Here are the results of a similar situation back in 2005 where the flowswitch cycled back and forth before eventually going into alarm at over 4 minutes.
To all who responded to this thread, I am pleased to announce that the time to alarm dropped from 4 minutes to 1 minute 40 seconds without moving the inspector's test. Thank you all for the education. Amazing what a few air bubbles can do. Best Regards, Ken Holsopple Design Manager Rowe Sprinkler Systems, Inc. 570-837-7647 fax 570-837-6335 Regards, mike Mike Henke CET Sprinkler Product Manager Potter Electric Signal Co. www.pottersignal.com 314-595-6740 Direct -----Original Message----- From: sprinklerforum-boun...@firesprinkler.org [mailto:sprinklerforum-boun...@firesprinkler.org] On Behalf Of Mike Henke Sent: Wednesday, February 20, 2013 8:39 AM To: Jay Stough; sprinklerforum@firesprinkler.org Subject: RE: Flow switch problem It is caused by trapped air. We have seen this many times. If the system is not vented when filled because the ITV is located just past the flowswitch or if it is at a far end it may not have been opened when filling, then all the air in that empty system has no where to go when the water starts filling. The air gets compressed and as the pressure builds, the check valve will close when system pressure equals supply pressure. When you open the ITV, the trapped compressed air can now expand and will push system water out of the ITV. When the system pressure drops enough, the backflow will open. Supply water enters the system and moves the paddle. More water is coming in than what is going out the ITV. The extra water will begin to compress the air again. The pressure will build back up and the check will close when the pressure equals. The cycle just keeps repeating. There is a steady stream of water coming out of the ITV but there is not a steady stream of water flowing past the flowswitch. The only way the flowswitch will reset is if water stops flowing past the paddle. Keeping the ITV open will not help. The air migrates up. You need to go to a high point and loosen a fitting or sprinkler. Or install an automatic or manual air vent. I will try to find the message I received from someone on this forum a few years ago about this same subject. He climbed up, loosened a fitting, air bled out for a minute or two and his 5 minute flowswitch operation time was reduced to less than 60 seconds. It is the same problem. Regards, mike Mike Henke CET Sprinkler Product Manager Potter Electric Signal Co. www.pottersignal.com 314-595-6740 Direct -----Original Message----- From: sprinklerforum-boun...@firesprinkler.org [mailto:sprinklerforum-boun...@firesprinkler.org] On Behalf Of Jay Stough Sent: Wednesday, February 20, 2013 7:25 AM To: sprinklerforum@firesprinkler.org Subject: Flow switch problem >From a drain valve w/ broken sprinkler. Jay Stough ________________________________ From: Justin Reid <justinreid00...@gmail.com> To: Jay Stough <jaycs7...@yahoo.com>; "sprinklerforum@firesprinkler.org" <sprinklerforum@firesprinkler.org> Sent: Wednesday, February 20, 2013 8:06 AM Subject: Re: Flow switch problem Is the flowing water coming from a pressure relief valve? Or from the drain valve? Justin Reid Sent from my iPhone On Feb 20, 2013, at 7:37 AM, Jay Stough <jaycs7...@yahoo.com> wrote: > I'll try to answer all the ideas in one email. The system does have an Ames > 2000SS backflow, but the water flow from the inspector's test is continuous, > so I don't think the backflow is preventing the water from flowing. We > observed the lever and it is going up and down, not staying down. The switch > is new out of the box, doing the same as the old. We set the delay at the > middle setting. If it is set too low, they get false alarms. If they set it > up all the way, it does not give a signal for 2 minutes. I will have the > guys check for air in the system since we are doing work there and taking the > system up and down every day. It's an old scheduled system from the mid > 70's. We've had systems with air in it, but have never had this type of > problem with a flow switch that replacing the globe valve didn't fix. > > > > Jay Stough -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://fireball.firesprinkler.org/mailman/private/sprinklerforum/attachments/20130220/346d765d/attachment.html> _______________________________________________ Sprinklerforum mailing list Sprinklerforum@firesprinkler.org http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum _______________________________________________ Sprinklerforum mailing list Sprinklerforum@firesprinkler.org http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum _______________________________________________ Sprinklerforum mailing list Sprinklerforum@firesprinkler.org http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum
