Abstract: A transformer including a transformer tank, an expansion tank, and piping connecting the tanks enabling liquid to flow there between. The piping includes a valve configured for liquid to flow from the transformer to the expansion tank when the pressure is above a predefined first threshold and for preventing the liquid to flow from the transformer to the expansion tank when the pressure is below the first threshold. The valve is also configured for liquid to flow from the expansion to the transformer tank when the pressure is below a predefined second threshold and for preventing the liquid to flow from the expansion to the transformer tank when the pressure is above the predefined second threshold.

Abstract: A transformer including a transformer tank, an expansion tank, and piping connecting the tanks enabling liquid to flow there between. The piping includes a valve configured for liquid to flow from the transformer to the expansion tank when the pressure is above a predefined first threshold and for preventing the liquid to flow from the transformer to the expansion tank when the pressure is below the first threshold. The valve is also configured for liquid to flow from the expansion to the transformer tank when the pressure is below a predefined second threshold and for preventing the liquid to flow from the expansion to the transformer tank when the pressure is above the predefined second threshold.