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Cellophane Covers for Sprinkler Heads

E

EH&S1

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Joined
Jan 23, 2012
Messages
1
The requirement comes from NFPA 33:

9.4.7 Sprinklers shall be protected against overspray residue,

either by location or covering, so that they will operate quickly

in event of fire.

9.4.7.1 Sprinklers shall be permitted to be covered only by cellophane

bags having a thickness of 0.08mm(0.003 in.) or less or

by thin paper bags. These coverings shall be replaced frequently

so that heavy deposits of residue do not accumulate.

Does anyone have any info on where you can purchase these particular bags?

Thank you very much in advance!!
 
can use paper bags also, if you know where to buy paperbags anymore
 
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The cheap plastic sandwich or storage bags are generally acceptable.

Don't use the expensive heavy duty freezer bags they tend to be too thick.
 
NFSA e-Tech notes

Editor-Russell P. Fleming, P.E. Issue No. 229 Issued: January 3, 2012

Question 6 – Thickness of Cellophane Bags

NFPA 25 – Section 5.4.1.7.1 specifies protection for sprinklers subject to overspray accumulation using cellophane bags having a maximum thickness of .076 mm.

It appears to us that a standard cellophane bag is approximately 1 to 1.5 mm. Do you know of a cellophane bag that is available in the specified thickness?

Answer: Be very careful regarding this section. The typical sandwich bags that you can buy in the grocery store are not cellophane. These bags are plastic and cannot be used on sprinklers. During a fire, the plastic bags could melt onto the sprinkler and possibly impair the correct operation of the sprinkler.

You may want to contact true cellophane bag manufacturers through the Internet. In the meantime, NFPA 25 also allows “thin” paper bags. Since the word “thin” is not defined in this context, it should be easier to use paper bags that comply with the standard.
 
You beat me to it! I was going to respond to Franks post...... Cellophane or paper bag ONLY, not a polyethylene "Baggie".

In my first post, I provided a link to 1-1.5 MIL cellophane bags which are under the maximum .003" requirement

It appears to us that a standard cellophane bag is approximately 1 to 1.5 mm
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I think that person is mixing MIL's with Milimeter's.......... cellophane bags are measured in MILS which equate to 1 MIL = .001"
 
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Cellophane can be catagorized by calling it "Plastic" as a generic term, but NFPA specifically states "Cellophane", which has different burn/melt characteristics than a "Poly" bag.
 
2011-25 5.4.1.7.1 "

In prior editions, NFPA 25 allowed the use of a plastic bag, but this was changed due to concerns about the potential for a plastic bag to shrink prior to sprinkler activation and disruupt the discharge pattern."

A.5.4.1.7.1 Typical sandwich bas purchased in a grocery store are generally plastic, not cellophne. .............Bags placed over sprinklers need to be true cellophane or paper.
 
Use a paper bag, any inspector that comes in will ask you to prove it meets the NFPA standards if you use plastic and or cellophane. MOST inspectors will be able to tell what a paper bag looks like. :p Always use the KISS principle make life easy. :D
 
I'll let them use whatever the code allows, I agree paper bags are easier on everyone, but I thought the op was more interested in cellophane
 
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"looks like paper bags is an easier way to go"
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FWIW, me thinks that the cellophane will facilitate the ability to seewhat "not to paint over or to hit"........Just sayin'.



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Que¿¿¿.......

north star said:
= =

FWIW, me thinks that the cellophane will facilitate the ability to see

what "not to paint over or to hit"........Just sayin'.



= =
Click to expand...
 
Do not forget the sprinkler heads you can not see, such as behind the dry filters and at the top of the duct.:eek:ops I always tell the owner change the bag(s) when you change the filters.:cheers
 
This thread made me chuckle a bit. Regradless what you use, paper or plastic....if the head goes off, you're gunna git wet. Aluminum foil works well since you don't use a rubber band or tape to hold it on so in theory, the foil will pop off if the head activates. We also use the dollar store cling wrap kind of stuff with a rubber band. When they use paper or a plastic baggie, you have to use a lot of tape and most of the head ends up getting covered with the tape.

NFPA should took into foil. Just me 2 cents.
 
I would have to say that "Technically", you would be in violation.....however, I see your point that the water pressure, theoretically, would just blow any cover off if the sprinkler got hot enough (the foil would probably delay the response). I would still write a violation, because it doesn't meet the NFPA standard.

I doubt NFPA would add foil, you can't even paint a recessed sprinkler cover unless it's applied by the factory, due to delayed response and possibly "Gluing" the cover to the ceiling...... and that's just paint!
 
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