Yep. But try finding this one in the archives! Cliff Whitfield, SET Fire Design, Inc.
-----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Matthew J. Willis Sent: Friday, May 23, 2008 9:28 AM To: [email protected] Subject: RE: Its tough getting old You have to love this forum... What started as a joke about old age and forgetting, turned right back on topic with technical discussion. R/ Matt Matthew J. Willis Living Water Fire Protection, LLC. 1160 McKenzie Rd. PO Box 877 Cantonment, FL. 32533 850-937-1850 Voice 850-937-1852 Facsimile [EMAIL PROTECTED] ----- >-----Original Message----- ----- >From: [EMAIL PROTECTED] ----- >[mailto:[EMAIL PROTECTED] On ----- >Behalf Of Pip Males (Shared Services, IT, Manchester) ----- >Sent: Friday, May 23, 2008 8:18 AM ----- >To: [email protected] ----- >Subject: RE: Its tough getting old ----- > ----- >"Anything with a flow and a pressure, like a system ----- >demand, can be converted to a K factor." ----- > ----- > ----- > ----- >NOT STRICTLY TRUE:- ----- > ----- > ----- > ----- >Any pipe work system has a characteristic (system curve) ----- >similar to (but not the same as) a discharging device. ----- >As a pipe work system has pipes which perform to a 1.85 ----- >law and discharging devices that perform to a square law ----- >the form of the system curve is somewhere between a pure ----- >square law and a pure 1.85 law. ----- > ----- > ----- > ----- >It is quite a common practice to take the demand point ----- >and use the flow and pressure in the discharging device ----- >formula (Q = KvP) to calculate a k-factor for the ----- >system. This is then used to produce a square law system ----- >curve or to add an existing calculated system to a ----- >larger system. This is incorrect and should be avoided ----- >whenever possible. ----- > ----- > ----- > ----- >The following graph illustrates the problem. The system ----- >curve was generated by effectively producing lots of ----- >demand points by setting the minimum pressure ----- >requirement at the most remote head to various values. ----- > ----- > ----- > ----- >The nozzle characteristic is a square law curve produced ----- >by equating the system to a k-factor derived from the (Q ----- >= KvP) formula using the flow and pressure at the ----- >original demand calculation. As can be seen the only ----- >place that the curves agree is at the demand point. ----- > ----- > ----- > ----- > ----- > ----- > ----- > ----- >Of course if you use a computer program and model all ----- >systems discharging in the one model you get the true ----- >result and do not have a problem. ----- > ----- > ----- > ----- >Best Regards, ----- > ----- > ----- > ----- >Pip Males ----- > ----- >CAD Manager(FIRECAD(r)) ----- > ----- >Tyco Fire & Integrated Solutions ----- > ----- >Manchester ----- > ----- >UK ----- > ----- > ----- > ----- >-----Original Message----- ----- >From: [EMAIL PROTECTED] ----- >[mailto:[EMAIL PROTECTED] On ----- >Behalf Of George Church ----- >Sent: 22 May 2008 20:26 ----- >To: [email protected] ----- >Subject: RE: Its tough getting old ----- > ----- > ----- > ----- >K equals q over radical p ----- > ----- > ----- > ----- > ----- > ----- >********************************************************* ----- >************* ----- >Tyco Fire & Integrated Solutions (UK) Ltd. ----- > ----- >Registered in England, Number 1952517 ----- >Registered office: Tyco Park, Grimshaw Lane, Newton ----- >Heath, Manchester M40 2WL, England ----- > ----- >This e-mail is intended to be delivered only to the named ----- >addressee(s) and may contain information that is ----- >confidential and proprietary. If this information is ----- >received by anyone other than the named addressee(s), ----- >the recipient(s) should immediately notify the sender by ----- >e-mail and promptly delete the transmitted material from ----- >your computer and server. In no event shall this ----- >material be read, used, stored, or retained by anyone ----- >other than the named addressee(s) without the express ----- >written consent of the sender or the named addressee(s). ----- > ----- >This footnote also confirms that this email message has ----- >been swept by MIMEsweeper for the presence of computer viruses. ----- > ----- >www.mimesweeper.com ----- >********************************************************* ----- >************* ----- > ----- > _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum To Unsubscribe, send an email to:[EMAIL PROTECTED] (Put the word unsubscribe in the subject field) _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum To Unsubscribe, send an email to:[EMAIL PROTECTED] (Put the word unsubscribe in the subject field)
