Dynamic switching capacity:
States the pressure p and flow rate Q at which a directional valve can still be switched (Figure S 16). This is particularly important in the case of directly controlled, solenoid actuated valves. The electrical switching capacity is reached when the actuating element (e.g. solenoid or return spring) does not return the valve gate to the desired position.
This is often caused by excessive flow forces, which counteract the actuating forces of the solenoid or return spring.
Static switching capacity:
The static power limit of a directional valve is greatly dependent on the length of time for which the operating pressure is applied. Under the influence of pressure, time and other factors, such as contamination, an adhesive force is created between the piston and the housing, which counteracts the movement of the valve control spool.
When the directional valve is used frequently, the adhesive force is hardly noticeable. Only in the case of extended dwell times and high pressure will it cause the valve control spool to stick.
Figure S 16: Switching capacity