See the video below. Fast forward to the spray foam test at about 3 minutes in. Spoiler: flashover takes 44 seconds. Since you are probably acting as the only fire professional on this project, I would suggest you share the video with your customer so they understand the gravity of the situation. They should invest in a very expensive system. If it were me, I would flood the thing, fast. I know there are some foams that have a fire retardant mixed in, but I'm not sure what kind of impact it would have.
https://youtu.be/mUPp-Ipt-Pk Good luck, Skyler Bilbo Wente Plumbing and Fire Protection On Tue, Oct 12, 2021 at 4:21 PM David L. Miller, P.E. via Sprinklerforum < [email protected]> wrote: > Does anyone have advice as to how one would calculate a "spray booth" for > spraying foam insulation that is approximately 90' tall X 25' diameter with > five levels of working platforms? > > > > Typically, when I have done paint booths for vehicles (even as large as > fire > trucks) I have calculated the system as a deluge system because of concerns > regarding flames in a vapor cloud opening heads throughout the booth. In > this case, there will likely be 8 - 10 sprinklers at each level of the > working platforms plus 20 sprinklers at the roof (due to structural > obstructions). This totals 60 - 70 sprinklers flowing at Extra Hazard > Group > 2 densities if the system is treated as a deluge system for hydraulic > calculation purposes. > > > > NFPA 33:9.6.3 (also NFPA 13:26.4.1.4) "The water supply shall be sufficient > to supply all sprinklers likely to open in any one fire incident without > depleting the available water for use in hose streams." > > > > I am wondering about the likelihood of sprinklers at the roof operating > simultaneously with multiple levels of sprinklers below the operating > platforms. Or, as the Annex to NFPA 33:9.6.3 puts it, what is a "credible > fire scenario" for a spray booth such as this? > > > > Is it a reasonable assumption that sprinklers installed 15' AFF will > operate > while the flame front continues to open sprinklers at different elevations > up to and including the roof level at approximately 90' AFF? Conversely, > is > it reasonable to make the assumption that a fire will not open all of the > sprinklers? > > > > If I had an unlimited water supply I would simply calculate the system as a > deluge system. If I had an unlimited budget, I would make each level a > separate deluge system with flame detectors at each level. Unfortunately, > we do not operate with unlimited water supplies and unlimited budgets. > > > > Any advice would be greatly appreciated. > > > > > > David L. Miller, P.E. > > Engineered Fire Protection, LLC > > 11920 Richcroft Avenue > > Baton Rouge, Louisiana 70814 > > 225-273-5040 > > > > _______________________________________________ > 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
