Adjustable pressure relief valve

An adjustable pressure relief valve for generating a pressure output signal corresponding to one of an input valve and a signal in a valve connection, wherein the pressure relief valve comprises:

• a duplex valve which includes a distributing valve housing of a standard way-valve design equipped with not greater than four connections, said housing having a piston bore wherein an exchangeable valve core is positioned in said bore, said valve core being equipped on opposite sides thereof with a separately controllable seat valve element and which is selectively closable on one side thereof against the pressure in said first and second output connections wherein individually adjustable pressure systems are connected to each of said opposite sides of said valve and wherein said valve core comprises a sleeve-shaped element which comprises on an inside portion thereof two valve seats that are connected by separate control oil ducts to a central pressure connection area.