Model Code Definition

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

4707 = Factory preset zero-overlap four-way spring-centered metering spool with dedicated optimized flow gain, null position fully OEM pre-calibrated, standard factory amplifier circuit without K custom modification

Technical Specifications

Hydraulic Parameters

Rated Flow:472 L/min @35bar single-land differential pressure; peak instantaneous flow 1590 L/min @70bar supply differential pressure

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

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

Control Precision:Hysteresis＜0.25%FS, Resolution＜0.070%FS, total thermal drift(-20~+80℃)＜2.1%FS after factory gain optimization

Null Leakage:0.28~1.85 L/min subject to 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:5.67kg

Electrical Parameters

Input Power Supply:24VDC wide input range(18~32VDC), static standby current ≤880mA

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

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

EMC Compliance:Conforms to EN55011 industrial electromagnetic compatibility specification

Port & Connection Configuration

Hydraulic Interface:ISO4401 NG25 standard hole layout containing 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, standard X pilot port sealed with factory blank plug for non-external pilot oil setup

Electrical Interface:11-pin circular socket integrates 24V power supply, ±10V command signal and full-range 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 far better contamination resistance than traditional nozzle-flapper pilot, securing long-term continuous stable operation under medium-dirty hydraulic oil of metallurgical workshop and test laboratory.

2.Optimized fixed flow gain of 4707 spool matches high-flow closed-loop control requirement; four-way zero-lap spool realizes high-precision position/speed/force closed-loop regulation for heavy rolling mill and large hydraulic test bench; onboard LVDT dynamically compensates temperature-induced spool drift.

3.Spring-centered fail-safe neutral design: main spool automatically returns to middle position once power cuts off, isolating A/B oil passages to lock hydraulic cylinder and prevent unexpected equipment runaway damage.

4.Factory pre-calibrated amplifier features strong anti-interference for long-distance field analog wiring under harsh industrial site environment.

Typical Application

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

Installation & Maintenance Instructions

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

2.Arrange power cable and shielded control wire inside separated wiring ducts to avoid inverter harmonic interference to analog control signal; fix valve with factory specified bolt tightening torque and standard flat washers.

3.Flow gain and null offset parameters of standard 4707 version are fully pre-calibrated at MOOG factory; only minor on-site potentiometer fine-tuning is permitted; complete disassembly of ServoJet pilot assembly and main spool unit is strictly prohibited.

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.