True. However, xcov sidewalls are listed with very specific flow and pressure per coverage. As are residential sidewalls. All have fixed 16 ft spray widths. In the exception I am citing, a pressure deduction is allowed for a decrease in width alone. To me this seems inconsistant and may actually produce an undesired result. It would make more sense to figure the area based on the actual throw x 16ft. If the testing proves me wrong, I'd like to see it.
Sent from my iPhone On Dec 10, 2009, at 1:40 PM, Ron Greenman <[email protected]> wrote: > Todd, > > I think you're making the mistake of trying to apply thought to this > process wherein you're not sure of what the testing criteria is. For > my students I always draw out the test scenario for a residential head > then ask them what happens if the third head operates. Good or bad? > There always confused when I tell them the head fails the test > particularly when I say not opening for the first two would also be a > failure. They have problems with understanding that head fusing has to > do with heat transfer rates in mass rather than ceiling temperature. > They have trouble getting that concept that a model may or may not > model the actual event but only be a device to predict acceptable > results. And of course the all time biggie is that sprinklers aren't > even designed to suppress, and that when they do it's a bonus, and of > course the corollary that it's a success if the building (under 13D or > 13R) burns to the ground as long as the occupants are outside watching > it. At some point I have to accept that someone tasked with developing > testing protocols has done so and that test somehow reflects > performance vis-a-vis a set of rules and if I follow the rules, all > other things being equal, I will obtain results equal to or better > than the performance desired. The minute I start to logic this stuff > out without knowledge of the criteria the performance requirement was > subject to I'm start the long, slippery slope inducted Aristotelian > explanations of phenomena. > > On Thu, Dec 10, 2009 at 9:38 AM, Todd - FPDC <[email protected]> wrote: >> I get all that. But I assume most of the pressure in a sidewall is >> for >> throw and not width, how can we justify a significant decrease in >> pressure based on a decrease in width alone? >> >> Sent from my iPhone >> >> On Dec 10, 2009, at 12:14 PM, <[email protected]> wrote: >> >>> What Roland has stated in both posts is correct.Most,if not >>> all,residential sprinklers are listed for 13,13d,and 13r in >>> residential applications.The minimum flow rates indicared in the >>> data is that which is required to generate flow and pressure to >>> achieve the spray pattern indicared.You still must discharge the >>> minimum flow rate (.05 or .10) while at the same time the minimum _______________________________________________ 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)
