What would be the hazardous classification of this application. Paint spray booth, open on one side, three walls, and painting taking place 2 hours a day maybe a couple of times a week. It is well ventalated. The booth is about 20 feet by 20 feet with about 15 foot ceilings. My first time in this forum and thanks for your help
Spray Booth,
- Thread starter emg0fnv
- Start date
- Status
- Location
- Mission Viejo, CA
- Occupation
- Professional Electrical Engineer
From your description so far, it is Division 1. Since you mentioned it was paint I assume it is Class I. See Section 516.3(B) (1). The frequency of use and ventilation are irrelevant in this case.
Pierre C Belarge
Senior Member
- Location
- Westchester County, New York
I am curious...was this a manufactured spray booth or something built at the site?
megloff11x
Senior Member
Powder coating shows up under NFPA 33, a really thin book that NFPA will sell you for about $40 (a buck a page).
It also shows up in the NEC under Article 516.
Basically the immediate spray area is Class II Division 1 because flammable powder is in the air and dust is everywhere. If you are using a non-combustible powder (passes ASTM E 136 - another thin but expensive book) you can be exempt, but I know of no powder that passes this. It has to not ignite at 700 deg C (about 1300F) in some special tube test.
Nearby (ambiguous) is Division 2.
Powder coating is normally done in a non-sparky area (even though electrostatic guns are usually involved) and then the coated parts are carted to the oven.
The spray booth should suck the dust out vigorously and completely.
I've had to deal with this kind of installation and it is as prohibitive as it gets.
How often you spray is irrelevant as the powder builds up over time as creosite in a chimney.
This is more dangerous than it seems and I doubt if even a small fraction of powder coating set ups adhere to the rules.
Don't get in over your head. Make the booth vendor stand behind the system or find one who will.
Don't despair. Every gas station is Class I Dvision 1, and they have that figured out despite smoking customers and owners who stick non-listed for Hazloc pop machines out next to the pumps.
Matt
It also shows up in the NEC under Article 516.
Basically the immediate spray area is Class II Division 1 because flammable powder is in the air and dust is everywhere. If you are using a non-combustible powder (passes ASTM E 136 - another thin but expensive book) you can be exempt, but I know of no powder that passes this. It has to not ignite at 700 deg C (about 1300F) in some special tube test.
Nearby (ambiguous) is Division 2.
Powder coating is normally done in a non-sparky area (even though electrostatic guns are usually involved) and then the coated parts are carted to the oven.
The spray booth should suck the dust out vigorously and completely.
I've had to deal with this kind of installation and it is as prohibitive as it gets.
How often you spray is irrelevant as the powder builds up over time as creosite in a chimney.
This is more dangerous than it seems and I doubt if even a small fraction of powder coating set ups adhere to the rules.
Don't get in over your head. Make the booth vendor stand behind the system or find one who will.
Don't despair. Every gas station is Class I Dvision 1, and they have that figured out despite smoking customers and owners who stick non-listed for Hazloc pop machines out next to the pumps.
Matt
- Status