Patent ID: 7080546

Claim:
A system for detecting a leak in a double-walled fuel piping having an outer annular space that carries fuel from an underground storage tank in a service station environment, comprising: a pressure sensor that is coupled to the outer annular space to detect a vacuum level in the outer annular space; a sensing unit controller that is coupled to the pressure sensor to determine the vacuum level in the outer annular space; a submersible turbine pump that is fluidly coupled to the fuel in the underground storage tank to draw the fuel out of the underground storage tank wherein the submersible turbine pump is also coupled to the outer annular space; the submersible turbine pump creates a vacuum level in the outer annular space wherein the sensing unit controller determines the vacuum level in the outer annular space using the pressure sensor; a controller that is electrically coupled to the submersible turbine pump wherein the submersible turbine pump creates a defined initial threshold vacuum level in the outer annular space after receiving a test initiation signal from the controller, wherein the controller is electrically coupled to the sensing unit controller to receive the vacuum level in the outer annular space; and a drain valve coupled to the outer annular space to drain any leaked fuel out of the outer annular space wherein the controller or the sensing unit controller indicates a pass condition to a vacuum leak test when the drain valve is manually opened and the controller or sensing unit controller determines that the vacuum level in the outer annular space fell below a threshold vacuum level.