If there's a BFP downstream, you might try moving the sensing lines downstream from it, you could have checks fighting checks and bouncing pressure. Sometimes, sensing lines (per the book) are just tied to lines with too little capacity and the slightest movement of a checkvalve or pump create huge pressure swings. I've corrected telegraphing jockeys by moving the sensing line (and jp discharge) beyond the valves and checks. This is something that's always situation dependent, you have to look at what and why. I've even done a third orifice in the sensing line. TD
-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Mike Hairfield Sent: Tuesday, November 06, 2012 3:27 PM To: AFSA SprinklerFORUM Subject: RE: Water Hammer Problem We used restricted unions with 3/32" holes. Mike > Subject: Re: Water Hammer Problem > From: [email protected] > Date: Tue, 6 Nov 2012 15:24:36 -0500 > To: [email protected] > > Are the two checks with with small holes present in the sensing lines, > might solve your problem. See NFPA 20 for suggested arrangement > > Regards, > Jamey > > On 2012-11-06, at 2:52 PM, Mike Hairfield <[email protected]> wrote: > > > > > > > I have a dry system fed by a booster pump that takes suction off of > > a pumped well system feeding a plant. > > > > The darn dry pipe valve keeps tripping and my thoughts are that when > > the plant well pumps shut off it's sending a water hammer into the fire pump suction line. > > > > I believe the water hammer is causing the pump sensing line to act > > erratic causing the pump to run thus tripping the dry pipe valve. > > > > Anyone have any suggestions about how to fix my problem, a expansion > > tank or water hammer arrestor comes to mind. > > > > Thanks, > > > > Mike Hairfield > > > > > > -------------- next part -------------- An HTML attachment was > > scrubbed... > > URL: > > <http://fireball.firesprinkler.org/mailman/private/sprinklerforum/at > > tachments/20121106/3f3e2708/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 -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://fireball.firesprinkler.org/mailman/private/sprinklerforum/attachment s/20121106/eb61a0c1/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
