This facility has a plethora of problems, including the fire pump not starting. However, if the fire pump did not start when a sprinkler discharged (say due to a fire), and the flow without the pump was not sufficient to activate the flow switch, would an alarm be sent?
At 12:03 PM 11/2/2009, you wrote: >UL requires The flowswitch to operate between 4-10 gpm. They typically >operate much closer to 10 than 4, usually in the 8-10 gpm range but plan >on 10 to be safe. > >If the trip rod went back to the no flow condition than there may be >less than 4 gpm flowing past the paddle. > >The flow must be continuous and must last longer than the retard time. > >Is the IT just a 1/2" ball valve or calibrated test gauge? > >Is it discharging directly to a drain or the ground or is a hose >connected to it? > >Is it possible to discharge the IT into a 5 gallon bucket for 30 seconds >to see if you are near 10 gpm? > >Regards, > >mike > >Mike Henke CET >Sprinkler Product Manager >Potter Electric Signal >WWW.Pottersignal.com >1-800-325-3936 > >-----Original Message----- >From: [email protected] >[mailto:[email protected]] On Behalf Of Todd >Williams >Sent: Monday, November 02, 2009 10:54 AM >To: [email protected] >Subject: RE: pump failure/flow alarm > >Just had another conversation with the fitter. When the IT is opened, >the paddle goes up for about 3 seconds and then settles back to >neutral. My guess is that the majority of water is discharged in the >first few seconds and the pressure pretty quickly dissipates to >elevation head only and the flow would be only a trickle. At 50 psi, >a 1/2" sprinkler would discharge 39.6 gpm initially, rapidly >declining. How long would the 8 gpm need to be maintained for the >flow switch to activate? The duration of the delay? > >The 39.6 gpm translates to 0.66 gallons per second. If that 50 psi >remained steady, it would take 12 seconds to discharge 8 gallons, >well under the 30 second setting on the FS. The minimum 8 gpm flow >requires a 2 psi discharge out of a 1/2" orifice. Will the pressure >at the orifice drop from 50 psi to 2 psi in 30 seconds in a closed >system? Probably. > >Am I over thinking again? > > > >At 11:21 AM 11/2/2009, you wrote: > >Are the jockey and fire pump not using sensing lines? > > > >Joe Burtell > > > >-----Original Message----- > >From: [email protected] > >[mailto:[email protected]] On Behalf Of Todd >Williams > >Sent: Monday, November 02, 2009 9:07 AM > >To: [email protected] > >Subject: pump failure/flow alarm > > > >A situation came up this morning that I probably should know the > >answer to, but I don't. A building is protected by a 500 gpm at 40 > >psi diesel pump taking suction from a tank (no public water). The > >pump feeds to 2 sprinkler risers with riser checks and flow switches. > >The jockey pump pressure is set to approximately 50 psi. If the > >inspector's test opens and the pump does not turn on, there is not > >enough flow in the system to activate the flow switch. Consequently, > >if a sprinkler goes off and the pump does not activate, then no alarm > >is sent. Having never run into this or heard of it being tested, I > >don't know if this is normal but it seems like it shouldn't be. Is > >this normal? Is it ever tested? > > > >My first reaction is what is the delay on the flow switch set to (30 > >seconds). I told them to set to delay to 0 and see what happens. It > >may be just a situation of getting the setting right. Thoughts? > > > >Todd G. Williams, PE > >Fire Protection Design/Consulting > >Stonington, Connecticut > >www.fpdc.com > >860.535.2080 > >_______________________________________________ > >Sprinklerforum mailing list > >[email protected] > >http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum > > > >For Technical Assistance, send an email to: [email protected] > > > >To Unsubscribe, send an email >to:[email protected] > >(Put the word unsubscribe in the subject field) > > > >_______________________________________________ > >Sprinklerforum mailing list > >[email protected] > >http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum > > > >For Technical Assistance, send an email to: [email protected] > > > >To Unsubscribe, send an email >to:[email protected] > >(Put the word unsubscribe in the subject field) > >Todd G. Williams, PE >Fire Protection Design/Consulting >Stonington, Connecticut >www.fpdc.com >860.535.2080 >_______________________________________________ >Sprinklerforum mailing list >[email protected] >http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum > >For Technical Assistance, send an email to: [email protected] > >To Unsubscribe, send an email >to:[email protected] >(Put the word unsubscribe in the subject field) >_______________________________________________ >Sprinklerforum mailing list >[email protected] >http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum > >For Technical Assistance, send an email to: [email protected] > >To Unsubscribe, send an email to:[email protected] >(Put the word unsubscribe in the subject field) Todd G. Williams, PE Fire Protection Design/Consulting Stonington, Connecticut www.fpdc.com 860.535.2080 _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [email protected] To Unsubscribe, send an email to:[email protected] (Put the word unsubscribe in the subject field)
