R983030768 4WMM10J3X/ Rexroth manual directional valve

FAQ - Frequently Asked Questions

Q1: What is the "J" spool function in 4WMM10J3X?

A:​ The "J" spool function​ defines the internal flow path in the center (neutral) position. For the J-type, the typical configuration is: P port is blocked, A and B ports are connected to T (tank). This allows the connected actuator (cylinder or motor) to float freely​ when the valve is in the center position, as both sides are unloaded to the tank. Always verify the exact flow path in the technical drawing for your specific application.

Q2: Does this valve have a detent (position lock) or spring return?

A:​ The standard 4WMM10J3X/​ (without "/F" suffix) is typically a spring-centered, manually operated valve. This means when you release the lever, it automatically returns to the center (neutral) position. If you require the lever to stay in the left or right position (detent), you would need a variant with the /F​ suffix (e.g., 4WMM10J3X/F).

Q3: What is the maximum flow rate for NG10 size?

A:​ The nominal flow rate for comfortable operation (low pressure drop) is around 120 L/min. The absolute maximum flow can reach 160 L/min, but at this rate, the pressure drop will be significant, and switching forces may be high. For flows above 120 L/min, consider an NG16 size valve.

Q4: Can I use this valve with water glycol (HFC) fluid?

A:​ Yes.​ The standard NBR seals are compatible with Water Glycol (HFC)​ fluids. However, if you are using Phosphate Ester (HFD) fluids, you must select a variant with FKM (Viton®) seals, which typically have a /V​ suffix (e.g., 4WMM10J3X//V).

Q5: What is the difference between 3X and 5X series?

A:​ The 3X​ (30-series) and 5X​ (50-series) refer to different generations or design series of the valve. The external mounting dimensions (ISO 4401 NG10)​ are generally interchangeable. However, internal spool tolerances, leakage rates, and some performance characteristics may differ. Always confirm compatibility with your existing subplate.