AUTOMATIC TANK GAUGING SYSTEM FOR YOUR FACILITY
An automatic tank gauge (ATG) is an electronic device, whose basic function is to monitor the fuel level in the tank over a period of time to see if the tank is leaking. It can also tell the facility operator what is going on inside the tank (example: fuel level, volume and temperature, water level and volume, high and low fuel level warnings).
ATG can be used to meet leak detection requirements in several ways:
• Monitoring the fuel level in the tank: This method of leak detection uses the basic ATG function of monitoring the fuel level over a period of time, when no fuel is added or removed from the tank, to see if the level is changing. This approach to leak detection is applicable to single-walled tanks only, and only if the ATG system has been registered with the DEP.
• Monitoring pressurized piping: This method of leak detection uses a special sensor that monitors the pressure inside the fuel-piping system between customer transactions, when the pressure should be stable. A loss of pressure in the piping may indicate a leak. The pressurized piping sensor (often called an electronic line leak detector) is an add-on device that plugs into the ATG console, just like a printer or scanner can be plugged into a computer. This approach to leak detection is applicable to single-walled pressurized piping only. (Regulatory requirements for monitoring pressurized piping as a method of leak detection are described in the TankSmart Piping: Pressurized Pumping Systems module.)
• Monitoring sensors in interstitial spaces: This method of leak detection uses liquid sensors that are installed in the interstitial spaces of double-walled tanks and piping. Like the pressurized-piping sensor, the interstitial sensor is an add-on device that plugs into the ATG console. This approach to leak detection is applicable to double-walled tanks and piping only. (Regulatory requirements for interstitial monitoring as a method of leak detection are described in the TankSmart double- walled tanks and piping modules.)
Tank gauging is needed wherever liquids are stored in large tanks. Such storage tanks are found in:
• Petrochemical industry
• Distribution terminals
• Pipeline terminals
• Fuel depots
• Air fueling storage at airports
• Chemical storage
How to read an ATG test report.?
The ATG test report typically provides you with basic information about product volume and temperature in the tank at the beginning and end of the test. It also prints out the results of the test, usually “pass” or “fail.” You may occasionally get an “inconclusive” result if conditions are not right for conducting a test over the testing period. If the result is “pass,” file the printout with your leak detection records and retain it onsite for 3 years. If the result is “fail,” you have evidence of a possible leak. You must report this to the DEP within 24 hours and investigate to figure out what happened. If the result is “inconclusive,” or you have a similar message indicating that a test was not successfully completed, you need to run another test. If you continue to get inconclusive test results, call your service technician to investigate and correct the problem.