exterior kerosene tank

[paulmonti]

I have an exterior 300 hundred gallon kerosene tank with a motor operated pump mounted on the tank. I have already installed a 3/4" rigid metal conduit underground to the tank platform(cement slab). I will be installing seal fittings at each exit point from the ground. At the tank I plan to install an explosionproof box with a switch for the motor. Can I use liquidtight flexible non-metalic conduit from this box to the motor? Thanks Paul.

 

[petersonra]

does the presence of kerosene make it a classified area?

if its a classified area, then you have to use materials identified for such an area. flexible conduit is made for that purpose but is not cheap.

 

[jumper]

I am not sure of the classification of this area (I am trying to look it up right now); however, I replaced the motor for a gas tank at work and it has a flexible coupling similar to this:
http://www.electriciansupplies.com/...Appleton_Electric__EXGJH-136__-__1__Each.html

and as the other poster stated, it is expensive.

 

[Cow]

That's right, explosion proof flex sure is nice, especially when they change to a different brand pump in the future. I'm paying about $150 for a 1/2"x12" piece.

 

[jumper]

I am going to try calling this Class 1 Division 2 accorrding to T514(B)(1)

 

[rbalex]

What you have described is in the scope of Article 515 and electrical area classification is determined by Table 515.3. It will generally be Division 2 with some possible Division 1, depending on containment, vapor pressure relief and filling methods.

Sections 515.7 through 515.16 have some requirements more or less unique to bulk storage. Review them.

LFNC with listed fittings is acceptable in Division 2; however, review Sections 356.60, 250.102 and 250.134(B) for proper grounding and bonding.

 

[charlie]

What you have described is in the scope of Article 515 and electrical area classification is determined by Table 515.3. . .

Bob, are you sure? "No. 1-D diesel fuel oil and kerosene have flash points higher than 100?F and therefore do not emit flammable vapors unless heated above their flash points. They are considered combustible liquids." The quote is from the NFPA 2008 Edition of the NEC Handbook. I am way outside my area of expertise but I have always thought that wiring for diesel oil and kerosene was permitted to use Chapter 3 wiring methods.

 

[don_resqcapt19]

Charlie,
I looked at some MSD sheets for kerosene yesterday and found a range of flash points between 85 and 125?F. The most common one seemed to be 37?C (98.6?F)

 

[charlie]

Charlie,
I looked at some MSD sheets for kerosene yesterday and found a range of flash points between 85 and 125?F. The most common one seemed to be 37?C (98.6?F)

Thanks Don. As stated before, I am way outside my area of expertise.

 

[rbalex]

Thanks Don. As stated before, I am way outside my area of expertise.

Well Charlie, you weren't that far out and between you and Don you still raised a very good point - It's worth reviewing the MSDS. In this case, I used NFPA 497, Table 4.4.2 instead.

First you are correct that kerosene is often a considered a "light" oil or diesel and we routinely say (almost out of hand) that diesel doesn't require classification. Don's point is also well taken. All fuel oils and diesels are actually distillate blends. Many have "trade" names, such as kerosene, jet fuel, bunker 1, 2, 3,..., diesel 1, 2, 3 etc; or sometimes "common names" such as distillate fuel oils, diesel fuel oils, light fuel oils, gasoil or just distillate.

Of the general group, kerosene, light fuel oils, gasoil and the various "1s" are often close enough to be considered "flammables" rather than "combustibles." Because they are actually blends they will often have flash points below 100F - so checking the MSDS is essential.

With most of the fuel oils and diesels in other posts, I believe you will find I have usually recommended checking the MSDS; but kerosene essentially has an “official” rating in NFPA 497.

 

[charlie]

So, if I were to ask the question, "Does the presence of kerosene make it a classified area?" Then the answer is a definite maybe, ya gotta check the MSDS ta see what the flash point is for that type for kerosene (I used to call it coal oil even though coal oil was a different material).