I’m used to winter being the low flow condition for the water utilities. One of the water districts I worked with had 4-6 mgd in winter, and 16 mgd in summer.
I used to ask FF’s when highest use was. Never got a good guess. 0200-0400. All those automatic ornamental and lawn sprinklers are bigger use than dinner dishes and clothes washing machines. Best. Bruce Verhei > On Jun 16, 2018, at 12:30, Bruce Verhei <[email protected]> wrote: > > Ron must be feeling mellow. Sort of a mild rant. Caused by M’s being 20 games > over 0.500? > > Best. > > Bruce > >> On Jun 16, 2018, at 09:25, Ron Greenman <[email protected]> wrote: >> >> Where is the data that supports the need? I don't have the exact numbers in >> my head this morning, nor am I willing to look them up but the statistics >> are that somewhere above 90% of all fires are controlled by a single or two >> sprinklers operating, and above 95% are controlled by three (anybody jump in >> with the exact numbers), and since we design to nine or usually more >> typically I'd say a safety factor is already built-in. I think if you look >> at systems that have been overwhelmed you'll mostly find that maintenance >> was not carried out properly, or TIs were not addressed, or fires got into >> unsprinklered or under sprinklered attics, or any number of things that were >> existing code deficient. I also think you'd find that many fires were >> controlled by systems that were existing code deficient. My mind could be >> changed if I were shown a significant amount of loss due to inadequate water >> in the original design in buildings where there were no other factors as >> stated above, but I'm not seeing a need. Additionally, in my neck of the >> woods, all the metropolitan jurisdictions are already imposing a 10# or 10% >> factor already. Most are holding to that number like it's gold and even if >> the hose stream allowance takes you over the supply line by 1/2# you're >> surely going to have to re-design. This is unreasonable already, and I >> realize the FDs already often act like over-indulgent parents, so I'm >> especially worried that if this 10#s is codified it will be an add-on to the >> already existent 10#s. I see tanks and pumps in everyone's future because of >> mistrust of municipal water systems. Rant over. Ron out. >> >> >> Ron Greenman >> >> [email protected] >> >> 253.576.9700 >> >> The Universe is monstrously indifferent to the presence of man. -Werner >> Herzog, screenwriter, film director, author, actor and opera director (1942-) >> >> >>> On Sat, Jun 16, 2018 at 7:50 AM Scott Futrell <[email protected]> wrote: >>> As a plan specifier, plan reviewer and an investigator I see designs right >>> to the supply and then as-built conditions far worse (read more demanding) >>> than the design submitted with the calcs. This is not a regional >>> observation. >>> >>> >>> >>> Additionally, I am aware of communities that lower elevated tank levels 20’ >>> in winter to lower heating costs. Contractors in those areas do NOT adjust >>> flow tests for this seasonal variation. >>> >>> >>> >>> No safety margin what-so-ever in NFPA 13 is unreasonable for a design >>> standard. >>> >>> >>> >>> Arguments on the floor including ‘requiring all systems to have back-up >>> power’ were ridiculous. >>> >>> >>> >>> Scott >>> >>> >>> >>> Office: (763) 425-1001 x2 >>> >>> Cell: (612) 759-5556 >>> >>> >>> >>> From: Sprinklerforum >>> [mailto:[email protected]] On Behalf Of Steve >>> Leyton >>> Sent: Friday, June 15, 2018 2:16 PM >>> To: [email protected] >>> Subject: RE: Safety Margin >>> >>> >>> >>> That was the conversation on the floor of the code hearing. The concerns >>> underscored by the CAM were not about whether safety factor is a good >>> practice, it was that a fixed minimum value as high as 10 PSI could trigger >>> all sorts of cost-impact consequences, particularly in areas where >>> pressures are middling to poor – in Rhode Island, 10 PSI could be 25-30% of >>> the available pressure. >>> >>> >>> >>> In the West, due primarily to the politics of drought, water districts are >>> using models in lieu of physical flow tests. Prudent and conservative >>> programming makes it possible for them to issue safeguarded values from >>> which it’s not necessary to reduce the available pressure. For ex., City >>> of San Diego uses a three-level safety factor in their (highly accurate) >>> models: starting with legacy drought water levels in the reservoirs, then >>> factor the highest seasonal demand, then the highest peak day demand of >>> that season. The values we’re getting are usually significantly lower >>> than what can be measured on the hydrant, and this practice isn’t without >>> controversy because there are obvious complications that can and do occur, >>> particularly with existing systems based on 20-year old (and older) >>> pressures that were physically measured (with crappy equipment) when first >>> designed and built. >>> >>> >>> >>> But if modeling becomes the new normal, prudent water district engineering >>> departments and fire departments they serve can coordinate manipulating >>> data to include reasonable safety factors. The range of variation in >>> pressures, accuracy of flow test equipment, the use of modeling in many >>> areas … there are too many variables to set a fixed minimum safety factor >>> based on PSI, IMHO. >>> >>> >>> >>> SML >>> >>> >>> >>> From: Sprinklerforum >>> [mailto:[email protected]] On Behalf Of >>> Parsley Consulting >>> Sent: Friday, June 15, 2018 12:00 PM >>> To: [email protected] >>> Subject: Re: Safety Margin >>> >>> >>> >>> Richard, >>> >>> If my memory is accurate of the issues raised in the discussion that >>> ambiguity was a part of the differing viewpoints. >>> >>> Some argued that 10 psi was not workable in their locale as their pressures >>> were so limited that an imposition of 10 psi was simply to drastic and >>> would result in much larger pipe sizes as a result. >>> >>> Others argued that 10 psi was not enough, and in their area 10 psi didn't >>> equal 10%, and there was some reluctance to base their designs on a >>> pressure greater than 90% of the available. >>> >>> It was quite a discussion. >>> >>> Ken Wagoner, SET >>> Parsley Consulting >>> 350 West 9th Avenue, Suite 206 >>> Escondido, California 92025 >>> Phone 760-745-6181 >>> Visit the website >>> >>> On 06/15/2018 10:23 AM, Richard Carr wrote: >>> >>> Even though it is not in NFPA most AHJ’s require some sort of safety >>> margin, 10%, 10 psi which we have had to provide for a long time so most >>> designers know to leave safety margin in the calc’s. it would be nice if >>> they all used the same amount. >>> >>> >>> >>> Richard M. Carr, SET >>> >>> Project Manager/Design >>> >>> Diboco Fire Sprinklers, Inc. >>> >>> 325 Jackson Loop Road >>> >>> Flat Rock, NC 28731 >>> >>> >>> >>> [email protected] >>> >>> 828-696-3400 >>> >>> 828-696-2288 Fax >>> >>> 828-708-9118 Mobile >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> From: Sprinklerforum <[email protected]> On >>> Behalf Of Parsley Consulting >>> Sent: Friday, June 15, 2018 1:22 PM >>> To: [email protected] >>> Subject: Safety Margin >>> >>> >>> >>> Scott, >>> >>> Based on the material which was presented to the -24 and -291 committee >>> meetings I believed the proposed safety margin and the means to calculate >>> that margin there was some merit in the proposal. >>> >>> For reasons I don't quite remember the PI was voted down at the 2nd draft >>> meeting. I listened to some of the discussion, and there were some good >>> points made. I'm not terribly surprised it failed at the convention level. >>> Perhaps the attendees were following the lead of the technical committees, >>> and declining to overrule their decision. >>> >>> sincerely, >>> >>> Ken Wagoner, SET >>> Parsley Consulting >>> 350 West 9th Avenue, Suite 206 >>> Escondido, California 92025 >>> Phone 760-745-6181 >>> Visit the website >>> >>> On 06/15/2018 8:09 AM, Scott Futrell wrote: >>> >>> Only that the 'safety margin' inclusion in the 2019 edition of NFPA 13 >>> failed, so it won't be included or required. >>> >>> I consider this unfortunate, but I'd guess that not everyone on the forum >>> would agree. >>> >>> Scott >>> >>> Office: (763) 425-1001 x2 >>> Cell: (612) 759-5556 >>> >>> -----Original Message----- >>> From: Sprinklerforum >>> [mailto:[email protected]] On Behalf Of >>> [email protected] >>> Sent: Thursday, June 14, 2018 5:46 PM >>> To: [email protected] >>> Subject: NFPA Vegas Convention >>> >>> I didn't make it again this year. >>> "Caputo" is the only speaker name I recognized. >>> Anybody have any earthshaking epiphanies? >>> >>> >>> _______________________________________________ >>> Sprinklerforum mailing list >>> [email protected] >>> http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org >>> _______________________________________________ >>> Sprinklerforum mailing list >>> [email protected] >>> http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org >>> >>> >>> >>> >>> >>> >>> _______________________________________________ >>> Sprinklerforum mailing list >>> [email protected] >>> http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org >>> >>> >>> _______________________________________________ >>> Sprinklerforum mailing list >>> [email protected] >>> http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org >> _______________________________________________ >> Sprinklerforum mailing list >> [email protected] >> http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org
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