Cesar, first I don't know the exact wording of the requirement you cited. The size of the system does not in itself affect the time from the start of water flowing until the alarm is initiated. Air in the system, however, definitely can affect delay time. This is because no water flows past the alarm valve or waterflow detector, until system pressure is reduced as air forces water out of the system.More air in the system causes longer delay time. Once supply and system water pressures equalize, the retarding mechanism of a waterflow detector or the delay due to the filling of a retard chamber adds more time to the delay.
You can have an inspectors test valve opened, and count the time it takes to open the alarm valve. If you are using a waterflow indicator you can remove its cover and watch the extension arm. This time is the part of the delay caused by air in the system. There will be no alarm until the retard time of the waterflow indicator or the retard chamber has had its effect. The retard time of the retard chamber is usually fixed. For an electric alarm, a switch is often mounted on top of the retard chamber. Some switches have an additional time delay capability. If so, this time must be added to the others. If your system does not meet the required time limit, delay time of the riser delay functions must get first attention. If these functions are causing too much delay, corrections must be made. Nothing you could to about the amount of air in the system would get you to an acceptable level. If the alarm device delays are within the time limits, but overall time is too long, the air effect must be attended to. If a system is emptied, and water returned without there being any water flowing out of the system, all the air in the system is compressed.This can result in long delay times. If water is being discharged (as through a remote inspectors valve) some air can be discharged, prior to water coming out the outlet. It is best, then, to keep a remote ITV open when filling the system.This does hot help, though, if the ITV is at the riser. One or more air release valves can be used to automatically remove unwanted air. Google sprinkler air release valve to learn more about them. On Mon, Apr 24, 2017 at 5:13 PM, Cesar Lira <[email protected]> wrote: > We are considering both, alarm valve and water flow switch connect to an > alarm monitoring system. > > > > *De:* Sprinklerforum [mailto:sprinklerforum-bounces > @lists.firesprinkler.org] *En nombre de *Cliff Whitfield > *Enviado el:* lunes, 24 de abril de 2017 05:48 p. m. > *Para:* [email protected] > *Asunto:* RE: TIME OF INITIATE AN ALARM > > > > Are you using an alarm valve or a water flow switch? Are you connected to > an alarm monitoring system or is it only local alarm bells that you are > trying to ring? > > > > Cliff > > > > *From:* Sprinklerforum [mailto:sprinklerforum-bounces > @lists.firesprinkler.org] *On Behalf Of *Cesar Lira > *Sent:* Monday, April 24, 2017 6:13 PM > *To:* [email protected] > *Subject:* RE: TIME OF INITIATE AN ALARM > > > > Wet. > > > > *De:* Sprinklerforum [mailto:sprinklerforum-bounces > @lists.firesprinkler.org <[email protected]>] > *En nombre de *Matt Grise > *Enviado el:* lunes, 24 de abril de 2017 03:27 p. m. > *Para:* [email protected] > *Asunto:* RE: TIME OF INITIATE AN ALARM > > > > Wet system or dry? > > > > Matt > > > > > > *From:* Sprinklerforum [mailto:sprinklerforum-bounces > @lists.firesprinkler.org <[email protected]>] > *On Behalf Of *Cesar Lira > *Sent:* Monday, April 24, 2017 4:38 PM > *To:* [email protected] > *Subject:* TIME OF INITIATE AN ALARM > > > > FM say, that any fire alarm shall initiate within 60 seconds. > > How can I get in calculations the time of the alar respond? My system is > too large and the insurance company is question to me about if I’m sure > that alarm shall sound in this time. > > > > Thks. Everybody. > > CLR > > > > > > > > [image: Imagen quitada por el remitente.] > <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient&utm_term=icon> > > Virus-free. www.avast.com > <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient&utm_term=link> > > > > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-f > iresprinkler.org > > -- Ed Vining 4819 John Muir Rd Martinez CA 94553 925-228-8792 <(925)%20228-8792> Cell 925-787-0465 <(925)%20787-0465>
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