Class I Div II extensions?

[MD88]

Hello,

A building I'm working on has a painting room that is rated as Class I Div II. The booth has a number of doors leading to and from it, so would this classification extend to those rooms as well? The room has a substantial exhaust system so I don't think it'd be a problem, but I'm not the one stamping the drawings

Does anyone have a code reference explaining under what circumstances the ratings would extend to connecting rooms?

Thanks!!

 

[benaround]

Have you looked thru Article 516 ?

 

[weressl]

Hello,

A building I'm working on has a painting room that is rated as Class I Div II. The booth has a number of doors leading to and from it, so would this classification extend to those rooms as well? The room has a substantial exhaust system so I don't think it'd be a problem, but I'm not the one stamping the drawings

Does anyone have a code reference explaining under what circumstances the ratings would extend to connecting rooms?

Thanks!!

It is Class I, Division 2.

NFPA 497 gives you guidance of how to determine classification of areas.
NFPA 496 gives you guidance how to lower the extent or level of classification by purging, wenting.

In general; enclosed areas would always be Division 1, unless continous ventilation assures that the explosive mixture of fuel/air can only occur due to process failure. If this ventilation creates a negative pressure in relationship to adjacent accessible rooms, then those rooms may be considered non-hazardous. Note that I am describing a general approach in a short summary, the actual classification should be performed by professionals, documented and kept on file.

 

[MD88]

Hello,

I've actually found my answer. A paint booth is a special case (at least here in Canada). The interior of the booth is Class 1 Div 1, and 3' in all directions from any opening is Class 1 Div 2. There's a caveat that the booth must have "adequate ventilation" and ANSI/API 505 defines what that means.