I can affirm that was the reasoning for the requirement in NFPA 14 that all sprinkler connections to standpipes have both a control and check valve.
Steve L. This time it's NOT my opinion only - you can look it up in the ROP and ROC logs. -----Original Message----- From: Sprinklerforum on behalf of J. Scott Mitchell, PE Sent: Wed 1/21/2015 5:23 PM To: [email protected] Subject: RE: Why are check valves required on each system in buildings over2 stories but not in multisystem 1 story buildings I think it's to allow for work on the common riser without draining all the floors. J. Scott Mitchell, PE Sent from my Verizon Wireless 4G LTE smartphone <div>-------- Original message --------</div><div>From: [email protected] </div><div>Date:01/21/2015 10:42 AM (GMT-06:00) </div><div>To: [email protected] </div><div>Subject: Why are check valves required on each system in buildings over 2 stories but not in multisystem 1 story buildings </div><div> </div>Consider NFPA 13 (2013) as the applicable standard. Question - Why are check valves required on each sprinklers system riser when buildings are over 2 stories in height but they are not required on each system riser when the building is single story (ex: warehouse with multiple systems on a manifold)? Please assume for this question each system will have a DCBFP device between the city water connection and the building. Also please assume the FDC (with check valve) is tied directly into the manifold/standpipe downstream of the DCBFP and prior to any system control valves. My code references are as follows: 3.5.12 System Riser - The aboveground horizontal or vertical pipe between the water supply and the mains (cross or feed) that contains a control valve (either directly or within its supply pipe), pressure gauge, drain, and water flow alarm device. 8.16.1.5.1 - Multistory buildings exceeding two stories in height shall be provided with a floor control valve, check valve, main drain valve, and flow switch for isolation, control, and annunciation of water flow on each floor level. 8.17.5.2.2(1) - Each connection from a standpipe that is part of a combined system to a sprinkler system shall have an individual control valve and check valve of the same size as the connection. [This is identical to NFPA 14 (2013) - 6.3.5.1] What I do not understand is why check valves would be required on each system riser when you go vertical, but not horizontal. Any clarity on this question, specifically "WHY" would be greatly appreciated. Thanks, Sean _______________________________________________ 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
