Pressure means storage device

Pressure fluid accumulator, comprising:

• a housing having its interior subdivided into first and second chambers by a media-separating element, wherein the first chamber is filled with a gas and the second chamber is filled with a liquid,
• a hydraulic port coupled to said housing,
• a bottom valve coupled to said hydraulic port, said bottom valve including a first bore having parallel side walls,
• a closure member adapted to reciprocate within said bottom valve first bore, wherein said closure member is operable by the media-separating element and which permits filling the second chamber with fluid from an evacuation port of said bottom valve and prevents complete evacuation of the second chamber, wherein the closure member includes a first cup seal disposed around an outer periphery of said closure member, wherein said cup engages and slides along the parallel side walls of the first bore to effect a hydraulic seal between the second chamber and the evacuation port, and wherein the closure member is movable within said first bore by the media-separating element.