Rexroth DBD20 direct operated G304/1 subplate mounting pressure adjustment relief valves are pressure relief function, when the flow changes in the valve, the size of open spool and spool position change accordingly, the spring force on the spool is much smaller because the small movement of spool position and little rigid spring.
When the inlet port opens, some partial oil from the cylinder flows to oil tank through relief valve, the pressure on the P oil port is stable and the system pressure changes as per the
pressure relief valves is the important indicator quality measurement of the pressure relief valve.
Rexroth DBD20 Direct Operated G304/1 Subplate Mounting Pressure Adjustment Relief Valve
The P port of pressure relief
valve can be adjustable by adjustment of bolts and spring force
The pressure relief valve is charged with pressure as a signal to change the amount of compression of the spring, changing the valve opening area of the through-flow and overflow to achieve the purpose of the fixed pressure. When the system pressure increases, the spool increased, increase in the flow area of the valve port, the overflow flow rate increases, thereby enabling the system pressure drop. The
relief valve internal balance and movement of the spool is constituted by this negative feedback effect is the basic principle of the fixed pressure, but also all the basic working principle of the constant
pressure valve.
The direct proportion to the size of the control pressure of the spring force, so if improve charged with pressure and available on the one hand to reduce the area of the spool to achieve, on the other hand, which is need to increase the spring force, due to structural constraints, the need to use more rigid of the springs.