Relief Valve for Multiple Systems
“NFPA 13, Section 7.1.2.1, indicates a relief valve is required on all wet systems. When multiple systems are fed from one manifold,is a relief valve required on each or does one suffice for the entire system?” We have reviewed NFPA 13, 2016 edition as the applicable standard. Our informal interpretation is that each system requires a relief valve. Section 7.1.2.1 (the wording is not being quoted from the standard) indicates that a wet pipe system shall be provided with a relief valve. NFPA 13 is basically written to address individual systems, regardless of the number of systems within a building. There are exceptions naturally, such as water supplies and some fire department connections. As such, each individual system must have a relief valve. The intent of the relief valve is to relieve excessive pressure within the system (whether from trapped surges or thermal expansion). If the relief valve was on the manifold, each system would be isolated from it by the riser check valve or system valve. Actually some systems will require multiple relief valves. As pointed out by 7.1.2.3, combined standpipe / sprinkler risers have additional check valves and additional relief valves are required downstream of them. Although not stated, the same concern exists when a sectional check valve is installed. This occurs for buildings with more than two stories when a floor control valve assembly is required per Section 8.2.4. Although these contain all the components required by a system riser, except for pressure gauges, they are not called a system so there’s no explicit requirement to protect this portion of piping against higher pressures. ------------ Technical Update is prepared by the Technical Services Dept. of the AFSA: Roland Huggins, a PE registered in fire protection engineering, Vice President of Engineering and Technical Services; and Tom Wellen, a PE registered in fire protection engineering. This is provided with the understanding that the AFSA assumes no liability for this opinion or actions taken on it and they are not to be considered the official position of the NFPA or its technical committees. Copyright 2016, American Fire Sprinkler Association. All Rights Reserved. Ada Dickson Ada Dickson Administrative Assistant Technical Services Dept. PH: (214) 349-5965 ext. 124 Fax: (214) 343-8898 E-mail: adick...@firesprinkler.org -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.firesprinkler.org/private.cgi/sprinklernotes-firesprinkler.org/attachments/20161031/001d71d7/attachment.htm>
