it seems borderline absurd to insist the Building is still Division1, other than to avoid some sort of litigation.
It's impossible to argue since you're the only one who knows what we're talking about. The rest of us are flying blind.
However, the conclusion should be scientifically and legally defensible. If you don't think you're on solid enough ground to convince an expert in the field, it's probably incorrect.
If the situation really is that absurd, you should have no difficulty listing 6-12
specific reasons why you think the area isn't Div 1. Or Div 2. Or whatever.
This phrase:
> Where experience indicates that a particular design concept is sound, a more hazardous classification for similar installations may not be justified.
This would be more defensible if the "experience" cited:
- Included
specific experience with the actual design concept(s), construction, or other elements that make up this particular area; and
- Included experiments, measurements, or other empirical data; and
- The ventilation systems necessary for the area classification were redundant, alarmed, or otherwise failsafe; and
- Spanned a very long period of time; and
- so on and so on.
There are limits to experience as well. For example, it would be possible to take 10 years of gas detection measurements across a number of sites, plus a full review of the site records, and conclude the area(s) should be declassified from Div 2 to non-hazardous because there had never been a leak. And then go on to apply this to other similar sites.
But there still
could be a leak in the future, making both the initial conclusion and the subsequent application to other sites incorrect. Meaning experience doesn't trump basic area classification principles.
The moral of the story is that you do have to work the worst-case situation. It's not just what should happen, nor what's intended to happen. It's what
may happen. I'm not getting the right vibe in that respect, hence my concern.
In this context, what
may happen is unusually broad. Pressurized pipelines
are considered subject to leaks; containment systems
are presumed to fail; ventilation systems
could break down; malfunctions
do occur; spillage and leakage during transfers
does occur; mistakes and accidents
are presumed to happen. Usually, none of these items are expected, routine, or intended, and we actively work to prevent them, but they must be taken into consideration nevertheless.
I would highly recommend you scour the various area classification standards for something that is more defensible than simply a gut feeling that it "feels borderline absurd".
So how is this accurately communicated on an Area Classification drawing? Do I show the building as Division 1 with a note stating its really Division 2?
Area classification drawings show conclusions, not explanations. You would classify it as Div 2.
