D91FHB31F1NE00 Parker Proportional Valve NG25

Product Overview

Parker D*1 series proportional directional control valves (typical models D91FHB31F1NE00 and D31FBE01CC1NF00) are high-performance pilot-operated proportional directional valves covering D1F, D3F, D1FB, D1FV, D1FP, D1FH and D3 series. The D91FHB31F1NE00 is an NG25 (CETOP 08) high-response version with spool position feedback and onboard electronics (OBE); the D31FBE01CC1NF00 is an NG10 (CETOP 05) standard-performance version. Maximum operating pressure 350 bar, featuring low hysteresis, high repeatability and precise flow control. Fully compliant with ISO 4401 mounting patterns and highly interchangeable with original Parker D*1 valves. Every unit undergoes rigorous simulated duty-cycle testing for reliable performance in industrial and mobile hydraulic systems.

Technical Specifications 

• Models: D91FHB31F1NE00 (D91FH), D31FBE01CC1NF00 (D31FB)
• Size: D91 = NG25 (CETOP 08); D31 = NG10 (CETOP 05)
• Type: Pilot-operated proportional directional control valve with/without spool position feedback and OBE
• Maximum Operating Pressure: 350 bar (ports P, A, B)
• Rated Flow (at Δp = 5 bar): D91 series up to approx. 400 L/min; D31 series approx. 75–120 L/min
• Hysteresis: D*1FH series <0.5%; D*1FB series typically <5%
• Step Response: D91FH approx. 65 ms; D31FB approx. 50–75 ms
• Supply Voltage: 18–30 V DC (OBE versions)
• Command Signal: ±10 V or ±20 mA (ordering code dependent)
• Weight: D91FH approx. 20.7 kg; D31FB approx. 8.6–9.3 kg

Key Technical Advantages

1. Closed-loop spool position feedback (D*1FH): Main spool equipped with position sensor and OBE for high-precision closed-loop control with very low hysteresis and excellent repeatability.
2. High dynamic response and high flow: Optimized pilot-operated design delivers fast step response and supports high-flow applications for rapid positioning and precise speed control.
3. 100% drop-in interchangeability: Standard ISO 4401 subplate mounting interface is fully compatible with original Parker D*1 valves — no modifications required.
4. Robust high-pressure construction and testing: Rated to 350 bar, precision-machined spool and body with quality seals and 100% duty-cycle testing ensure long-term reliability.

Application Areas

• Injection molding, die-casting and forming machines requiring precise directional and flow control
• Machine tools, presses and industrial automation hydraulic systems
• Construction and mobile equipment high-performance proportional circuits
• Test stands and specialty systems demanding high dynamic response and accurate positioning

Expert Maintenance Tips

Verify subplate flatness and O-ring condition before installation; maintain fluid cleanliness at ISO 4406 18/16/13 or better. Keep pilot pressure in the optimal dynamic range (around 50 bar). Use matching connectors with proper shielding and select command signal according to the ordering code. Periodically check spool position feedback signal and leakage. Prefer identical spool code and electronics interface for replacement to preserve control characteristics. Perform system bleeding and functional testing after service.