Protective Instrument Loop Final Element Records

Protective Instrument Loop Final Element records store details about final elements for a protective instrument loop. This topic provides an alphabetical list and description of the fields that exist for the Protective Instrument Loop Final Element family. The information in this table reflects the baseline state and behavior of these fields. This list is not comprehensive.

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Field	Data Type	Description	Behavior and Usage
Approved Custom Device	Logical	Indicates whether the final element is approved to be used.	This field is disabled and selected if the final element has been approved to use via the Validation Failure Rate Reference Data feature.
Base SFF	Number	Safe Failure Fraction without diagnostic detection.	This field is disabled. The GE Digital APM system calculates this value based on the final element, the interfaces, and the pneumatic elements for the final element.
Custom PVST Coverage	Number	A numeric value representing the percentage of possible failures that could be detected by the partial valve stroke test.	This field is enabled only if the Partial Valve Stroke Testing check box is selected.
Dangerous combination of outputs?	Logical	Indicates whether the output associated with the final element can lead to a hazardous event if it occurs simultaneously with the output associated with another final element.	By default, this check box is cleared. When you select this check box: The Potential Dangerous Combination of Outputs Description field is enabled and required. You must link another final element whose output can be hazardous if it occurs simultaneously with the output of this final element. You can clear this check box only if no final element is linked to the current final element as a dangerous combination of outputs.
Description	Character	A description for the final element.	None
Final Element	Character	The name of the final element.	The values in this list are from Exida's Safety Equipment Reliability Handbook (SERH) and approved custom devices in the GE Digital APM system. After you select a value from the list, the following details about the final element appear in the Devices pane: ID Device Tag Dangerous Detected Dangerous Undetected Safe Detected Safe Undetected
Final Element ID	Character	An ID for the final element.	This value is displayed in the diagram to identify the final element. This field is required.
Interface Module	Character	The interface between the final element and the logic solver.	The values in this list are from Exida's Safety Equipment Reliability Handbook (SERH) and approved custom devices in the GE Digital APM system and are based on the value in the Final Element field.
Potential Dangerous Combination of Outputs Description	Text	A description of the hazard that can occur based on the position or combination of two or more final elements.	This field is enabled and required only if the Dangerous Combination of Outputs? check box is selected. Otherwise, this field is disabled.
Severe Service	Logical	Indicates that the final element is exposed to severe service conditions such as heat, corrosion, fluid composition, and so on, which can influence the effectiveness of the final element.	This is applicable only if the final element is a valve.
SFF	Number	Safe Failure Fraction after applying diagnostics for the final element.	This field is disabled. The GE Digital APM system calculates this value, which is used to calculate MTTFS.
Tight Shutoff Required	Logical	Indicates that a tight shut off is required to achieve a safe state.	This is applicable only if the final element is a valve.
Use Combination	Logical	Indicates that remotely operated valves are used to include common valve and actuator combinations.	This is applicable only if the final element is a valve.
Valve Trip Open	Logical	Indicates that the valve, which is the final element, will trip open to achieve a safe state.	This is applicable only if the final element is a valve.