Model Code Definition

D662 = NG16 ISO4401 mounting dimension, two-stage ServoJet jet-pipe pilot construction, built-in integrated electronics base series

4951 = customized specification code defining fixed rated flow, zero-lap linear spool profile, preset null bias, flow gain and dual T/Y drain fixed configuration.

Technical Specifications

Hydraulic Parameters

Rated Flow: 320 L/min at 35bar single land pressure drop; peak bulk flow 535 L/min under 70bar supply differential pressure

Max Working Pressure: P/A/B main ports 350bar; internal T drain ≤50bar; standalone Y external drain rated 350bar

Dynamic Response: Full stroke 0~100% step response ≤29.2ms at 210bar supply pressure

Control Accuracy: Hysteresis＜0.20%FS, Resolution＜0.08%FS, overall thermal drift (-20℃~+55℃)＜2.5%FS

Null Leakage: 0.65~3.72 L/min

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

Net Weight: 3.93kg

Electrical Parameters

Input Power Supply: 24VDC wide input range (18~32VDC), no-load quiescent current ≤765mA

Standard Control Command: ±10VDC differential analog input; optional ±10mA /4~20mA current signal on special order

EMC Compliance: Conforms to EN55011 industrial EMC standard; 7-pin military circular connector with IP65 protection ratingMoog Inc..

Port & Communication Configuration

Hydraulic Interface: Standard ISO4401-07 NG16 hole layout, P supply port, A/B actuator control ports, built-in T drain and separated external Y drain port

Electrical Interface: 7-pin military circular receptacle integrating power supply, analog command and full-range LVDT feedback wiring; double-shielded control cable with single-point cabinet grounding

Communication Mode: Pure analog closed-loop regulation, no digital fieldbus interface equipped.

Core Functions

Patented ServoJet jet-pipe pilot outperforms conventional nozzle-flapper design on anti-clogging property, enabling long-term stable continuous operation under moderately polluted hydraulic fluid in harsh production environments.

Embedded drive amplifier cooperates with full-travel LVDT closed-loop circuit to automatically compensate temperature-induced null shift, supporting 24-hour nonstop full-load running.

Standard spring-centered spool design; spool mechanically returns to neutral upon power failure to seal A/B oil chambers and lock load position for equipment fail-safe protection.

Precision linear spool metering edge maintains consistent flow gain, supporting flexible switching among position, velocity and pressure closed-loop control modes on single valve assembly.

Typical Application

Large hot forging hydraulic press, automotive heavy sheet stamping production line, hot rolling mill strip tension control system, multi-channel high-power hydraulic fatigue test bench, large tonnage injection molding clamping hydraulic unit, aerospace composite thermal forming hydraulic equipment.

Installation & Maintenance Instructions

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

Separate high-power power cables and shielded control wires into individual wiring ducts to avoid inverter harmonic interference to analog control signals.

Null offset and flow gain parameters are fully factory pre-calibrated; only slight onsite potentiometer trimming allowed; full disassembly of ServoJet pilot module and main spool group is strictly prohibited.

Block all unused hydraulic ports with standard blank plugs during long-term spare storage; store inside dry dustproof warehouse to prevent seal degradation and unintended fluid leakage.