As Steve said the horse is dead. I hope everyone has a great weekend.
Travis Mack, SET MFP Design, LLC "Follow" us on Facebook: https://www.facebook.com/pages/MFP-Design-LLC/92218417692 Send large files to MFP Design via: https://www.hightail.com/u/MFPDesign Sent from my iPhone > On Oct 29, 2016, at 11:06 AM, Brad Casterline <[email protected]> wrote: > > Damien - > I think so, using Hazen-Williams. It disturbs me though that a fitting or > valve, installed and anchored, can shrink or grow depending on the flow. > With Darcy-Weisbach, using a "K-Value" for fittings and valves that doesn't > happen. > This is because friction head is directly proportional to the square of the > velocity, and D-W is all about the velocity, whereas H-W gets similar results > with much less effort over an acceptable range of fire protection velocities. > > Ron - > I kicked myself right after I posted that for not saying something like, "the > only reason I can think of why a 1" threaded tee or 1" pipe-o-let is EQL=5ft > whilst a 1" mechanical tee is EQL=11ft is it must have something to do with > gaskets. > (I miss the aroma of warm oil, taking smoke breaks in the fab shop-- been 15 > years-- even then that's the closest I got to the reality of mech tees). > > Steve - > I was just trying to help Russell. I think he would have had more replies if > I had just stayed out of it. > He contacted me off Forum, I said I would see if I could get a formal interp, > I got one, and here we are. > The problem is, I'm not sure the question was expressed adequately, I > apologized for letting him down, he is back... > You are a TC member-- is it a dead horse or not? > I could care less how it turns out-- I do what my P.E. tells me to do. > > Brad >> On Oct 29, 2016 12:03 PM, "Steve Leyton" <[email protected]> wrote: >> There's a saying in our business that we design systems with computers, use >> lasers to measure pipe for fabrication, then mark with a paint pen and cut >> it with a chop saw. In other words there are some weak links in the chain of >> events that we take for granted every day. >> >> The hydraulic design method that we use, the number of sprinklers and sizes >> of design areas that we include in our models, all provide for conservative >> safety factors. So to the point of whether or not a rubber gasket reduces >> the inside diameter compared to a weld-o-let or a threaded fitting, my >> reaction to that is so what, who cares? >> >> All these formulas and algorithms and commentary amount to a whole lot of >> over-analysis and here's why: if you were to actually account for that >> hundredth or thousandth an inch, the impact would be an almost indiscernibly >> higher starting pressure at the end sprinkler. Thereafter, you would have an >> almost indiscernible lower net K-factor at each successive sprinkler thus >> reducing overflow,making the system demand lower by a fraction of a fraction >> of a PSI here and a GPM there. >> >> So if you want to spend an extra 3 or 4 hours per calc boilng down these >> metrics, be my guest but as far as this discussion thread is concerned I'm >> pretty sure the horse is dead and beyond resuscitation. >> >> >> Steve >> >> >> -------- Original message -------- >> From: "rongreenman ." <[email protected]> >> Date: 10/29/16 9:44 AM (GMT-08:00) >> To: [email protected] >> Subject: Re: Hydraulic losses when using a Mechanical Tee on Sprinkler Outlet >> >> In y experience with mech tees I always used the type with the lip so the >> hole size was substantially bigger for it than a elder outlet and the rubber >> was well away from the hole. That aside dramatic is a pretty heady word Brad >> (pun intended). The fitting the head is screwed into, including welded >> outlets and mech tees, do not need to be calculated per NFPA. Ig the listing >> requires it then that would trump the standard but to my knowledge no head >> requires that fitting be included. Given all the slop in the model we use, >> and that it is a model I'm always amazed that a bunch of engineering types >> act like it is an actual and mathematically accurate representation of what >> goes in each piece of the system in all cases. >> >>> On Sat, Oct 29, 2016 at 9:23 AM, Brad Casterline <[email protected]> >>> wrote: >>> This is actually pretty dramatic Ron. In Russell's case, if the K25 head is >>> in a 1" welded pipe-o-let the pressure required at the branch line is the >>> same as at the head, where as if it is in a 1" mechanical tee the pressure >>> required at the branch line is the same as if the head was on a 1" x 11'-0" >>> sprig or drop! >>> >>> Of course if the K for a K25 was established when it was in a 1" mech tee, >>> it could rightly be excluded. >>> >>> Both welded outlets and mech tees have similar hole sizes, but I think the >>> gaskets on mech tees reduce the AREA of the hole, which plays the biggest >>> part of the ultimate Coefficient of Discharge, aka, K-Factor. >>> >>> Just my two no nonsense :) >>> >>> Brad >>> >>>> On Oct 29, 2016 11:02 AM, "rongreenman ." <[email protected]> wrote: >>>> Are we once again worrying about the difference between 0.003 psi and >>>> 0.004 psi? >>>> >>>> If I recall the number we're trying to compare demand against supply is >>>> based on a formulae with a constant (average), an average C-factor of >>>> deterioration based on variable conditions over many years, a nominal >>>> diameter, and a velocity pressure determined by holding a pitot in a >>>> stream of water that's trying to rip the pitot out of your had while you >>>> take an average reading from a bouncing gauge that has a +/– built in. >>>> Then we do the math, round to the nearest 50 gpm, and apply it to a graph >>>> so small that the width of the line has an effect. >>>> >>>> And as Brad said the fitting is calculated into the K factor of the >>>> sprinkler. And as someone else noted the flexible drop is a drop, not a >>>> fitting. It has a fitting the sprinkler screws into. It also has a >>>> friction loss value that has to be an average as it doesn't take the >>>> curves into account. And do we calculate the gain from the elevation >>>> change? >>>> >>>>> On Fri, Oct 28, 2016 at 8:33 AM, Brad Casterline >>>>> <[email protected]> wrote: >>>>> Here is my original reply, for what it's worth... >>>>> >>>>> >>>>> >>>>> >>>>> >>>>> Russell, >>>>> >>>>> >>>>> >>>>> My understanding is we do not have to figure the loss for the fitting the >>>>> >>>>> sprinkler is in because when the K Factor was being established it was in >>>>> a >>>>> >>>>> fitting. >>>>> >>>>> NFPA 13 (2016) 23.4.4.8.1 (9) confirms that. >>>>> >>>>> But it's a good question because we're supposed to use a manufacturer's >>>>> >>>>> published loss if they have one. >>>>> >>>>> So would it make sense to, if the published loss is greater, subtract the >>>>> >>>>> loss shown in 13, and include that difference? >>>>> >>>>> >>>>> >>>>> Brad >>>>> >>>>> >>>>> >>>>> >>>>> >>>>> From: Sprinklerforum >>>>> [mailto:[email protected]] On Behalf Of Brad >>>>> Casterline >>>>> Sent: Friday, October 28, 2016 10:19 AM >>>>> To: [email protected] >>>>> Subject: RE: Hydraulic losses when using a Mechanical Tee on Sprinkler >>>>> Outlet >>>>> >>>>> >>>>> >>>>> Here is the e-mail I sent to our in-office guy whom submits questions to >>>>> NFPA: >>>>> >>>>> >>>>> >>>>> >>>>> >>>>> ***** >>>>> >>>>> "From NFPA 13- 2016 >>>>> >>>>> >>>>> >>>>> >>>>> >>>>> 23.4.3.1.1 Table 23.4.3.1.1 shall be used to determine the >>>>> >>>>> equivalent length of pipe for fittings and devices unless manufacturer’s >>>>> >>>>> test data indicate that other factors are appropriate. >>>>> >>>>> >>>>> >>>>> 23.4.4.8.1 >>>>> >>>>> (9) Friction loss shall be excluded for the fitting directly >>>>> >>>>> connected to a sprinkler. >>>>> >>>>> >>>>> >>>>> >>>>> >>>>> A 1" tee in the table is 5' equivalent length. >>>>> >>>>> A mechanical tee with 1" outlet is 11' equivalent length. >>>>> >>>>> >>>>> >>>>> If the sprinkler is directly attached to the mechanical tee do we still >>>>> exclude it?" >>>>> >>>>> ***** >>>>> >>>>> >>>>> >>>>> >>>>> >>>>> When we got the recent response Gregory pasted, I asked the guy for the >>>>> exact wording of the submitted question, but since submitting a question >>>>> on-line 'disappears' once submitted, it was not available. He said he >>>>> reworded mine a little, but thinks the last line (which is what this is >>>>> all about) was clear. >>>>> >>>>> >>>>> >>>>> Personally, I like my original reply to Russell, but I'm just a Tech, so >>>>> there's that :) >>>>> >>>>> >>>>> >>>>> Brad >>>>> >>>>> >>>>> >>>>> >>>>> >>>>> From: Sprinklerforum >>>>> [mailto:[email protected]] On Behalf Of >>>>> Russell & Carol Gregory >>>>> Sent: Thursday, October 27, 2016 10:01 PM >>>>> To: [email protected] >>>>> Subject: RE: Hydraulic losses when using a Mechanical Tee on Sprinkler >>>>> Outlet >>>>> >>>>> >>>>> >>>>> Ken, and others, >>>>> >>>>> We have been excluding the loss for a welded outlet or a mech tee when a >>>>> sprinkler is directly attached. If the outlet is to feed a pipe >>>>> (regardless of length) then the standard loss for a branch on tee would >>>>> be used, however if the Manufacturers Data Sheet states that the loss in >>>>> a clamp tee is greater than the loss in Table 23.4.3.1.1 (NFPA 13 2016) >>>>> for a side outlet of tee, THEN the ADDITIONAL LOSS shall be included. I >>>>> think they should say the Higher EQL Loss should be used so you don’t use >>>>> less than the Table Loss. >>>>> >>>>> >>>>> >>>>> Here is a recent NFPA Response to a similar question; >>>>> >>>>> >>>>> >>>>> Table 23.4.3.1.1 is required to be used to determine the equivalent length >>>>> >>>>> of pipe for fittings and devices unless manufacturers' test data indicate >>>>> >>>>> that other factors are appropriate. In your situation since the >>>>> manufacturer >>>>> >>>>> specifies an equivalent length of 11 feet, you are required to use 11 feet >>>>> >>>>> for the equivalent length. >>>>> >>>>> >>>>> >>>>> In regards to Section 23.4.4.8(9) of the 2016 edition of NFPA 13, if an >>>>> >>>>> extension is used with a tee, that tee must be included in the hydraulic >>>>> >>>>> calculations. The allowance to use an extension is restricted to >>>>> sprinklers >>>>> >>>>> with a relative low discharge volume. They will most likely be used for >>>>> >>>>> minor adjustments to interface with the ceiling. >>>>> >>>>> >>>>> >>>>> This answers some of the other Forum responses to my questions but does >>>>> not answer my problem. >>>>> >>>>> >>>>> >>>>> What I would like to see is a practical flow test done with a K36 (us >>>>> k25) head and see if there is a significant difference between welded >>>>> outlet, threaded tee and clamp tee. Does anyone know if this has been >>>>> done??? >>>>> >>>>> >>>>> >>>>> Our AHJ has asked for the full loss to be included and this will nearly >>>>> double the pressure required at a K-36 sprinkler from 345kPa(50psi) to >>>>> around 600kPa(90psi), if clamp tees are used. There is quite a variation >>>>> between Brands for the stated EQL. >>>>> >>>>> Makes life difficult if site staff change from welded to mechanical >>>>> fittings and then buy a variety of brands!!!!! >>>>> >>>>> >>>>> >>>>> Thanks for the responses. >>>>> >>>>> Russell Gregory >>>>> >>>>> >>>>> >>>>> >>>>> >>>>> From: Sprinklerforum >>>>> [mailto:[email protected]] On Behalf Of >>>>> Parsley Consulting >>>>> Sent: Friday, 28 October 2016 3:56 AM >>>>> To: [email protected] >>>>> Subject: Re: Hydraulic losses when using a Mechanical Tee on Sprinkler >>>>> Outlet >>>>> >>>>> >>>>> >>>>> Russell, >>>>> Mark and Todd are both correct. >>>>> If the sprinkler is directly attached to the fitting, in this case >>>>> the welded outlet or mechanical tee, the friction loss through that >>>>> fitting is excluded from the hydraulic calculations, per NFPA 13, >>>>> 23.4.4.7.1(9). I don't know that I've ever had a set of calculations >>>>> sent back with a comment that I didn't include the friction loss >>>>> equivalent for the welded outlet or mechanical tee which was directly >>>>> attached to the sprinkler. >>>>> Todd's comment is valid as well, however it's worth noting, I >>>>> believe, that when you're designing a system with flexible drops you must >>>>> account for the equivalent length of the device, using the manufacturer's >>>>> data. My own experience has been that those values are substantial. >>>>> sincerely, >>>>> >>>>> Ken Wagoner, SET >>>>> Parsley Consulting >>>>> 350 West 9th Avenue, Suite 206 >>>>> Escondido, California 92025 >>>>> Phone 760-745-6181 >>>>> Visit our website >>>>> >>>>> On 10/27/2016 1:30 AM, Russell & Carol Gregory wrote: >>>>> >>>>> I posted a message on this subject early this month but only received one >>>>> reply(thanks Brad). This was surprising as I thought it was a serious >>>>> problem if the full EQL for tee had to be added to calculations. >>>>> Especially if the change was made on-site after design had been completed >>>>> with welded outlets. >>>>> >>>>> So my query is as follows; >>>>> >>>>> >>>>> >>>>> When calculating a Range Pipe with welded threaded outlets for sprinklers >>>>> it is not necessary to include a loss for the water leaving the range >>>>> pipe and entering the sprinkler. The total pressure is assumed to apply >>>>> to the sprinkler orfice. >>>>> >>>>> This means that a 80nb pipe with a 25nb outlet and a k36 sprinkler does >>>>> not have an additional loss added for the outlet fitting. >>>>> >>>>> >>>>> >>>>> If I change my design and fabricate the 80nb range pipe with 80 x 25 >>>>> Mechanical Tees for the Sprinkler outlet do I have to apply an additional >>>>> loss factor for that fitting? The published EQL for Mech tees varies >>>>> greatly between brands,( 0.8m up to 2.4m). This means a head pressure of >>>>> 345kPa would need around 600kPa in the range if this additional loss is >>>>> added. >>>>> >>>>> >>>>> >>>>> Questions; >>>>> >>>>> 1. Is it common practice in USA to use 80 x 25 clamp/mechanical >>>>> tees for attaching large bore Storage Sprinklers directly to 80nb range >>>>> pipes? >>>>> >>>>> 2. Is it common practice to add in an additional loss for the clamp >>>>> tee, in the hydraulic calculation, where the sprinkler is directly fitted >>>>> to the tee outlet? >>>>> >>>>> >>>>> >>>>> I would appreciate the Forum members advise as to what is the standard >>>>> practice in the USA. >>>>> >>>>> >>>>> >>>>> Russell Gregory >>>>> >>>>> Christchurch >>>>> >>>>> New Zealand >>>>> >>>>> >>>>> >>>>> e-mail [email protected] >>>>> >>>>> >>>>> >>>>> >>>>> >>>>> _______________________________________________ >>>>> 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 >>>>> >>>> >>>> >>>> >>>> -- >>>> Ron Greenman >>>> >>>> 4110 Olson Dr., NW >>>> Gig Harbor, WA 98335 >>>> >>>> [email protected] >>>> >>>> 253.576.9700 >>>> >>>> The Universe is monstrously indifferent to the presence of man. -Werner >>>> Herzog, screenwriter, film director, author, actor and opera director >>>> (1942-) >>>> >>>> _______________________________________________ >>>> 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 >>> >> >> >> >> -- >> Ron Greenman >> >> 4110 Olson Dr., NW >> Gig Harbor, WA 98335 >> >> [email protected] >> >> 253.576.9700 >> >> The Universe is monstrously indifferent to the presence of man. -Werner >> Herzog, screenwriter, film director, author, actor and opera director (1942-) >> >> _______________________________________________ >> 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
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