Model Explanation

D661：MOOG D660 platform ISO4401-05 standard two-stage integrated electronic servo valve series with ServoJet pilot structure

Z：Built-in internal LVDT spool displacement closed-loop feedback + fully integrated onboard servo drive amplifier configuration

571：Base specification coding: rated flow 180L/min@ΔP=35bar per single spool land, internal X pilot oil supply, internal Y drain back to T port, mechanical spring auto-centering upon power loss, 12-pin circular electrical connector

C：Zero-lap four-way spool structure, standard NBR sealing material for normal industrial working temperature range

Technical Specifications

Hydraulic Parameters

Rated Flow：180 L/min (@ΔP=35bar per single spool land)

Max Working Pressure：P/A/B main ports:350bar(5000PSI); internal Y drain T port:210bar(3000PSI)

Pilot Mode：Internal pilot oil intake from P channel, internal Y drain inside valve body without external pilot pipeline

Working Medium：Mineral hydraulic oil complying with DIN51524/ISO11158, recommended oil cleanliness NAS6~7

Net Weight：Approx5.7kg

Fail-safe Property：Power-off mechanical spring auto-centering, spool returns neutral zero position automatically to lock actuator

Electrical Parameters

Power Supply：DC24V(18～32VDC), total power consumption ≤37W

Control Signal：Differential ±10VDC analog input; ±10mA current signal available as optional customization

Full Stroke Step Response(0~100% stroke, supply pressure210bar):7~10ms

Electrical Connector：12-pin circular industrial plug

Built-in Protection：Overcurrent, reverse polarity and short-circuit protection for onboard amplifier

Environmental Conditions

Operating Temperature：-20℃～+70℃; Storage & Transportation:-40℃～+85℃

Humidity：5%~95%RH non-condensing; compliant with EN61000 industrial EMC anti-interference standard

Protection Grade：Electrical connector IP65, valve body IP54

Channel & Feedback Configuration

Hydraulic Port：Standard 4-way P/A/B/T layout following ISO4401-05 manifold installation dimension; X pilot and Y drain realized internally inside valve

Feedback Mode：Built-in high-precision non-contact internal LVDT displacement sensor for real-time spool closed-loop feedback, no external mechanical feedback rod required

Communication & Interface Configuration

Control Wiring：Shielded analog hardwire connection with D137 analog output channel of MSCⅡ control system; control instructions programmed via MACS software and transmitted by screened control cable

Auxiliary Interface：Side-mounted zero trimming potentiometer for field zero-offset calibration; only analog hardwire control, no onboard EtherCAT/Profibus fieldbus interface

Core Function

Convert analog control signal from D136 main controller into proportional hydraulic flow to drive hydraulic cylinder/motor for high-precision closed-loop regulation of position, speed and test load under medium-large flow working conditions.

Internal LVDT collects real spool position and feeds back to integrated amplifier to form valve inner closed loop, improves control linearity and restrains zero drift induced by oil temperature and supply pressure fluctuation.

Fault signal from amplifier protection circuit can be collected by D137 DI channel for system fault alarming and equipment safety interlock.

Power-off spring centering structure prevents actuator runaway accident and improves running safety of test equipment.

Side zero-adjust potentiometer compensates zero shift caused by installation deviation and slight oil contamination.

Applicable Scenarios

Auxiliary electro-hydraulic regulation of steam turbine EH speed governing system; durability fatigue test for automobile chassis and structural parts; precision forming control of medium-large hydraulic press; static & dynamic performance test of aerospace medium-flow hydraulic actuator; mechanical property testing of metal composite materials.

Instructions for Installation and Maintenance

Install on standard ISO4401-05 hydraulic manifold in horizontal or vertical orientation; avoid installation in areas with dense oil mist, water splash and intense high-temperature radiation.

Install 3μm high-pressure precision filter at upstream of P main oil inlet to prevent ServoJet pilot nozzle clogging by hydraulic impurities.

Inspect and retighten all electrical terminals every six months; separate shielded analog signal cable from high-power power cable inside wiring duct to reduce electromagnetic interference.

Complete full-range zero calibration of servo valve once per year; regularly inspect external leakage of all ports and replace NBR sealing parts when abnormal leakage occurs.

Keep 24VDC power supply fluctuation within ±10% rated voltage; overvoltage will permanently damage internal integrated amplifier board.