4WEH10E4X/6EW110N9ETK4/B10 CSA

The 4WEH10E4X/6EW110N9ETK4/B10 CSA valve is produced by Bosch Rexroth within the WEH Directional Spool Valves series. It directs hydraulic flow in automated circuits by shifting a spool with electro-hydraulic actuation. The NG10 nominal size establishes the mounting envelope and matches medium-frame manifolds in power units. A maximum operating pressure of 280 bar on ports P, A, and B allows the valve to work in high-pressure circuits found in presses and injection machines. The unit passes up to 160 l/min, so it can control cylinders and motors with significant flow demand without excessive pressure drop. An ISO 4401-05-05-0-05 porting pattern aligns the subplate holes for straightforward replacement of older NG10 valves. Internal pilot oil supply, indicated by the letter E, feeds the pilot stage directly from the main pressure port, eliminating external pilot lines. Internal pilot oil return, denoted by T, sends pilot exhaust back through the body to reduce leakage points. A concealed manual override, coded N9, lets maintenance personnel shift the spool during commissioning or in the event of power loss without exposing moving parts.

For reliable service the valve must be installed with hydraulic fluid filtered to ISO 4406 class 20/18/15, which limits particle contamination that could score the spool. Electrical power reaches the pilot solenoids through a DIN EN 175301-803 K4 connector, allowing quick removal during maintenance. The pilot stage tolerates a maximum pressure of 250 bar, while the internal drain passage marked y is limited to 160 bar, so system designers must keep back-pressure below this value. Normal operation of the spring-centered model requires at least 12 bar pilot pressure to shift the spool consistently. Four M6 × 45 screws in accordance with ISO 4762 secure the body to the subplate, and each screw should be tightened to 12.5 Nm to maintain sealing without distorting the casting. When installed as specified, the mean time to dangerous failure for the WEH design reaches 100 years, supporting long-term machine safety targets.