Positioner

Role of a Positioner                                                       

Conventional vs SMART Positioners                   

Mechanical Construction

• Bellows and Linkages

Requires alignment / adjustment

High Hysterisis & Deadband

Difficult to Calibrate

Modular Construction

Universal Compatibility & Mounting

Ease of Calibration & Mounting (Local or Remote)

High Accuracy

Diagnostics & Tuning capabilities

 Friction: Deadband & Hysteresis                                    

Limit Cycle: Result of Friction                                   

Overcoming Friction Effects

Improving Process Variability                                

• Set point often higher than desired/ optimum to cater for errors/ hysterisis/ deadband in pneumatic or analog instrumentation

• Digital instrumentation allow for better process control and reduced variability

• Allow opportunities for revised setpoints
• Savings derived in using lesser process medium to achieve process requirements; eg: lesser steam/ glycol to achieve heating/ cooling setpoints

Justification Summary

Operational Improvement

• Better control/ lower variability allows
  
  • Reduction in wastage from excessive steam/ glycol usage
  • Better product quality & output
• Lower air consumption with DVC2000 (2.3scfh) as compared to 3661 (8.8scfh) leads to savings in utilities usage/ compressor efficiency
• Simplified inventory from a common platform
• Simplified Engineering & Selection

Design - Reduces Cost                                                       

• Linkage free
• No contacting parts
• Hall sensor / magnet array in the channel on the back of the DVC2000 housing
• Approximately 80% of your positioner problems are linkage related - These problems will be eliminated

DVC2000 Communication Options

• Local User Interrface
  • Pushbuttons/LCD on every unit
• 375 Field Communicator
  • New Device Descriptions (DD’s)
• Powers PlantWeb
  • AMS Software
  • AMS ValveLink Software