RELIEF VALVE MECHANISM WITH A PILOT

Port a is connected to the high-pressure main and ports b and c to the low-pressure main. When the pressure of the fluid in port a is within the preset value, pilot valve spool 2 is held by helical spring 4 in its lower position and through slots d it connects chamber f, above valve spool 1, to the high-pressure main. By means of land e of pilot valve spool 2, chamber f is disconnected from the lo…