Abstract: A fluid storage-expulsion system composed of a tank having two poles and being shaped by one or more surfaces of revolution, the tank having a diametral plane and being substantially symmetrical thereabout, a fluid inlet-outlet on one side of the diametral plane, a pressurant inlet on the other side of the diametral plane and a reversible expulsion metallic diaphragm having a pole adjacent the pressurant inlet and conforming substantially to the interior shape of the tank on one side of the diametral plane, the tank being under tension and the diaphragm being under compression, whereby to prevent the diaphragm from uncontrolled buckling and to cause the diaphragm to reverse in an orderly fashion by flexural yielding upon actuation thereof by the pressurant introduced through the pressurant inlet. A method for producing such storage and expulsion system is also disclosed.