What type nozzles are you using? When there is a deflector, the deflector absorbs some of the reaction and helps to neutralize it. The arm over's will torque from the reaction. What are the nozzle pressures you are expecting?
Arthur Tiroly ATCO Fire Protection Design Tiroly and Associates 24400 Highland Rd rm 25, CLE 44143 216-621-8899 216-570-7030 Cell WWW.ATCOfirepro.com -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Jeff Garrison Sent: Monday, January 09, 2012 1:35 PM To: [email protected] Subject: RE: NFPA 15 - Nozzle Reaction I suspect the reaction forces are so small as to be insignificant to your attachments or the structural components. The method that your pipe is braced should determine which directional force you need to examine... Jeff Garrison On Jan 9, 2012 12:28 PM, "Jimmy Waite" <[email protected]> wrote: > LOL. > > That's the exact same example we got from the AHJ (which I found in my > fire department hydraulic text book). After looking at the example I > think our situation is a little more complex since our nozzle is at a > fixed 60 degree angle. So, if I remember my college physics > correctly, we'll have a vertical and horizontal reactionary force. > But I'm pretty rusty so Im looking for some back-up and confirmation. > > Jimmy Waite, CET > Design Engineer > [email protected] > mobile: 919.622.7030 > > > 3609 Bastion Lane | Raleigh, NC 27604 | ': 919.212.2356 | 6: > 919.212.2357 | www.piedmontfire.com > > -----Original Message----- > From: [email protected] [mailto: > [email protected]] On Behalf Of Jeff Garrison > Sent: Monday, January 09, 2012 11:55 AM > To: [email protected] > Subject: Re: NFPA 15 - Nozzle Reaction > > *Jimmy,* > *As an example.....* > ** > *Calculating the Nozzle Reaction for a 1.25-inch-Bore-Diameter Nozzle > *The solid bore discharge formula is gallons per minute (gpm) = 29.71 > D² NP¹/². The formula can be rewritten to solve for the unknown, > nozzle > pressure: > > *Nozzle Pressure = NP psi = [(gpm)/(29.71 x D²)]² > *Where: > > gpm = 400 gpm > > bore diameter (D) = 1.25 in > > *therefore: > *NP = [(400gpm)/(29.71 x 1.25²)]² > > NP = 74.25 psi > > *The formula for nozzle reaction (NR) for solid bore nozzles is NR = > 1.57 D²NP > **therefore: > *NR = 1.57 x 1.25² x 74.25 > > NR = 182 lb reactive force > > > On Mon, Jan 9, 2012 at 11:29 AM, Jimmy Waite <[email protected] > >wrote: > > > We are working on a fixed water spray system that is cooling the > > exterior of a vessel at a soy bean processing plant. The AHJ is > > asking for > reactionary > > force calculations per 6.3.2.8 of NFPA 15 ('07 ed.). We have > > contacted > the > > nozzle manufacturer and NFPA and neither were able to provide any > guidance. > > Has anyone out there come across this issue before? Does anyone > > have any good ideas of where to start? We do have a structural > > engineer that > we're > > working with, but he is mainly evaluating the structure supporting > > the > pipe > > and the vessel. > > > > > > > > > > > > Thanks, > > > > > > > > Jimmy Waite, CET > > > > Design Engineer > > > > > > <mailto:[email protected]> [email protected] > > > > mobile: 919.622.7030 > > > > > > > > cid:[email protected] > > > > 3609 Bastion Lane | Raleigh, NC 27604 | ': 919.212.2356 | 6: > > 919.212.2357 | <http://www.piedmontfire.com/> www.piedmontfire.com > > > > > > > > -------------- next part -------------- An HTML attachment was > > scrubbed... > > URL: < > > > http://fireball.firesprinkler.org/mailman/private/sprinklerforum/attac > hments/20120109/4a6870d4/attachment.html > > > > > -------------- next part -------------- A non-text attachment was > > scrubbed... > > Name: image001.jpg > > Type: image/jpeg > > Size: 5814 bytes > > Desc: not available > > URL: < > > > http://fireball.firesprinkler.org/mailman/private/sprinklerforum/attac > hments/20120109/4a6870d4/attachment.jpg > > > > > _______________________________________________ > > Sprinklerforum mailing list > > [email protected] > > http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum > > > -------------- next part -------------- An HTML attachment was > scrubbed... > URL: < > http://fireball.firesprinkler.org/mailman/private/sprinklerforum/attac > hments/20120109/6c03e6e9/attachment.html > > > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum > > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://fireball.firesprinkler.org/mailman/private/sprinklerforum/attachment s/20120109/e1119f3a/attachment.html> _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum
