Description：

A tap, manually controlled by the operator, allows inlet flow from V2 to pass  through the check valve to C2: as a result, the motion of the actuator (typically the  extension and positioning of an outrigger) happens under the operator’s direct  sight. The valve is normally closed (checked) and virtually leak-free from C2 to  V2 in order to prevent reverse motion. Flow outlet from C2 to V2 and reverse  motion (i.e. outrigger retraction or lifting up) is possible with manual tap open and  if sufficient pilot pressure is present at V1-C1 so that the pilot piston may push  the poppet from its seat.