Overfill prevention is one of the many important components of storage tank management. Essentially, overfill prevention involves monitoring the tank before, during, and after delivery to ensure that no product is spilled. This is done both through human monitoring, as well as to overfill prevention devices present in the tank itself. Learn more about overfill prevention in our blog.
Storage Tank Management: Overfill Prevention
The 3 Methods of Overfill Prevention
The overfill alarm goes off when the product reaches a certain level in the tank during delivery. The alarm goes off with enough time to allow the delivery driver to stop product flow and prevent a release.
Automatic Shutoff Device (Flapper Valve)
Automatic shutoff devices also work by monitoring the level of the product during delivery. But instead of alerting the operator, the device automatically stops the flow of the product once it reaches a certain point. This is known as a flapper valve and is located in the drop tube in the fill pipe riser.
Flow Restrictor (Ball Float Valve)
This device works by slowing (but not stopping completely) the flow of the product once it reaches a certain level in the tank. The device is a ball float valve that prevents vapors from leaving the tank once the product reaches a certain level. Because the vapors cannot escape, it’s more difficult for the product to enter to replace them. “The top of the tank must be tight during deliveries so that vapors can not escape,” according to the EPA.
It’s important to note that “Ball float valves should not be installed on tanks with suction piping, pumped delivery, coaxial Stage I vapor recovery, remote fill pipes with gauge openings, or when shutoff valves are used for overfill prevention.”
Additional Storage Tank Management for Overfill Prevention
- Only order enough product to fill 90% of the tank.
- Periodically inspect overfill prevention devices to ensure they are in proper working order.
- “Pay close attention before, during, and after product delivery to help the delivery person avoid overfilling your UST.”
To learn more about storage tank management, contact Tanks Direct today.