Charles , The AHJ can require new calculations if you are reducing pipe size . In your case you are increasing the end piece which always tends to balance the head flows more efficiently.This should actually make the system better.JMHO BTW , make sure you are using the same type of pipe.
---- John Drucker <[email protected]> wrote: > 2002 NFPA-13 > > 14.1.2 Deviation from approved plans shall require permission of the > authority having jurisdiction. > > 14.4.4.5 Friction Loss. Pipe friction loss shall be calculated in accordance > with the Hazen-Williams formula with C values from Table 14.4.4.5, as > follows: > (1) Include pipe, fittings, and devices such as valves, meters, flow > switches in pipes 2 in. or less in size, and strainers, and calculate > elevation changes that affect the sprinkler discharge. > > John Drucker, CET > Fire Protection Subcode Official > Fire/Building/Electrical Inspector > Fire Marshals Office > Borough of Red Bank, NJ > > > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of > [email protected] > Sent: Tuesday, May 11, 2010 5:09 PM > To: [email protected]; [email protected] > Subject: RE: Pipe Size > > If you change pipe sizes, then yes you'd have to recalc. That's pretty much > a given since your system hydraulics can change and you'll have no idea of > the overall affect on the system performance. > > Craig L. Prahl, CET > Fire Protection Specialist > Mechanical Department > CH2MHILL > Lockwood Greene > 1500 International Drive > Spartanburg, SC 29304-0491 > Direct - 864.599.4102 > Fax - 864.599.8439 > [email protected] > http://www.ch2m.com > > > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of Charles > Thurston > Sent: Tuesday, May 11, 2010 4:32 PM > To: sprinklerforum > Subject: Pipe Size > > Hello All you Fine folks of the Sprinklerforum, > > I am looking at replacing all the pipe in a 2 story parking deck due to > external corrosion (The fitters will love to be to look at the beach while > they "work"). 3" main fed from a 500 GMP ??PSI pump. The building the pump > feeds is 16 stories of condos. > > > Each branch line feeds 5 heads now. > 1 1/4" from main feeds heads 1-4 and 1" to the 5th head. It will be cheaper > to run the branch line all the way out in 1 1/4 fitting and machine > adjustment wise. The AHJ "ask" if it was allowable to change the pipe size > without re-calcing the entire system. It is planned to measure out the pipe > lengths and out the heads back in the same locations. I have not found > anything in NFPA 13 2007 addressing this. Does anybody know a reason not to > run 1 1/4" all the way out other than to "balance the flow" in the last > head. > > -- > Best regards, > Charles Thurston mailto:[email protected] > Coastal Fire Protection/ Myrtle Beach Fire & Safety Group. > AFAA Guest > > Electronic Privacy Notice: > This e-mail, and any attachments, contains information that is, or may > be, covered by electronic communications privacy laws, and is also > confidential and proprietary in nature. If you are not the intended > recipient, please be advised that you are legally prohibited from > retaining, using, copying, distributing, or otherwise disclosing this > information in any manner. Instead, please reply to the sender that > you have received this communication in error, and then immediately > delete it. Thank you in advance for your cooperation > > > > > > ======= > Email scanned by PC Tools - No viruses or spyware found. > (Email Guard: 7.0.0.18, Virus/Spyware Database: 6.14970) > http://www.pctools.com/ > ======= > _______________________________________________ > 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) _______________________________________________ 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)
