|
NFPA 33, 2018 Section 9.6.2.1 reads "The sprinkler design area shall not be required to exceed the area of the booth or room in which spraying or resin application is conducted."
My project has a large downdraft paint booth for buses. There are two concrete pits (4-ft height, 3-ft width, 80-ft long) beneath the paint booth that are covered by open grate flooring. (1) Does the above reference mean that the exhaust duct sprinklers do not need to be included in the booth hydraulic calculation? I have a large paint booth, and it has 4 exhaust ducts. (2) Is sprinkler protection required within the pit? Do these heads have to be included in the booth calculation or can they be considered heads under obstruction? If sprinkler protection was within the pit, the bags had to be regularly changed, which creates an issue for the end user and adds a large demand to the calculations. I think it would be unlikely that the sprinklers would operate in the concrete pit, as the overhead system should adequately protect the booth itself. Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe
10 Comments
Can you use a different k-factor for sprinklers in a duct and plenum versus the k-factor for the booth sprinklers in a paint spray booth?
I was told I could not use different k-factors to calculate the hazard. Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe We are providing sprinkler protecting inside a spray/paint booth and its associated exhaust ducts.
The question we have is if the sprinkler(s) inside the exhaust duct require the same protective covering as the heads inside the booth below. Thank you in advance for your input. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I am working on a design for a wet sprinkler system in an industrial oven. This oven has steel mandrils with fiberglass strands coated in epoxy rolled through them, heated to 350 degrees. Then, they are rolled through another machine that blows ambient-temperature air onto the mandrils to cool them down. This process forms fiberglass/epoxy-reinforced conduits. There are (3) total exhaust ducts, one penetrating the roof and two extending 5'-0" above the top of the machine and into the open building. No dipping, flow coating, or spraying happens in this machine. Strictly heating and cooling. I am guided by NFPA 13's rules on ducts, but I don't believe NFPA 33's design criteria would apply here. I am also guided to NFPA 13 2022 9.3.8 and A9.3.8, but I am unclear on whether 15 psi is required at each head based on the wording. My thinking is that a 0.2 over the whole oven would be the design criteria, protecting the hazard (OH2) in a non-FM building.  What would your design criteria for this be?
Would you calculate the heads in the exhaust ducts? Would you put heads in the exhaust ducts that don't extend through the roof or say they're protected by the overhead system? I have my thoughts, but a lot is left up to interpretation. Thank you for any information. P.S. in the attached file, (2) ducts that don't extend through the roof are shown as actually extending through the roof. There is a revision drawing I am waiting on. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe The hot topic of AFFFs and PFOS. Where is the requirement stating foam must be used for fire protection for a diesel generator inside a building?
We're looking to eliminate the need for foam instead of replacing it with "fluorine" free foam. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe I have a project involving spray application of resin, and an exhaust system including multiple 60-ft tall exhaust stacks.
We are located in Ontario Canada, and the Ontario Building Code takes precedence. Any other codes cited need to be enacted by the OBC, or by a code enacted by OBC in order to be relevant. NFPA 13 is relevant here. Chapter 26 (NFPA 13-2019) includes material from other codes. Section 26.4 relates to Spray Application Using Flammable or Combustible Materials, and references NFPA 33. I have not found a reference in NFPA 13 that states that an in-duct sprinkler system SHALL be provided. It appears to me that Section 26.4 states requirements for IF a system is provided. Unless otherwise stated, are the requirements of Chapter 26 to be used in isolation, without enacting the full text of the other NFPA Code/Standard cited? If another NFPA Code/Standard is cited in Chapter 26, is the full text of the cited document to be followed? Where is the line drawn between the two documents? I have the NFPA 13 Handbook, and the supplemental text does not clarify this for me. Thank you very much for taking the time to read through this one. Spray Room vs Spray Booth: When to use the requirements for one or the other?
I am working on a flammable spray application and was wondering if anyone has a any good metrics for when to determine if an enclosure is a "spray room" vs a "spray booth". I am working on a 40-ft by 10-ft enclosure which I would argue is a room, but NFPA 33 provides discernable direction even with Annex sections, especially with "this definition is not intended to limit the term spray booth to any particular design." This shows up in A.3.3.19. From NFPA 33 2021: Spray Booth 3.3.19 "A power-ventilated enclosure for a spray application operation or process that confines and limits the escape of the material being sprayed, including vapors, mists, dusts, and residues that are produced by the spraying operation and conducts or directs these materials to an exhaust system." Annex A.3.3.19: "Spray booths are manufactured in a variety of forms, including automotive refinishing, downdraft, open-face, traveling, tunnel, and updraft booths. This definition is not intended to limit the term spray booth to any particular design. The entire spray booth is part of the spray area. A spray booth is not a spray room." Spray Room 3.3.20 "A power-ventilated enclosure for a spray application operation or process that confines and limits the escape of the material being sprayed, including vapors, mists, dusts, and residues that are produced by the spraying operation and conducts or directs these materials to an exhaust system." Annex A.3.3.20 "The entire spray room is considered part of the spray area. A spray booth is not a spray room." Based on definitions there are no official metrics to determine when to use either definition. Is this perhaps a constructed room vs a manufactured structure? Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe We have been asked if a 20+ year old wet pipe sprinkler system we installed into a paint application room is the correct method of protection for a specific paint product that is currently being used.
The MSDS sheets for a few of the products they now use indicate protection with dry chemical, foam, or water fog. I have been told that the MSDS sheets typically refer to the product as its being stored and not necessarily as its being applied. The storage is not happening in this room of course, but in approved fire-rated storage cabinets outside the area. None of the typical requirements for alternate protection are met per NFPA 33. Basically other than the product data sheets, this is a run of the mill paint application area. Nothing automated or fancy. Anyone have any experience with a similar situation? Sent in anonymously for discussion. Discuss This | Submit Your Question | Subscribe |
ALL-ACCESS
SUBSCRIBESubscribe and learn something new each day:
COMMUNITYTop May '25 Contributors
YOUR POSTPE EXAMGet 100 Days of Free Sample Questions right to you!
FILTERS
All
ARCHIVES
June 2025
PE PREP SERIES |
RSS Feed
