Are microdistilleries considered Class 1 Div1 or Div 2

In most distillery operations (like the actual distilling) ethanol vapor is only marginally present as long as all gear is operating normally. I would think this makes it a Class 1 Div 2 occupancy. Is this an AHJ determination or has the code figured this one out yet? Since the recent fire at a Micro in NJ I suspect that the industry will be under greater scrutiny. Any experience out there would be helpful
THX
 

kwired

Electron manager
Location
NE Nebraska
In most distillery operations (like the actual distilling) ethanol vapor is only marginally present as long as all gear is operating normally. I would think this makes it a Class 1 Div 2 occupancy. Is this an AHJ determination or has the code figured this one out yet? Since the recent fire at a Micro in NJ I suspect that the industry will be under greater scrutiny. Any experience out there would be helpful
THX
I think whatever the reason for that fire will make a big difference in what if anything gets greater scrutiny as it relates to distillery operations.
 

Fulthrotl

~~Please excuse the mess. Sig under construction~~
In most distillery operations (like the actual distilling) ethanol vapor is only marginally present as long as all gear is operating normally. I would think this makes it a Class 1 Div 2 occupancy. Is this an AHJ determination or has the code figured this one out yet? Since the recent fire at a Micro in NJ I suspect that the industry will be under greater scrutiny. Any experience out there would be helpful
THX
i did a lighting cert on a vodka distilllary in LA.
the actual stills were separate from everything else.

they were CL1 DIV1

lights, pumps, everything was under that classification.

occupancy sensors and dimming controls, theoretically,
needed to be present. that wasn't gonna happen...
 

gadfly56

Senior Member
Location
New Jersey
Occupation
Professional Engineer, Fire & Life Safety
i did a lighting cert on a vodka distilllary in LA.
the actual stills were separate from everything else.

they were CL1 DIV1

lights, pumps, everything was under that classification.

occupancy sensors and dimming controls, theoretically,
needed to be present. that wasn't gonna happen...
I'm surprised it was Div 1 and not Div 2. Div 1 is for when the hazard is always present (like a dip tank). Div 2 is for when it is infrequently present or present only as a result of containment failure (tank or pipe leak).
 

rbalex

Moderator
Staff member
I'm surprised it was Div 1 and not Div 2. Div 1 is for when the hazard is always present (like a dip tank). Div 2 is for when it is infrequently present or present only as a result of containment failure (tank or pipe leak).
Not quite. Read the formal definition in Section 500.5(B)(1)(1). A hazardous atmosphere only needs to be present under normal operation; i.e., it, "... can exist under normal operating
conditions." Frequency or faulty operation is not a consideration. I can show a Division 1 location that may never actually be hazardous - the area around a relief vent that never actually "relieves."

This is one of the subtle differences between NEC Divisions and "classic" IEC Zones. Your example would be IEC Zone 0. While it would certainly be Division 1, there are several other cases for Division 1. In fact, see Sections 500.5(B)(1)(2) and (3) for cases of frequency or faulty operation.

As a side comment, Class II is incredibly unlikely. There is not enough milling of grain in the process to create sufficient "dust".

In order to correctly classify a particular still, one needs the full P&IDs, a material balance flow chart with process pressures and temperatures, plot plan, HVAC study, etc. It isn't a trivial activity. NFPA 497 [2017] outlines the usual procedure.
 

Fulthrotl

~~Please excuse the mess. Sig under construction~~
I'm surprised it was Div 1 and not Div 2. Div 1 is for when the hazard is always present (like a dip tank). Div 2 is for when it is infrequently present or present only as a result of containment failure (tank or pipe leak).
my understanding, and it's probably inaccurate, as it was learned
before the invention of combustion was this:

CL1 DIV1 is where explosive vapor may be present during manufacturing, as in a refinery.
CL1 DIV2 is where explosive vapor may be present during dispensing, as in a gas station.

CL 2 DIV 1&2 are the same, but for flammable liquid only. no vapor present.

CL 3 is flammable dust. no liquid or vapor.

how far off am i, bob?
 

rbalex

Moderator
Staff member
my understanding, and it's probably inaccurate, as it was learned
before the invention of combustion was this:

CL1 DIV1 is where explosive vapor may be present during manufacturing, as in a refinery.
CL1 DIV2 is where explosive vapor may be present during dispensing, as in a gas station.

CL 2 DIV 1&2 are the same, but for flammable liquid only. no vapor present.

CL 3 is flammable dust. no liquid or vapor.

how far off am i, bob?
Well, pretty far. See Section 500.5 for the basic descriptions.

Class I is gases and vapors.
Class II is dusts
Class III is fibers and flyings.

Basically, for Classes I and II (there is a little bit of variation on the themes):

Division 1 is based on possibility of volatiles existing under normal operation including maintenance operations and/or concurrent failures where an electrical failure will also result in the release of volatiles.
Division 2 is based on abnormal but not catastrophic failures.

For Class III there is virtually no difference as can be seen in the installation methods in Article 503.
 

gadfly56

Senior Member
Location
New Jersey
Occupation
Professional Engineer, Fire & Life Safety
my understanding, and it's probably inaccurate, as it was learned
before the invention of combustion was this:

CL1 DIV1 is where explosive vapor may be present during manufacturing, as in a refinery.
CL1 DIV2 is where explosive vapor may be present during dispensing, as in a gas station.

CL 2 DIV 1&2 are the same, but for flammable liquid only. no vapor present.

CL 3 is flammable dust. no liquid or vapor.

how far off am i, bob?
Found this in Rockwell's paper which is pretty good as far as I can tell:

Class Definition.jpg

and

Division Definition.jpg
 

rbalex

Moderator
Staff member
OK, you posted while I was fiddle-fart'n with the PNG's. Sheesh. :roll:
When US manufacturers attempt to explain IEC Zones, they should have someone (like me ;)) that has classified by both systems "vet" their paper. Division 1 is not the same as IEC Zone 0 and 1 combined. It is the same as NEC Zone 0 and 1 combined because CMP 14, "force fit" it to be.

IEC Zones are defined in terms of probability not possibility as NEC Divisions and Zones are. IEC Zone 1 is more of a glorified Division 2. See my paper for a more thorough comparison.
 

rbalex

Moderator
Staff member
When US manufacturers attempt to explain IEC Zones, they should have someone (like me ;)) that has classified by both systems "vet" their paper. Division 1 is not the same as IEC Zone 0 and 1 combined. It is the same as NEC Zone 0 and 1 combined because CMP 14, "force fit" it to be.

IEC Zones are defined in terms of probability not possibility as NEC Divisions and Zones are. IEC Zone 1 is more of a glorified Division 2. See my paper for a more thorough comparison.
One note to the above. The paper was written just as the ATEX Directive was being published so it is a bit outdated with respect to certifications. Otherwise, it is still pretty accurate.
 

StarCat

Senior Member
Location
Moab, UT USA
I'm surprised it was Div 1 and not Div 2. Div 1 is for when the hazard is always present (like a dip tank). Div 2 is for when it is infrequently present or present only as a result of containment failure (tank or pipe leak).
Your correct in that under normal and correct operational circumstance, Div.2 is more likely. I will suggest you go to ADI Forum and others that are trade specific and take note of some of the discussions.
This type of operation is undergoing unchecked growth, similar to what has happened in Microbrewing more than 1x. The setups are very diverse with respect to where they are being put and how they are being run. As you can imagine, there is all kind of incentive on certain ends to do things on the ULTRA Cheap, and everyone that " thinks " they are a Mechanic is attempting to reinvent the wheel.
If said operation is in a town or city the scrutiny is more than if its in a tin shed in the woods, but the supposed uniformity is not happening. I did not see much awareness during the final inspection of this facility. They were more interested in the sight of the shiny equipment. I had the opportunity to tour a larger production facility in another state of this type. The Electrical and Mechanical systems were a complete nightmare. The comments about ventilation are correct. In this case the system is 100% conditioned outside air in slight offset with exhaust air. We saw the need to add additional interlocks to the process after seeing what can go wrong in real world terms. The process area is supposed to have in this case an ethanol sensor that can be used to trigger an alarm and also shutdown process. How far this goes is likely down to the local inspector and his interpretation of the dangers involved. The problem with Technology is laypersons mostly do not understand or have a significant grasp of what can go wrong, and what not to do.
 
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