Control function

The Pressure reducing valve reduces the primary pressure on port P to a previously set secondary pressure in port A. For primary pressures up to 400 bar, reduced pressures can be set between 20 and 380 bar. A hydraulic accumulator (6), which is prefi lled with nitrogen on the gas side, serves as a preload element. The pressure in the hydraulic accumulator (6) is set by the control pressure (X) by opening the pilot valve (4). Readjustment of the set pressure is possible by releasing the pressure via the pilot valve (5) into the tank connection (T). In the basic valve position, pressure medium fl ows through the valve seat (2) from primary side (P) to secondary side (A). The pressure in the hydraulic accumulator (6) acts to surface (F1) of piston (3). The primary pressure acts to surface F2 and F3. As long as the primary pressure is lower than the set pressure, the valve bolt (1) remains open since the surface F1 to F2-F3 are balanced.

When the set pressure in the hydraulic accumulator is reached or exceeded, the piston (3) and thus the valve bolt (1) moves and closes the open valve seat. In closed position, the primary pressure acts to surface (4). The surface F3 is just as large as the surface F4 so that the secondary pressure is kept constant by permanently opening and closing the valve bolt (1). The pressure relief valve (7) prevents an unwanted pressure increase in the event of leaks at the valve seat. The excess pressure is discharged via the tank connection (T).