To provide a spool valve with reduced cavitation damage.

The spool valve 10 includes a valve spool 22 having a circumferential-shaped control edge. The spool valve further includes a means 50 for applying an intermittently or continuously rotation to the valve spool 22. A part of the control edge, which is subjected to interaction with a port 32 for controlling a fluid flow, is uniformly distributed in a circumferential region of the control edge.