Abstract: The invention concerns a pressure tank comprising a rigid casing having opposite first and second orifices, and an elastically deformable separator extending inside the casing between the two orifices and subdividing the inside volume of the casing into variable-volume first and second compartments. The second compartment communicates with a hydraulic circuit via the second orifice. The first compartment is filled with elastically deformable solid elements, and the resulting assembly behaves like a spring. In the non-compressed state, the overall volume of the elastically deformable solid elements is substantially equal to the volume of the first compartment when the separator is at rest.