Todd. Exactly correct in my book. That is where I also ended up. Just needed a little reinforcement. Thanks
-----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Todd Williams - FPDC Sent: Thursday, May 22, 2008 10:20 AM To: [email protected] Subject: Re: Tanks Geoff, Let me see if I have this right. The hose demand is 500 gpm and the sprinkler demand is 600 gpm for a total demand of 1100 gpm combined. The duration is 90 minutes, so the total water demand is 99000 gallons. Your flow test shows only 600 gpm at 29 psi, therefore a tank, and presumedly pump, is required. In this situation, would the hose demand be taken before of after the proposed tank? It sounds like it might be taken before the tank. Therefore, you need to make the 600 gpm sprinkler demand off of the tank. The available tank capacity would need to be 600 x 90 or 54,000 gallons. The actual tank would be around 60,000 gallons. What you want to do is try to decrease the size of the tank by deducting the fill rate. Your assumption is that 100 gpm at 29 psi would be available after the hose streams to fill the tank. Somehow I don't think that you can automatically assume that because you cannot predict what the actual fill rate would be, based on a flow test alone. I think that factors such as pipe size, supply vs tank elevation, etc need to be considered. Also, If you have 20 ft of head in the tank, then you have a 8.7 psi fighting the 29 psi, which could decrease the potential flow. Personally, I don't like to include refill rate in sizing the tank, because it is not predictable. Besides, you are only potentially dealing with a 50,000 gallon tank vs. a 60,000 gallon tank. How much of a savings would there really be? At 09:33 AM 5/22/2008, you wrote: >Situation.....Flow test shows water flow at 600 gpm at 29 psi >Hose requirement is 500 gpm at the main hydrant >System requires 600 gpm for 90 minutes >Using a tank, can I say under a flowing situation, the tank will >fill at a rate of 100 gpm because of the hose requirement? >Would I then require a tank based on 500 gpm for 90 minutes or a >tank of 45,000 gallons? >Thanks for your help > >Geoffrey H. Dyce >Sales Manager >Contractor I, #87582700012007 >NICET IV >Industrial Fire & Safety Inc. >Ph: 727-573-1556 >Fx: 727-572-7266 >Cell: 727-644-8872 > >_______________________________________________ >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) Todd G. Williams, PE Fire Protection Design/Consulting Stonington, Connecticut www.fpdc.com 860.535.2080 _______________________________________________ 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)
