Three-Stage Electrohydraulic Flow Controlling Servo Valve with Two Nozzles and Flapper Force Feedback
Design Features:
(1) Using a double-nozzle flapper valve as the pilot stage, and furnished with electric feedback for main valve core position.
(2) Good dynamic behavior, and low energy consumption. Able to meet requirements for valves with high frequency response and flow from industrial fields.
(3) Using an external controlling amplifier for easy adjustment, and allowing a user selecting external controlling and discharging way for pilot controlling oil

Specification:
Model: QDY3
Supply oil pressure range (MPa)2-21
Rated supply oil pressure (MPa)21
Rated flow Qn (L/min) (at valve pressure drop of 7MPa)400,500
Rated signal ±10mA, ±10V
Hysteresis (%)≤4
Resolution (%)≤1
Non linearity (%)≤±10
Asymmetry (%)≤±10
Pressure gain (%Ps/1%In)>30
Internal leakage (L/min)≤4
Bias (%)≤±3
Zero drift of supply oil pressure (80-110% Ps) (%)≤±3
Zero drift of return oil pressure (0-20% Ps) (%)≤±2
Zero drift in temperature (-30~+150 ℃) (%))≤±4
Frequency characteristics
Amplitude frequency width (-3dB) (Hz)≥30
Phase frequency width (-90°) (Hz)≥35
Net weight (kg)9.8

Model: QDY8
Supply oil pressure range (MPa)2-21
Rated supply oil pressure (MPa)21
Rated flow Qn (L/min) (at valve pressure drop of 7MPa)10,30
Rated signal ±10mA, ±10V
Hysteresis (%)≤3
Resolution (%)≤0.5
Non linearity (%)≤±8
Asymmetry (%)≤±8
Pressure gain (%Ps/1%In)>30
Internal leakage (L/min)≤1.1
Bias (%)≤±3
Zero drift of supply oil pressure (80-110% Ps) (%)≤±2
Zero drift of return oil pressure (0-20% Ps) (%)≤±2
Zero drift in temperature (-30~+150 ℃) (%))≤±4
Frequency characteristics
Amplitude frequency width (-3dB) (Hz)≥200
Phase frequency width (-90°) (Hz)≥220
Net weight (kg)1.4

Model: QDY18
Supply oil pressure range (MPa)2-31.5
Rated supply oil pressure (MPa)21
Rated flow Qn (L/min) (at valve pressure drop of 7MPa)800,1000
Rated signal ±10mA, ±10V
Hysteresis (%)≤4
Resolution (%)≤1
Non linearity (%)≤±12
Asymmetry (%)≤±12
Pressure gain (%Ps/1%In)>30
Internal leakage (L/min)≤8
Bias (%)≤±3
Zero drift of supply oil pressure (80-110% Ps) (%)≤±2
Zero drift of return oil pressure (0-20% Ps) (%)≤±2
Zero drift in temperature (-30~+150 ℃) (%))≤±4
Frequency characteristics
Amplitude frequency width (-3dB) (Hz)≥10
Phase frequency width (-90°) (Hz)≥12
Net weight (kg)13.6