Not a benefit, but a detriment. The losses thru the 1" add up quick 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 Jeff Hewitt ----- >Sent: Thursday, June 28, 2007 11:22 AM ----- >To: [email protected] ----- >Subject: Re: Gang Drain for Attic Dry System ----- > ----- > ----- >Ok, I guess I'm still missing something. I am not ----- >understanding/following the logic for why it is ----- >necessary/beneficial to include this drain line (grid ----- >effect) in the hydraulic calculations. ----- > ----- >Are you implying that you want the designer/technician ----- >to downsize pipe sizes if the hydraulic calculations ----- >prove it can be done, just because of the presence of a ----- >drain line, and the improved flow thru this portion of ----- >the system? ----- > ----- >I do not believe that is what the standard intends. ----- >There should be no benefit from any "gridding effects" ----- >included in HYDRAULIC calculations, regardless of ganged ----- >drain, single drain, whatever. ----- > ----- > ----- >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]> ----- >Sent: Thursday, June 28, 2007 10:20 AM ----- >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) ----- >> ----- >> ----- > ----- > ----- >_______________________________________________ ----- >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)
