And I never suggested pigging. I said that if the purpose of the flush was to scrub the interior walls of the pipe and you couldn't get a sufficient velocity to do so then you could pig. And for some relatively short UG lead-in you could drag pig. But the crux was why would you be descaling newly installed pipe? You would only be flushing loose material to somewhere where it could be jettisoned from the pipe and if you needed more velocity you could choke the end and then remove any left over debris that wouldn't pass the check point before making the final connections.
On Wed, Mar 31, 2010 at 10:44 AM, <[email protected]> wrote: > Whatever proceedure is used,an issue just as important is for someone in > authority to follow through to assure that the flushing actually is done.And > this should be done by the installing contractor of all the main underground > piping,not the sprinkler contractor who is only responsible for the 5 ft. > stub-in. > > Lamar Vaughn,SET > > > ---- [email protected] wrote: >> So if the max. velocity is only 2fps there's no issue? >> >> Then why the talk of 10fps in the appendix with mention of high velocity and >> Table relating to 10fps? >> >> If any velocity was acceptable then why not just say it doesn't matter or >> say nothing at all? >> >> >> Craig L. Prahl, CET >> Fire Protection Specialist >> Mechanical Department >> CH2MHILL >> Lockwood Greene >> 1500 International Drive >> PO Box 491, 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 Roland Huggins >> Sent: Wednesday, March 31, 2010 12:51 PM >> To: [email protected] >> Subject: Re: Underground flushing velocities >> >> The 10 fps applies only to option 2, not all the options. As long as you >> meet any ONE of the options, where's the beef? >> >> The objective is to keep loose objects in the main from potentially blocking >> the sprinkler system. Option 2 assures us that we will remove the loose >> objects. The other options assure us that the objects will not reach the >> system since the maximum possible velocity (being less than 10 ft/s) has >> removed the objects that will move at system demand (which would be the >> likely lowest velocity). Option 3 allows us to simply open multiple outlets >> and let it flow whatever flows without having to prove anything. >> >> Roland >> >> On Mar 30, 2010, at 1:47 PM, <[email protected]> <[email protected] > >> wrote: >> >> > NFPA 24 says the following: >> > >> > NFPA 24: 10.10.2.1.3 The minimum rate of flow shall be not less than >> > one of the following: >> > (1) Hydraulically calculated water demand flow rate of the system, >> > including any hose requirements >> > (2) Flow necessary to provide a velocity of 10 ft/sec (3.1 m/sec) in >> > accordance with Table 10.10.2.1.3 >> > (3) Maximum flow rate available to the system under fire conditions >> > >> > >> > >> > >> > >> > Debate is whether that means that the flow rate dictates the velocity >> > and it has no absolute requirement or the minimum is 10fps. >> > >> > Based on wording in the Appendix it would appear that 10fps is the >> > desired minimum. >> > >> > So for example I have a flow rate of 8000 gpm (fire flow per local >> > AHJ) and the line size ends up being 24" Vel= 6.74 fps. Is that >> > acceptable per NFPA 24, 10.10.2.1.3? There are issues with the >> > distance between source and pump suction and larger pipe equal less >> > friction loss but also lowers velocities. >> > >> > I read it that it can be less than any one of the following with >> > 10fps being the minimum. Sometimes simpler wording for non-FP >> > types would make life easier. <sigh> >> > >> > Thought, comments, etc????????? >> > >> > Craig L. Prahl, CET >> > Fire Protection Specialist >> > Mechanical Department >> > CH2MHILL >> > Lockwood Greene >> > 1500 International Drive >> > PO Box 491, Spartanburg, SC 29304-0491 Direct - 864.599.4102 Fax - >> > 864.599.8439 [email protected] http://www.ch2m.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) > -- Ron Greenman Instructor Fire Protection Engineering Bates Technical College Tacoma, WA Member: SFPE, ASCET, NFPA, AFSA, NFSA AFAA, NIBS, WSAFM, WFC _______________________________________________ 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)
