4WEH22C7X/6EG24N9SK4

The 4WEH22C7X/6EG24N9SK4 directional valve belongs to the WEH Directional Spool Valves series and is produced by Bosch Rexroth for automated hydraulic circuits. It switches flow paths with an NG25 nominal size, so the channel dimensions support medium-to-high flow rates in mobile and industrial machinery. A porting pattern conforming to ISO 4401-08-08-0-05 allows direct exchange with other NG25 subplates, and the subplate mounting interface keeps the body rigid while simplifying manifold service. Installation uses six M12 × 60 screws tightened to 100 Nm to maintain gasket compression under load. The solenoids operate from a 24 V DC supply, providing consistent actuation from common control panels. Pilot oil is taken internally from pressure port P, which eliminates separate pilot lines, while the return is routed externally through port Y to keep pilot chambers at low back-pressure. Acceptable fluid viscosity spans 2.8 to 500 mm²/s to accommodate both low-temperature start-up and warmed-up operating oil.

The valve withstands system working pressures up to 280 bar on ports P, A, and B, enabling it to direct high-force actuator flows without seat distortion. Back-pressure on the tank and external pilot return lines can reach 250 bar, so the housing and seals are sized for elevated return loads. The pilot stage tolerates a maximum of 210 bar, giving designers freedom to use full system pressure for control. For a three-position spring-center spool, reliable shifting begins at a minimum pilot pressure of 10.5 bar, while internal pilot operation requires at least 4.5 bar so low-pressure standby modes remain possible. Hydraulic oil may be used from –20 °C to +80 °C when NBR seals are fitted, covering cold starts and high ambient sites. Component service life depends on maintaining fluid cleanliness at ISO 4406 class 20/18/15 or better to reduce spool wear and prevent silting.