Gayle, The argument that I have used with some success is a basic risk comparison between the possibility of a backflow incident and the danger from a fire in the building. I don't think you will have much luck with arguing that the RPZ and double check are no different. According to the cross-connection field, the RPZ is definitely safer. However, if you can do some rough hydraulic analysis and find that the extra 10 psi or so of friction loss from an RPZ results in the need for a fire pump (which it often does), then you can make an argument. The argument is that the fire pump adds a mechanical component to the sprinkler system making it a little less reliable in the event of a fire which must be weighed against the marginal increase in safety that an RPZ provides over the existing double-check BFP's you have. All of this is notwithstanding the additional expense to the building owner. It's a tradeoff between the safety of the building inhabitants from fire and the safety of the community from a backflow incident.
The few times that I have explained this to the water guys, they have backed off the requirement. Good luck, Steve -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of GAYLE KNOWLES Sent: Tuesday, October 09, 2007 2:26 PM To: [email protected] Subject: RE: Double-check vs RPs Thanks for the info. I guess what I'm looking for is something that states that all these existing double-check backflows are not a threat and replacing them all with RPZ is a lot of unnecessary extra cost for the owner. As Matt stated, it may very well be a losing argument as long as it has been "adopted". The info will be used to fight to keep the existing double-checks.> Date: Tue, 9 Oct 2007 14:10:20 -0400> From: [EMAIL PROTECTED]> To: [email protected]> Subject: RE: Double-check vs RPs> > Gayle, Perhaps our regulations in New Jersey would be of assistance.> > John Drucker, Fire Protection Subcode Official, NJ> ------------------------------------------------------------------------> ------> > STATE OF NEW JERSEY> > DEPARTMENT OF ENVIRONMENTAL PROTECTION> > BUREAU OF SAFE DRINKING WATER> > SAFE DRINKING WATER ACT REGULATIONS> > (N.J.A.C. 7:10)> > ADOPTED: November 4, 2004> > 7:10-10.4 Installation> > (a) The approved physical connection installation shall be> installed on the customer's side of the water meter on the> pipe(s) conveying the water from the public community water> system into a facility, shall be installed as close to the meter as> is reasonably practicable, and shall be prior to any other> connection, unless such other connection is also protected by> means of an approved physical connection installation. For a> fire service line, the approved physical connection installation> shall be installed prior to the alarm check and siamese> connection.> (b) The approved physical connection installation shall be> installed so as to allow easy access, with adequate space for> maintenance, inspection, and testing. No part of the device> shall be submerged or subjected to freezing temperatures unless> such part is thermally protected.> > (c) The approved physical connection installation shall not> be installed in a pit or vault.> > 1. This subsection shall not apply to any physical> connection installation operated under a current physical> connection permit issued before the operative date of this> chapter until such time as the existing physical connection> installation is replaced or modified> > _______________________________________________> Sprinklerforum mailing list> [email protected]> http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum> > To Unsubscribe, send an email to:[EMAIL PROTECTED]> (Put the word unsubscribe in the subject field)_______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum To Unsubscribe, send an email to:[EMAIL PROTECTED] (Put the word unsubscribe in the subject field) _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum To Unsubscribe, send an email to:[EMAIL PROTECTED] (Put the word unsubscribe in the subject field)
