Model Code Definition

D664 = D660 high-flow subseries, ISO4401-08 NG25 mounting, ServoJet jet-pipe pilot, built-in amplifier + full-travel LVDT spool closed-loop feedbackMoog Inc.

339 = Exclusive spool trim number: four-way spring-centered zero-lap linear metering spool, factory fixed amplifier gain & null offset preset calibration

No suffix = Standard nitrile rubber seal, dual independent drain ports (internal T + external Y), conventional anti-vibration amplifier layout

Technical Specifications

Hydraulic Parameters

Rated Flow:530 L/min @35bar single-side differential pressure; peak instantaneous flow 745 L/min @70bar supply differential pressure

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

Full Stroke Step Response:≤39ms under standard 210bar supply hydraulic pressureMoog Inc.

Control Precision:Hysteresis＜0.28%FS, Resolution＜0.085%FS, overall thermal drift(-20~+80℃)＜2.6%FS

Null Leakage:0.45~2.40 L/min derived from zero overlap spool structure

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

Net Weight:5.25kg

Electrical Parameters

Power Supply:24VDC wide input range(18~32VDC), static standby current ≤920mAMoog Inc.

Default Control Input:Factory pre-calibrated ±10VDC differential analog signal; ±10mA /4~20mA current signal configurable via factory modification

Connector:Standard 11-pin circular aviation plug, IP65 protection after cable fitting

EMC:Compliant with EN55011 industrial electromagnetic compatibility standard

Port & Connection Configuration

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

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

Core Functions

1.Patented ServoJet jet-pipe pilot features superior contamination resistance compared with traditional nozzle-flapper pilot, enabling continuous stable operation under moderately contaminated hydraulic oil condition.

2.Zero-lap four-way main spool realizes high-precision large-flow pressure/position/force closed-loop regulation; onboard LVDT closed-loop dynamically offsets spool thermal expansion drift, dual T/Y drain improves low-pressure backflow stability for heavy-load continuous running.

3.Spring-centered fail-safe design: main spool automatically returns neutral upon power cut-off to block A/B oil paths and lock hydraulic cylinder for equipment overload protectionMoog Inc..

4.Factory fixed amplifier gain optimized for medium-large flow heavy-duty working condition; ±10VDC analog input delivers reliable anti-interference performance for long-distance wiring precision closed-loop control.

Typical Application

Large tonnage hydraulic forging press master cylinder closed-loop force control, metallurgical medium-size hot rolling mill roller positioning servo system, heavy-duty vehicle component fatigue test bench hydraulic drive, large aluminum alloy die-casting machine injection & clamping closed-loop control, ship hydraulic test bench high-flow precision servo control equipment.

Installation & Maintenance Instructions

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

2.Separate power cable and shielded control wire in independent wiring ducts to avoid inverter harmonic interference on analog control signal; install valve with factory specified tightening torque and standard flat washers.

3.Flow gain and null offset parameters are fully pre-calibrated at factory; only slight on-site potentiometer fine-tuning allowed; complete disassembly of ServoJet pilot assembly and main spool assembly is strictly prohibited.

4.Plug unused spare T/Y hydraulic ports with original factory blank plugs for spare inventory; store in dry dustproof warehouse to avoid NBR rubber seal ageing and oil leakage.