Neles ™ NDX ™ Compact intelligent valve controller (positioner)

Product Overview

NDX compact intelligent valve controller, optimized for single acting pneumatic actuators, compatible with various types of regulating valves such as rotary and linear stroke; Equipped with excellent control performance, a complete set of valve diagnostics, capable of predictive maintenance of equipment assets, and full lifecycle technical support.

Total cost advantage

Quick and reliable installation and debugging;

Low power consumption of gas source and low steady-state gas consumption;

Built in comprehensive diagnosis to determine the timing of valve maintenance;

High output aerodynamic capability, no need for additional relay amplifiers;

Single model can adapt to valves of different sizes: rotary, straight stroke, single acting actuator;

Provide intrinsically safe explosion-proof version.

Core Key Features

Durable and reliable modular design, resistant to vibration and impact; Protection level IP66/NEMA4X;

Industry leading pneumatic output capability;

Benchmark level control performance;

No need to open the local human-machine interface LUI, easy and fast debugging; Support local/remote operations;

The maximum straight stroke is 220 mm, and the rotation angle is 30-160 °;

Standard HART7 protocol (compatible with HART6);

Complete diagnosis: self diagnosis, online diagnosis, historical trends, communication diagnosis, offline extended testing;

Explosion proof certification in multiple countries worldwide;

Scalable architecture, supporting FDT/EDD, compatible with multiple vendor systems;

Contactless position measurement, maintenance free.

Optional configuration

Built in isolation two-wire position transmitter PT (4-20mA valve position feedback output);

Gauge block (gas supply/actuator pressure display) for pressure gauge module.

Control performance benefits

The flow characteristics of the valve can be linearized by software;

Excellent dynamic and static control performance, responding quickly to changes in control signals;

High precision internal measurement (valve position, gas supply pressure, actuator chamber pressure, body temperature).

Configuration debugging approach

Local user interface LUI: The casing does not need to be disassembled, with capacitive touch buttons, and the LUI module can rotate to adapt to different installation positions; Support password locking to prevent accidental operations; Multilingual (including Chinese); Support guided startup wizard, automatic/manual/one point calibration, three-point linearization.

Remote: DCS asset management software, PC based Neles Valve Manager (FDT/DTM);

Transformation compatibility: can directly replace the old Neles NE700, ND9000, and also adapt to a large number of third-party regulating valves;

Open architecture, driver files can be downloaded from the Valmet official website.

Installation adaptation

Mainly suitable for single acting pneumatic actuators, also supports double acting;

Interface standards: VDI/VDE 3845, IEC 60534-6;

Straight stroke: standard 5-120mm; long stroke 120-220mm; rotation 30-160 °;

Guided startup, automatic/manual calibration.

Predictive maintenance capability

FDT/DTM software reads all data collected by the device;

Patent online valve characteristic curve Signature;

Continuously collect trends and histograms online;

Enrich offline testing and calculate key performance indicators;

Online alarm notification;

Valve Manager software visualizes the health status of five dimensions: locator, actuator, valve, control, and environment, with fault explanations and handling suggestions.

Working principle

NDX is a 4-20mA circuit powered microcontroller locator.

Circuit 4-20mA input set valve position;

Real time sensor collection: input signal, non-contact valve position, actuator pressure, gas supply pressure, equipment body temperature;

The microcontroller calculates the output signal to control the I/P converter (front-end);

I/P drives pneumatic power relay (output stage) to change the air pressure output to the actuator;

The actuator drives the valve to move; The position sensor provides feedback on the actual valve position and adjusts it in a closed-loop manner until the actual valve position matches the given signal.

Equipped with self diagnosis, monitor whether all measurement channels are normal.

Main technical specifications

General Parameters

Power supply: 4-20mA circuit power supply, no external power supply required;

Form of action: single action, positive/negative action can be set by software;

Travel range:

Straight stroke standard: 5-120mm; Long stroke: 120-220mm

Rotation angle: 30-160 °

Whole machine temperature: -40 ° C~+85 ° C; LUI operating temperature -25~+65 ℃

Shell: Copper free aluminum alloy (epoxy resin anodized); Lid polycarbonate; Protection IP66; Transport and storage IP67;

Weight: 2.0 kg;

Gas port: supply gas, output actuator 1/4 NPT/G1/4; Exhaust 3/8   NPT/G3/8; Cable port 2 × 1/2NPT (can be equipped with M20 adapter).

pneumatic parameters

Gas supply pressure: single acting 1.4-8 bar; Double acting 2-8 bar; Maximum 8 bar;

Media: dry air, nitrogen, clean natural gas;

Air quality ISO 8573-1: Particle level 7, humidity level 1, oil level 3 (<1 ppm);

Pneumatic output capacity: 80 Nm ³/h @ 4 bar; Steady state gas consumption is only 0.1 Nm ³/h;

Electrical HART

Protocol: HART   7 (standard, backward compatible with HART6);

The minimum loop current is 3.8 mA, with a minimum control of 3.95 mA; the maximum current is 120 mA;

Equipped with reverse polarity protection and overcurrent protection; The wire diameter is 0.5-2.5 mm ² (14-20AWG).

Control performance (medium constant load actuator)

Project indicators

Dead zone ≤ 0.2%

Return difference<0.5%

Linear error<0.5% (long stroke<1.5%)

Repeatability<0.2%

Local LUI human-machine interface

4 capacitive touch buttons (UP, DOWN, ENTER, BACK), no need to open the cover; Function: Password lock, power on wizard, multiple languages, multiple calibration modes, three-point linearization, configuration of valve/actuator parameters, monitoring of all real-time variables, local manual control of valves.

Optional built-in position transmitter PT

Isolation 4-20 mA output, isolation voltage 600 VDC; Power supply 12-30 VDC;

Linearity<0.05% FS; optional fault output of 3.5 mA or 22.5 mA.

Explosion proof certification

Complete ATEX, IECEx, cCSAus, CCC-Ex, Inmetro, KOSHA and other certifications; Including: intrinsic safety Ex ia, Ex ib, explosion-proof Ex db, increased safety Ex ec, dust explosion-proof; Different temperature groups T4/T5/T6 correspond to different allowable ambient temperatures; Support hazardous areas such as Zone0/1/2 and Division1/2.

Order code

NDX is a 21 bit character encoding, with each encoding bit defined as:

Product series NDX; 2-5: Model version (compact); 6: Communication protocol H (HART7); 7: Temperature level G (-40~+85 ℃ universal); 9-10: Explosion proof certification code (X=ATEX/IECEx; U=cCSAus; C=CCC-Ex; Z=Inmetro; W=KOSHA; N=No Explosion proof); 11: Gas port thread and pressure gauge module: 0=NPT without gauge; 1=NPT with pressure gauge; 2=G1/4 without table; 3=G1/4 with pressure gauge; 12: Variant; 13: Diagnostic level; Other reserved and partner codes.