The easy way to do it is flow test the system and brace what moves. Mark at Aero
-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Jimmy Waite Sent: Monday, January 09, 2012 10:29 AM To: [email protected] Subject: RE: NFPA 15 - Nozzle Reaction 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 I’m 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/attachments/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 _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum
