George, Am I missing something or is this a standard water supply (NFPA-291) test plotted on N185 ? Take it out to 20psi and whatever it is it is. If it's less than 1500 gpm at 20 psi the water supply needs to be improved, i.e. infrastructure or storage tank.
The 1500 gpm at 20 psi minimum is standard fare out of the IFC, Table B105.1, B105.2 and AWWA M-31. John Drucker, CET Fire Protection Subcode Official Fire/Building/Electrical Inspector Fire Marshals Office Borough of Red Bank, NJ -----Original Message----- From: sprinklerforum-boun...@firesprinkler.org [mailto:sprinklerforum-boun...@firesprinkler.org] On Behalf Of George Medina Jr Sent: Monday, October 18, 2010 10:02 PM To: sprinklerforum@firesprinkler.org Subject: Re: Fire Hydrant Calculation Method I am calcing for the system (private fire hydrant). I do not need a hose stream ( I was told to add the 1500 as a hose stream allowance in the Hass program [not by any Hass Rep's] to simulate 1500 gpm flowing to the hydrant) There is going to be a new private fire hydrant on private property. I requsted a fire flow test for the address where the new private fire hydrant is going. The fire flow availabilty form was: 90psi static, 82psi residual at 4657 gpm. The fire inspector wanted the new private fire hydrant to produce a minimum of 1500 gpm @ 20psi. George Medina Jr. -----Original Message----- From: Ron Greenman <rongreen...@gmail.com> To: sprinklerforum@firesprinkler.org Sent: Mon, Oct 18, 2010 5:29 pm Subject: Re: Fire Hydrant Calculation Method George, If you're calcing for the flow at a certain residual (20 psi) and you ave residual from a hydrant and the actual flow why do you need a ose stream? Are you calcing the water availability or the system? On Mon, Oct 18, 2010 at 4:01 PM, George Medina Jr <fireg...@aol.com> wrote: That is the formula I was looking for, Thanks. Now to change the subject slightly, I am about to calculate a fire hydrant sing the Hass program. The Inspector wants a minimum of 1500gpm at 20psi. The ydrant is a Clow 4"x4"x2½" hydrant ( I was told to just enter the flow in the Toggle Hose Stream' which only goes up to 1000gpm (so I tried 1000gpm just for icks) and it gave me a warning: END HEAD FLOW CONDITION SPECIFIED BUT NO LOWING SPRINKLERS WERE FOUND' which would not balance out. So I used the ormula of K=Q/sqrt of P to get a k factor to input. I was able to calculate with a k of 333 which only gave me 1,489 gpm. I have one many hydrant calcs in Hydracalc and even some in HASS in the past and can't eem for the life of me what I am doing wrong? should I adjust the k until I get he flow I am looking for? That does not sound correct either. Any advice for his absent minded designer? George Medina Jr. -----Original Message----- From: Scott A. Futrell <sco...@ffcdi.com> To: sprinklerforum@firesprinkler.org Sent: Mon, Oct 18, 2010 8:24 am Subject: RE: Fire Hydrant Calculation Information Another method, from a parasite, without determining a K-factor first, but sing 91 (Dave's info) for the water flow test development. Flow at any pressure: Q=((PS-P)/(PS-PR))0.54xQR Where Q=flow at any given pressure P=Pressure at which you want to know Q PR=Residual pressure measured in test PS=Static pressure measured in test QR=Residual flow measured in test Scott -----Original Message----- rom: sprinklerforum-boun...@firesprinkler.org [mailto:sprinklerforum-boun...@firesprinkler.org] n Behalf Of David de Vries ent: Sunday, October 17, 2010 11:08 PM o: sprinklerforum@firesprinkler.org ubject: Re: Fire Hydrant Calculation Information George, you can look up NFPA 291 on NFPA's website and read all about it. If ou don't have a copy, go to the Codes and Standards link at www.nfpa.org, then alf way down the page the List of Codes and Standards link, then NFPA 291, hen iew 2010 edition on line. The gist of a hydrant flow is this: Q (flow in gpm) = 29.84 x C x D (diameter n inches) squared x square root of P (pitot pressure in psi). The hydrant oefficients for 2-1/2 inch butts are 0.90 for rounded interior corner, 0.80 or quare interior corner and 0.70 for an interior where the butt extends into the nterior of the hydrant (I have never found one of these). Read 291 if you are lowing from a steamer port (4 inch or 4-1/2 inch), cause more coefficents pply. Also, if you attach a playpipe to the hydrant butt, you should use a C f 0.97 and the actual diamter of the tip of the playpipe. There are two ways to determine the flow at 20 psi: graph it on N1.85 paper nd xtend the flow line to 20 psi, or calculate. Either way you will need the low from above), the static pressure and residual pressure. Once you have those, hen calculate the K for the system: K = Q / (Pstatic - Presidual) to the 0.54 ower. You will need a scientific calculator to do that (I use a TI-30 or I-55). Then the flow at 20 psi: Q (at 20 psi) = K x (Pstatic - 20) ^0.54. his whole methodology is based on Hazen Williams and assumes that the water istribution system charactersitics are constant (the "K") and the variables re low and friction (Pstatic - Presidual). Example: You did a hydrant flow test and measured a static pressure of 60, a esidual pressure of 35 with a pitot of 16 from a 2-1/2 inch rounded interior utt. The flow is Q = 29.84 x 0.90 x 2.5 squared x square root of 16 = 671 pm. for your system is K = 671 / (60 - 35) ^0.54 = 118. Then your flow at 20 psi s Q = 118 x (60 - 20) ^0.54 = 865. Ron and Cecil, let us know if I have been doing this the hard way for the last 0 years and show us an easier way. Dave David A. de Vries, P.E., CSP Firetech Engineering Incorporated --- On Fri, 10/15/10, George Medina Jr <fireg...@aol.com> wrote: From: George Medina Jr <fireg...@aol.com> Subject: Fire Hydrant Calculation Information To: sprinklerforum@firesprinkler.org Date: Friday, October 15, 2010, 6:39 PM Forum, What is the formula to find Hydrant flows at 20 psi? ( Was that said orrectly) I used to have the formula set up in an excel spread sheet but lost it during ile transfer from old computer to new computer. I also remember having a spreadsheet containing coefficients for the three ypes f 2½" outlets. If I could be directed to the location of the information or if anyone has an old notebook with the following information it would be reatly appreciated if shared. Thanks, George Medina Jr. 323-278-0021 fireg...@aol.com _______________________________________________ Sprinklerforum mailing list Sprinklerforum@firesprinkler.org http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: supp...@firesprinkler.org To Unsubscribe, send an email to:sprinklerforum-requ...@firesprinkler.org (Put the word unsubscribe in the subject field) _______________________________________________ Sprinklerforum mailing list Sprinklerforum@firesprinkler.org http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: supp...@firesprinkler.org To Unsubscribe, send an email to:sprinklerforum-requ...@firesprinkler.org (Put the word unsubscribe in the subject field) _______________________________________________ prinklerforum mailing list prinklerfo...@firesprinkler.org ttp://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: supp...@firesprinkler.org To Unsubscribe, send an email to:sprinklerforum-requ...@firesprinkler.org Put the word unsubscribe in the subject field) _______________________________________________ Sprinklerforum mailing list Sprinklerforum@firesprinkler.org http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: supp...@firesprinkler.org To Unsubscribe, send an email to:sprinklerforum-requ...@firesprinkler.org (Put the word unsubscribe in the subject field) -- on Greenman nstructor ire Protection Engineering Technology ates Technical College 101 So. Yakima Ave. acoma, WA 98405 rgreen...@bates.ctc.edu http://www.bates.ctc.edu/fireprotection/ 253.680.7346 53.576.9700 (cell) Member: FSA, SFPE, ASCET, NFPA, NFSA, AFAA, ASEE, NIBS, WSAFM, WFC They are happy men whose natures sort with their vocations. -Francis acon, essayist, philosopher, and statesman (1561-1626) ______________________________________________ prinklerforum mailing list prinklerfo...@firesprinkler.org ttp://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: supp...@firesprinkler.org To Unsubscribe, send an email to:sprinklerforum-requ...@firesprinkler.org Put the word unsubscribe in the subject field) _______________________________________________ Sprinklerforum mailing list Sprinklerforum@firesprinkler.org http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: supp...@firesprinkler.org To Unsubscribe, send an email to:sprinklerforum-requ...@firesprinkler.org (Put the word unsubscribe in the subject field) _______________________________________________ Sprinklerforum mailing list Sprinklerforum@firesprinkler.org http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: supp...@firesprinkler.org To Unsubscribe, send an email to:sprinklerforum-requ...@firesprinkler.org (Put the word unsubscribe in the subject field)
