compressed lubricants room

[malachi constant]

Hi all,

I am the electrical engineer on a project under construction trying to verify whether a couple rooms require classification.

1. Compressed Lubricants Room. Contains the following materials: antifreeze, transmission fluid, diesel exhaust fluid, gear oil SAE 80W-90, lubricating grease, motor oil SAE 15W-40, windshield washer fluid. Vehicles drive into an adjacent bay and pump fluids into the appropriate container.

2. Compressor Room. Contains acetylene and oxygen tanks. These tanks are used to supply welding equipment. They are filled off-site, and once brought into this room are hard-piped into some lines, or are on a cart that allows them to travel around the maintenance bay where welding occurs.

Both spaces have adequate mechanical ventilation to prevent buildup of gases.

The issued drawings call for these rooms to be fully classified at Class 1 Div 2. I think per 500.5 (B)(2)(2) this is likely correct. The contractor has asked us to verify so I thought I would get a second opinion here. Any comments?

Thanks!

 

[IntrinsicSafety]

It's pretty difficult to say for sure from just a description.

However, from NFPA 497:

"5.1.1.2 Class I, Division 2.

A Class I, Division 2 location is a location

(1) In which volatile flammable gases, flammable liquid–
produced vapors, or combustible liquid–produced vapors
are handled, processed, or used, but in which the liquids,
vapors, or gases will normally be confined within closed
containers or closed systems from which they can escape
only in case of accidental rupture or breakdown of such
containers or systems or in case of abnormal operation of
equipment,"

"5.3.2 Division 2 Classified Locations. The criterion for a Division
2 location is whether the location is likely to have ignitible
mixtures present only under abnormal conditions. The term
abnormal is used here in a limited sense and does not include a
major catastrophe.
5.3.2.1 For example, consider a vessel containing liquid
hydrocarbons (the source) that releases combustible material
only under abnormal conditions. In this case, there is no Division
1 location because the vessel is normally tight. To release
vapor, the vessel would have to leak, and that would be abnormal.
Thus, the vessel is surrounded by a Division 2 location."

Sounds like both your situations may fall under these descriptions.

For the liquids, I'd look first at their flash points. If they are not stored/handled/used above the flash point, there may be no ignitable concentration in the air, and you can call it unclassified. See 4.2.7.1 of NFPA 497. Calling it Div 2 would be safe but possibly over-conservative.

The gases are tougher and they're probably going to result in a Div 2 location, at least if the ventilation is adequate. See Fig 5.10.14 and 5.10.16 of NFPA 497 for starters. (Make sure your ventilation is considered "adequate" per the standard.)

Also, if memory serves, there are additional specific codes for rooms where compressed gases are stored; you should find those to verify. They might be OSHA codes or something; I can't recall.

Hope this helps.

 

[GoldDigger]

Lubricating oils, etc. may be pressurized (under pressure ton aid dispensing) but are generally considered not themselves be compressible.
Pressurizing hydrocarbons with air at high enough pressure can lead to an ignition hazard all by itself. (Higher than the pressures used for dispensing, of course.)

Sent from my XT1585 using Tapatalk

 

[rbalex]

IntrinsicSafety correctly cited NFPA 497 [2017 latest edition] as good place to start. In addition to the Figures cited (I believe he meant Fig 5.10.15 instead of 5.10.14), I would give Section 5.5 a careful review, particularly 5.5.1(1). If you do have acetylene, you have a real bear on your hands. See its listing in Table 4.4.2.

I do NOT want to give the impression that the rest of Part 5 can be ignored either. If necessary, get a consultant familiar with your type of installation. The total volume of the cylinders is also an important consideration. See NFPA 30 [2015 latest edition]

 

[IntrinsicSafety]

Bob is right as usual: Fig 5.10.15 (along with corresponding section 5.10.15), or section / Figure 5.10.16 for heavier than air.

[Edit]: May as well point out that when evaluating area classifications, you don't have to stick with just the NFPA standards. You can use any other published information that is useful to the cause to supplement or additionally justify the NFPA method(s).

FWIW I do agree with Bob. When in doubt, get a specialist to look at it. Area classification is one of those things that requires experience.

 

[rbalex]

Bob is right as usual: Fig 5.10.15 (along with corresponding section 5.10.15), or section / Figure 5.10.16 for heavier than air.

[Edit]: May as well point out that when evaluating area classifications, you don't have to stick with just the NFPA standards. You can use any other published information that is useful to the cause to supplement or additionally justify the NFPA method(s).

FWIW I do agree with Bob. When in doubt, get a specialist to look at it. Area classification is one of those things that requires experience.

While the underlined statement is true, I would caution that the source should be a recognized industry standard such as AGA XF0277 unless it is ANSI sanctioned; otherwise, it may run afoul of the AHJ, especially if that AHJ is OSHA. Several readily acceptable reference standards are listed in the Informational Notes of Section 500.4(B). This list is NOT exclusive though; in fact, the two major general standards, NFPA 497 and API RP 500 recognize experience alone may be justified.