Why couldn't each trapped branch be provided with a drum drip, aside from the economics?
-----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Todd Williams - work Sent: Thursday, June 28, 2007 1:33 PM To: [email protected] Subject: Re: Gang Drain for Attic Dry System Am I missing something here? 8.15.2.5.3.4 states: 'Tie-in drains SHALL be provided for multiple adjacent trapped branch lines.....'. Shall is just a grammatically correct way of saying y'gotta. If you have the multiple adjacent trapped branch lines, they have to be connected with a tie-in drain. Section 14.4.4.5 says not to include them in hydraulic calculations. To me, that's a pretty open and shut deal. Does it create a gridded dry system, technically yes, but to me, this section says that this arrangement is allowed. Keep in mind that the cross sectional area of 1" pipe is roughly 1/4 of the CSA of 2" and 1/16th of 4". That creates a very different scenario than say 4" and 3" where the ratio is 9/16. It would be interesting to check trip times of a system with the tie-in drains attached and one where they are plugged off. At 01:02 PM 6/28/2007, you wrote: >There is a flaw in your reasoning. IF 14.4.4.5 was a connection from >different pipes to the drain without any interconnection, how could it >impact the hydraulic calculation since the flow would only be out of >the system to the drain? > >The tie-in drain is used only 8.15.2.5.2.4 and 8.15.2.5.3.4 (which >provides the basic definition of interconnection branch lines). Then >chap 14 tells use tie-ins are not to be part of the hydraulic >calculation which is conservative since only a gain (small as it might >be) would be seen. > >It is intended to minimize their use IF POSSIBLE but the explicit text >in the drain section trumps the general text on forbidding grids in dry >pipe systems. > >Roland > >On Jun 28, 2007, at 8:59 AM, [EMAIL PROTECTED] wrote: > >>Easy. 8.15.2.5.3.4 specifically addresses multiple adjacent trapped >>branch pipes and 14.4.4.5 does not. 14.4.4.5 is general and is not >>addressing the connecting of the ends of branch lines. 14.4.4.5 is >>addressing a drain that connects to a pipe in the system and drains to >>an outlet without connection to other piping in the system. >> >>Thank You >> >>Rahe Loftin, P.E. > >_______________________________________________ >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) Todd G. Williams, PE Fire Protection Design/Consulting Stonington, Connecticut 860-535-2080 www.fpdc.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)
