FF-102 609 Force Feedback Servo Valve Moog 31

Product Overview

The FF-101, FF-102, FF-106, FF-106A, and FF-113 series are dual-nozzle flapper force feedback two-stage electro-hydraulic flow control servo valves developed by the AVIC 609th Research Institute (Nanjing Electro-Hydraulic Engineering Research Center), covering a complete product matrix from small-flow precision control to large-flow industrial drive applications. The series features an all-stainless steel housing with a compact internal structure, high structural strength, and relatively small volume and weight. They offer fast dynamic response, good linearity, small zero drift, and advantages including stable working performance, high reliability, long service life, small internal leakage, and low power consumption.

The FF series is divided into three tiers by flow capacity: FF-101 is a small-flow precision servo valve with rated flows of 1, 1.5, 2, 4, 6, or 8 L/min, suitable for aviation flight control surface actuator applications; FF-102 is a medium-flow servo valve with rated flows of 2, 5, 10, 15, 20, or 30 L/min, suitable for small and medium-sized rolling mills, blow molding machines, and test equipment; FF-106 and FF-106A are large-flow industrial servo valves with rated flows of 63 and 100 L/min, where FF-106A adds an optional fifth supply port on the FF-106 base, changes mounting screw hole spacing, and allows separate pilot stage supply; FF-113 is the largest flow specification with rated flows of 95, 150, and 230 L/min, used in heavy-load industrial scenarios.

The series is fully interchangeable with Moog series in terms of technical data and dimensions: FF-101 corresponds to Moog 30, FF-102 to Moog 31, FF-106 to Moog 35, FF-106A to Moog 760, and FF-113 to Moog 72. Every unit undergoes 100% simulation-based testing prior to shipment, covering null stability, flow linearity, pressure gain, and internal leakage.

Technical Specifications

All parameters below are based on the JLC FA Mechanical Design Handbook, Made-in-China supplier technical pages, and verified supplier documentation:

FF-101 Series Technical Specifications:

• Product Type: Dual-nozzle flapper force feedback two-stage flow servo valve

• Rated Flow Qn: 1, 1.5, 2, 4, 6, 8 L/min

• Rated Supply Pressure Ps: 21 MPa

• Supply Pressure Range: 2~28 MPa

• Rated Current In: 10 mA or 40 mA

• Coil Resistance: 50 Ω / 700 Ω

• Hysteresis: ≤ 4%

• Resolution: ≤ 1%

• Non-linearity: ≤ ±7.5%

• Unsymmetry: ≤ ±10%

• Pressure Gain: > 30% Ps / 1% In

• Internal Leakage: ≤ 0.25 + 5% Qn

• Null Bias: ≤ ±3%

• Amplitude Frequency Response (-3dB): ≥ 100 Hz

• Phase Frequency Response (-90°): ≥ 100 Hz

• Operating Temperature Range: -55°C to +150°C

• Working Medium: YH-10, YH-12 aviation hydraulic oil

• Net Weight: ≤ 0.20 kg

FF-102 Series Technical Specifications:

• Product Type: Dual-nozzle flapper force feedback two-stage flow servo valve

• Rated Flow Qn: 2, 5, 10, 15, 20, 30 L/min

• Rated Supply Pressure Ps: 21 MPa

• Supply Pressure Range: 2~28 MPa

• Rated Current In: 10 mA or 40 mA

• Coil Resistance: 50 Ω / 700 Ω

• Hysteresis: ≤ 4%

• Resolution: ≤ 1%

• Non-linearity: ≤ ±7.5%

• Unsymmetry: ≤ ±10%

• Pressure Gain: > 30% Ps / 1% In

• Internal Leakage: ≤ 0.5 + 4% Qn

• Null Bias: ≤ ±3%

• Amplitude Frequency Response (-3dB): ≥ 100 Hz

• Phase Frequency Response (-90°): ≥ 100 Hz

• Operating Temperature Range: -30°C to +150°C

• Working Medium: YH-10, YH-12 aviation hydraulic oil

• Net Weight: Approx. 0.4 kg

FF-106 Series Technical Specifications:

• Product Type: Dual-nozzle flapper force feedback two-stage flow servo valve

• Rated Flow Qn: 63, 100 L/min

• Rated Supply Pressure Ps: 21 MPa

• Supply Pressure Range: 2~28 MPa

• Rated Current In: 15 mA (63 L/min) / 40 mA (100 L/min)

• Coil Resistance: 80 Ω / 200 Ω

• Hysteresis: ≤ 4%

• Non-linearity: ≤ ±7.5%

• Pressure Gain: > 30% Ps / 1% In

• Internal Leakage: ≤ 3 L/min

• Amplitude Frequency Response (-3dB): ≥ 50 Hz

• Phase Frequency Response (-90°): ≥ 50 Hz

• Operating Temperature Range: -30°C to +100°C

• Net Weight: Approx. 1.0 – 1.2 kg

FF-106A Series Technical Specifications:

• Product Type: Dual-nozzle flapper force feedback two-stage flow servo valve, with optional fifth supply port

• Rated Flow Qn: 63, 100 L/min

• Rated Supply Pressure Ps: 21 MPa

• Rated Current In: 15 mA (63 L/min) / 40 mA (100 L/min)

• Hysteresis: ≤ 4%

• Amplitude Frequency Response (-3dB): ≥ 40 Hz

• Phase Frequency Response (-90°): ≥ 50 Hz

• Internal Leakage: ≤ 3 L/min

• Net Weight: Approx. 1.43 kg

• Features: Adds an optional fifth supply port on the FF-106 base, allowing separate pilot stage supply

FF-113 Series Technical Specifications:

• Product Type: Dual-nozzle flapper force feedback two-stage large-flow servo valve

• Rated Flow Qn: 95, 150, 230 L/min (at 7 MPa pressure difference)

• Rated Supply Pressure Ps: 21 MPa

• Rated Current In: 40 mA (95 L/min) / 15 mA (150 L/min) / 40 mA (230 L/min)

• Coil Resistance: 80 Ω / 200 Ω / 80 Ω

• Internal Leakage: ≤ 7 L/min (95/150 L/min) / ≤ 10 L/min (230 L/min)

• Phase Frequency Response (-90°): ≥ 40 Hz / ≥ 30 Hz / ≥ 30 Hz

• Operating Temperature Range: -30°C to +100°C

• Features: Large-flow industrial servo valve, external null adjustment available, replaceable filter with high anti-contamination performance

Note: Specifications are based on the JLC FA Mechanical Design Handbook (jlc-jdgf.com), Made-in-China supplier technical pages, and Qingdao Beizhong bzzbkj.com. The FF-101 and FF-102 series are fully interchangeable with Moog 30 and Moog 31 in terms of technical data and dimensions. This series is manufactured by multiple manufacturers; specific parameters may vary slightly. Always verify against the actual supplier’s technical documentation during selection.

Key Technical Advantages

1. Force Feedback Closed-Loop Control Architecture for High Precision and Fast Dynamic Response

The FF series employs a dual-nozzle flapper force feedback architecture. When an electrical command signal is applied to the torque motor coils, the flapper deflects between two nozzles, creating a differential pressure across the spool ends that drives spool displacement. Spool movement applies force through a feedback spring to the torque motor armature assembly, establishing a mechanical force feedback closed loop. This architecture does not rely on electronic displacement sensors, offering exceptional immunity to electromagnetic interference and long-term stability. The FF-101 and FF-102 achieve amplitude and phase frequency responses of no less than 100 Hz, delivering rapid dynamic response for high-frequency dynamic loading and rapid switching control requirements.

2. All-Stainless Steel Housing with Wide Temperature Range for Demanding Environments

The FF series features an all-stainless steel housing with a compact internal structure, high structural strength, and relatively small volume and weight. The stainless steel housing provides excellent corrosion resistance and wide temperature adaptability. The FF-101 operating temperature range covers -55°C to +150°C, and the FF-102 covers -30°C to +150°C. Suitable for aviation, aerospace, and industrial systems with demanding environmental conditions and high reliability requirements.

3. Low Null Drift and Low Internal Leakage Design

The FF-101 and FF-102 achieve supply pressure null shift of no more than ±2% (80%~110% Ps) and return pressure null shift of no more than ±2% (0~20% Ps), with temperature null shift not exceeding ±4%, ensuring stable null output under varying pressure and temperature conditions. Internal leakage is limited to ≤ 0.25 + 5% Qn (FF-101) and ≤ 0.5 + 4% Qn (FF-102), effectively conserving energy and maintaining control accuracy.

4. Complete Moog Series Drop-In Interchangeability System

The FF series is fully interchangeable with Moog series in terms of technical data and dimensions: FF-101 corresponds to Moog 30, FF-102 to Moog 31, FF-106 to Moog 35, FF-106A to Moog 760, and FF-113 to Moog 72. Users can directly replace corresponding Moog servo valves with FF series without modifying hydraulic circuits, mounting interfaces, or control wiring. The series is widely used in aviation, aerospace, marine, power, metallurgy, chemical, machinery manufacturing, geological exploration, postal and telecommunications, textile, printing, and various test equipment fields.

5. 100% Simulation-Based Testing and Drop-In Interchangeability

Every FF series servo valve undergoes 100% simulation-based testing prior to shipment. Test protocols cover rated flow calibration, hysteresis and linearity measurement, pressure gain verification, and internal leakage detection. The series has received numerous honors including the National Science Conference Award, National New Product Golden Dragon Award, and awards from the National Defense Industry Office, the former Ministry of Aviation Industry, and Hubei Provincial Science and Technology Achievement Award, with product performance reaching advanced international levels.

Application Areas

• Small and Medium-Sized Rolling Mills: Precision position and pressure closed-loop control for rolling mill hydraulic gap systems (FF-102)

• Blow Molding Machines: Parison wall thickness control and mold clamping pressure regulation (FF-102)

• Test Equipment: Precision flow control for electro-hydraulic servo loading systems (FF-102/FF-106)

• Aviation Hydraulic Systems: Electro-hydraulic servo control of flight control surface actuators (FF-101)

• Aerospace Hydraulic Systems: Precision control of spacecraft hydraulic drive mechanisms (FF-101/FF-102)

• Large-Flow Industrial Drives: Metallurgical equipment, presses, and other industrial systems requiring large-flow precision control (FF-106/FF-113)

• Material Testing Systems: Loading control for electro-hydraulic servo fatigue test rigs (FF-106/FF-106A)

• Petroleum Pipeline Systems: Flow metering and control accuracy improvement (FF-106A)

• Industrial Automation Lines: Integration with PLC and motion controllers for precision position, velocity, or force control

Expert Maintenance Tips

Pre-Installation Checks:

• Verify mounting surface dimensions are compatible with the corresponding Moog model interface (FF-101 ↔ Moog 30, FF-102 ↔ Moog 31, FF-106 ↔ Moog 35, FF-106A ↔ Moog 760, FF-113 ↔ Moog 72)

• Flush all piping with clean hydraulic fluid prior to installation; ensure system cleanliness meets servo valve requirements

• Inspect O-ring seals for damage and confirm compatibility with the hydraulic fluid in use

• Verify electrical connector (plug and socket) contact integrity; confirm coil wiring mode matches the controller. FF-101 coil connection modes support differential, parallel, or individual coils, with rated current options of 10 mA (700 Ω) or 40 mA (50 Ω)

Operational Maintenance:

• Use precision pressure filters matched to the servo valve (≤ 10 μm absolute filtration recommended); replace filter elements at regular intervals

• Recommended working medium: YH-10, YH-12 aviation hydraulic oil

• Maintain supply pressure within 2~28 MPa range; rated supply pressure is 21 MPa

• Periodically verify coil resistance remains within rated range; confirm electrical connector contact integrity

• System return back pressure must not exceed 20% Ps to avoid excessive back pressure causing null offset

• Periodically monitor internal leakage; FF-101 should be ≤ 0.25 + 5% Qn, FF-102 should be ≤ 0.5 + 4% Qn

Troubleshooting Guide:

• Spool fails to actuate or responds abnormally: Check command signal reaches the coil (rated current 10 mA or 40 mA), measure coil resistance against 50 Ω or 700 Ω range (FF-101/FF-102), confirm plug and socket engagement is reliable

• Null-point drift: After ruling out fluid contamination, inspect feedback spring for fatigue or deformation; verify pilot stage nozzle-flapper clearance has not changed due to wear

• Insufficient flow: Confirm system supply pressure is within the 2~28 MPa allowable range; check spool metering edges for partial blockage by contaminant particles

• Increased internal leakage: Check system cleanliness level; inspect spool/sleeve for wear; replace seals if necessary

• Slow response: Check system cleanliness level; verify pilot stage nozzles are not partially blocked by contaminant particles