Plus a little more for the jockey, they're supposed to equal maximum pump pressure and with fluctuations, I usually set them at 5 PSI above churn at the time of testing the pump. Stay away from main regulation if you can and do it at the individual supply points (pilot type), I suggest. PLD's are nice but have very limited applications and you need a main relief after them. I think they're great for sprawling huge storage and retail but are problematic when you get into multi-story mid-rise or high-rise. Just my take.
Tom Duross FGOL Go Red Sox!!! That's fine for the flow, but when you add the static pressure of the water supply with the churn pressure of the pump, you can get real close to the 175 psi threshold. This is problem increases as steepness of the public water supply curve increases. At 12:01 PM 2/7/2007, you wrote: >This does not compute. > >If you have a six-story building it's what, 70' high? With static >and friction head, that shouldn't be more than about 40-43 PSI from >the street, unless you're using 3" risers ... > >And remember that the 100 PSI is at the discharge side of the valve; >most hose valves have at least 3 PSI and sometimes as much as 7 or 8 >PSI head loss (we've had this discussion on-forum before). > >Steve > > >I seem to be running into several situations lately where there is a >very fine balancing act between meeting the 100 psi at the top outlet >of the standpipe and not exceeding 175 psi at the base of the riser. >(6 story hotels are a good example) Does anybody have any good ideas >they'd care to share on making these work? I'd like to limit the use >of extra-heavy pipe and fitting (especially larger sizes) and PRVs. I >have several tricks up my sleeve, but I'm running out of sleeves. > _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum
