MOOG D765-102-4

Technical & Hydraulic Specifications

• Valve Stage Structure: Single-stage torque motor flapper-nozzle pilot controlled servovalve
• Standard Mounting Pattern: NFPA standard compact four-port manifold mounting interface
• Maximum Rated Supply Pressure: 310 bar (4500 psi)
• Rated Flow Volume @ 1000 PSI Valve Pressure Drop: 32 L/min
• Torque Motor Control Input Signal: ±10 mA differential analog current command signal
• Hysteresis Index: ≤2.0% full spool stroke
• Flow Linearity Deviation: ≤4% full operating stroke range
• 90° Phase Lag Dynamic Response Frequency: 100 Hz at 10% rated spool stroke small signal input
• Permitted Hydraulic Fluid Viscosity: 60–450 SUS at 38 °C operating temperature
• Fluid Cleanliness Requirement: ISO 4406 Code 14/11 recommended, maximum allowable 16/13 particulate code
• Ambient Valve Housing Operating Temperature: -30 °C to +85 °C
• Hydraulic Fluid Operating Temperature Range: -35 °C to +135 °C

Functional Features

1. Classic permanent magnet torque motor flapper-nozzle pilot stage with ultra-fast transient flow response
2. Zero-lapped precision ground main spool eliminating mechanical deadband for micro-position control resolution
3. Built-in internal pilot fluid bypass drain circuit to maintain stable flapper-nozzle differential pressure
4. Integrated torque motor thermal isolation barrier preventing heat transfer from hot hydraulic fluid to electrical windings
5. External single sealed electrical connector for differential ±10 mA analog command signal wiring
6. Hardened internal flow passages resisting abrasive particulate wear under moderate contamination fluid conditions

Working Principle

Material Composition

• Valve Main Body: Precision machined cast carbon steel with anti-corrosion phosphate surface treatment
• Main Control Spool: Martensitic stainless steel with plasma nitride hardening finish
• Torque Motor Assembly: Alnico rare-earth permanent magnet stator, copper wound insulated torque motor coils
• Flapper-Nozzle Pilot Components: Hardened tool steel precision ground nozzle orifice sleeves
• Sealing Components: Standard NBR nitrile rubber O-rings for general industrial hydraulic oil compatibility, optional FKM high-temperature fluorocarbon seals
• Electrical Connector Housing: Glass-filled PA66 flame retardant plastic with nickel-plated copper pin terminals

Structural Characteristics

• Compact miniaturized single-stage monolithic valve body reducing manifold installation footprint
• Top-mounted single multi-pin sealed electrical connector vertical orientation for simplified wiring routing
• Bottom four-port NFPA standard manifold mounting flange with four symmetrical mounting bolt holes
• Side external pilot fluid drain port with threaded pipe connection for pilot leakage fluid recovery
• Integrated internal metal heat barrier separating torque motor electrical assembly from hot hydraulic fluid flow passages

Advantage Highlights

1. Miniaturized single-stage body design cuts manifold installation space requirement by 50% compared to equivalent flow two-stage servovalves
2. High 100 Hz small-signal frequency response delivering fast dynamic axis positioning correction
3. Low hysteresis and zero deadband spool machining achieving sub-micron positioning repeatability
4. Simple single-current analog command signal interface compatible with all standard hydraulic motion controllers
5. Low internal pilot fluid leakage volume reducing hydraulic system heat generation and cooling load
6. Cost-effective compact architecture for medium-flow light-duty precision hydraulic closed-loop systems

Applicable Industries

Installation Requirements

1. Mount to flat precision machined NFPA standard steel manifold surface with mounting bolt torque 38 N·m
2. Install 5 μm absolute inline hydraulic filter upstream of valve supply inlet port
3. Use shielded twisted pair wiring for ±10 mA torque motor command signal with single-point shielding grounding at motion controller cabinet
4. Connect external pilot drain port to hydraulic reservoir return line with unrestricted low-pressure tubing

Usage Precautions

1. Strictly adhere to recommended ISO 4406 14/11 fluid cleanliness standard to avoid flapper-nozzle orifice blockage
2. Do not apply input control current exceeding ±12 mA to prevent permanent torque motor coil overheating damage
3. Replace all NBR sealing components every 2500 operating hours; upgrade to FKM seals for fluid temperature exceeding 90 °C
4. Conduct annual flow linearity and hysteresis performance testing per factory calibration procedure