R900323180 ZDR6DPO-4X/40YMW80 German hydraulic valve Rexroth pressure reducing valve

Frequently Asked Questions (FAQ) for ZDR 6 DPO-4X/40YM/W80 (Order Code: R900323180)

Q1: What is a pilot-operated proportional pressure reducing valve, and how is it different from a standard DR valve?

A:​ This valve (ZDR) is a two-stage valve. It combines a small, fast pilot valve​ (the DPO section) with a larger main spool valve. The pilot valve controls the pressure to the main spool, which then meters the flow. This design provides higher flow capacity, better stability, and faster response​ at high flows compared to the direct-acting DR​ series valves, which are single-stage.

Q2: What does the full model designation "ZDR 6 DPO-4X/40YM/W80" mean?

A:

• ZDR 6:​ Main valve series and nominal size (NG6, for high flow relative to its size).

• DPO-4X:​ Specifies the internal pilot valve design and configuration.

• 40:​ Maximum adjustable reduced pressure is 40 bar.

• Y:​ Proportional solenoid control.

• M:​ On-Board Electronics (OBE) for direct PWM input.

• W80:​ A specific factory variant code, typically indicating a special performance characteristic, production batch, or hardware revision. The exact meaning should be confirmed with the official datasheet.

Q3: Why is the reduced pressure only 40 bar on this valve?

A:​ This 40 bar setting is a common specification for pilot pressure applications. The valve excels at providing a very stable, precisely controlled, and clean flow of hydraulic fluid at a constant pilot pressure (typically 20-40 bar)​ to operate other control valves (like large directional or proportional valves) in a system. Its high-flow capability makes it ideal for supplying multiple pilot circuits.

Q4: How does the control and wiring work with the "YM" designation?

A:​ The "YM"​ designation means the integrated pilot valve has a proportional solenoid with On-Board Electronics (OBE). It is controlled by a standard 24V DC PWM signal, which can be supplied directly from a PLC or controller, simplifying installation by eliminating the need for an external analog amplifier.

Q5: How is this valve installed?

A:​ It is a subplate-mounted valve. It installs onto a dedicated NG6 interface subplate​ (mounting surface per ISO 4401) which is then piped to the system. This differs from the sandwich-style DR valves and is common for standalone, high-performance valves.