Classification around gasoline dispenser on top of tank

[SD Inspector]

Here is my question.
I have a big bulk gasoline tank on a farm, the dispenser sits on top of the tank.
The tank is in a containment area with a 3 foot high dike all around it. The dispenser
and tank is about 2 feet inside the containment area. The classification around a dispenser
is 18 inches out on all sides of the dispenser from top of dispenser to grade, then 20 feet in
all directions up to 18 inches above the ground. With the dispenser inside the containment dike
is there still a div. 2 outside the dike, 20 feet in all directions? Even though the dispenser hose
can fill vehicles and containers outside the dike.

I have seen this a lot, and do not know how this should be classified.

Dan

 

[rbalex]

You have two Articles to deal with here: Arts 514 and 515. However, the electrical area classification inside and outside the dike is ultimately the same.

As you have described it, the classification inside the dike is Class I, Division 1 since the height of the dike is greater than the distance from the tank. See Table 514.3(B)(1), Tank, Aboveground and Table 515.3, Tank - aboveground.

The "upside" is that beyond the dike is unclassified 10' beyond the dike. Typically there will be an 18" Division 2 above the dike and above grade. There are still potential underground wiring implications. [Section 514.8]

With modern vapor recovery systems at dispenser heads there is little need to classify around them.