Damien- I'd highly recommend you: 1. Read James G's white paper "Variables that affect the Performance of Dry Pipe Systems" at http://www.tyco-fire.com/index.php?P=show&id=DryPipeSystems_Rev&B=&BK=archiv e_news
2. Look into obtaining FDT calculation software to either prove your systems' ability to meet the water delivery requirements, or what you can save, or what you can change to make them work. www.stinkcad.com Ok, just kidding, my plugs come with a sense of humor- http://www.sprinkcad.com/sprinkfdt.php There, now there's no chance this plug will get me a discount on the SprinkCAD seat I ordered yesterday. No, we're not abandoning our friends in NH. We've had HUGE systems that delivered water in a fraction of what would have been expected, far faster than NFPA requires. Low pressure will allow water to be diverted into non-flowing branchlines. Its really obvious when you watch the results of a system tripping and then watch the water go up the lines and mains not flowing, then change the gas pressure and see the changes possible. You may, depending on the AHJ, be able to not wait until a field test to see if you really only needed 5 risers or if you needed 12. or if even 12 wouldn't help cause bulk mains eat up all your time. The problem is, without the software you just don't know. And not knowing until the acceptance test is a really stupid way to determine your needs when the answers are available before steel goes up. We were up at their Tech Center last week and I gotta tell you, the stuff is amazing. Yes, there is certainly a sweet spot in the gas pressure settings. And those are far easier to determine on a pc than in the field when its too late to change the piping, or find out maybe you could have installed a few less valves. glc -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Damien Shannon Sent: Wednesday, June 17, 2009 12:55 PM To: [email protected] Subject: RE: Slow responding dry pipe valves Frans, Very curious to know how you got on with the Victaulic valve w/ 1300 gallons to make the 60 sec requirement after making the adjustments discussed (or anywhere close). I need to do a building with 8 dry systems (new construction) that requires all the valves at a main header. The bulk main to the actual area of protection for some of the systems is forcing capacity well beyond 750 gallons (approx 900). The client originally was going with Victaulic valves, based on the premise that the lower air pressure would lead to less air to be exhausted prior to water being discharged. Trying to find out if there's a 'sweet spot' where the low air pressure versus 'higher pressure' Dry Pipe valves work best. Thank you for any insight you can provide. Damien Shannon QED Sprinkler Designs Inc. (773) 704 2571 -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Frans Stoop Sent: Tuesday, April 28, 2009 8:25 PM To: [email protected] Subject: Slow responding dry pipe valves Dear colleagues, Our client has a rather large dry pipe system supplied by a Victaulic dry pipe valve complete with an accelerator. The system responds to slow to the ITC: more than 3 minutes. The contents of the system is approx. 1300 gallon. The air pressure in the system was set lower (in compliance with the Victaulic installation sheets) than we are used to with dry pipe valves of other manufacturers. The sprinkler contractor and the local Victaulic representative couldn't find the cause yet. My personal impression is that the Victaulic mat take much more time between opening the test valve and water delivery than dry pipe valves of other brands. Does anyone share this impression or had the same experience ? If you prefer, you may react off-forum. Frans Stoop TOS architecture & fire protection Netherlands <[email protected]> Tel. +31-24-324 0112 _______________________________________________ Sprinklerforum mailing list http://lists.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 http://lists.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 http://lists.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)
