4WEH22HD7X/6EG24N9ETK4/B08

The 4WEH22HD7X/6EG24N9ETK4/B08 directional spool valve is produced by Bosch Rexroth as part of the WEH Directional Spool Valves series. It directs hydraulic flow in automated circuits through electro-hydraulic actuation, allowing an electrical signal to shift the spool without manual force. The valve is sized NG25, identified in the catalog as W.H 22, so it fits manifolds built for 25 mm nominal passages. The spool follows symbol D and offers two hydraulic end positions, delivering binary flow states for extend-and-retract cycles. System lines A and B can be pressurized up to 350 bar, supporting high-pressure industrial power units, and the pilot stage needs at least 8 bar to move the main spool reliably. Both the pilot oil supply and return are internal, coded ET, so no external drain or separate pilot feed lines are necessary. A throttle insert with a 0.8 mm orifice tagged B08 is integrated to moderate pilot flow and damp switching shocks.

The mounting face follows the ISO 4401-08-08-0-05 porting pattern, making the valve interchangeable with other components that share this interface. Electrical connection is provided through a DIN EN 175301-803 plug in the K4 orientation, simplifying wiring to standard industrial cables. The valve is compatible with mineral oils whose viscosity ranges from 2.8 to 500 mm²/s, covering both light and heavy grades encountered in mobile and stationary equipment. Acceptable hydraulic fluid temperature spans −20 °C to +80 °C when NBR seals are fitted, allowing operation in cold storage areas as well as warm process zones. A cleanliness level of ISO 4406 class 20/18/15 must be maintained to protect the precision spool and reduce wear during extended service. Bosch Rexroth machines the housing to tight tolerances so that the spool maintains low leakage during rapid directional changes, and the standardized interface helps maintenance teams swap units quickly to minimize downtime.