Model Code Explanation (D661-4624)

• D661: Series (ISO 4401‑05 mounting, integrated 24 VDC electronics)

• 4: 4‑way, zero‑lap, linear flow characteristic

• 62: Rated flow ≈ 80 L/min (Δp = 35 bar per land)

• 4: High dynamics, single LVDT feedback, standard null stability

• (No suffix letter): Command signal = ±10 mA (current), non‑explosion‑proof

Technical Specifications

Part Number

• D661-4624

Mounting (Real Standard)

• Standard: ISO 4401‑05 (NG10), 4‑hole, M6 bolts

• Torque: 13 Nm ±10%, diagonal tightening sequence

• Mounting Surface: Flatness ≤0.02 mm/100 mm; Ra <1 μm (MOOG factory standard)

• Manifold Requirement: Min. length 80 mm; P/A/B/T ports Ø9 mm

Control Function

• 4‑way/3‑position, spring‑centered, zero‑lap, closed‑loop spool position control

Hydraulic Parameters

• Rated Flow (Δp = 35 bar): 80 L/min (±8%)

• Max Operating Pressure (P/A/B): 350 bar (5,000 psi)

• Pilot Pressure (X): 21–280 bar (internal P or external X)

• T Port Pressure (Y internal): 210 bar; (Y external): 350 bar

• Fluid: Mineral oil (DIN 51524), viscosity 15–45 mm²/s

• Temperature: Ambient −20°C to +60°C; Fluid −20°C to +80°C

• Weight: Approx. 5.7–6.0 kg

Electrical Parameters

• Supply: 24 VDC (18–32 VDC), quiescent 270 mA, dynamic ~600 mAMoog Inc.

• Command Signal: ±10 mA (impedance 500 Ω, current mode)Moog Inc.

• Feedback Signal: 4–20 mA (single LVDT spool position, ±0.02% FS accuracy)

• Connector: 6+PE (EN 175201‑804, IP65)Moog Inc.

• Step Response (0→100%): 6.5–7.5 ms @ 210 bar (high dynamics for 80 L/min)

• Hysteresis: <0.22% (closed‑loop)

• Linearity: <±0.25%

• Resolution: <0.05%

• Null Shift (ΔT=55K): <0.7%

Interface & Communication Configuration

• Electrical: 6+PE connector; 24 VDC power, ±10 mA current command, 4–20 mA LVDT feedbackMoog Inc.

• Feedback: Single integrated LVDT (full‑stroke closed‑loop, high accuracy)

• Ports: P, A, B, T; optional external X (pilot) and Y (return)

• Seal Material: NBR (standard) or FKM (optional, high‑temperature)Moog Inc.

Core Functions

• 80 L/min Medium Flow: For mid‑size precision hydraulic systems

• High Dynamic Response: 6.5–7.5 ms step response, fast and stable

• ±10 mA Current Command: Excellent noise immunity for long cable runs

• Precision Closed‑Loop Control: LVDT feedback with ultra‑low hysteresis

• ServoJet® Pilot: Jet‑pipe design reduces energy use and contamination sensitivity

Applicable Scenarios

• Precision CNC Machine Tools: High‑speed, accurate positioning for medium‑size machines

• Aerospace Component Test Benches: Dynamic load/position control with fast response

• Plastic Injection Molding Machines: High‑precision flow/pressure control

• Light‑Duty Industrial Presses: Stamping, forming with high repeatability

Compatibility & Installation Notes

• Mechanical: Interchangeable with D661 (G/C/D/E), D662/D663 (ISO 4401‑05)

• Upgrade: Drop‑in replacement for 40 L/min models (e.g., D661‑4614C) when higher flow is needed

• System Requirements: 24 VDC supply, ±10 mA current‑mode controller, ISO 4401‑05 manifold

Usage & Maintenance Instructions

• Installation: Mount on flat surface (flatness ≤0.02 mm/100 mm; Ra <1 μm) with M6×55 bolts (13 Nm, diagonal)

• Fluid: ISO VG 32–46, NAS 1638 cleanliness class ≤8 (ISO 4406 17/14/11 recommended)

• Maintenance: Replace internal filter every 5,000 hours; inspect leaks/connectors periodically

• Precautions: Avoid voltage spikes/reverse polarity; do not open in field