H-4WEH25E6X/6EW110N9ETS2DAL/B10D3

The H-4WEH25E6X/6EW110N9ETS2DAL/B10D3 directional spool valve is manufactured by Bosch Rexroth as part of the WEH Directional Spool Valves series and is intended to shift hydraulic flow paths in automated machinery. It uses an ISO 4401 mounting interface so it can be placed on standardized manifold plates, while its NG25 nominal size gives passage dimensions that accommodate the required service flow. The unit employs a three-position, spring-centered spool to provide two actuated flow states and an automatic return to neutral for fail-safe circuit rest. A maximum operating pressure of 350 bar enables the valve to handle high-pressure supply lines common in industrial presses and mobile equipment. Hydraulic media must respect a viscosity range of 2.8 to 500 mm²/s to ensure predictable switching times, and cleanliness must meet ISO 4406 class 20/18/15 to protect the precision spool fit. The permitted fluid temperature spans −20 to +80 °C so the valve can be installed in unheated plants or warm power units. With two solenoids and the spring-centering assembly installed, the valve weighs 19.0 kg, allowing secure manifold mounting without additional supports.

Pilot actuation is obtained from the system pressure port because the pilot oil supply is internal from P, and exhausted inside the valve body to the tank gallery through an internal return to T, reducing external hose work. The pilot stage accepts up to 250 bar, while a spring-centered spool needs at least 13 bar to shift reliably; this range matches typical charge pump outputs and prevents inadvertent movement during low-pressure startup. When the shortest switching time is required, the pilot flow of 35 l/min feeds the control chamber to accelerate spool movement. In the main stage, the valve delivers up to 700 l/min at 280 bar and 650 l/min at 350 bar, giving designers clear flow limits for sizing pumps and accumulators. These performance values allow the unit to direct large oil volumes to cylinders or motors without excessive pressure drop.