Underground Storage Tanks

An automatic shutoff device installed in an underground storage tank (UST) fill pipe can slow down and then stop the delivery when the product has reached a certain level in the tank. This device--sometimes simply called a "fill pipe device"--has one or two valves that are operated by a float mechanism. The illustration on the left below shows one type of automatic shutoff device. Note that the float is down and the fill valve is open. The illustration on the right below shows the same shutoff device with the float up and the fill valve closed.

Some automatic shutoff devices work in two stages. The first stage drastically reduces the flow of product to alert the driver that the UST is nearly full. The driver can then close the delivery valve and still have room in the UST for the product left in the delivery hose. If the driver does not pay attention and the liquid level rises higher, the valve closes completely and no more liquid can be delivered into the UST, leaving the driver with a delivery hose full of product.

Automatic Shutoff Device With The Float Down And The Fill Valve Open

Automatic Shutoff Device With The Float Up and The Fill Valve Closed

Return to the Preventing Underground Storage Tank Releases page.

Top of page