H-4WEH25E6X/6EW110N9DAL

The H-4WEH25E6X/6EW110N9DAL directional valve is produced by Bosch Rexroth within the WEH Directional Spool Valves series for hydraulic actuation tasks. It is a 4-way design, so it directs pressure to two service ports while providing two return paths in closed-center circuits. The NG25 size establishes the flow section available in the body and matches standard subplates of the same nominal diameter. A mounting interface conforming to ISO 4401-08-08-0-05 allows straightforward installation on manifolds without additional adapters. The spool is identified by symbol E, giving predefined overlap and metering characteristics for proportional control schemes. With symbol E at 350 bar the valve can pass up to 650 l/min, supporting high cylinder or motor speeds. The main ports p, A, and B withstand a continuous operating pressure of 350 bar, enabling use on medium-pressure power units. Pilot supply is taken internally from port P, reducing external pipework, while pilot oil is returned externally through port Y to prevent back-pressure in the control chamber. Proper piloting requires at least 13 bar and may reach 250 bar, which defines the usable command range. A concealed manual override permits local actuation during commissioning without leaving exposed push pins.

In service, the valve must receive oil filtered to ISO 4406 class 20/18/15 to limit wear on moving components. Port T is designed for a maximum of 250 bar, so back-pressure in the tank line shall not exceed this value, and the external Y line is limited to 160 bar to protect the pilot exhaust gallery. The specified cleanliness rating aligns with common β10 ≥ 1000 filtration elements, helping maintain spool fit geometry over long cycles. The unit’s functional mean time to dangerous failure is 100 years, indicating a low statistical probability of hazardous malfunction during prolonged duty. At 19.0 kg in its spring-centered, two-solenoid form, the housing demands sturdy mounting while still permitting single-person handling with lifting aids. The defined mass also contributes to mechanical stiffness, reducing the likelihood of resonance in manifold stacks. When applied in presses or die-casting machines, the separate Y drain prevents dynamic pressure spikes from disturbing pilot stability. These pressure and reliability ratings enable the valve to manage energy levels typical of 350 bar systems without compromising service life.