Bob, That's kind of what I was getting at. I'll probably just have to submit a separate calc showing the 150% pump rating through the pump to the tank to prove the losses are acceptable. Does anyone know if there is a way to do this in a single calc in hydracalc? I can put in an additional water 'source' but then would have to enter in a static, res, and flow for the tank to get it to run through the program and these numbers are unknown (except for static).
Thanks, RB --- On Mon, 6/6/11, Bob <[email protected]> wrote: From: Bob <[email protected]> Subject: RE: Pump, Tank, 1000 ft suction line..... To: [email protected] Date: Monday, June 6, 2011, 11:05 PM Ralph, Looking at this I'm coming up with 20.3 psi loss in 1000' of pipe not counting fittings and valves. (4.52*1000.00^1.85)/(140^1.85*6.4^4.85) = .0203 .0203 * 1000 = 20.3. 6.4" is ID of 6" Tyton Joint Pipe DI. Fittings and valves will increase your losses. At 1500 gpm you will have .43 psi / ft loss. These numbers will vary depending on pipe type and ID. As far as how to do it; I think I would simply run the numbers through the calculation back to the tank. Or better yet, if there are hydrants fed off of the tank have a flow test performed and calc back to that point of connection. Bob Knight, CET III 208-318-3057 www.firebyknight.com -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Vince Sabolik Sent: Monday, June 06, 2011 4:37 PM To: [email protected]; [email protected] Subject: Re: Pump, Tank, 1000 ft suction line..... Ralph - My rough calcs say about 16 psi loss at 100% flow and 34 psi loss at 150% flow. Unless this is an elevated tank, or your source is uphill from the pump, this won't work. At 06:32 PM 6/6/2011, you wrote: >at 1000 gpm, you are going to lose about 2 psi per 100' of 6" >ductile iron pipe. At 1500 gpm, you are going to lose about 5 psi / >100' of DI pipe. You need to have enough elevation between the tank >and pump to provide a positive pressure at the suction flange. > >On 6/6/2011 3:28 PM, Ralphy Henderson wrote: >>Hi All, >> >>Can someone explain to me how one would go about calculating a fire >>pump being fed solely from a water storage tank but with a 6" x >>1,000 ft suction line? I've calculated fire pumps off of tanks that >>had a small 10 ft. suction lines directly off the tank but never one >>with this amount of underground line and I'm concerned about making >>sure friction losses in the suction are properly accounted for. The >>pump is 75 psi @ 1000 gpm. >> >>We use hydracalc, and typically when a fire pump and tank scenario >>comes up we have only one 'source', the pump, being specified. >>Would this change in this instance? I guess the main thing I'm >>concerned about is coming up with a negative pressure at the suction >>flange due to such a long run. >> >>Any help? >> >>-RB >> >>_______________________________________________ >>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) > >__________ Information from ESET NOD32 Antivirus, version of virus >signature database 6185 (20110606) __________ > >The message was checked by ESET NOD32 Antivirus. > >http://www.eset.com > > Vince Sabolik Christi Fire Protection, Inc. 11351 Pearl Road Strongsville, Ohio 44136 T 440 572-7730 F 440 572-7719 Email: <mailto:[email protected]>[email protected] _______________________________________________ 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)
