Model Code Definition

D664 = D660 high-flow subfamily, ISO4401-08 NG25 installation dimension, ServoJet jet-pipe pilot structure, onboard amplifier + full-stroke LVDT spool closed-loop feedback design

4003 = Custom large-flow spool trim number, spring-centered four-way spool with special metering overlap profile, factory preset fixed amplifier gain and null point calibration

No suffix = Standard NBR rubber sealing, dual separated drain (internal T + external Y), conventional anti-vibration amplifier layout

Technical Specifications

Hydraulic Parameters

Rated Flow:620 L/min @35bar single-side differential pressure; peak instantaneous flow 835 L/min @70bar supply differential pressure

Max Working Pressure:P/A/B main ports up to 350bar; internal T drain ≤210bar; external Y drain rated full 350barMoog Inc.

Full Stroke Step Response:≤42ms under 210bar nominal supply pressure

Control Precision:Hysteresis＜0.30%FS, Resolution＜0.09%FS, total thermal drift(-20~+80℃)＜2.8%FS

Null Leakage:0.50~2.55 L/min based on customized spool overlap

Working Medium:Anti-wear mineral hydraulic oil, cleanliness NAS6~7 / ISO4406 17/14/11, fluid temperature range -20℃~+80℃

Net Weight:5.52kg

Electrical Parameters

Input Power Supply:24VDC wide range(18~32VDC), static standby current ≤950mA

Default Control Command:Factory pre-set ±10VDC differential analog input; ±10mA /4~20mA current signal available via factory modificationMoog Inc.

Connector:Standard 11-pin military circular receptacle, IP65 protection after full cable assembly

EMC Compliance:Conforms to EN55011 industrial electromagnetic compatibility standard

Port & Connection Configuration

Hydraulic Interface:ISO4401-08 NG25 standard hole layout with independent P supply, A/B actuator control ports, separated built-in T drain and dedicated external Y drain, factory pre-installed NBR mounting gasket

Electrical Interface:11-pin circular socket integrates 24V power, ±10V command signal and full-stroke LVDT feedback wiring; double-shielded control cable required with single-point cabinet grounding, no digital fieldbus communication function

Core Functions

1.Patented ServoJet jet-pipe pilot delivers superior contamination resistance vs traditional nozzle-flapper pilot, supporting long-term stable operation under moderately contaminated hydraulic fluid.

2.Custom extra-large-flow four-way spool realizes high-capacity position/force/pressure closed-loop adjustment; onboard LVDT closed-loop dynamically compensates spool thermal drift caused by wide ambient temperature fluctuation.

3.Spring-centered fail-safe neutral design: main spool auto returns to center upon power loss to block A/B oil circuits and lock hydraulic cylinder for equipment safety protection.

4.Factory fixed amplifier gain optimized for heavy-duty large-flow continuous operation; ±10VDC analog input provides excellent anti-interference for long-distance wiring precision closed-loop control.

Typical Application

Super-large tonnage hydraulic forging press master cylinder closed-loop force control, heavy metallurgical hot rolling mill roller high-precision positioning system, large-scale aircraft structural part hot-forming hydraulic test bench, ultra-large die-casting machine clamping & injection servo control, marine heavy-load hydraulic power servo system.

Installation & Maintenance Instructions

1.Install 3μm high-pressure inline precision filter on upstream P supply pipeline; replace filter cartridge after 15 working days of equipment commissioning startup.

2.Arrange power cable and shielded control wire inside separate wiring troughs to avoid inverter harmonic interference to analog control signal; mount valve with specified tightening torque and standard flat washers during installation.

3.Flow gain and null offset parameters are fully pre-calibrated at MOOG factory; only minor on-site potentiometer fine adjustment permitted; full disassembly of ServoJet pilot and main spool assembly is strictly forbidden.

4.Seal unused spare T/Y drain ports with original factory blank plugs for spare storage; store inside dry dustproof warehouse to prevent NBR rubber seal ageing and hydraulic oil leakage.