• Valve Diagnostics based on FDT/DTM-Technology

• Predictive Maintenance capabilities

• Intelligent Alarm Management

• Service Management

• Self-surveillance in accordance with NE107

• Histograms for Valve Position- and Response-History

• Data collected
  up to 60 months

• Data stored inside positioner memory

• Determination of Stem Friction to prevent leakage and stuck stem

• Histogram for Friction-History

• Partial Stroke Test function for ESD applications

The valve diagnostic software VALcare™ is available as Device Type Manager (DTM) for integration into control systems based on the Field Device Tool (FDT) technology such as the Foxboro I/A™ Series System.
It is designed to support methods for evaluation of the valve health, operation and configuration.
The DTMs support the communication protocols HART, Profibus PA, FOUNDATION Fieldbus (FF) and FoxCom.
 

• DTMs based on FDT-specification 1.2

• DTMs for HART, Profibus PA, FOUNDATION Fieldbus and FoxCom

The FDT/DTM concept specifies a “frame application” with a uniform platform for software tools and provides the particular advantage of a simple, standardized and common implementation and engineering environment to integrate field devices into any FDT compliant control system.
   It defines interfaces and mechanisms which provide a simple method of running a type of “printer driver” for field devices, the Device Type Manager (DTM).
   DTM describe the field device specific software component. VALcare™ is such a “driver” and supports the communication protocols HART, Profibus PA, FOUNDATION Fieldbus and FoxCom. FDT supplements the DDL-technology and offers much more, a unified architecture for all devices in a plant. Benefit, the “driver” can be integrated into any FDT compliant control system.
 

• Continuous evaluation of the state of the valve

• Self-surveillance methods following the NAMUR Recommendation NE107

The internal diagnostic-routines continuously evaluate the state of the valve and inform the operator of any irregularities by executing a status- and/or diagnostic-message by using the self surveillance methods following the NAMUR Recommendation NE107.
  The total operating hours of the device can be displayed. Service Intervals can be timed, using the Service Management. Histograms show the Valve Position History or Valve Response History. The Stem Friction can be measured to identify possible problems caused by a reduced or increased friction on the stem packing.
  The measured values are then displayed in the Histogram for the Friction History.


 

• Intelligent alarm-management

• Color coding for each alarm level

• Trouble-shooting for each alarm

Self-surveillance and diagnosis monitoring following the Namur Recommendation NE107. This recommendation defines unified status messages for field devices, providing the user with information about the state of the field instrument.
  The available information indicates clearly what device-alarm was activated, where the alarm initiated from, possible reason for the alarm and what corrective actions need to be initiated to restore a normal operating state. In the illustration below the realization is shown. All alarms are generated in the positioner and can be uploaded at any time.
  The columns show the displayed status messages, e.g. control difference, air supply pressure alarm, high friction alarm, current or historical message, a full text description explaining the possible reason for the status message, and the actions for maintenance.
  Status indicators are distinguished by messages and color-coding similar to traffic signals:
Green indicates that no status messages are present; grey that a status message is present but no maintenance is required; yellow that maintenance is required but an operation is still possible; red indicates a device failure that requires an immediate service.
  Comparing the historical and current alarm supports the operator if all messages have been eliminated.

Diagnosis List:

 

• Data collected up to 60 months

• Data stored inside positioner memory

• Color coding shows the operator if this is a critical (red) or non-critical (green) operation

The positioner database can be analysed at a later time by loading the data to a Control System or to a PC while the valve is still in the process. Unnecessary down times are optimized, because the valve can be inspected while it’s still in operation. The data can be visualized in different freely definable time intervals.
  This allows the observation of the last 15 minutes, 24 hours, 30 days and up to 60 months.

Position History:

Response History:

 

• Determination of Stem Friction to prevent leakage and stuck stem

• Histogram for Friction-History

The Stem Friction is an indispensable feature for today’s predictive maintenance capabilities of any control valve.
  This feature allows predicting possible leakages or stuck valves; and, in return, prevents dangerous spills, injuries to personnel, damage to plant equipment and the environment. This also saves expensive downtime of the valve.
  Internal pressure sensors (optional) measure the output- pressure for each setpoint change. In Milliseconds, the Microprocessor of the positioner calculates the friction of the stem against the packing. The actual friction value is then displayed as Measuredand Average-Value with additional drag-pointers for the Maximum- and Minimum-Value.
  Friction Alarms can be configured to inform the operator if the Friction values have exceeded or gone below certain thresholds limits.
  Setting a Friction Reference allows the operator to set a fingerpoint showing the initial Average Friction in connection with the Reference Time. This value will then be highlighted as a vertical line in the Histogram for the Friction History.

Friction Alarms:



Friction History
The Histogram for the Friction History is an easy tool to show the operator the actual condition of the stem packing over time.
  The vertical line shows the Reference value defined by the operator after the valve has “broken in”. From that moment everything is done automatically by the positioner. If there is Less friction, the histograms will shift to the left, if there is More friction, the histograms will shift to the right.
  If Friction Alarms are set, the positioner will automatically execute a Diagnosis Alarm once the values of the configured thresholds are reached.
  A comparison can be done between two different historians from 1 to 30 days and 1 to 60 months.


 

• Testing of ESD-valves in applications such as ON-OFF-, Blow Down- and Venting

• Manual or automatic testing modes

• Test result for partial stroke test

Final control elements in ESD applications such as ON-OFF-, Blow Down- and Venting-Valves remain in one position over a longer time without any mechanical movement.
  These valves can show a tendency to get stuck; and, as a result, might not operate on demand. This can have a severe impact to the functionality of a Safety System and damaging result to the operating personnel, plant equipment, and environment.
  The Partial Stroke Test (PST) offers operators a tool to identify the trouble-proof function of such ESD valves. The test can be easily executed via the operation and diagnostic tool VALcare™.
  In the Manual mode the test can be activated via a Start button and in Automatic within a freely defined time interval in hours that allows stroking the valve periodically. In both cases the valve can be stroked within a stroke-ratio of up to 30 %. The maximum wait time allows taking into account that each valve has a different dynamical behaviour e.g. caused by the process media or the valve itself.
  If the valve has performed the test without any problems, the status for the partial stroke test will go to "OK". In case the valve does not move and could be stuck, the operator will be informed by an alarm indicating an “Error”.
  Besides this the device continuously monitors the health of the control valve, among others such as the stem friction, supply- and output-pressure.