R901036556 4WRE6V16-2X/G24K4/V-822 Original German proportional valve from Rexroth

FAQs for Rexroth 4WRE6V16-2X/G24K4/V-822

1. Q: Does this valve have built-in electronics (OBE), or do I need an external amplifier?

   A:​ This valve requires an external amplifier. The model code "4WRE" (without an extra "E") and the "K4" connector code indicate it is a "dumb" valve with only a position sensor (LVDT) and solenoids. You must purchase a separate proportional amplifier card (e.g., Rexroth VT-VSPA1 series) to provide power and the control signal (±10V) to drive the valve. Do not connect it directly to a PLC analog output.

2. Q: What is the difference between the "V" spool and the "W" spool?

   A:​ The "V" spool is a zero-overlap (critical center) spool, while "W" is also zero-overlap but with a different flow gain characteristic. The "V" spool provides very high resolution at the center position, making it ideal for applications requiring precise control at low speeds or when holding a position. It has minimal internal leakage but requires a closed-loop controller for stability.

3. Q: What does the "-822" suffix mean in the part number?

   A:​ The "-822" is a special variant code​ assigned by Rexroth. It typically indicates a specific factory calibration, a particular LVDT sensor batch, or a special shipping configuration (e.g., included accessories or documentation). The exact meaning is internal to Rexroth's ordering system, but it does not change the core hydraulic performance (flow, pressure).

4. Q: The datasheet mentions the drain port (Y). How critical is its installation?

   A:​ Critical.​ The drain port (Y) must be connected directly to the tank with a dedicated line, and this line must never be pressurized. If the drain line is blocked or pressurized above ~2 bar, it can cause the valve to malfunction, leak internally, or damage the LVDT position sensor. The line should be free-flowing and not shared with other valves.

5. Q: Can I replace this valve with a 4WRAE series valve (which has built-in OBE)?

   A:​ Not directly.​ While the mounting footprint (ISO 4401) and port sizes may be identical, the electrical control system is completely different. The 4WRAE series has onboard electronics (OBE) and accepts a direct command signal, whereas this 4WRE valve requires an external amplifier. A swap would require rewiring and potentially changing the control software/PLC program.

6. Q: What is the purpose of the "2X" in the model code?

   A:​ "2X" denotes the component series​ (20-29). This indicates the physical dimensions and mounting pattern are standardized within this range. Valves with "2X" have identical installation dimensions, so a 4WRE6V16-2X can be replaced by another 4WRE6...-2X valve without modifying the manifold or subplate.