4WRH16W6-150-7X/V

The 4WRH16W6-150-7X/V proportional directional valve is produced by Bosch Rexroth within the WRZ Proportional Directional Valves series. It meters hydraulic flow in closed-loop automation circuits where variable speed and precise positioning are required. The valve is built for mineral oil classified as HL or HLP according to DIN 51524, ensuring compatibility with common industrial fluids. A nominal size of 16 defines the interface dimensions and sets the flow capacity for medium-frame manifolds. With a nominal flow of 150 l/min at a 10 bar pressure drop, the unit can supply actuators that demand steady volume without excessive energy loss. Hysteresis of no more than 6 percent stabilizes spool positioning so repeatability remains within tight limits during proportional control. The main stage tolerates operating pressures up to 350 bar, allowing it to direct high-pressure pump output without damage. Ports a, b, p, and t share a diameter of 20 mm to match standard manifold passages, and the bottom face follows the ISO 4401-07-06-0-94 pattern for straightforward interchange with other components. Subplate mounting secures the valve to a manifold block, keeping service replacement quick and minimizing pipework.

Pilot operation is handled separately so fine spool movement is maintained under varying load conditions. The pilot oil circuit accepts a maximum pressure of 25 bar at the main stage and uses a flow of 5.5 l/min to drive the spool through a full 0–100 percent stroke, while a pilot oil volume of 4.6 cm³ limits response lag. Return line design permits up to 250 bar at port t, and port Y withstands 30 bar, allowing flexible tank routing in systems where back-pressure exists. An FKM seal package resists mineral oil and elevated temperature, preventing external leakage. The mounting face must remain flat within 0.01 mm over 100 mm to avoid internal bypass, and a surface roughness of 4 µm on the mating plate ensures the seals seat correctly. These geometric requirements support consistent metering accuracy during long-term service.