4WEH10HD4X/6EG12N9K4

The 4WEH10HD4X/6EG12N9K4 directional spool valve belongs to the WEH Directional Spool Valves series produced by Bosch Rexroth. Designed for hydraulic automation, it shifts flow paths in machinery circuits by means of an externally piloted mechanism. The valve is built in size NG10, provides a 4-way flow pattern, and offers two discrete spool positions for on-off or reversing control. Pilot actuation is handled by a 4WE6D valve that uses a single solenoid, while a concealed manual override identified as N9 allows local operation during commissioning or power loss. Electrical connection is made through a DIN EN 175301-803 plug coded K4, simplifying cabinet wiring. The pilot oil is supplied through port X so the main system pressure does not reach the control head, and the return oil exits through port Y, keeping pilot drainage separate from the tank line.

During operation, the valve withstands 350 bar at ports P, A, and B, enabling it to direct high-pressure flows typical of industrial presses or mobile work functions. When supplied from an external source, the hydraulic stage passes up to 160 l/min without excessive pressure drop, supporting medium-size actuator groups. The pilot circuit tolerates pressures up to 250 bar, yet it only needs 7 bar to shift the two-position spool, which limits energy use in the control loop. Port Y in the pilot return may see continuous pressures as high as 210 bar in direct-current service, so back-pressure filtration must be sized accordingly. Together these limits define safe boundaries for users who employ external pilot supply and return lines to separate control oil from the main circuit.