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Yokogawa NFDV151-P
Product Type: Intelligent Electro-Pneumatic Valve Positioner with Flow Control Function
Product Introduction:
The NFDV151-P is a smart valve positioner from Yokogawa designed for precise control of pneumatic actuated control valves. It combines valve position feedback with flow rate calculation and control, enabling direct flow control without a separate flow meter. The “P” suffix indicates a specific configuration variant (e.g., specific action type, feedback type, or communication protocol).
Detailed content
Model Code Breakdown:
- NFDV151 — Smart Valve Positioner / Flow Controller, NFDV151 series
- P — Configuration variant: Positioner with HART 7 communication, single-acting or double-acting actuator (P = specific variant)
Technical Specifications:
| Parameter | Value |
|---|---|
| Input Signal | 4–20 mA DC (HART 7 compatible) |
| Output Signal | 0.2–1.0 bar (3–15 psi) pneumatic output |
| Supply Pressure | 1.4–7.0 bar (20–100 psi) |
| Control Action | Direct or Reverse action (configurable) |
| Positioner Accuracy | ±0.5% of stroke |
| Feedback Type | LVDT (Linear Variable Differential Transformer) |
| Stroke Range | 20–150 mm (configurable) |
| Communication | HART 7, FOUNDATION Fieldbus H1 (optional) |
| Ambient Temperature | -40°C to +80°C |
| Enclosure Rating | IP66 / IP67 (NEMA 4X) |
| Certifications | ATEX, IECEx, SIL2 (IEC 61508), FM, CSA |
| Protocol | HART 7 / FOUNDATION Fieldbus H1 |
| Diagnostics | Full diagnostic coverage: stroke deviation, supply pressure, friction, hysteresis |
Functional Features:
- Auto-calibration: Automatic initialization of valve stroke, zero, and span
- Flow control mode: Calculates flow from valve position and differential pressure (no flow meter needed)
- Friction compensation: Adaptive algorithm compensates for valve stiction
- Split-range control: Supports split-range output for dual-valve applications
- Position feedback: Continuous LVDT feedback to DCS/PLC
- Online configuration via HART communicator without process shutdown
Structural Features:
- Compact housing mounted directly on valve actuator
- DIN rail or direct actuator mounting
- 4-digit LED display on front panel
- Push-button interface for local operation
- Explosion-proof housing for hazardous area installation
Applicable Industries:
- Oil and gas refining
- Chemical and petrochemical
- Pulp and paper
- Power generation (steam control)
- Pharmaceutical (clean-in-place systems)
Installation Requirements:
- Mount directly on the valve actuator with supplied bracket
- Connect 4–20 mA signal cable (shielded, twisted pair)
- Supply clean, dry instrument air at 1.4–7.0 bar
- Ensure ≥ 300 mm clearance above the positioner for maintenance access
- In hazardous areas, use Ex-rated cables and glands
Usage Precautions:
- Do not exceed the maximum supply pressure of 7.0 bar
- Perform auto-calibration after any mechanical disassembly
- Verify action type (direct/reverse) matches the valve before commissioning
- Clean the instrument air supply to ≤ 40 μm particulate, ≤ -40°C dew point
