The series of Daewoo excavator DH55 cartridge type low pressure hydraulic relief valve is to rely on the direct effect of the oil pressure in the system in equilibrium situation, with the spring force on the spool to control the opening and closing movement of the spool.
Inlet pressure oil into the spool at the bottom of the spool orifice through into the oil pressure is low, the spool is in the lower end of the position under the action of the spring will be separated from the inlet and the oil outlet to the tank for overflow state
Hydraulic thrust spool suffered more than the pressing force of the spring, the spool lift ports and connectivity, so that the excess oil to drain back into the oil tank that overflow into the oil pressure rises. The role of the orifice is to enhance the stationarity of the valve work, reduce the pulsation of hydraulic pressure, the pressing force of the spring can be adjusted by adjusting nut.
