But is that with the valve all the way open? 2/3? 1/2-way? K is often referred to as a "constant" in algebraic and calculaic formulae; valves aren't constant. It's kinda' what defines them as valves.
Steve L. -----Original Message----- From: sprinklerforum-boun...@firesprinkler.org [mailto:sprinklerforum-boun...@firesprinkler.org] On Behalf Of Thompson, Pat Sent: Thursday, April 05, 2012 9:47 AM To: sprinklerforum@firesprinkler.org Subject: RE: k -- WHAT? K factor as applied in our industry is a coefficient for a smooth bore orifice. I am not aware of how this could be applied to a hose valve since it is not a smooth bore orifice, but I can offer some input from fire department hydraulics: GPM (Q) = (29.7*diameter squared)*square root of pressure. This is the formula applied by fire departments in their field applications. This does not apply to fog or adjustable nozzles. 29.7 is a constant, diameter is the diameter of the smooth bore orifice - combined these numbers result in a 'k' value for the orifice. Manufacturers of sprinklers have done this calculation for us and conveniently provide the value for us to plug into our familiar K,Q,P formula to determine GPM and pressure. I believe the 29.7 constant is a rounded number; but it should be close enough to give a fairly accurate result. Pat Thompson Special Hazard Sales NICET #101475 SimplexGrinnell A Tyco International Company 907-743-9128 direct 907-561-4650 fax pthomp...@simplexgrinnell.com -----Original Message----- From: sprinklerforum-boun...@firesprinkler.org [mailto:sprinklerforum-boun...@firesprinkler.org] On Behalf Of Vince Sabolik Sent: Thursday, April 05, 2012 7:45 AM To: sprinklerforum@firesprinkler.org Subject: k -- WHAT? Good morning -- Anyone have an approximate K value for a 2½" hose valve? Vince Sabolik, West Tech Fire Protection, Inc. 11351 Pearl Road / Strongsville, Ohio 44136 440 238-4800 Fax 440 238-4876 ____________________________________________________________________ -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://fireball.firesprinkler.org/mailman/private/sprinklerforum/attachments/20120405/bddfbfe1/attachment.html> _______________________________________________ Sprinklerforum mailing list Sprinklerforum@firesprinkler.org http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum _______________________________________________ Sprinklerforum mailing list Sprinklerforum@firesprinkler.org http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum _______________________________________________ Sprinklerforum mailing list Sprinklerforum@firesprinkler.org http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum
