A high pressure separator/accumulator that uses dual bellows is provided. The dual bellows are not mechanically linked but rather operationally coupled through a fluid medium. The high pressure separators includes a housing defining a first internal space. The housing is in fluid communication with a first fluid system and a second fluid system. A first bellows is coupled to the interior of the separator and defines a space with a variable volume. The space is in fluid communication with the first fluid system. A second bellows is coupled to the interior of the separator, generally opposed to the first bellows, and defines a space with a variable volume. The space is in fluid communication with the second fluid system. The two fluid systems, however, are isolated from each other by the separator. The housing is charged with a fluid medium that transmits force between the first and second bellows.