Abstract: A valve arrangement for hydraulic control of a piston-cylinder of a power switch contains a main stage having a first main valve and a second main valve, and a pilot stage having at least one pilot valve. In order to permit the first main valve to remain securely in the opened state, even in the event of pressure oscillations, the main valve has a total of four control surfaces, of which a second and a third control surface operate in a closing manner and a fourth control surface operates in an opening manner. For this purpose, the second control surface is connected to the high-pressure line, the third control surface is connected to the low-pressure line, and the fourth control surface is connected to the output-side valve connection of the first main valve.

Abstract: A valve arrangement for hydraulic control of a piston-cylinder of a power switch (7) contains a main stage having a first main valve (31) and a second main valve (32), and a pilot stage having at least one pilot valve (3, 4). In order to permit the first main valve (31) to remain securely in the opened state, even in the event of pressure oscillations, the main valve has a total of four control surfaces, of which a second (F5) and a third (F6) control surface operate in a closing manner and a fourth control surface (F7) operates in an opening manner. For this purpose, the second control surface (F5) is connected to the high-pressure line (P), the third control surface (F6) is connected to the low-pressure line (T), and the fourth control surface (F7) is connected to the output-side valve connection (35) of the first main valve (31).