I. Basic Structure Information

Structure Type: Dry Torque Motor + Dual Nozzle Baffle Pilot Stage + Four-way Main Valve Core + Mechanical Position Feedback

Control Method: Pure Current Control, No Built-in Amplifier Board, External Servo Amplifier Required

Standard Drive Current: ±100mA

Installation Specifications: ISO4401-05 Standard Installation Surface

Oil Supply Form: Main Oil Circuit Supply + Independent External Pilot Oil Port X Ports

Compatible Media: Ordinary Hydraulic Oil, Power Plant Special Anti-Fuel EH Oil

II. Full Model Interpretation

D631: Classic Two-stage Mechanical Feedback Servo Valve Series

335: Flow Specification Code, Rated Flow 120L/min (Single Side Pressure Difference 35bar)

C: Standard Valve Body Structure, Fluororubber Oil-Tight Sealing

F: External Independent Pilot Supply + Customized Configuration for Precision Low Zero Leakage

-4: Fourth Type Custom Electrical Plug and Outlet Specification, Special Wiring Specification for Power Plant Control Cabinets

III. Core Technical Parameters

Rated Flow: 120L/min

Maximum Working Pressure: 315bar

Frequency Response Band (-3dB): 60Hz

Full Stroke Step Response: 25ms

Control Hysteresis: ≤3%

Control Resolution: ≤0.5%

Zero Position Leakage: ≤2.5L/min, Much Lower than Conventional Models

Applicable Oil Temperature: -20℃~80℃

Environmental Temperature: -20℃~60℃

Oil Cleanliness Grade: NAS6-7

Overall Weight: Approximately 2.4kg

IV. Core Product Advantages

External Independent Pilot Supply, More Stable Control in High Flow Conditions,

Precise Grinding of Valve Core Clearance， Extremely Low Zero Position Leakage， More Energy-Efficient and Cost-Efficient Long-Term Operation

Strengthened Anti-Vibration and Temperature Resistance Design， Perfectly Compatible with High-Temperature Machine Rooms in Power Plants and Thermal Power Plants

Material Compatibility with Anti-Fuel Oil， Tailored for Steam Turbine DEH Electro-Hydraulic Regulation System

-4 Custom Wiring Ports， Neat Wiring at the Site， Compatible with Power Plant Standard Control Cabinet Wiring Definitions

Mechanical Feedback Structure Mature and Durable， Capable of Meeting Year-Round 24/7 Continuous Operation Requirements

V. Main Application Scenarios

Steam Turbine Main Steam Valve， Regulating Steam Valve Electro-Hydraulic Regulation Control in Thermal Power Plants

Precise Flow and Pressure Regulation of Generator Set EH Hydraulic System

Large Heavy Industry High-Pressure High-Flow Closed-loop Control System

Hydraulic Loading Circuit of Large Power Heavy-Duty Fatigue Test Bench

High-Pressure Servo Control Circuit of Large-scale Rolling Mills