From: McCormick, Mark <[EMAIL PROTECTED]> To: Los Angeles Area Fire Marshals Association <[EMAIL PROTECTED]> Sent: Tue Apr 01 21:48:50 2008 Subject: [laafma] Pipe Velocity in 3/4" Water Service Lateral
We adopted a sprinkler ordinance in January for SFDs and now are dealing with some of the vacant lots in town that have a ¾ copper water service lateral with a 1 meter. Our Water Department (regulates from the corporation stop to the customer side of the meter) has a maximum velocity standard of 15 feet per second. When you flow 26 gpm through a ¾ inch service lateral the velocity is in the 30 fps range. I am proposing we stay with NFPA 13D, the guiding design standard for residential sprinklers in SFDs. 13D does not seem to have a velocity requirement and does allow ¾ pipe as long as hydraulically the pressure and flow is available. New subdivisions will have a 1.5 lateral so we wont have the problem in the future. Has anyone ran into the velocity issue for residential 13D systems? If so, were you successful in getting around the hurdle? We do not believe exceeding the velocity in ¾ copper for a test and possible fire will be an issue. Thanks for any information you have. Mark _______________________________________________ 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)
