Parker-Hannifin Corporation
NEGATIVE SPACE FUEL TANK GAUGING SYSTEM AND ULLAGE GAS CONTROL

Abstract:

A fuel gauging system for a fuel tank containing fuel and an ullage gas in an ullage of the tank. The fuel gauging system pressurizes/depressurizes the ullage gas and measures changes in conditions of the ullage gas to determine ullage gas volume and thus volume of the fuel. The system may infer one or more values in the volume calculation to reduce the number of measurements involved. The inferred values may come from known operating characteristics of an inerting system integrated with the fuel gauging system. The system may use a control valve that operates within the limits of a climb-dive valve to generate the system response. The control valve may control delivering or receiving ullage gas from another tank to preserve the ullage gas. An inerting system may be integrated into such a paired-tank fuel gauging system.