R900953885 4WRZ16W6-150-7X/6EG24N9K4/D3V Rexroth proportional directional valve

Key Differences & Selection Guide

1. Q: What is the difference between 4WRZ and 4WRZE series?

   A:​ The 4WRZ​ series typically features integrated on-board electronics (OBE)​ and a wider range of configurable spool options (like the W6 overlap spool in this valve). The 4WRZE​ series you inquired about earlier often uses external or simpler electronics. The 4WRZ is generally more modern and feature-rich.

2. Q: What does the /D3V suffix mean?

   A:​ The /D3​ suffix indicates an integrated pressure reducing valve (ZDR 6)​ for regulating pilot pressure. The /V​ suffix specifies FKM (Viton®) seals, which are suitable for higher temperatures (up to 80°C) and aggressive hydraulic fluids (e.g., certain biodegradable oils or oils with additives) compared to standard NBR seals (/M).

3. Q: Does this valve have LVDT feedback?

   A:​ No.​ This standard 4WRZ model with a W6 spool does not​ have LVDT feedback for the main spool position. It operates in open-loop for the main stage. For closed-loop control, you would need a model with an "E" or "E1" spool designation.

4. Q: What is the purpose of the W6-spool?

   A:​ The W6-spool​ is an overlap spool​ designed for applications requiring smooth acceleration and deceleration​ (e.g., crane or winch control). It has a progressive flow characteristic that reduces shock at the start of movement.

5. Q: What is the critical installation note?

   A:​ This valve requires external pilot oil supply (X port) and external drain (Y port). You must connect the Y port directly to the tank with minimal backpressure (max 30 bar). The main T-port backpressure must be below 210 bar. Maintain high oil cleanliness (recommended NAS 1638 Class 8 or better for the main stage).