Model Code Definition

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

4311 = Factory preset zero-overlap four-way spring-centered metering spool with fixed original flow gain, pre-calibrated null offset at production line

K = Custom modified amplifier version, gain & thermal drift compensation optimized for long-cycle fluctuating load of hot/cold rolling production line, non-standard default factory amplifier parameter setting

Technical Specifications

Hydraulic Parameters

Rated Flow:355 L/min @35bar single-land differential pressure; peak instantaneous flow 1350 L/min @70bar supply differential pressure

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

Full Stroke Step Response:≤34ms under nominal 210bar 210bar supply hydraulic pressure

Control Precision:Hysteresis＜0.30%FS, Resolution＜0.085%FS, total thermal drift(-20~+80℃)＜2.5%FS after K-version circuit optimization

Null Leakage:0.35~2.00 L/min determined by factory spool machining tolerance

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

Net Weight:5.52kg

Electrical Parameters

Input Power Supply:24VDC wide input range(18~32VDC), static standby current ≤915mAMoog Inc.

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 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 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 superior anti-pollution ability compared with traditional nozzle-flapper pilot, ensuring long-term stable continuous operation under medium contaminated hydraulic oil of metallurgical rolling workshop.

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; 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 prevent roller runaway damage.

4.Factory optimized fixed gain matching cyclic variable load of rolling line; ±10VDC analog input owns strong anti-interference performance for long-distance on-site wiring of metallurgical production line.

Typical Application

Hot & cold rolling mill roll gap automatic 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 flow precision regulation, hydraulic fatigue test bench for large hydraulic component.

Installation & Maintenance Instructions

1.Install 3μm high-pressure inline precision 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 command signal; mount 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 permitted; complete disassembly of ServoJet pilot unit and main spool assembly is strictly prohibited.

4.Block 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.