Location |
Class I Group D division |
Extent of classified area |
| Tank vehicle and tank car:1 Loading through open dome ————————— |
1 |
Within 3 feet of edge of dome, extending in all directions. |
| 2 | Area between 3 feet and 5 feet from edge of dome, extending in all directions. | |
| Loading through bottom
connections with
atmospheric venting ———————— |
1 |
Within 3 feet of point of venting to atmosphere, extending in all directions. |
| 2 | Area between 3 feet and 5 feet from point of venting to atmosphere, extending in all directions. Also up to 18 inches above grade within a horizontal radius of 10 feet from point of loading connection. | |
| Loading through closed dome with atmospheric venting ———————— |
1 |
Within 3 feet of open end of vent, extending in all directions. |
| 2 | Area between 3 feet and 5 feet from open end of vent, extending in all directions. Also within 3 feet of edge of dome, extending in all directions. | |
| Loading through closed dome with vapor recovery ———————— |
2 |
Within 3 feet of point of connection of both fill and vapor lines, extending in all directions. |
| Bottom loading with vapor
recovery or any bottom unloading ——————— |
2 |
Within 3 feet of point of connections extending in all directions. Also up to 18 inches above grade within a horizontal radius of 10 feet from point of connection. |
| Drum and container filling: Outdoors, or indoors with adequate ventilation ——————— |
1 |
Within 3 feet of vent and fill opening, extending in all directions. |
| 2 | Area between 3 feet and 5 feet from vent or fill opening, extending in all directions. Also up to 18 inches above floor or grade level within a horizontal radius of 10 feet from vent or fill opening. | |
| Outdoors, or indoors with
adequate ventilation ——————— |
1 |
Within 3 feet of vent and fill opening, extending in all directions. |
| 2 | Area between 3 feet and 5 feet from vent or fill opening, extending in all directions. Also up to 18 inches above floor or grade level within a horizontal radius of 10 feet from vent or fill opening. | |
| Tank -- Aboveground: Shell, ends, or roof and dike area —————— |
2 |
Within 10 feet from shell, ends, or roof of tank, area inside dikes to level of top of dike. |
| Vent ————————— | 1 | Within 5 feet of open end of vent, extending in all directions. |
| 2 | Area between 5 feet and 10 feet from open end of vent, extending in all directions. | |
| Floating roof —————— | 1 | Area above the roof and within the shell. |
| Pits: Without mechanical ventilation ——————— |
1 |
Entire area within pit if any part is within a Division 1 or 2 classified area. |
| With mechanical ventilation ——————— |
2 |
Entire area within pit if any part is within a Division 1 or 2 classified area. |
| Containing valves, fittings or piping, and not within a Division 1 or 2 classified area —— |
2 |
Entire pit. |
| Pumps, bleeders, withdrawal fittings, meters and similar devices: Indoors ———————— |
2 |
Within 5 feet of any edge of such devices, extending in all directions. Also up to 3 feet above floor or grade level within 25 feet horizontally from any edge of such devices. |
| Outdoors ——————— | 2 | Within 3 feet of any edge of such devices, extending in all directions. Also up to 18 inches above grade level within 10 feet horizontally from any edge of such devices. |
| Storage and repair garage for tank vehicles ———————— |
1 |
All pits or spaces below floor level. |
| 2 | Area up to 18 inches above floor or grade level for entire storage or repair garage. | |
| Drainage ditches, separators, impounding basins ————————— |
2 |
Area up to 18 inches above ditch, separator or basin. Also up to 18 inches above grade within 15 feet horizontally from any edge. |
| Garages for other than tank vehicles —————— |
Ordinary |
If there is any opening to these rooms within the extent of an outdoor classified area, the entire room shall be classified the same as the area classification at the point of the opening. |
| Outdoor drum storage ————— | Ordinary | |
| Indoor warehousing where there is no flammable liquid transfer ———————— |
Ordinary |
If there is any opening to these rooms within the extent of an indoor classified area, the room shall be classified the same as if the wall, curb or partition did not exist. |
| Office and rest rooms ————— | Ordinary | |
| 1 | When classifying the extent of the area, consideration shall be given to the fact that tank cars or tank vehicles may be spotted at varying points. Therefore, the extremities of the loading or unloading positions shall be used. |