Forumites, NFPA 20 - 2007 par. 5.7.6.2 ( = 2010 par. 4.7.7.2) says: "Pressure relief valves and pressure regulating devices in the fire pump installation shall not be used as a means to meet the requirements of 5.7.6.1." (= 2010 par. 4.7.7.1)
I ask this question because it seems to be not unusual in my country to fit fire pumps with a pressure relief valve to limit the churn pressure below 175 psi in systems that need a high pressure (e.g. 165 psi) in the point of operation. Thus flattening the first part of the curve up to the point of operation. This happens to both, engine driven as well as electric driven fire pumps. In engine driven pumps they use for this purpose the same relief valve as mentioned in section 5.18 "Relief Valves for Centrifugal Pumps" (= 2010 section 4.18). Can anyone tell me why this par. 5.7.6.2 says: "shall not be used" ? Why did the committee put this in the code ? I remember times when it was not in there. Is this based on bad experiences? When I point other technicians to this rule a common response is "Why ? We do it all the time! " Can anyone of you shed some light on this issue? Frans Stoop TOS architecture & fire protection Netherlands <f.st...@tosfire.com> Tel. +31-24-324 0112 _______________________________________________ Sprinklerforum mailing list Sprinklerforum@firesprinkler.org http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: supp...@firesprinkler.org To Unsubscribe, send an email to:sprinklerforum-requ...@firesprinkler.org (Put the word unsubscribe in the subject field)
