But again that wasn't the issue: Is replacing a system, like for like, any different than replacing a head with a different head with the same K as the old one (another twist)? This started with a question about calcing a system that was having some old main replaced. If I were to read into this I'd say the question is does it matter because it's big pipe or that it's main? If George's scenario holds and I "change" a pipe to a bigger size do I need to calc it? If I replace a pipe with the same size do I need to then? And if I change it to a smaller size, what then? I think what one needs to get out of one's head is that size matters regarding replace. If all things remain unchanged then replacing like for like is replacement, not change. If any condition has changed (storage where no storage existed before) then anything done may be change.I've had an AHJ make me calc both identical systems in a single building off the same manifold, wherein each was a mirror of the other with each covering half of the building. His argument was that I didn't understand calcs, it needed to be done because the design areas were at separate ends of the building. I didn't argue since the time it took to Xerox the single calc and mark one set system 1 and the other system 2 was worth the laugh over this guy "understanding ho calcs work."
On Wed, Jan 12, 2011 at 4:04 PM, Todd Williams <[email protected]> wrote: > George, > > Replacing a 3" main because of MIC is very different than replacing an > entire system. On the situation you described, I agree that it is a > maintenance issue and analysis and hydraulics are not necessary. My > rhetorical question is at what point does maintenance end and a new system > begin? > > Being a cynical PE, I don't always accept that what was done before is > necessarily correct. In my history of doing 3rd party review, approximately > 2/3 of the drawings have been rejected the first time around due to > technical errors. That and some of the things that I have seen AHJs miss, > make me take a second look at everything. When I see a main replacement come > across my desk I try to take a look and see if what we have for a design > appears to be OK. If I have to prepare drawings to submit for a main > replacement, because the contractor cannot get a permit without a stamped > drawing, I want to be covered. I will typically push for a letter from the > AHJ stating that he accepts the present installation and there is no need > for analysis. Or if there is an issue, sometimes I will flash my PE plumage > and say we may have a problem and see where it goes. It's something I see as > my professional responsibility but also a little bit of CYA. I want to have > some basis for my actions in case I'm dragged into court if something > happens. > > As you say, if you want credibility, you need to earn it. > > > At 06:05 PM 1/12/2011, you wrote: >> >> This is pretty basic, and certainly there are exceptions for every rule. >> Existing system, we're to assume it was designed, installed and tested in >> accordance with applicable codes/laws at that time, pipe schedule. >> No change in occupancy, same owner doing same processes. >> You're replacing a 3" main because of MIC. >> You're going to somehow find a requirement to provide calcs for the MRA, >> using 3/4" end lines? >> Could be adding 30% to the MRA for that sloped roof that didn't impact the >> pipe schedule? >> So your calcs show it massively undersized. >> You go to the owner and point out he needs to replace the existing 4" >> lead-in with 8", new city tap and pit, new 6" riser to replace the 4" that >> is functional and meets code cause the new requirements aren't retroactive. >> He looks at the $85,000 you want to add to replacing a couple lengths of >> pipe- or a 600' run- to get rid of some drippage. >> Think he's opening up his checkbook to give you a deposit? >> Or is he kicking your butt out the door for trying to sell him something >> he's NOT required to do? >> If you want credibility, you need to earn it. You could tell em its >> prudent, but if he's not getting sky-high insurance quotes or the AHJ isn't >> padlocking his door, then I doubt he'll be doing anything but replacing the >> 3". And likely it will be someone other than you doing the work. >> >> George Church' >> Rowe Sprinkler >> [email protected] >> 570-837-7647 >> >> -----Original Message----- >> From: [email protected] >> [mailto:[email protected]] On Behalf Of Todd Williams >> Sent: Wednesday, January 12, 2011 2:31 PM >> To: [email protected] >> Subject: RE: Hydraulic Calcs >> >> If a system is installed that is an exact duplicate of an existing system, >> which it is to replace, is that considered a new system under the Code or a >> "repair" of a system under 25? Where is the cut-off between the two? How >> would any of the AHJ's out there address this? >> >> Now George, supposed your building has 12ft storage of expanded plastics >> or flammable liquid storage? Most likely the pipe schedule system is not >> going to be able to protect those occupancies. Would you swap the system old >> for new as it was installed? How would the attorney for the plaintiff react >> to that? >> >> I didn't even bring up the issues about 3/4", 3-1/2" and 5" pipe. >> >> >> >> At 12:33 PM 1/12/2011, you wrote: >> >So you run new UG into a building that was legally pipe schedule >> >because the calc (that wasn't required under the valid but old design >> >criteria) doesn't work? It doesn't have to, its designed to the >> >applicable code at installation. >> > >> >George Church' >> >Rowe Sprinkler >> >[email protected] >> >570-837-7647 >> > >> >-----Original Message----- >> >From: [email protected] >> >[mailto:[email protected]] On Behalf Of Todd >> >Williams >> >Sent: Wednesday, January 12, 2011 12:20 PM >> >To: [email protected] >> >Subject: Re: Hydraulic Calcs >> > >> >Ok, so in Doug's situation, it constitutes a new installation and not >> >repair work (based on your first statement) and it is based on a prior >> >design. However, as a new installation wouldn't the design need to meet >> >current Codes irregardless of when the design was done and probably >> >require hydraulic calculations? >> > >> >> Todd G. Williams, PE >> Fire Protection Design/Consulting >> Stonington, CT >> 860.535.2080 >> www.fpdc.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) > > Todd G. Williams, PE > Fire Protection Design/Consulting > Stonington, CT > 860.535.2080 > www.fpdc.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) > -- Ron Greenman Instructor Fire Protection Engineering Technology Bates Technical College 1101 So. Yakima Ave. Tacoma, WA 98405 [email protected] http://www.bates.ctc.edu/fireprotection/ 253.680.7346 253.576.9700 (cell) Member: AFSA, SFPE, ASCET, NFPA, NFSA, AFAA, ASEE, NIBS, WSAFM, WFC They are happy men whose natures sort with their vocations. -Francis Bacon, essayist, philosopher, and statesman (1561-1626) _______________________________________________ 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)
