Considering all sprinklers are tested at 500 PSI, I doubt that they raise that to 700 and market those that stay together as high pressure. Dave, assuming the dry system supply- fire pump?- is 215, you could run a water delivery calc with a head operating and see if the pressure in the system really reaches 215 PSI with the decrease in pressure as water fills the pipe, and then when its "full (or its equalized with trapped air) is one head flowing enough to bring the pressure below 175?
Or depending on what the value of the contents is, susceptibility to water damage, owner tolerance for risk, it wouldn't be a quantum leap to allow a little over 200 PSI- where we often hydro for min 2 hrs anyway- and ask the AHJ to APPROVE the higher pressure. If I was entitled to an opinion, it would be that this would be fine. glc -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Ron Greenman Sent: Thursday, November 11, 2010 3:28 PM To: [email protected] Subject: Re: High Pressure Dry Pendents What's the criteria for that 175 psi limit. I don't think it's burst pressure. Is it that haven't been tested for operation any higher than 175? Are 225 heads a special more robust head than 175 heads? Or are they just 175 heads that got tested and listed to 225. I remember PT tests in the Army. The performance criteria was always X number in Y time. You were done when you exhausted either so it was that one could meet X in <Y in be done and pass although not out of strength and so still be able to continue and perform >X in Y. I this a similar thing? And if so how willing are you to put that PE behind exceeding the listing? On Thu, Nov 11, 2010 at 3:43 AM, Matt Grise <[email protected]> wrote: > Have you looked into pressure reducing valves? I don't know if there are any that are listed for dry system use though... > > Matt Grisé PE*, LEED AP > Sales Engineer > Alliance Fire Protection > *Licensed in KS & MO > > 913.888.0647 ph > 913.888.0618 f > 913.927.0222 cell > www. AFPsprink.com > > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of David > de Vries > Sent: Wednesday, November 10, 2010 10:42 PM > To: AFSA SprinklerForum > Subject: High Pressure Dry Pendents > > I have an open parking garage under a high rise. Fire pump sized for standpipe demand, so it has over 200 psi at the garage level. Most of the dry pipe system in the garage has uprights, but there are some finished ceiling areas that need dry pendents. I have not found any dry pendents listed for more than 175. Suggestions? > > Of course, for most of the time the system will only see the ~50 psi air, but when the valve trips, it will be about 215. Am I wrong to think the DP's should be listed for the static system pressure? > > Dave > > David A. de Vries, P.E., CSP > Firetech Engineering Incorporated > > > > --- On Wed, 11/10/10, Coastal <[email protected]> wrote: > > > From: Coastal <[email protected]> > Subject: Re: Pipe Expansion > To: "Fletcher, Ron" <[email protected]> > Date: Wednesday, November 10, 2010, 6:41 PM > > > Hello Ron, > > It is not a building, Wooden walkway to a floating dock. > > Wednesday, November 10, 2010, 5:16:36 PM, you wrote: > >> Since the building and the sprinkler system are subject to the same >> ambient conditions wouldn't the expansion rates kind of offset each >> other? > >> Ron Fletcher >> Aero Automatic >> Phoenix, AZ > >> -----Original Message----- >> From: [email protected] >> [mailto:[email protected]] On Behalf Of Thom >> Sent: Wednesday, November 10, 2010 3:04 PM >> To: [email protected]; [email protected] >> Subject: RE: Pipe Expansion > >> Also remember that a simple change in direction can provide the same >> protection as a full expansion loop. > > >> Subject: Re: Pipe Expansion > >> The expansion is the expansion no matter what fittings are employed, >> well on unrestrained steel. A fitting does not in itself restrain >> the pipe. >> Either >> the pipe moves or the want to move is translated into some internal >> force. >> The effect of the expansion it dependent on the fittings and the >> restraintment. > >> _______________________________________________ >> 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) > > > > -- > Best regards, > Charles Thurston > Coastal Fire Protection > Coastal mailto:[email protected] > > _______________________________________________ > 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) > -- Ron Greenman Instructor Fire Protection Engineering Technology Bates Technical College 1101 So. Yakima Ave. Tacoma, WA 98405 [email protected] http://www.bates.ctc.edu/fireprotection/ 253.680.7346 253.576.9700 (cell) Member: AFSA, SFPE, ASCET, NFPA, NFSA, AFAA, ASEE, NIBS, WSAFM, WFC They are happy men whose natures sort with their vocations. -Francis Bacon, essayist, philosopher, and statesman (1561-1626) _______________________________________________ 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)
