2H2+O2<->2H2O I imagine a 1x2-0 transparent sprig- the water looks more bubbly at the top. I remove the water, now I just have air, right? Half the time. From the chemistry law of mass action, half the time the bubble is 'full of air', and the other half it is 'full of water'. The right side of the above reaction is water in the vapor state. Low pressure favors dissociation (right to left), high pressure goes left to right. As the temperature and pressure go up and down, the reaction goes more one way than the other, to maintain 'dynamic equilibria'. The same thing happens when some air or some water is removed. Instead of thinking each bubble is air half the time and water the other half, it might be equivalent to think half the bubbles are air and the other half water- if so, I am shocked by the practical implication: say after the hydro, or drain down and recharge, a fitter spends an hour going around to the high points getting the air out of the water--- 30 minutes of that time was spent getting the water out of the water! :) And what does the 4/5 nitrogen do during the reaction? Maybe it elopes with the carbon in the steel, and they name every one of their kids Mic Foreman. The only explanation I have been able to come up with for myself as to why, given systems across the street from each other, one has mic and false alarm problems but the other one does not, is simply one has continuous high pressure maintenance, i.e., jockey pump, and the other does not. It has to be deeper than this, but it might be a start-- some stats would be nice.
-----Original Message----- From: Bobby McCullough [mailto:[email protected]] Sent: Saturday, January 15, 2011 2:13 PM To: [email protected] Subject: RE: Code reference for replacing remote end inspectors test withalisted Test N' Drain Valve.... Venting the air has been around a long time but I don't believe it is an everyday practice nor is it required by code (yet). A listed, automatic device might change both. System inspector's test connections and drains are not usually in an ideal location for releasing the air. Going into an attic or up to the roof of a warehouse can be a time consuming activity every time a system is drained and refilled; an expensive task from an ITM perspective. Specifying the protocol might get it done for an original install but it would not happen on later ITM activity. The hardware sounds better to me. Mike's explanation may facilitate installing new hardware on existing systems where the flow switch / false alarm problem exists. Bobby McCullough Atlanta Sprinkler ________________________________ From: [email protected] on behalf of Bill Brooks Sent: Sat 1/15/2011 11:12 AM To: [email protected] Subject: RE: Code reference for replacing remote end inspectors test with alisted Test N' Drain Valve.... This seems like a good idea but I'm wondering why a sprinkler contractor would not fill the system this way all the time? Is it because it takes more time or because the method to prevent the condition is not widely known in the industry? Should I specify a proper system filling protocol or should I specify additional hardware, or both? I do appreciate the theory behind Ed's concern for detecting minimum flow at the riser location. A 60 ft building with 100 psi riser pressure would see 74 psi static at the highest head. Calculate the friction loss in the system all the way to the inspector's test orifice (let's say 10 psi) and that end head will be flowing about 45 gpm. At the riser location the same k=5.6 orifice will flow 56 gpm so this would have to be adjusted by using a k=4.5 orifice at the riser test. Each system would have a separately machined test orifice to assure equivalent flow conditions. Or, more appropriate, we should assure flow switch response under UL minimum flow conditions at any point in the system. In the case above this would mean detecting a 14.8 gpm flow at the riser. The 100 psi riser would need a k=1.48 orifice. For a 81 psi service pressure a k=1.64 orifice is needed, etc, etc. Bill Brooks William N. Brooks, P.E. Brooks Fire Protection Engineering Inc. 372 Wilett Drive Severna Park, MD 21146-1904 410-544-3620 410-544-3032 FAX 412-400-6528 Cell -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of George Church Sent: Friday, January 14, 2011 5:19 PM To: [email protected] Subject: RE: Code reference for replacing remote end inspectors test withalisted Test N' Drain Valve.... We were one of those phone calls a couple years ago. Experienced fitter shaking his head- new flow switch, 5 minutes to alarm, spin dial, still not better- Bleed air off, bang- wfs acts like a wfs. Mike isn't selling anything, he's alerting us to the problem, and they've developed an answer with the auto air bleed, or throw in a ball va with hose. Mike, hopefully this will cut off some of the calls, and possibly sell a few nifty solutions. George Church' Rowe Sprinkler [email protected] 570-837-7647 -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Mike Henke Sent: Friday, January 14, 2011 4:48 PM To: [email protected] Subject: RE: Code reference for replacing remote end inspectors test withalisted Test N' Drain Valve.... One thing to consider if the ITV is at the flowswitch instead of at a remote location is trapped air. If there isn't a vent or remote valve that can be opened when filling, then all of the air that is in the empty system has no where to go when you begin filling. This air will compress as the water enters, building up system pressure until the Back Flow Preventor closes even though the system is only partially filled with water. This trapped compressed air can cause multiple problems including increased oxygen corrosion, cycling of the flowswitch when testing and/or delayed operation of the flowswitch. When the ITV is opened the compressed air pushes system water out of the test valve. When the pressure drops enough the BFP will open allowing supply water to flow in and start the flowswitch retard. Since the system is not full of water, more water is flowing in than what can flow out of the ITV. This compresses the air again building up pressure until the BFP closes. Supply water stops flowing in allowing the flowswitch to reset. The compressed air pushes system water out of the ITV until the pressure drops and the whole cycle starts over again. There will be a steady stream of water flowing out of the ITV but there is not a steady stream of supply water flowing past the flowswitch. The flowswitch cycles back and forth. The flowswitch will either go in and out of alarm or may not go into alarm at all depending on the length of cycles and retard time. Leaving the ITV open for a long time doesn't help much because most of the air works towards the top of the system. Setting the retard for a shorter time delay doesn't help because opening the ITV bled of any excess pressure that may have built up and a prolonged increase in supply pressure such as the city turning on pumps early in the morning to meet the demands of the day can create a surge long enough to overcome the retard and cause a false alarm. I'm not saying the ITV shouldn't be installed at the flowswitch, I know it saves time and money for installation & testing. I'm just saying that there should also be a vent, either manual or automatic to vent off the air as the system is being filled to aid in the reduction of oxygen corrosion and cycling or delayed flowswitch operation. Sorry to be so wordy but we receive calls about this on a regular basis. Regards, mike Mike Henke CET Sprinkler Product Manager 1-800-325-3936 314-595-6740 Direct www.pottersignal.com -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Steve Leyton Sent: Friday, January 14, 2011 2:40 PM To: [email protected] Subject: RE: Code reference for replacing remote end inspectors test withalisted Test N' Drain Valve.... True, but the latest editions are very clear that it is not required nor even recommended to locate the ITV at the most remote portion of the system: NFPA 13, 2010 8.17.4.4 The alarm test connection shall be permitted to be installed in any location on the fire sprinkler system downstream of the waterflow alarm. A.8.17.4.2 (Partial second paragraph) "... Putting the test connection at the most remote portion of the system causes the introduction of fresh oxygen into a large part of the system each time the alarm is tested and increases the corrosion that will occur in the piping." The prevailing attitude has changed significantly since the 2002 edition. On top of that, here in Southern California (as in other areas of this state, and some areas in other states) we have to contend with stormwater pollution prevention regulations that now strictly preclude and prohibit sprinkler discharge onto hard surfaces that will run toward, or directly into storm drain systems. It is much easier to coordinate a floor sink or hub drain at the base of the riser, into which we can dump both alarm test and main drain discharges, than to deal with the routing and accessory sanitary sewer connections that come with remote test locations. Steve -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Tony Liddic Sent: Friday, January 14, 2011 11:16 AM To: [email protected] Subject: RE: Code reference for replacing remote end inspectors test with alisted Test N' Drain Valve.... Sean, The 2002 Handbook says the following after 8.16.4.2.3: "Ideally the inspector's test connection is located at the end of the most remote branch line in the upper story. Such a location is not, however, required. For a wet pipe system, the exclusive purpose of the inspector's test is to verify operation of the alarm attachment, which is the reason that the test connection is not mandated at the remote portion of the system. The test connection is only required to be located downstream of the alarm device." Tony Liddic, CET MRH Sprinkler Design LLC 356 Laurel Glen Dr. Springboro, OH 45066 937-369-7926 http://www.mrhsprinklerdesign.com <http://www.mrhsprinklerdesign.com/> [email protected] -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Sean Lockyer Sent: Friday, January 14, 2011 1:44 PM To: [email protected] Subject: Code reference for replacing remote end inspectors test with a listed Test N' Drain Valve.... Does anyone know the specific code reference from NFPA 13, 2002 Edition, that allows for the deletion of the remote end inspectors test when you use a test and drain valve on the riser (Such as an AGF). I found it once but I'm having a heck of a time finding it again... Any help would be great appreciated as I would be in your debt... -- Sean Lockyer Project Designer Delta Fire Sprinklers (407) 328-3000, ext 139 _______________________________________________ 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) _______________________________________________ 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) _______________________________________________ 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) _______________________________________________ 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)
