METSO - NELES Positioner - ND9000 Series - ND9206HE1I09-KCE09A3

The Neles ND9000 is an intelligent positioner that uses a microcontroller to interpret a control signal, measure the actual valve position, and adjust pneumatic pressure to achieve the desired position. It works by comparing the input signal with the position feedback from a sensor and uses a control algorithm to modulate a pre-stage coil. This changes the pilot pressure to a spool valve, which directs air to the double diaphragm actuator, moving the valve until the position matches the setpoint.

Working principle

1. Input and measurement: A microcontroller (μC) receives an electrical input signal (e.g., 4-20 mA) and simultaneously reads the current valve position from a position sensor (α).
2. Control loop: The μC's control algorithm compares the input signal to the measured position to detect any difference or error.
3. Pneumatic control: Based on the error, the μC modulates the current to a pre-stage (PR) coil.
4. Spool valve adjustment: A change in the PR coil's current alters the pilot pressure, which in turn moves the spool valve.
5. Actuator movement: The spool valve directs the pneumatic supply pressure to one side of the double diaphragm actuator while allowing air to exhaust from the other side.
6. Position feedback: The resulting movement of the diaphragm piston causes the actuator and a feedback shaft to rotate.
7. Position sensor: The position sensor (α) measures the new angle of rotation and sends this feedback to the μC.
8. Correction: The process repeats, with the μC continuously adjusting the PR current until the actual position matches the setpoint, effectively correcting any error and ensuring precise control.

The Metso Neles ND9000 is a microprocessor-based intelligent valve controller that uses a digital control loop with continuous feedback to accurately position a pneumatic valve actuator according to an input signal.

Working Principle

The ND9000 operates as a closed-loop control system, continuously measuring the actual valve position and comparing it to the desired position (setpoint) received from a control system (e.g., DCS).
The core steps of the working principle are:

1. Signal Input and Measurement: The microcontroller μC in the positioner receives an electrical input signal (either a 4-20 mA analog signal or a digital signal via fieldbus communication like HART, PROFIBUS PA, or FOUNDATION fieldbus) representing the desired valve position. Simultaneously, the μCreads measurements from several internal sensors:

• Valve position: Measured by a contactless position sensor (angle a).
• Actuator pressures: Two independent measurements (P1, P2).
• Supply pressure (P_s)
• Spool valve position (SPS).
• Device temperature.

2. Error Detection and Calculation: A control algorithm within the  μC compares the input signal (desired position) with the actual valve position measured by the position sensor. If there is a difference (an error signal), the μC calculates a new value for the current sent to the prestage (PR) coil.
3. Pneumatic Control: The change in current to the PR coil alters the pilot pressure that controls the main spool valve. This pressure change moves the spool.
4. Actuator Movement: The movement of the spool opens the flow of high-pressure air from the supply to one side of the pneumatic actuator (diaphragm or cylinder type) and opens the exhaust from the other side. The resulting pressure difference forces the actuator's diaphragm or piston to move, which in turn moves the valve stem or shaft.
5. Feedback and Modulation: As the actuator and the feedback shaft rotate or move, the position sensor continuously measures the new position and sends this feedback to the μC. The μC repeatedly modulates the PR current until the actual valve position matches the target position dictated by the input signal, ensuring high control accuracy and stability.

This continuous feedback loop allows the ND9000 to maintain precise control, compensate for external disturbances (like changing process forces or air pressure fluctuations), and perform advanced diagnostics.

 Full Datasheet

Positioner Transmitter Feature  

• Manufacturer: Metso - ND9000 Series
• Product No. : ND9206HE1I09-KCE09A3                                              
• PRODUCT GROUP - ND - Intelligent Valve Controller
• Series Code: 9 - Series 9000 valve controller with universal shaft and attachment face according to standard VDI/VDE 3845.
• ENCLOSURE: 2 - Flameproof (Ex d) IP66 / NEMA 4X enclosure
• SPOOL VALVE / PNEUMATIC CONNECTIONS (S, C1,C2): 06 -SPOOL VALVE High capacity. Stroke volume
  of actuator > 3 dm³  / PNEUMATIC CONNECTIONS (S, C1, C2 ) G 1/4 (ND9100), 1/4 NPT (ND9200/ND9300/ND9400).
• COMMUNICATION / INPUT SIGNAL RANGE: H - 4–20 mA, HART (6 and 7) communication.
• PAPPROVALS FOR HAZARDOUS AREAS: E1 -ATEX and IECEx certifications:
• LIMIT SWITCH TYPE: I09 - P+F; NCB2-12GM35-N0, 2-wire type, DC; > 3 mA; < 1 mA, NAMUR NC
  Temperature range: -25° to +85 °C / -13° to +185 °F.
• Filter regulator for supply air: K - Driver set for ND72/92/93 on actuators with VDI/VDE 3845 attachment face.
• CONDUIT ENTRY NIPPLES: CE09 - 1/2 NPT conduit entry nipples Brass M20x1,5 / 1/2 NPT, Exd approved (ND9200)
• PRESSURE GAUGES AND CONNECTION BLOCKS: A3 - Pressure gauges, scale bar/psi/kPa, basic material brass, nickel

There are several Model of positioner, for more details read the PDF below 

Basic Ordering Information