US Patent 7248791 Heater control

A tank heater control that will control a heater used for heating pressurised tanks over a broad range of temperatures. The system uses a sensor for providing a signal to a processor, in which the signal is indicative of flow of gas from the tank. The processor energizes the heater when gas flows from the tank. In various embodiments, the sensor may be a flow sensor on an outlet from the tank, temperature sensors that detect a difference in temperature of the tank from ambient temperature, or a pressure sensor on an outlet from the tank.