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Classification areas, i.e. Class 1, Division 1
- Thread starter nmui
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Re: Classification areas, i.e. Class 1, Division 1
Assuming you are talking about a gas station tank, Table 514.3(B)(1) indicates the circular area within 10 feet of the fill opening of the tank, up to 18 inches above grade is Class I, Div. 2. Around the vent, a hemisphere of radius 3 feet is Class I, Div. 1, and the remainder of a hemisphere of radius 5 feet would be classified Class I, Div. 2. Also any pit, box, or space below these areas is classified Class I, Div. 1. All other areas would not be classified by the presence of the tank.
Assuming you are talking about a gas station tank, Table 514.3(B)(1) indicates the circular area within 10 feet of the fill opening of the tank, up to 18 inches above grade is Class I, Div. 2. Around the vent, a hemisphere of radius 3 feet is Class I, Div. 1, and the remainder of a hemisphere of radius 5 feet would be classified Class I, Div. 2. Also any pit, box, or space below these areas is classified Class I, Div. 1. All other areas would not be classified by the presence of the tank.
Re: Classification areas, i.e. Class 1, Division 1
Another question. This one is for a sump pit that may contain hazardous gases in an emergency, but not under normal operating conditions. The pit opens into a open enviornment, so is the area right outside the pit considered unclassified or would it be the Class 1, Division 2 bubble of 18 inches above in a radius of 10 feet?
Another question. This one is for a sump pit that may contain hazardous gases in an emergency, but not under normal operating conditions. The pit opens into a open enviornment, so is the area right outside the pit considered unclassified or would it be the Class 1, Division 2 bubble of 18 inches above in a radius of 10 feet?
friebel
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- Pennsville, N.J.
Re: Classification areas, i.e. Class 1, Division 1
To: nmui,In answer to your question about a pit with an electrical classification of 1-1-D. You can never go from a 1-1-D area into a non-classified area. You need to go into a 1-2-D area for a certain distance, and then you can go to a non-classified area. Now all of these distances depends upon the material, density, flash point, Auto Ignition temperature, Flammability Limits Percent by Volume in Air.
This all sounds complex, and it is. You need to know what you are doing when you classify an area, and the distances for classification.
When we classify an area, we will have a Chemical type person,(Chemist or Chemical engineer) an Electrical Engineer, or suitable knowlegable electrical person, and possibly a safety engineer.
This is spelled out in NFPA 30 and Section 1910.106 of the OSHA regulations.
If I can be of any help give me a private message.
To: nmui,In answer to your question about a pit with an electrical classification of 1-1-D. You can never go from a 1-1-D area into a non-classified area. You need to go into a 1-2-D area for a certain distance, and then you can go to a non-classified area. Now all of these distances depends upon the material, density, flash point, Auto Ignition temperature, Flammability Limits Percent by Volume in Air.
This all sounds complex, and it is. You need to know what you are doing when you classify an area, and the distances for classification.
When we classify an area, we will have a Chemical type person,(Chemist or Chemical engineer) an Electrical Engineer, or suitable knowlegable electrical person, and possibly a safety engineer.
This is spelled out in NFPA 30 and Section 1910.106 of the OSHA regulations.
If I can be of any help give me a private message.
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