Flow rate which continues to flow for proportional valves, high response proportional valves and servo valves when the consumer ports are closed and at a system pressure p o. It results from the leakage around the control spool in the centre position (zero or positive overlap/underlap) and is pressure-controlled.
With servo valves, the quiescent flow comprises the flow for the first stage and the leakage for the second stage. It changes in line with the inlet pressure and the input current and reaches its maximum level at hydraulic zero (Figure N 7).
Figure N 7: Quiescent flow for a continuously adjustable valve with zero overlap and positive overlap/underlap