Overfill Protection on Above Ground Flammable Storage Tank

[tomb-mich]

IFC 5704.2.9.7.5 requires overfill protection as follows:

1. The overfill prevention system shall include the following:
1.1. An independent means of notifying the person filling the tank that the fluid level has reached 90 percent of tank capacity by providing an audible or visual alarm signal, providing a tank level gauge marked at 90 percent of tank capacity, or other approved means.
1.2. Automatic shut off of the flow of fuel to the tank when the quantity of liquid in the tank reaches 95 percent of tank capacity. For rigid hose fuel-delivery systems, an approved means shall be provided to empty the fill hose into the tank after the automatic shutoff device is activated.

The client has a level sensor that goes to a Delta V panel and annunciates a strobe light and horn at the fill location at 90% full. A separate radar level sensor closes the fill automatically if it reaches 95%.

My understanding is that the audible and/or visual signals at 90% comprise the "independent means of notifying the person filling the tank". Am I correct?

 

[RBK]

Correct. They are using the first option (audible or visual alarm). A tank level gauge is another acceptable method in the IFC.