Ron: You are right about the vegetable oil and high efficiency deep fryer issues that led to the UL 300 standard and predominance of wet chem systems. 17A is the standard for pre-engineered wet chem systems whose application is for the protection of commercial cooking operations. The pre-engineered part really amounts to what the manufacturer sets as the limit for their system and UL tests to determine that it meets it. As far as I know, all the mfrs. of wet chem systems focus on typical restaurant appliances, not the large, production cooking equipment that has been the topic of this thread. As to a hard limit of 16 square feet; I don't think so. For example, one mfr. has a listed 6 gallon system that can cover 18 flow points. A nozzle to protect a typical single well deep fryer is 2 flow points, while a typical two to four burner range can be protected with a 1 flow point nozzle. So, if you had a gang of range tops and protected four burners per nozzle, you could have about 12 four burner range tops of about 4 sq ft each for 48 sq feet of appliances, plus the plenum and duct nozzles, protected by a 6 gallon system. There are, of course, other limitations like total volume of piping, length of the detection cable, etc. that could further limit the system. On the other hand, at least one mfr. has an option for ganging cylinders together to cover up to 48 flow points. Bottom line, if the mfr. does not have instructions that is part of their UL listing for protecting a particular appliance, then a wet chem 17A system is not appropriate, as you pointed out. Disclaimer: The above is my opinion only and is not the opinion of NFPA or the Tech Comm on Dry and Wet Extinguishing Systems.
Dave David A. de Vries, P.E., CSP Firetech Engineering Incorporated --- On Fri, 10/23/09, Ron Greenman <[email protected]> wrote: From: Ron Greenman <[email protected]> Subject: Re: Re[2]: Report: Antifreeze sprinkler system may havecontributedtofatalexplosion To: [email protected], "Coastal" <[email protected]> Date: Friday, October 23, 2009, 8:57 PM Charles, 17A does not address any dry chem at all but I'll assume you meant 17. In truth 17 is merely a dry chem standard and 17A one for wet chem. Neither say where they can be used. UL 300 is the listing protocol for systems protecting cooking appliances. Cooking lines using only animal fats or not having a tilting tray skillet, flat grill or deep fat fryer could use dry chem. Only wet chem have been able to meet the protocols that include vegetable oils and the described appliances above. Since none of these scenarios are likely to occur there is no incentive for manufacturers to list anything but wet chem. The big issues are the vegetable oil and it's higher auto ignition point and the increased insulation on the appliances that delays the cool down so much that reflash occurs. As far as I know the largest surface area that any wet chem restaurant system is listed for is 16 square feet. Kitchen restaurant systems are not appropriate for industrial applications under their prescriptive installation manuals. I suppose you could have systems engineered with any protection scheme. I once did a donut fryer with H-Ex foam that satisfied the fire department. Lots of numbers and lots of critical thinking. On Fri, Oct 23, 2009 at 6:15 PM, Coastal <[email protected]> wrote: > Hello Craig, > > Kitchen hoods procted to NFPA 17A standard are now UL300 and are a wet > chemical for the appliance protection and have been for a few years. Yes Dry > chem is still allowed by NFPA 17A for the duct and plenum BUT the > manufactures do not allow that combo anymore. > > Friday, October 23, 2009, 12:01:03 PM, you wrote: > >> See that makes no sense. In kitchen equipment hoods it's usually always >> some kind of DC or CO2, never water. > > >> Craig L. Prahl, CET >> Fire Protection Specialist >> Mechanical Department >> CH2MHILL >> Lockwood Greene >> 1500 International Drive >> PO Box 491, 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 Fletcher, Ron >> Sent: Friday, October 23, 2009 11:57 AM >> To: [email protected] >> Subject: RE: Report: Antifreeze sprinkler system may >> havecontributedtofatalexplosion > >> It's vegetable oil. > >> -----Original Message----- >> From: [email protected] >> [mailto:[email protected]] On Behalf Of >> [email protected] >> Sent: Friday, October 23, 2009 8:55 AM >> To: [email protected] >> Subject: RE: Report: Antifreeze sprinkler system may >> havecontributedtofatalexplosion > >> If the oil is not miscible, good luck with that scheme. What did the >> insurer use as the basis for that idea? > >> Typically for oil quenching or dip tanks or similar you would use local >> app. DC or Foam or maybe CO2 depending on conditions and MSDS data. > > > > >> Craig L. Prahl, CET >> Fire Protection Specialist >> Mechanical Department >> CH2MHILL >> Lockwood Greene >> 1500 International Drive >> PO Box 491, 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 Fletcher, Ron >> Sent: Friday, October 23, 2009 11:45 AM >> To: [email protected] >> Subject: RE: Report: Antifreeze sprinkler system may have >> contributedtofatalexplosion > >> It isn't a very thin layer of oil. We are doing 4 fryers that are 6 ft wide >> by 18 ft >> long and hold about 250 gallons of oil at 325F. They run potato chips >> through on a >> conveyor. I'm not sure but I think the oil is at least 4-6 inches deep. I >> even have a >> letter from an FM type insurance company confirming the water deluge for the >> fryers. > >> One of my concerns was amount of free board in the fryers. At about 150 gpm >> we will >> over flow the free board in a couple minutes. Then everything goes to the >> trench drain. > >> We priced deluge, LP CO2 and Hifog. Deluge was least expensive, CO2 double >> the cost of >> deluge and mist was double the cost of CO2. The owner chose deluge. > >> Ron Fletcher >> Aero Automatic >> Phoenix, AZ > >> -----Original Message----- >> From: [email protected] >> [mailto:[email protected]] On Behalf Of Roland Huggins >> Sent: Friday, October 23, 2009 7:40 AM >> To: [email protected] >> Subject: Re: Report: Antifreeze sprinkler system may have >> contributedtofatalexplosion > >> that's for a flat surface (thin layer of oil) verses a pan of oil (or deep >> aft fryer) > >> Roland > >> On Oct 23, 2009, at 5:51 AM, Fletcher, Ron wrote: > >>> Interesting video. Have you seen FM Data Sheet 7-20 Oil Cookers? It >>> says to put a deluge system discharging at 0.5 gpm per sqft over the >>> hot oil surface. > >>> Ron Fletcher > >> _______________________________________________ >> 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) >> _______________________________________________ >> 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) > > > > -- > Best regards, > Charles Thurston > Coastal Fire Protection > Coastal mailto:[email protected] > > > _______________________________________________ > 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 Bates Technical College Tacoma, WA Member: SFPE, ASCET, NFPA, AFSA, NFSA AFAA, WSAFM _______________________________________________ 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)
