I agree with your reasoning for including the pipe in the calculations. However, I don't see how you can say that the "Tie-in drains" in 14.4.4.5 (2) are different from the "Tie-in drains" mentioned in 8.15.2.5.3.4.
Tony Liddic, CET AEC Fire & Security 400 Fame Rd. West Carrollton, OH 45449 937-866-4158 937-865-0212 fax [EMAIL PROTECTED] -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED] Sent: Thursday, June 28, 2007 11:20 AM To: [email protected] Subject: RE: Gang Drain for Attic Dry System 14.4.4.5 (2) is not referring to a ganged drain line. It is referring to a single drain. Ganging the drains together by connecting the ends of the branch lines is creating a grid system. Leaving this pipe out of the calculations will not make the water flow differently. The hydraulic calculations should provide a clear indication of the actual hydraulics in the system. If that 1 inch pipe connecting the ends of the branch lines is actually in the system then it should be in the calculations. 8.15.2.5.3.4 (02) is actually the most applicable section in regard to this issue and allows 1 inch piping maximum to limit the delay of the sprinkler discharge. Typically, for large systems, a 1 inch pipe will have little effect. However, for small systems it could have a greater effect. The size of the 1 inch pipe will have more of an effect if the main is 2 inches than if it is 4 inches. The proper thing to do is to calculate the system with the 1 inch pipe and see the effect. Here is the applicable commentary from the handbook for this section: Tie-in drains on multiple adjacent branch lines should be avoided if possible, because the use of tie-in drains in effect creates a gridded system. Gridded dry pipe systems and gridded double interlock preaction systems are prohibited by 7.2.3.5 and 7.3.2.5. In these types of systems, all of the air in the piping must be evacuated before a steady flow of water is discharged from the operated sprinklers. A gridded pipe arrangement is very likely to result in excessive time delays before effective sprinkler discharge occurs. Tie-in drains are considered necessary to allow rapid drainage of systems protecting cold environments. The restriction that tie-in drains be limited to 1 in. (25.4 mm) should help minimize any delays. Thank You Rahe Loftin, P.E. Region 7 - GSA Office - 817-978-7299 Fax - 817-978-8644 Cell - 817-371-3102 "Ed Kramer" <[EMAIL PROTECTED]> To Sent by: [email protected] sprinklerforum-bo cc [EMAIL PROTECTED] er.org Subject RE: Gang Drain for Attic Dry System 06/28/2007 10:01 AM Please respond to [EMAIL PROTECTED] resprinkler.org I thought I was having a senior moment, but then found it. Section 14.4.4.5 (2) (02 edition) says to NOT include tie-in drain piping in hydraulic calcs. Ed Kramer Littleton, CO > >If it is a drain line, you would include it in the hydraulic calculations >WHY?? > > > >Jeff Hewitt, PE, SET, SFPE (Prof. Member) >Corporate Engineer >Bi-State Fire Protection Corporation >636-946-0011 >636-946-5172 (FAX) > >This e-mail and any attachments are CONFIDENTIAL and may be protected by >one >or more legal privileges. It is intended solely for the use of the >addressee identified above. If you are not the intended recipient, any >use, >disclosure, copying or distribution of this e-mail is unauthorized. If >you >received this e-mail in error, please notify the sender immediately at the >above captioned address. > >----- Original Message ----- >From: <[EMAIL PROTECTED]> >To: <[email protected]> >Cc: <[email protected]>; ><[EMAIL PROTECTED]> >Sent: Thursday, June 28, 2007 9:39 AM >Subject: RE: Gang Drain for Attic Dry System > > >> Even though the 1 inch pipe does not seem to increase the gridding >effect, >> it still must be provided in the hydraulic calculations where it can end >> up >> show some surprising effects. >> >> Thank You >> >> Rahe Loftin, P.E. >> Region 7 - GSA >> Office - 817-978-7299 >> Fax - 817-978-8644 >> Cell - 817-371-3102 _______________________________________________ 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) No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.5.476 / Virus Database: 269.9.10/875 - Release Date: 6/27/2007 9:08 PM No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.476 / Virus Database: 269.9.10/875 - Release Date: 6/27/2007 9:08 PM _______________________________________________ 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)
