Proportional directional valve Bosch Rexroth art. R978012423

Externally pilot-operated proportional directional valves Types 4WRH… and 5WRH.52…
Valves of type 4WRH… are pilot-operated proportional directional valves for external actuation via pressure control valves.
Set-up:
The valve basically consists of:
Main valve (10) with main control spool (11) and centering spring (12)
Diversion plate (16)
Function:
The diversion plate (16) connects control port A to the pressure chamber (13) with port Y and control port B with port X.
If port X is pressurized, the main control spool (11) is moved to the right (P to B and A to T). If port Y is pressurized, the main control spool is moved to the left (P to A and B to T).
The pilot pressure at the main valve must not exceed 25 bar (16 bar with NG52)!
Notice:
Due to the design principle, internal leakage which may increase over the life cycle is inherent to the valves.