yeah, that guy. I've tried to call him but.... And he never replies to RFIs.
On Tue, Mar 22, 2016 at 10:05 AM, Bill Brooks <[email protected]> wrote: > And sometimes the hose used to connect the pumper to the FDC is an issue as > well if it is not rated for higher pressures. > > I know this is something we toss back a forth but shouldn't the Engineer of > Record be the person to do this legwork ahead of time? > > Bill Brooks > Brooks Fire Protection Engineering > > -----Original Message----- > From: Sprinklerforum [mailto: > [email protected]] > On Behalf Of Steve Leyton > Sent: Tuesday, March 22, 2016 12:34 PM > To: [email protected] > Subject: RE: Standpipe Calc: Adding City Demand to Pumper Truck? > > Attention Everybody (and Sean): > > It is time for us as an industry to move outside the box. Prescriptive > codes and standards are convenient, and most AHJ's will defer to them > without amendment or interpretation because it's usually not required to do > so. But sometimes we have to address situations that ARE subjective and > this is one of those - you have to meet with the serving fire department to > verify their operational practices and pumping capabilities. Your > statement > that the pumper is "... sized for 150psi at 1000gpm" isn't accurate; > generally, modern pumpers and engines can make up to 300 PSI at either > 1,000 > or 1,500 GPM so available pressure isn't the issue. Design of the system > and identification of the demand are the issues. 150 PSI is an industry > practice, not an absolute threshold that can't be crossed and NFPA 14 has a > requirement that you must hang a sign on the FDC informing the FD of the > required pressure to meet the calculated demand. > > As with sprinkler systems, Pressure = $$, so the more you have the smaller > the piping can generally be and you save $$. 150 is a safe starting > pressure so most FD's will require that you use that as a source pressure; > if a manual standpipe system is a little longer or taller and requires more > pressure we can make that up by subbing 6" for 4" and it still works at > 150. > But in taller buildings, you will need more pressure so, if you want to do > a > 70' tall building with 4" risers all the way up the shafts, then you have > to obtain FD approval to pump at 195 or 215 or whatever it turns out to be. > And, you have to build the system out of components rated for that > pressure, > which is actually no big deal these days. And when it's over, you badge > the FDC with a sign that states, "PUMP 1000 GPM AT 215 PSI TO MEET DEMAND > AT > STAIR #2 ROOF" or something like that (your FD will tell you how to word > the > sign). > > Partner up people ... > > The preceding is my opinion only and does not represent the opinion of or > an > interpretation of the standard by NFPA or the Technical Committee on > Standpipes. > > Steve L. > > -----Original Message----- > From: Sprinklerforum [mailto: > [email protected]] > On Behalf Of [email protected] > Sent: Tuesday, March 22, 2016 8:31 AM > To: [email protected] > Subject: RE: Standpipe Calc: Adding City Demand to Pumper Truck? > > Sorry for coming into this a week late. We have recently been dealing with > specs and AHJ requirements that state we need to supply 130psi and/or > 140psi > at the top outlet regardless of whether it is manual or automatic. Same > flows as outlined in NFPA 14 (500gpm +250gpm per standpipe up to 1000gpm). > The fire pumper truck is still sized for 150psi @ 1000gpm. What do you > suggest we do if we can only set the FDC to be the source of 151@0 and > 150@1000? Some building are still 70ft tall and the standpipe is still a > manual wet. Only accounting for elevation we are looking at 160psi/170psi > demand at the FDC. Even if your answer is make it an automatic standpipe, > the 140psi requirement limits the "manual" standpipe building height to > 23ft > when we don't account for friction loss using your calculation procedure. > So we can't even meet these manual FDC 150psi calcs on a building that > doesn't even need a standpipe. > > Thanks, > Sean VG > > > > -----Original Message----- > From: Sprinklerforum [mailto: > [email protected]] > On Behalf Of Steve Leyton > Sent: Monday, March 14, 2016 3:57 PM > To: [email protected] > Subject: RE: Standpipe Calc: Adding City Demand to Pumper Truck? > > Tony: > > You (or the submitter) are over-simplifying what the annex says. It's not > the intent that you take the city flow test and add it to the pumper curve. > NFPA 1901 sets the basic performance curve for a pumper at 150 PSI/1,000 > GPM. NFPA 13E is the standard for FD Operations for buildings equipped > with sprinklers and standpipes - that standard goes into the company > engineer's procedure for calculating the discharge pressure of the pump > based on suction pressure, friction loss in hose and other variables. But > the bottom line is that it's all targeted at discharging 150 PSI residual > at > 1,000 GPM. This has NOTHING to do with pressure at the FDC; it has to do > with calculating the performance of the apparatus. What gets to the FDC > is > up to the engineer. > > Which is why 7.7.4 states, "When the system demand to be supplied by the > fire department at the fire department connection is being determined, the > local fire department shall be consulted regarding the water supply > available from a fire department pumper." FROM A FIRE DEPARTMENT PUMPER. > It's up to the incident commander and his or her engineer to determine the > suction pressure and set their discharge to whatever is required to make > their programmed starting pressure. And based on the nationwide standard > and best practices, that is almost certain to be 150 PSI at the prescribed > flow rate. The engineer will calculate the friction loss in the discharge > hose that's connected to the building. If you are reviewing plans that > show > 150 PSI residual plus a positive suction head at that flow rate as the > inlet > pressure, then that is almost certainly not correct. > > To answer your question, if I have a building with two (750 GPM) or three > or > more (1,000 GPM) standpipes, we plug in a "flow test" static pressure of > 151 > PSI and a residual of 150 PSI at the target flow rate and we run the calc' > using the FDC as the "city connection". We plug in a 500 PSI hose stream > allowance at the most remote standpipe outlets and at 250 GPM hose streams > at those points in the bulk main system where the other risers take off. > We > allow 5 PSI for loss in a standard hose valve so the minimum pressure at > any > node is 105 PSI. > > The foregoing is my opinion only and does not represent the opinion of or > any manner of interpretation by NFPA or the Technical Committee on > Standpipes. > > Steve Leyton > > -----Original Message----- > From: Sprinklerforum [mailto: > [email protected]] > On Behalf Of Tony Eggster > Sent: Monday, March 14, 2016 3:24 PM > To: [email protected] > Subject: Standpipe Calc: Adding City Demand to Pumper Truck? > > Quick question: I'm reviewing some plans for a manual class I standpipe and > the designer added the city flow test to the usual 1000gpm fire pumper > curve > in order to keep all the pipe down to 4". I see in the NFPA 14 appendix > that > you can do this but personally I've always just calculated solely to the > pumper curve. How do you guys do it? > > Also, I'm assuming that if you do factor in city supply wouldn't that > frequently require high pressure pipe and fittings depending on city supply > psi? > > _TONY > _______________________________________________ > 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 > -- Ron Greenman Instructor Fire Protection Engineering Technology Bates Technical College 1101 So. Yakima Ave. Tacoma, WA 98405 [email protected] http://www.bates.ctc.edu/fireprotection/ 253.680.7346 253.576.9700 (cell) Member: ASEE, SFPE, ASCET, NFPA, AFSA, NFSA, AFAA, NIBS, WSAFM, WFC, WFSC They are happy men whose natures sort with their vocations. -Francis Bacon, essayist, philosopher, and statesman (1561-1626) A problem well stated is a problem half solved. -Charles F. Kettering, inventor and engineer (1876-1958) _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org
