How much time do you get in 8 hours to re-fill the tank? 8 (eight) hours or 480 minutes or 28,800 seconds, or however else you want to slice it. That's how much time you've got to refill the tank.
If tank "A" is the primary tank and supplies the required duration and you erect a backup tank adjacent to it as redundant and you drain tank "A", dump tank "B" into "A" and you've met the 8 hour requirement with no problem. Then however long it takes to fill tank "B" is of no consequence because it is not the primary supply for the system. Now if you have an event on day one of the 3-day re-fill of tank "B" and tank "A" is empty again, then you've got an issue. But you've also probably been attacked and overrun by alien zombies so no one will care. Craig L. Prahl, CET Fire Protection CH2MHILL Lockwood Greene 1500 International Drive Spartanburg, SC 29304-0491 Direct - 864.599.4102 Fax - 864.599.8439 CH2MHILL Extension 74102 [email protected] -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Brad Casterline Sent: Thursday, May 16, 2013 2:43 PM To: [email protected] Subject: RE: NFPA 22 2013 Water storage re-fill time. ok good, now then, if you are/were an A.H.J., how would you answer this question: "How much time do we get to be able to re-fill a water storage tank in 8 hours"? for example, 150,000 gallon capacity for demand*duration, say tank A, from which the pump takes suction. Now we build a twin tank B, and connect to tank A with 8" pipe with a shut-off valve normally closed. There is an event and tank A runs dry. We open the shut-off valve and tank A is re-filled in about 18 minutes. The well pump then starts refilling tank B, which will take 3 days. So the question is "how much time do we get to be able to re-fill the tank within in 8 hours?". -----Original Message----- From: Brad Casterline [mailto:[email protected]] Sent: Thursday, May 16, 2013 8:18 AM To: [email protected] Subject: NFPA 22 2013 Water storage re-fill time. asking for a co-worker: 1) Why are water storage tanks required to be re-filled in 8 hours? 2) Would the requirement apply to ponds (man-made with liner in this case)? 3) Are there any alternatives to the requirement? (the pond is large and filled by a well pump with a pumping rate that would take more than 8 hours) many thanks, Brad Casterline, NICET IV Fire Protection Division FSC, Inc. P: 913-722-3473 [email protected] www.fsc-inc.com Engineering Solutions for the Built Environment _______________________________________________ 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
