system. Could have been the latter if a flow switch was involved but at that time the system had an old ADT overpressure system that would have gone off every time that plumbing was used. After another battle got the check valve changed and the problem ceased. I bring these war stories up because they seem to typify water departments (this was in Seattle if you all haven't guessed). And just recently I was given water info that was impossible since I had a static reading at my location and the water data proffered had a lower static pressure forty feet below the gauge I was reading. When I told the helpful water dept. employee that her numbers were impossible she asked me who said so. I suggested Newton but since he didn't work in her division she didn't care. True story. Finally George Goodall at SFD got me some useful information from a hydrant test I was told didn't exist, the elevation differences calculated exactly as they should, and he told me exactly where the regulating valve separating the pressure zones between the one the project was actually on instead of the one my friend at the water dept. wanted me to be on. Here I was working for the EOR and who to give him his due was agreeing that the info was bogus, but had there not been an existing structure at the project site with a system and a gauge there would have been no basis to question the water people. In this case it would have resulted in a grossly overbuilt system, probably with a pump. And Rich, this was for the remodel at Seattle Central Com. Col. The water dept. was not giving me Broadway water but water from the residential area down the hill around Belmont & East Pine. I guess I'm just ranting about being at the mercy of totally unprofessional people and no matter how competent they are at delivering safe drinking water to the citizens does not absolve them of the need to understand (or care) about fire safety. Soapbox closed for this evening.
On Mon, Nov 30, 2009 at 3:20 PM, Chris Cahill <[email protected]> wrote: > Let me rephrase, the water folks should read AWWA standards as it applies to > what we need to know about their sacred systems. We can't adjust if the > water utility doesn't know any of the stipulated information. > > Chris > > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of John Drucker > Sent: Monday, November 30, 2009 4:54 PM > To: [email protected] > Subject: RE: Calcs-How much margin > > Chris, > > AWWA M-31 is right here next to 291, 22, 13, 14................... > > And you think I forgot ;-) > > M-31 - Chapter 5 is AFSS. > > http://www.prismce.com/AWWA%20Manual%20M31%20Regs%20-%20Fire%20Flow.pdf > > Hope that helps > > John Drucker, CET > Fire Protection Subcode Official > Fire/Building/Electrical Inspector > Fire Marshals Office > Borough of Red Bank, NJ > > > > > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of Chris Cahill > Sent: Monday, November 30, 2009 5:46 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] > (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) > > _______________________________________________ > 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) > -- Ron Greenman Instructor Fire Protection Engineering Bates Technical College Tacoma, WA Member: SFPE, ASCET, NFPA, AFSA, NFSA AFAA, WSAFM _______________________________________________ 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)
