Holy slippery slope Jake Pauls - this is a good one. NFPA 24 is indeed the applicable standard for the lead-in. The scouring velocity is 10 fps. But, the water supply, absent a pump sucking on it, may not be capable of giving you 10 fps. Flushing the lead-in before connecting to the pump is prudent. But, if you can't make 10 fps, a boroscope inspection might be in order. Bottom line, don't send anything gravel or smaller through the impeller.
Be careful with the idea of "flow as much as you can". If you are flushing an 8" lead-in and you put an 8" x 2" flanged reducer on the end to facilitate flushing and the results are below the scouring velocity, you did NOT flow as much as you can. Devices that restrict the flush activity are not acceptable reasons for the inability to achieve scouring velocity. J. Scott Mitchell, PE NFPA disclaimer unnecessary -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Dewayne Martinez Sent: Wednesday, November 16, 2011 6:08 AM To: SprinklerFORUM Subject: fire pump suction piping - flushing Where exactly does the flushing requirements of NFPA 24 come to play for the suction piping on a fire pump? It appears that the suction piping, even for a combined lead in, has to be flushed per NFPA 24 back to the point of connection to the city main. Am I correct on this thinking? This means 2350GPM for a 8in lead in instead of 1560GPM per NFPA 20. What happens if you can't get this flow rate? I don't see an exception, like in 24, to just flow as much as you can. Thanks, Dewayne Martinez Design Build Fire Protection 262-781-7900 (w) 262-781-8401 (f) 414-349-0468 (cell) -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://fireball.firesprinkler.org/mailman/private/sprinklerforum/attachment s/20111116/dd425575/attachment.html> _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum
