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section 18 CEC #171416 11/27/07 05:20 PM
Joined: Jul 2005
Posts: 183
jay8 Offline OP
I am not well versed on this section of the code, especially the 20th edition. What would be the classification of a room with a 40, 000 litre tank storing # 2 fuel oil be? IE this is diesel, so I dont know if with the flash point of diesel, the area isnt a hazardous location.
It seems that a room with a diesel genset is not a hazardous location either, and you are pretty much certain fuel is being stored there.

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Re: section 18 CEC [Re: jay8] #171502 11/29/07 04:31 PM
Joined: Jan 2006
Posts: 60
Rick Kelly Offline
#2 heating oil is not considered a volatile substance as its flash point is very high, 52 degrees C. Locations where it is stored is not considered a hazardous location for the requirements of sections 18 and 20 of the CEC.

Re: section 18 CEC [Re: Rick Kelly] #171634 12/02/07 11:07 AM
Joined: Jul 2005
Posts: 183
jay8 Offline OP
Thanks Rick, are you referencing a rule on flash point? I checked sections 18 and 20 and also the appendix, and did not find diesel/#2 heaing oil mentioned, so I assume it is not part of those sections.

Re: section 18 CEC [Re: jay8] #171647 12/02/07 01:56 PM
Joined: Oct 2007
Posts: 56
SP4RX Offline
Hi Jay.
If section 18 applies to diesel, it would have to be a Class 1 location as per 18-004 (a)---"Class 1 locations are those in which flammable gases or vapours are or may be present in the air in quantities sufficient to produce explosive gas atmospheres"

So I guess the question is whether diesel produces flammable gases "in quantities sufficient to produce explosive gas atmospheres".

Looking at the table in appendix B (18-066), I see that diesel is not listed. However, looking at fuel oil #2 msds sheets (section 5), it would appear that diesel does indeed give off explosive vapours.

I would think that 18-006-(c)-(ii) would apply, as you have "flammable volatile liquids...normally confined within closed containers...can escape only as a result of accidental rupture or breakdown..."

Just my $0.02


Re: section 18 CEC [Re: SP4RX] #171667 12/02/07 09:44 PM
Joined: Aug 2007
Posts: 853
leland Offline
Not technical.. well maybe. Mythe Busters, Did a show on a leaking gas tank catching up to a speeding away vehicle and blowing up. That didn't happen, The gas stayed up to speed at about 3 MPH.
Then the diesel test: Even slower and they had a difficult time even getting the vapors to ignite.

For what it's worth. (Just a lighter momment)

Re: section 18 CEC [Re: leland] #171688 12/03/07 10:33 AM
Joined: Jan 2006
Posts: 60
Rick Kelly Offline
NFPA 497 - "Recommended Practice for the Classification of Flammable Liquids, Gases, or Vapors and of Hazardous (Classified) Locations for Electrical Installations in Chemical Process Areas". Defines a "Flammable Liquid" as one that has a flash point lower then 100 degF.

This means Diesel or #2 heating oils, with a flash point of 152 degF, is a "combustible liquid" and not a "flammable" one. And as such, CEC sections 18 & 20 clearly do not apply to a combustible liquid, only a flamable one.

Here is a link with some reading on the subject... While this is a link that is based on the NEC, the situation is the same.;f=22;t=000043

Re: section 18 CEC [Re: Rick Kelly] #171781 12/05/07 03:11 PM
Joined: Jul 2005
Posts: 183
jay8 Offline OP
Again thanks. You have to do a bit of digging for it, but it appears section 18 and 20 do refer to flammable liquids and combustible dusts, I dont see combustible liquids.


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