Chris, I'll can tell you exactly where the SOB-PE is wrong. Consider a 16' x 16' room. How many residential sprinklers?
In the world of the listing criteria from Tyco, or any other manufacturer, this room requires a single sprinkler, absent anything that would prevent it not exceeding 10' from a wall. In the world of the PE who Todd is dealing with, the answer is no, you must install four sprinklers, because your coverage cannot exceed 12' x 12', or 6'-0" from any wall. He has quadrupled the number of sprinklers in the room, and I might add, quadrupled the cost of the sprinkler system to the customer. And this will hold true in every room in the building which is greater than 12'x12' in size. Here's another part of that consideration. The same aforementioned 16'x16' room, would require the hydraulic calculations to prove that 13.0 gpm would be delivered to the single sprinkler in the room, if the listing criteria and NFPA-13D were followed. In the world of the PE, that changes again, and now Todd has to prove that 26 gpm can be provided in the same room, all because the engineer doesn't accept the testing and listing data from the manufacturer, and has chosen to ignore the black and white text of the applicable standard. Now throw in the possible addition of 5 gpm for a domestic flow, which many AHJ's are requiring, and now you're potentially flowing more than 31 gpm through the meter. Depending on the manufacturer this might rule out the use of a 3/4" meter and force the homeowner into purchasing an upgraded meter, at a cost of thousands of dollars. Steve Leyton can give you more information on that than I can, but in one water district here in San Diego county the difference in a 3/4" vs. a 1" water meter is $14,000. Four times the sprinklers the listing would require, larger pipe than is necessary, an upgraded meter, and potentially a pump. What if the system were supplied from onsite storage? Now the tank must be twice the size as well. Doesn't add up to a "better" approach to residential fire protection from where I sit. He's spending four times the owners money necessary [not his own, mind you] to provide the same level of fire protection. Not "better", the same. At four times the cost. From perspective of this quite humble sprinkler layout technician that's just wrong. -- PARSLEY CONSULTING Ken Wagoner, SET 760.745.6181 voice 760.745.0537 fax [email protected] <mailto:[email protected]> e-mail www.ParsleyConsulting.com <http://www.ParsleyConsulting.com> website Chris Cahill wrote: > This is important - LET ME PLAY DEVIL'S ADVOCATE, where is the engineer > WRONG? Quick look at Tyco LF II 4.9 pendant 12' x 12' is 13 gpm. And at 18 > gpm it's a 13.49 psi start. The sidewalls at 4.2 will do 13gpm at 9.2 psi > so you are not forced under a 7 psi start. So he won't let you use 16' x 20' > spacing? Just because one won't allow what in essence is extended coverage > doesn't make one ignorant. > > Is this not the equivalent of not allowing sched 7 and only allowing sched > 40 threaded noting sched 7 has many more times the CRR? Both cases are text > book verse a real application. Perhaps some think 12' x 12' spacing is > better then EC and 40 is better than 7 when applied to a real project. How > often do we see a spec say no EC? How often do we see no reduction for QR? > > I acknowledge you did say he is reading out of the where not been listed > with special...so his argument may be flawed but his conclusion probably > isn't from his perspective. I'm sure you recall the 13/18 was the original > NFPA 13R/D spec and the first heads had no other spacing options. But it > also looks like at least in Tyco's case the low end it's the same on the > 13gpm side. Yeah the dual gpm is gone. But an engineer can spec any > density greater than the minimum. > > I didn't talk with the engineer perhaps he/she/it is ignorant or perhaps > just exercising engineering prerogative like all the other times we see it. > > > Again that was the other side of the coin. I'M ON YOUR SIDE TODD. I > wouldn't cost the owner extra money in what will probably be a lot of extra > heads but I don't see anything WRONG here. > > Chris Cahill, P.E. > Fire Protection Engineer > Sentry Fire Protection, Inc. > > 763-658-4483 > 763-658-4921 fax > > Email: [email protected] > > Mail: P.O. Box 69 > Waverly, MN 55390 > > Location: 4439 Hwy 12 SW > Waverly, MN 55390 > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of > [email protected] > Sent: Wednesday, May 19, 2010 8:39 AM > To: [email protected] > Subject: RE: 13R sprinklers > > Todd , > Are you saying the engineer has seen and has read these sections of 13R and > still doesn't understand the requirements ? If so , you may have to go over > his head to a higher authority or say a prayer and try to appease him as > best you can. > > Good Luck , > > Lamar Vaughn , SET > > > ---- Todd Williams <[email protected]> wrote: > >> Discharge - 6.7.1.1.1, Coverage - 6.7.1.3.1. NFPA 13R (2002) >> >> >> >> At 08:23 AM 5/19/2010, you wrote: >> >>> I'd ask him to please, for your edification, cite the sections of >>> the NFPA Standard where he derived his specification data. >>> >>> I guess he was looking at sprinkler data sheets and when it didn't >>> say that the sprinkler is designed for 0.10 or whatever gpm/sq. ft >>> he thinks it falls into that category? >>> >>> >>> Craig L. Prahl, CET >>> Fire Protection Specialist >>> Mechanical Department >>> CH2MHILL >>> Lockwood Greene >>> 1500 International Drive >>> 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 Todd >>> > Williams > >>> Sent: Wednesday, May 19, 2010 6:11 AM >>> To: [email protected] >>> Subject: 13R sprinklers >>> >>> I am working on a project with a rather ignorant engineer who will >>> not accept listed flow requirements for residential sprinklers. He is >>> insisting on using the 12 x 12 spacing, 13 gpm for multiple sprinkler >>> flow and 18 for single sprinkler flow (we have to calculate both). My >>> question may be one of semantics, but this is what the engineer is >>> hanging everything on. Both the above spacing and discharge >>> requirements are under sections entitled "Sprinklers That Have Not >>> Been Listed with Specific (Discharge/Coverage) Criteria". Since >>> virtually all of the residential sprinklers I am aware of have >>> specific design and coverage criteria, am I to assume based on the >>> wording that sprinklers with specific criteria cannot be used under >>> this section? If so, are there any sprinklers without specific >>> criteria currently on the market? >>> >>> 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) >> > _______________________________________________ > 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)
