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 subseriesMoog Inc.

4383 = 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 variant, gain setting & wide-temperature drift compensation optimized for frequent load swing of rolling & heavy forging equipment, non-standard factory default amplifier configuration

Technical Specifications

Hydraulic Parameters

Rated Flow:428 L/min @35bar single-side differential pressure; peak instantaneous flow 1510 L/min @70bar supply differential pressure

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

100% Full Stroke Step Response:≤30ms under nominal 210bar supply hydraulic pressure

Control Precision:Hysteresis＜0.27%FS, Resolution＜0.075%FS, total thermal drift(-20~+80℃)＜2.25%FS after K-version circuit optimization

Null Leakage:0.31~1.92 L/min depending on factory 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:5.61kg

Electrical Parameters

Input Power Supply:24VDC wide input range(18~32VDC), quiescent standby current ≤900mA

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

Connector:11-pin circular aviation receptacle, IP65 protection after complete cable assemblyMoog Inc.

EMC Standard:Compliant with EN55011 industrial electromagnetic compatibility specification

Port & Connection Configuration

Hydraulic Interface:ISO4401 NG25 standard hole layout consisting of 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 blocked 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 better anti-pollution performance versus conventional nozzle-flapper pilot, securing long-term stable continuous running under moderately contaminated hydraulic oil environment of metallurgical rolling and forging 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 induced by ambient temperature variation.

3.Spring-centered fail-safe neutral layout: main spool automatically returns to middle position upon power failure to isolate A/B oil circuits and lock hydraulic cylinder, preventing accidental roller runaway and equipment breakdown.

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

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 compression 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 independent 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 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 avoid NBR rubber seal ageing and subsequent oil leakage.