Active IPLs
About Active IPLs
An active IPL is a device or system that changes from one state to another in response to a change in process activity. For example, a pressure relief device is an active IPL that opens when there is an abnormal change in the pressure inside a vessel and remains open until the pressure in the vessel reduces to a value below the settings in the pressure relief device.
In LOPA, you can create an Active IPL record for each type of active IPL. This record stores the recommended probability of failure on demand (PFD) of the active IPL device or system. The PFD value indicates the likelihood that the active IPL system will fail to perform its safety function when required. The Active IPL records populate the IPL Sub Type field in the IPL Checklist section of the Safeguard, which is of type Active IPL.
Default Active IPL Records
By default, the following Active IPL records are available in GE Digital APM:
Active IPL ID | Lower Range | Upper Range | Default Value |
---|---|---|---|
Rupture disc | 1E-05 | 0.1 | 0.01 |
Relief Valve | 1E-05 | 0.1 | 0.01 |
Basic Process Control System | 0.01 | 0.1 | 0.1 |
Access an Active IPL
Procedure
Create an Active IPL
Before You Begin
- For the Active IPL that you want to create, you must create a system code in the MI_ACTIVE_IPL System Code Table. The System Code Table populates the Active IPL ID box. When you create the Active IPL, in the Active IPL ID box, you must select the value that you entered in the System Code Table.
Procedure
Results
- In the IPL Checklist section of the Safeguard of type Active IPL, the Active IPL that you created appears in the list of values in the IPL Sub Type box.
Delete an Active IPL
Before You Begin
- Before you can delete an Active IPL, you must delete the corresponding System Code that you created in the MI_ACTIVE_IPL System Code Table.
Procedure
Results
- In the IPL Checklist section of the Safeguard of type Active IPL, the Active IPL that you deleted does not appear in the list of values in the IPL Sub Type box.Note: The values in the existing Safeguards that have used the deleted Active IPL will not be affected when you delete the Active IPL record.