Conventional UST's are filled by means of a bl
black pipe elbow that projects upwardly from the tank and terminates with a fill pipe adapter, in a containment vessel designed to contain spilled fuel. The containment vessel has an opening covered by a manhole that provides access to the fill pipe and fill pipe adapter.
The fill pipe adapter: 1) permits coupling with the drop elbow of a hose of a tanker truck thereby preventing any leakage into the environment, and; 2) prevents dirt and other bits of foreign matter from dropping into the UST through the fill pipe. Conventional UST's also have a vapor pipe so that as the fuel is dropped into the UST, the displaced vapor is transferred to the tanker truck, replacing the volume of dropped fuel.
