Model Code Definition

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

4384 = Factory preset zero-overlap four-way spring-centered metering spool with fixed original flow gain, null position fully pre-calibrated during OEM production

K = Custom modified amplifier version, gain setup & wide-temperature drift compensation optimized for frequent load fluctuation of hot rolling and heavy forging equipment, non-standard factory default amplifier parameter configuration

Technical Specifications

Hydraulic Parameters

Rated Flow:435 L/min @35bar single-land differential pressure; peak instantaneous flow 1540 L/min @70bar supply differential pressure

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

Full Stroke Step Response:≤29ms under nominal 210bar supply hydraulic pressure

Control Precision:Hysteresis＜0.26%FS, Resolution＜0.072%FS, total thermal drift(-20~+80℃)＜2.2%FS after K-version circuit optimization

Null Leakage:0.30~1.90 L/min based on factory spool machining tolerance

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

Net Weight:5.63kg

Electrical Parameters

Input Power Supply:24VDC wide input range(18~32VDC), static standby current ≤895mA

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 specificationMoog 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, 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 delivers superior anti-contamination capability compared with traditional nozzle-flapper pilot, ensuring long-term stable continuous operation under moderately contaminated hydraulic oil environment of metallurgical workshops。

2.K customized amplifier effectively suppresses wide-temperature null drift; four-way zero-lap spool realizes high-precision closed-loop position/speed/force control for heavy-duty rolling mill and large forging press; onboard LVDT dynamically compensates spool deformation drift caused by ambient temperature variation.

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 avoid equipment runaway damage.

4.Factory pre-optimized fixed gain matches cyclic variable heavy load of rolling & forging production lines; ±10VDC analog input features excellent anti-interference for long-distance field wiring under harsh industrial conditions.

Typical Application

Hot & cold rolling mill roll gap closed-loop servo control, strip thickness AGC automatic adjustment system for continuous metallurgical rolling line, large slab hydraulic pressing equipment, heavy-duty metal forging master cylinder precision flow regulation, oversized hydraulic component fatigue test bench, large hydraulic extrusion forming equipment.

Installation & Maintenance Instructions

1.Mount 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 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 K customized edition 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.