Patent ID: 6978661

Claim:
A fuel dispensing system that receives fuel pumped by a submersible turbine pump from an underground storage tank to dispense to a vehicle, comprising: a fuel dispenser, comprising: a housing; a hose; a nozzle coupled to said hose; a double-walled fuel supply piping having an inner piping and an outer piping located around said inner piping forming an interstitial space between said inner piping and said outer piping, wherein said double-walled fuel supply piping is fluidly coupled to said submersible turbine pump and is located internal to said housing and carries the fuel to said hose for dispensing; and a pressure sensor coupled to said interstitial space to detect a vacuum level in said interstitial space; a vacuum generator coupled to said interstitial space; and a controller that is coupled to said vacuum generator to cause said vacuum generator to generate a vacuum in said interstitial space wherein said controller is coupled to said pressure sensor to determine the vacuum level in said interstitial space.