Ken, Thank you for the reply. In response to your points. 17.2.4.1.2 main text states k25 @ 15psi can be used. Item (4) specifies the slatted shelf heights for k11.2, k14, and k16.8, so wouldn't that mean this bullet point only applies to these k-factors. Item (8) also states 30ft max roof height when ESFR is used. Item (9), yes we were going to inform the owner he could not store over 20ft with this commodity.
Remember, I don't want to use slatted shelves, I want to use an open rack. But the slatted shelve design criteria is more favorable than the tables. So if I have to add them to make this design work, the cost of adding these slatted shelves is less than a fire pump install. Although I would like to avoid them altogether based on my logic that slatted shelves should require a more demanding design than an open rack. Thanks, Sean VG -----Original Message----- From: Sprinklerforum [mailto:[email protected]] On Behalf Of Parsley Consulting Sent: Thursday, November 12, 2015 10:21 AM To: [email protected] Subject: Re: NFPA 13 plastics up to 25ft roof 30ft with K25 heads Sean, You might want to take a closer look at 17.2.4.1.2(4), as it tells you quite clearly that the approach you're considering using the 14.0 or 16.8 K-ESFR's is fine if the slatted shelves do not exist above the 12'-0" level, and clause (8) which identifies the maximum roof height as 27' where ESFR's are used, and clause (9) which identifies the maximum storage height as 20'. As 17.2.4.1.2 requires that _*all*_ of those 10 conditions have to be met I don't believe you should start down the path of using the slatted shelf rules, since what you described does not conform to at least two of the ten items. sorry, *Ken Wagoner, SET *Parsley Consulting*** *350 West 9th Avenue, Suite 206 *Escondido, California 92025 *****Phone 760-745-6181* Visit our website <http://www.parsleyconsulting.com/> *** On 11/12/2015 8:27 AM, [email protected] wrote: > Hi Forum, > > The following is based on NFPA 13 (2013). We have a roof height of 30ft, > owner wants to store exposed unexpanded plastics in double row open racks up > to 25ft. No solid shelves or open top containers. Looking at Table 17.2.3.1 > my options are 14k@50psi OR 16.8k@35psi. We have low water pressure and the > owner doesn't want a fire pump, he also wants ESFR, so we want to use > K25@15psi. K25 doesn't come into play until storage is 25ft with a 40ft > roof, but it requires 50psi. This pressure wouldn't work for what we are > being asked to do. Using our K-factor formula equation the K14 and K17 heads > require roughly 100gpm based on this table. If I run the K25 at 15.7psi I > get 100gpm. Does anyone see this as being a problem? Is there an issue with > the water not being able to penetrate the fire if the pressure is so low on a > K25 while also being located so close to the top of the storage? > > To make this extra confusing If we read through section 17.2.4, it appears it > will allow me to use the K25@15psi so long as I meet the 10 requirements. > But this section is for when you want to use slatted shelves. Which would > seem to delay heat travel and water travel compared to open racks. I'm sure > I can convince the owner to follow these line an verse if he wants to do this > storage arrangement, but it doesn't make sense to me that adding slatted > shelves and wire mesh should be necessary. Since it specifically doesn't > state that open racks are also allowed with this design, I might run into a > reviewer that is checking boxes rather than trying to think it through. > > Thoughts? Thank you for your time an help. > > Thanks, > Sean VG > > > > > > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkl > er.org > _______________________________________________ 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
