I think I was misunderstood, because I raised two issues concerning the reliability of the calculations and mfg data.
A. New systems and B. Old systems. NEW SYSTEMS: In tests made across new service connections I got pressure losses ranging from 30% to 45%. Just last week on a brand new system I got 40% loss. Imagine a designer advising the principal that he can construct a warehouse with reliance on the public supply providing 910 gpm for sprinklers based upon ample water from the Public Supply, all based on Public Supply testing on the street and hydraulic calculation. Then, after completing the system, test is made next to the Risers and it appears at the design pressure there is only 600gpm available. The flow test was made inside the premises; residual pressure was measured both within the premises and in the street. The residual pressure within the premises was lower 40% from that on the street. All valves are open and there is no explanation based on Mfg data and any calculation. Now think about the liability of the people involved. OLD SYSTEMS: A total different situation is the old pipe. There I got loss of 75%. In one location there was a design of ESFR requiring 1750 gpm. In order to get that the principal had to replace a pump and to install 1500-2000 gpm pump. The test I made on behalf of Insurer proved that the mains can deliver only 500gpm at the required pressure. In another location, 6" connection from a pump to risers, the demand was 1780 gpm at 110 psi. The actual measured supply was 400 gpm at 110 psi. Dan Dan Arbel Tel: 972-4-8243337 Fax: 972-4-8243278 M: 972-52-2810593 -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Ron Greenman Sent: Monday, February 18, 2008 8:15 PM To: [email protected] Subject: Re: C-Factor for old piping There are the two extremes Dan was originally talking about. Old pipes with a 140 and old pipes with 40% degradation. Then you get the water purveyor that won't let you touch his stuff at all or at best will only allow flow testing at midnight (what percentage do you add to get a decent picture of peak use?) and only if you capture the water and process out the chlorine he put in it. Or he'll give you water data on a 50s system that was done in 1986 from a hydrant somewhere close. Or he'll model flow by computer since somehow his modeling data can magically disspell all the concerns we've been talking about for the past few days. And, by the way, running that program will take four to six weeks. On top of that nobody from the A&E team is going to take responsible charge and the GC who just accepted (verbal, not signed) George's design/build proposal didn't do it until two days before GEORGE was supposed to start and now George is holding up the project. And somehow we manage to get out a product with a huge success rate in spite of all that, public apathy, owner hostility and often spotty maintenance. There are few days that pass when I'm not sure that running a hot dog stand isn't a better idea. On 2/18/08, George Church <[EMAIL PROTECTED]> wrote: > Only time I had a requirement that we felt was obscene to degrade an > existing UG loop - the local AHJ wanted us to use like C=90 for 1960's (?) > UG loop around a plant being rebuilt after roof collapse (snow). > > Part of our work included cutting out a section of te existing UG and we > left a piece of the existing sitting there for the AHJ to examine; it was > clean as a whistle and he then, if memory serves me correctly, C=140 or at > least something closer to reality (and not requiring a booster pump after > the booster pump). Call it a flow test by visual examination:) > > glc > > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Roland > Huggins > Sent: Monday, February 18, 2008 12:24 PM > To: [email protected] > Subject: Re: C-Factor for old piping > > agreed. AS already stated by others, old underground water supplies > require a flow test to assign a reliable C value. Let's not forget > to assign a continued amount of degradation if the existing > conditions are accepted verses designing to what is tested today. I > must confess not exactly sure what NFPA 24 says (if anything) since > that memorized text is assigned to a portion of the memory bank that > is not longer accessible. > > Roland > > On Feb 18, 2008, at 8:43 AM, [EMAIL PROTECTED] wrote: > > > We > > certainly cannot go to the design standard as it is designing with new > > pipe. So, what is the answer? > > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum > > To Unsubscribe, send an email to:[EMAIL PROTECTED] > (Put the word unsubscribe in the subject field) > > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum > > To Unsubscribe, send an email to:[EMAIL PROTECTED] > (Put the word unsubscribe in the subject field) > -- Ron Greenman at home.... _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum To Unsubscribe, send an email to:[EMAIL PROTECTED] (Put the word unsubscribe in the subject field) No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.5.516 / Virus Database: 269.20.7/1285 - Release Date: 18/02/2008 05:50 No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.516 / Virus Database: 269.20.7/1285 - Release Date: 18/02/2008 05:50 _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum To Unsubscribe, send an email to:[EMAIL PROTECTED] (Put the word unsubscribe in the subject field)
