Model Code Definition

D664 = NG25 ISO4401 installation footprint, ServoJet jet-pipe pilot structure, built-in amplifier + full-travel LVDT spool closed-loop feedback, large-flow D660 subfamily

4759 = Factory preset zero-overlap four-way spring-centered metering spool with exclusive optimized flow gain, null position fully OEM pre-calibrated at factory, standard amplifier circuit without customized K parameter modification

Technical Specifications

Hydraulic Parameters

Rated Flow:505 L/min @35bar single-side differential pressure; peak instantaneous flow 1690 L/min @70bar supply differential pressure

Max Working Pressure:P/A/B main control ports up to 350bar; built-in T drain ≤210bar; external Y drain supports full 350bar working pressure

100% Full Stroke Step Response:≤28ms under nominal 210bar supply hydraulic pressure

Control Precision:Hysteresis＜0.22%FS, Resolution＜0.063%FS, total thermal drift(-20~+80℃)＜1.98%FS after factory gain fine-tuning

Null Leakage:0.24~1.75 L/min determined by original spool machining tolerance

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

Net Weight:5.79kg穆格中国

Electrical Parameters

Input Power Supply:24VDC wide voltage range(18~32VDC), static standby current ≤860mA

Default Control Signal:Factory standard ±10VDC differential analog input; ±10mA /4~20mA current signal available via factory custom modification

Connector:11-pin circular aviation socket, IP65 protection after complete cable assembly

EMC Standard:Conforms to EN55011 industrial electromagnetic compatibility regulationMoog Inc.

Port & Connection Configuration

Hydraulic Interface:ISO4401 NG25 standard hole layout including P supply port, A/B actuator control ports, separated built-in T internal drain and dedicated Y external drain; pre-installed original NBR mounting gasket, unused X pilot port blocked with factory blank plug for non-external pilot oil application

Electrical Interface:11-pin circular receptacle integrates 24V power supply, ±10V command signal and full-travel 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 much better dirt resistance than traditional nozzle-flapper pilot, ensuring long-term stable running under medium-impurity hydraulic fluid in metallurgical production workshops and test laboratories.

2.Optimized fixed flow gain of 4759 spool matches high-precision large-flow closed-loop control requirement; four-way zero-lap spool realizes accurate position/speed/force closed-loop adjustment for hot/cold rolling mill and heavy forging hydraulic cylinder; onboard LVDT automatically compensates spool drift caused by ambient temperature fluctuation.

3.Spring-centered fail-safe neutral design: main spool automatically returns to middle position upon power failure to cut off A/B oil circuit and lock hydraulic actuator, avoiding unexpected equipment runaway damage.

4.Factory pre-calibrated built-in amplifier possesses excellent anti-interference performance, adapting long-distance analog wiring under harsh industrial field environment.

Typical Application

Hot & cold continuous rolling mill AGC roll gap closed-loop servo regulation, heavy slab hydraulic forging press master cylinder precise flow control, full-scale hydraulic component fatigue test bench, large aluminum/steel extrusion forming equipment, marine hydraulic servo test system.

Installation & Maintenance Instructions

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

2.Arrange power cable and shielded control wire inside independent wiring troughs to prevent inverter harmonic interference on analog control signal; fix valve with factory specified bolt torque and standard flat washers.

3.Flow gain and null offset parameters of standard 4759 version are fully pre-set at MOOG factory; only slight on-site potentiometer fine adjustment is permitted; complete disassembly of ServoJet pilot assembly and main spool component is strictly forbidden.

4.Seal unused spare T/Y drain ports with original factory blank plugs during spare part storage; store valve in dry dustproof warehouse to prevent NBR rubber seal ageing and subsequent oil leakage.