There are different requirements regarding water supplies. First, NFPA Standards dictate the duration required based on the hazard and particular standard you are using. For example, NFPA 13 provides minimum water supply durations for various systems throughout the Standard. ESFR systems require no less than 1 hour, others 60 -90 minutes, some up to 2 hours. Look at Table 11.2.3.1.2 for example.
The other factor related to water supply duration comes from the Fire Code and that's related to Fire Flow. Few fire protection designers/engineers pick up on this requirement and it is often overlooked. See section 507 of the IFC relating to Fire Flow. There is a process here that is required to determine the correct Fire Flow values, it's not just open book, turn to page XX and there's your answer. Durations for Fire Flow can be 2 hours up to 4 hours. Craig L. Prahl Fire Protection Group Lead CH2MHILL Lockwood Greene 1500 International Drive Spartanburg, SC 29303 Direct - 864.599.4102 Fax - 864.599.8439 CH2MHILL Extension 74102 [email protected] -----Original Message----- From: Sprinklerforum [mailto:[email protected]] On Behalf Of Tony Silva Sent: Wednesday, June 18, 2014 11:08 AM To: [email protected] Subject: Re: 2 hour fire water supply Can anyone tell me from where the requirement for the two hour supply comes from? Is it a code requirement? If so, which? Thanks, Tony ----- Original Message ----- From: "Karen Lesko" <[email protected]> To: [email protected] Sent: Thursday, June 12, 2014 7:40:10 PM Subject: 2 hour fire water supply When evaluating fire water supply to ensure there is a 2 hour supply, do I have to take the head pressure loss of the fire water tank level drop into account over the 2 hours? The tank has makeup from wells that have normal and back-up power, and the well makeup into the fire water tank equals the output of the fire pump. Thank you in advance, Karen Lesko _______________________________________________ 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
