When sizing a water storage tank for fire protection do no forget the IFC code requirement for Fire Flow in section 507. It's an additional water supply requirement apart from sprinkler flow. This is especially critical if the municipal supply is not sufficient to meet the required flow rates as dictated by the Approved Method for determining Fire Flow.
But to your question. It sounds like you want to take credit for the incoming water supply flow rate to reduce your storage capacity, correct? If that is the case, there are a few things that you must consider and you must get approval from the AHJ and any insurer. 1. Is the municipal flow rate guaranteed to be available 24/7/365? 2. Will the local Fire Code official and the owner's insurer approve of the concept. In theory you could take the credit and use the municipal supply as a buffer against the increased tank size but at some point in time you reach a point where you could consume at a rate greater than can be made up especially with the fire flow demand rate. We've only been successful in incorporating this concept on one occasion. Typically, our projects tend to be high value and high hazard and the lack of an adequate water supply for fire suppression and firefighting is not something that the AHJs or Insurers were willing to compromise on. But when the owner asks, we'll oblige and ask the question of the AHJ. Craig Prahl | Jacobs | Group Lead – Fire Protection | 864.676.5252 | [email protected] | www.jacobs.com -----Original Message----- From: Sprinklerforum [mailto:[email protected]] On Behalf Of George W. Henderson Sent: Wednesday, June 13, 2018 2:29 PM To: [email protected] Subject: [EXTERNAL] Ground Storage tank I am attempting my first participation. We have the need for a ground storage tank. The MUD cannot supply volume or pressure. We size the tank to satisfy the code water supply duration. This tank about 200,000 gallons, Is it allowed to use the the MUD water supply refill to reduce the size of the tank? -- George W. Henderson VP RME 0054-GD Eagle Automatic Fire Sprinkler Inc 1777 Upland Dr. #107 Houston, TX 77043 713-939-0708 (office) 832-435-1393 (cell) _______________________________________________ Sprinklerforum mailing list [email protected] https://urldefense.proofpoint.com/v2/url?u=http-3A__lists.firesprinkler.org_listinfo.cgi_sprinklerforum-2Dfiresprinkler.org&d=DwIGaQ&c=OgZOSER8c1RLeytEexU279Q2qk0jVwkrOdYe5iSi-kk&r=6qYbbLx8x0UrMujmEGNoh-2hzoFD2d1EB5d2sQF0_OI&m=IjGuE8b8uSlg8Jr-VSUCrW37fKKQ-DnT0-mJlALaPVg&s=fqpzgBBqeBWkNGsyB3C517JIsF-D3XkgEBUwFFDmltM&e= ________________________________________________________________________________________ NOTICE - This communication may contain confidential and privileged information that is for the sole use of the intended recipient. Any viewing, copying or distribution of, or reliance on this message by unintended recipients is strictly prohibited. If you have received this message in error, please notify us immediately by replying to the message and deleting it from your computer. _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org
