R978017748 Rexroth Hydraulic Directional Valve 4WE6Y62/EG24N9K4/62 Genuine New
Product Overview
The Rexroth R978017748 is a direct-operated directional spool valve in the WE6 series — Rexroth's most widely deployed family of hydraulic directional control valves for industrial applications. At NG6 (D03) size with a single 24V DC solenoid and spring return, the 4WE6Y6X/EG24N9K4/62 is configured for 4/2-way switching with symbol Y spool geometry.
It controls hydraulic oil flow direction and circuit switching in industrial hydraulic power units, machine tools, press systems, and production machinery wherever a 24V DC signal from a PLC output card needs to translate directly into hydraulic cylinder or motor movement.
The R978017748 specifically provides the 4/2-way (Y-symbol) function, where the de-energised state connects P to B and A to T, and the energised state reverses this to P to A and B to T. This configuration is widely used where a cylinder must default to one end position on loss of electrical power, with positive actuation to the opposite position when commanded.
At 60 LPM rated flow and 350 bar maximum pressure, the valve serves the full working range of standard industrial hydraulic circuits. The concealed manual override allows operators to manually shift the valve spool during commissioning, fault diagnosis, or machine setup without applying solenoid voltage.
Key Specifications
| Parameter |
Value |
| Valve Code |
4WE6Y6X/EG24N9K4/62 |
| Function |
4/2-way, spring return |
| Nominal Size |
NG6 (D03) |
| Solenoid Voltage |
24V DC |
| Solenoid Power |
30W |
| Max Flow |
60 LPM |
| Max Pressure |
350 bar (5,076 PSI) |
| Manual Override |
Concealed |
| Connector |
3-pole (EN 175301-803) |
| Mounting Standard |
ISO 4401-03 / DIN 24340-A6 / CETOP R35H-03 / NFPA-D03 |
| Housing |
Cast iron |
| Seals |
NBR |
| Operating Temperature |
−15 to +80°C |
| Weight |
1.44 kg |
Spool Symbol Y — Circuit Function
In Rexroth's WE6 naming convention, the letter following "WE6" describes the spool's hydraulic symbol — the path configuration in both the energised and de-energised states. Symbol Y designates a specific arrangement that is common in single-acting circuits and return-motion applications:
- De-energised state (spring return, solenoid off): P → B, A → T — Hydraulic pressure from the supply (P) is directed to the B-port output, while the A-port drains back to tank (T).
- Energised state (solenoid on): P → A, B → T — Applying 24V DC to the solenoid reverses the flow path: P feeds to A, B drains to T.
This Y spool configuration is widely specified where fail-safe position requirements align with the spring-return direction — for example, tool unclamping on power loss in machine tools, or actuator retraction as the safe condition in press and forming machinery.
D03 (NG6) Mounting Interface
The NG6 / D03 mounting interface is the most widely standardised subplate mounting pattern for size 6 directional valves in industrial hydraulics. The same bolt pattern, port layout, and locating pin position appear under four different standards: ISO 4401-03, DIN 24340-A6, CETOP R35H-03, and NFPA-D03.
The /62 suffix on the valve ordering code specifies that the valve body has the locating pin hole in the ISO 4401 position. This distinction matters when specifying a replacement valve for an existing manifold. Check whether the installed subplate has a locating pin present; if it does, the /62 or equivalent suffix is required.
Wet-Pin Solenoid Construction
The WE6 series uses wet-pin (oil-immersed) solenoid construction. The solenoid push rod extends into the valve body's hydraulic oil environment, using the hydraulic fluid itself for lubrication and cooling. This eliminates the separate O-ring seal that would be required for a dry-pin design, reducing potential leak points.
The solenoid coil assembly is removable without disconnecting the valve from the subplate and without releasing hydraulic pressure from the circuit. The coil sleeve slides off the solenoid body after releasing the coil retaining nut, allowing coil replacement in-situ — a significant maintenance advantage in confined manifold positions.
Frequently Asked Questions
Q1: The valve's suffix is /62. What is the significance of this, and does it affect subplate compatibility?
The /62 suffix designates a specific locating pin hole configuration for the valve-to-subplate interface, corresponding to the ISO 4401 standard with locating pin. If your subplate has a locating pin installed, you must use a valve with the matching locating hole suffix. Mismatching the locating pin configuration will prevent the valve from seating correctly against the subplate face, leading to seal damage and external leakage.
Q2: This valve has a concealed manual override. How is it operated?
The concealed manual override is a recessed push-pin actuator on the solenoid end of the valve body, accessible using a small tool (typically a 3mm hex key or dedicated override tool). Pressing the pin inward manually shifts the spool, replicating the solenoid's actuation without applying electrical power to the coil. The concealed design prevents inadvertent manual actuation during normal operation.
Q3: The maximum flow is listed as 60 LPM. Can the valve handle higher transient flows without damage?
The 60 LPM rating is the maximum continuous operating flow, not an absolute damage threshold. Brief transient flows above 60 LPM are generally tolerated without damage. However, sustained flows significantly above this rating increase hydraulic forces on the spool, causing increased pressure drop, elevated temperatures, and accelerated internal wear. For circuits regularly operating above 60 LPM, a larger valve size should be specified.
Q4: What hydraulic fluids are compatible with this valve's NBR seals?
NBR (nitrile butadiene rubber) seals are compatible with standard mineral-based hydraulic oils (ISO VG 46 and ISO VG 68 are the most common). NBR seals are not compatible with phosphate ester (fire-resistant) fluids, polyol ester fluids, or water-glycol mixtures. For systems using fire-resistant fluids, Rexroth offers WE6 variants with FKM (Viton) seal specifications.
Q5: The solenoid is rated at 30W and 24V DC. What protection does the coil have against voltage spikes?
The /EG24N9K4 coil specification indicates a coil designed with an integrated suppressor diode (the "K4" element) for the 24V DC supply. When the PLC output switches the solenoid off, the collapsing magnetic field generates a back-EMF voltage spike. The integrated suppressor diode clamps this spike to a safe level, protecting the PLC output transistor and surrounding electronics.
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