Fisher instrumentation and software are designed to help you diagnose the condition of your control valve assembly.
The microprocessor inside the digital valve controller allows the positioner to run, analyze, and store diagnostic tests. Diagnostic information is useful in determining the health of the entire control valve assembly. Through the use of pressure sensors, temperature sensors, travel sensors, and internal readings, graphical representations of control valve performance and health are created and recommended actions are presented. This information is then used to identify elements of the control valve assembly that may require maintenance.
In-service diagnostics can detect problems with instrument air quality, leakage, and supply pressure restriction, and can identify control valve problems such as excessive friction, dead band, and falling out of calibration.
The status monitor enables real-time online monitoring of instrument operational parameters such as input current, travel setpoint, travels, and pressures. This diagnostic also allows for information about active alerts including Field Diagnostic alerts.
These are available with ValveLink Software and the FIELDVUE digital valve controller HART Communicating (HC) diagnostics level and above.
Out‐of‐service diagnostics such as valve signature, dynamic error band, and step response assist in the identification of emerging valve problems to identify issues and repairs before they impact performance.
•Evaluate valve friction, deadband, and shutoff capability
•Calculate actuator spring rate and bench set
•Identify potential packing problems
•Compare current condition to previous baseline condition
These are available with ValveLink Software and the FIELDVUE digital valve controller Advanced Diagnostics (AD) level and above.
Air mass flow diagnostics measure instrument air flow through the actuator assembly. Because of multiple sensors, this diagnostic can detect both positive (supply) and negative (exhaust) air mass flow from the digital valve controller. This diagnostic not only detects leaks in the actuator or related tubing, but also much more difficult problems. For example, in piston actuators, the air mass flow diagnostic can detect leaking piston seals or damaged o-rings.
These are available with ValveLink Software and the FIELDVUE digital valve controller Performance Diagnostics (PD) level.
The supply pressure diagnostic detects control valve problems related to supply pressure. This in-service diagnostic will detect both low and high supply pressure readings. In addition to checking for adequate supply pressure, this diagnostic can be used to detect and quantify droop in the air supply during large travel excursions. This is particularly helpful in identifying supply line restrictions.
These are available with ValveLink Software and the FIELDVUE digital valve controller Performance Diagnostics (PD) level.
The in-service friction and deadband diagnostic determines friction in the valve assembly as it is controlled by the control system. Friction diagnostics data is collected and trended to detect valve changes that affect process control.
These are available with ValveLink Software and the FIELDVUE digital valve controller Performance Diagnostics (PD) level.
A digital valve controller can be used as a partial stroke testing device. The instrument performs a valve partial stroke test by slowly moving the valve a portion of its total valve travel and then returns to the normal state. This exercises the mechanical components of the safety valve with minimal disruption to the process.
Furthermore, the digital valve controller has the ability to diagnose potential issues and communicate test results. A digital valve controller can provide complete documentation of any emergency event as well as documentation of all testing, which can be made available as proof of testing.
These are available with ValveLink Software and the FIELDVUE digital valve controller Partial Stroke Testing (PST) and Safety Instrument System (SIS) diagnostics level.
Learn about the diagnostic level options for Fisher FIELDVUE DVC6200 Series digital valve controllers.
