There are many issues to consider when entertaining thoughts of using hi-ex foam. Make sure it's the only valid choice before committing to using it.
The reason there is no mention of foam with wood pallets is because wood pallets are already addressed by 13 to be protected by water based sprinklers. Foam would not be appropriate or provide the same soaking that water would. There are structural issues and ventilation issues to deal with when using hi-ex foam. For a new install that might not be a big deal but for an existing building the cost impact can be rather significant. Water based sprinklers ought to be first choice unless the commodity being protected can not be effectively protected by water and foam is recommended by either MSDS or NFPA or other resource. 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 Frans Stoop Sent: Monday, November 23, 2009 12:50 PM To: [email protected] Subject: Storage of idle wooden pallets and hi-ex foam Dear colleagues, The 2 questions below caused some discussion in my professional environment: For Palletized, Solid Piled, Bin Boxes, or Shelf Storage NFPA 13 - 2007 paragraph 14.6 and 15.5, both tell us: "High Expansion Foam - Reduction to Ceiling Density. A reduction in ceiling density to one-half that required for Class I through Class IV commodities, idle pallets, or plastics shall be permitted without revising the design area, but the density shall be no less than 0.15 gpm/ft2 (6.1 mm/min)." For Rack Storage of Class I Through Class IV Commodities Stored Over 25 ft (7.6 m) in Height paragraph 16.3.5.1 tells us: "Where high-expansion foam systems are used for storage over 25 ft (7.6 m) high up to and including 35 ft (10.7 m) high, they shall be used in combination with ceiling sprinklers. The maximum submergence time for the high-expansion foam shall be 5 minutes for Class I, Class II, or Class III commodities and 4 minutes for Class IV commodities." Paragraph 12.12.2.2 tells us how to protect idle plastic pallets by the combination of hi-ex foam and sprinklers. Nothing in section 12.12.1 about idle wooden pallets and hi-ex foam. Questions: - Can high stacks or rack storage of idle wooden pallets be protected by the combination of hi-ex foam and sprinklers? - Can of idle wooden pallets be protected by hi-ex foam without sprinklers? My opinion is that hi-ex foam only (without sprinklers) will not extinguish a fire in high stacks or rack storage of idle wooden pallets, because wooden pallets contain a lot of air by themselves and the foam will not penetrate inside the stacks. The foam will only envelop the complete stacks but will not prevent the air (oxygen) inside the stacks from reaching the wood. Foam, however, may hinder the fire from jumping from one stack or rack to another, when sprinklers do their extinguishing job. Please share your opinion. Frans Stoop TOS architecture & fire protection Netherlands <[email protected]> Tel. +31-24-324 0112 _______________________________________________ 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)
