Mark and Chris,
I'll take a stab at this. The west coast is still grinding the coffee beans. The length of an armorer is not expected to be very long. The adjacent branch lines cannot exceed 20 feet apart for extended coverage sprinklers and 15 ft for standard spray sprinklers. If the armorer is over 10 ft long coming off a cross main or branch line, it should be considered to be piped from the adjacent branch line. The main objective is to use less pipe, correct? Why waste pipe length? So, if that is the case, the committee is not worried about a line with a single sprinkler and provided the definition of an armover. A line with two or more sprinklers is defined as a branch line where they can be of considerable length. The longer the line, the more it will have a whipping action. Thus, Table 9.6.3.4(a) specifies the spacing needed for restraints based on the Cp in that area and the pipe size ranging from 26 ft to 53 ft. An armorer shouldn't whip around so much due to its short length so restraint is not required. Can there be instances where there are long armorers? Sure, especially if there is a drop from a 40 ft ceiling to a ceiling at an 8 ft level. 9.3.6.7 Drops and armorers shall not require restraint. What a mess that would be to restrain a drop located 32 ft from the ceiling. Steve commented that ceiling grids should be rigidly braced. If not, then the oversized hole for the sprinkler is necessary in the ceiling to keep the ceiling from breaking the fusible element. Will fusible elements still still break during an earthquake from the ceiling? Probably. The cost benefit of providing restraints on every drop does not warrant them to be installed. NFPA 13 is full "lines in the sand" that we don't know the true history behind them but it seems mostly just to give a warm fuzzy (i.e. 4 ft obstruction rule, area limitations of 52,000 sf, etc….) and armorers and branch lines is just one of them. It doesn't fit all applications, but the baseline requirement is established. Tom Wellen AFSA On Oct 22, 2013, at 8:49 AM, "Mark A. Sornsin, P.E." <[email protected]> wrote: > This is true. Steve has and will again a lie to me. > > Like when he said he answered my question, "Why do we restrain branch lines > of 8 ft. length in EQ zones, but not 8 ft. long arm-overs?" > > His answer (paraphrased) was 'because sprinklers can move during > earthquakes.' And then he accused me of not bathing. Earlier he noted that > 'arm-overs aren't by definition branch lines.' > > Now, Steve AND Ken, please don't misunderstand me: I am not mad about this; > but I am a bit disappointed. That's because this isn't about just me. There's > another P.E. out there who initiated this thread who is likely as eager as I > to know the reasoning behind this. He looks up to both of you and is checking > his Forum emails regularly to learn the answer to this question. So far, he > has come up empty - and you can bet feels as bad as a kid who's dad didn't > get home from work as promised to take him to that big league game. > > So, c'mon, guys. If you won't answer this one for me, then do if for Chris > Cahill, P.E.* > (*Registered in MN) > > Mark A. Sornsin, P.E. | Karges-Faulconbridge, Inc. | Fire Protection Engineer > | Fargo, ND | direct: 701.552.9905 | mobile: 701.371.5759 | > http://www.kfiengineers.com > > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of Steve > Leyton > Sent: Tuesday, October 22, 2013 7:31 AM > To: [email protected] > Subject: RE: NFPA 13 '10 9.3.6 BL Restraint > > Thank you Ken - your kind words yesterday were the greatest endorsement of my > skills since ... well, since the last 27 emails I've received from LinkedIn. > And, in spite of his apparent skepticism, I'd like to express my respect for > Mark Sornsin, P.E. He has letters after his name after all, so I know that > he has at least shown an aptitude for scholastic binge drinking and > standardized tests. But I want to be perfectly clear that as much as I value > the relationships made and fostered on the Forum and in the Association, I > would most definitely lie to him. Sometimes, I look for opportunities to lie > to Mark. > > Mr. Muncy, I apologize for straying off of technical topics and making > questionable comments about a member's character and be with the starving > pygmies down in New Guinea. Amen. > > SL > > > -----Original Message----- > From: [email protected] on behalf of Ken > Sent: Mon 10/21/2013 6:14 PM > To: [email protected] > Subject: Re: NFPA 13 '10 9.3.6 BL Restraint > > He answered it perfectly, Mark. He deals with this kind of issue every > single day, as I do. > His answer was right out of the book, as was the notation on the drop > ceilings. > Pay attention to him, he wouldn't lie to you. > > Ken Wagoner, SET > 760.745.6181 voice > 760.745.0537 fax > http://www.parsleyconsulting.com > > > On 10/21/2013 6:20 PM, Mark A. Sornsin, P.E. wrote: >> Ken - are you out there? I don't think Steve really answered my question.... >> >> Mark A. Sornsin, P.E. | Karges-Faulconbridge, Inc. | Fire Protection >> Engineer | Fargo, ND | direct: 701.552.9905 | mobile: 701.371.5759 | >> http://www.kfiengineers.com >> >> -----Original Message----- >> From: [email protected] >> [mailto:[email protected]] On Behalf Of >> Steve Leyton >> Sent: Monday, October 21, 2013 1:06 PM >> To: [email protected] >> Subject: RE: NFPA 13 '10 9.3.6 BL Restraint >> >> Because in EQ land there's stuff going on in the Building Code and ASCE 7 >> that you unwashed people in non-EQ land can't see. Like, you either have to >> use a swing joint or flexible hose connection on your pendent drops to >> lay-in tile ceilings that aren't rigidly braced, or provide an oversized >> hole in the ceiling tile to prevent damage to the sprinkler. (For those >> who have never seen them, "filler" rings are available to enclose the >> annular space in these holes, which are larger diameter than the >> escutcheons. And they look like crap.) It is intended that there be some >> measure of movement in the drop piping that is independent of the main and >> branch piping, which are hung and braced and restrained to the roof or floor >> assembly above. >> >> >> Steve Leyton >> >> >> >> >> -----Original Message----- >> From: [email protected] >> [mailto:[email protected]] On Behalf Of Mark A. >> Sornsin, P.E. >> Sent: Monday, October 21, 2013 10:54 AM >> To: [email protected] >> Subject: RE: NFPA 13 '10 9.3.6 BL Restraint >> >> Well... I guess a Ken Wagoner power point hand-out will work. >> >> But I think the real question hidden in Chris' original query is why? Why is >> an 8' arm-over not required to be restrained in EQ land, but an 8' branch >> line with two heads on it would be? Does one NOT see the movements in an >> earthquake that the other would? Or is it just an oversight in the rule >> making process? >> >> Mark A. Sornsin, P.E. | Karges-Faulconbridge, Inc. | Fire Protection >> Engineer | Fargo, ND | direct: 701.552.9905 | mobile: 701.371.5759 | >> http://www.kfiengineers.com >> >> >> _______________________________________________ >> Sprinklerforum mailing list >> [email protected] >> http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkl >> er.org >> >> >> ----- >> No virus found in this message. >> Checked by AVG - www.avg.com >> Version: 2012.0.2242 / Virus Database: 3222/6270 - Release Date: >> 10/21/13 >> >> > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org > > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org > > ______________________________________________________________________ > This email has been scanned by the Symantec Email Security.cloud service. > For more information please visit http://www.symanteccloud.com > ______________________________________________________________________ > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org
