What is an overfill prevention device for storage tanks?

For any underground storage tank (UST) that is filled with more than 25 gallons of product at once, overfill prevention is mandatory. An overfill prevention system is installed within the tank to halt or reduce the flow of product, or to alert the delivery person during delivery, before the tank reaches capacity.

What is the function of overfill prevention equipment?

Overfill prevention devices serve the purpose of halting or limiting the flow of product into the tank, or notifying the transfer operator before the tank is filled to its maximum capacity.

How does an overfill prevention valve work?

The second stage of automatic overfill prevention takes place if the fuel delivery person fails to stop the flow from the tank. The float arm will continue to rise and shut the secondary orifice, ultimately shutting off the flow completely to prevent fuel from reaching the top of the tank.

During the first stage of overfill prevention, known as overfill detection, the float arm will push the valve flap beyond the protective bend in the upper tube. This action will immediately seal the main valve flap closed due to fuel flow. The fuel delivery person is alerted of the tank nearing full capacity when the hose jumps. To empty the hose, the fuel flow is reduced to 3-5 GPM through the secondary orifice.

What Happens When Tank Overfill Protection Systems Fail?

The consequences of having inadequate fuel management systems or mobile-equipment tank overfill protection solutions can be more severe than just financial losses. It can pose a threat to the safety of your people, employees, and acquaintances, surpassing any environmental concerns. Filling a diesel tank beyond capacity can cause internal pressure to build up, leading to the release of flammable liquids, sprays, or vapors that can ignite. The simplest and most cost-effective way to prevent such avoidable and catastrophic situations is to install and uphold an appropriate Tank Overfill Protection System.

Features & Benefits:

  • Low battery alarm.
  • Adjustable sensor level.
  • A standard 2 inch BSP fitting provided for mounting. Optional mounting fittings are available upon request.