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 APM:

Active IPL IDLower RangeUpper RangeDefault Value
Rupture disc1E-050.10.01
Relief Valve1E-050.10.01
Basic Process Control System0.010.10.1

Access an Active IPL

Procedure

  1. Access the LOPA Admin page.
  2. In the left pane, select Active IPL.
    A list of available Active IPLs appears.
  3. In the Active IPL ID column, select the link for the Active IPL that you want to access.
    In the Record Manager, the page for the selected record appears, displaying the datasheet for the record.
    Note: To modify the Active IPL, as needed, modify values in the available fields, and then select to save your changes. The values in the existing Safeguards that have used the modified Active IPL will not be affected by the changes. If you want to apply the changes to an existing Safeguard, in the IPL Checklist section of the Safeguard, in the IPL Sub Type box, you must reselect the Active IPL that you modified.

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

  1. Access the LOPA Admin page.
  2. In the left pane, select Active IPL.
    A list of available Active IPLs appears.
  3. In the upper-left corner of the workspace, select .
    A blank datasheet for Active IPL appears.
  4. As needed, enter values in the available fields.
  5. In the upper-right corner of the workspace, select .
    The Active IPL record is created.

Results

Delete an Active IPL

Before You Begin

Procedure

  1. Access the LOPA Admin page.
  2. In the left pane, select Active IPL.
    A list of available Active IPLs appears.
  3. In the row for each Active IPL that you want to delete, select the check box.
    In the upper-right corner of the workspace, the button is enabled.
  4. Select .
    The Delete Active IPL dialog box appears, asking you to confirm that you want to delete each selected Active IPL.
  5. Select OK.
    Each selected Active IPL is deleted.

Results