PL External Corrosion - Impressed Current CP

Take Note

This overview explains how to read and add data to the Impresses Currect CP section in the External Corrosion module. The Impressed Current CP section will be visible solely when the Corrosion Protection field in the Pipe Design Data section on the Equipment Details Page is set to "Impressed current” or “Both”.

In the Impressed Current CP section of the External Corrosion Assessment Module there are 5 tabs:

• CP test Post Potential

• CIPS

• Rectifier Station

• Wet Insulation detection

• DCVG

The layout of all five tabs is similar:

1. An ECH overview from where you can see existing or create new ECHs.

2. The Datagrid.

3. The Graph.

CP Test Post Potential

This section includes the ECH grid, the Availability, and Cathodic Protection for Potential graphs. The Availability grid contains twelve columns: the Testpost ID, the Measuring point ID, the Inspector, the Survey date, the (An)Aerobic mode, the Potential in OFF mode, the Potential in ON mode, Upstand Potential, Pipe AC Voltage, the Skip column which indicates whether the row should be skipped and a Comment field.

For Offshore Pipelines only the Potential ON is measured, therefore only the Potential ON values will be used in the Assessment. The column Potential OFF will then be empty in the grid.

For Pipelines that are both Onshore and Offshore, the Pot Off is empty for Offshore sections.

Note: The Availability and CP data should be filled in on the ECH Details Page or imported in bulk. See PL Cathodic Protection to learn how to import the data.

The ECH grid displays the ECH data and the corresponding CP Indicator color. The CP Indicator color is determined based on the "Potential OFF" values from the CP Testpost survey, as follows:

Red Indicator:

• Potential OFF value is greater than -650 mV.

• Potential OFF value is less than -1500 mV.

Orange Indicator:

• Potential OFF value is greater than -950 mV but less than or equal to -650 mV.

• Potential OFF value is greater than or equal to -1500 mV but less than -1150 mV.

Green Indicator:

• Potential OFF value is greater than or equal to -1150 mV and less than or equal to -950 mV.

There are currently no defined limits for the "ON potentials."

The Availability parameter determines the Protection effectiveness for the entire Pipeline from the Installation Date.

Potential Graph

The Potential Graph displays the Potential OFF and Potential ON data for the entire Pipeline or a specific location.

To see the Potential data for a specific location:

• On the right side of the graph, select Location.

• From the drop-down menu, select the Location on the Pipeline.

Potential Over Time

This tab displays all the CP data on one screen.

CIPS

The CIPS tab displays the Close Interval Potential Survey data. The grid and the graph contain the same information as the CP Test Post Potential ones but with the addition of the Potential ON/OFF readings per meter. CIPS is only applicable to Onshore Pipelines.

If CIPS data is available, the Excor model will utilize them, provided that the CIPS data was recorded within six months of the Test Post recording date.

Rectifier Station Output

The Rectifier Station tab displays the Rectifier Station Output for Current and Voltage. The grid contains, among others, the following columns: Condition Date, Rect Station ID, Capacity, Location, Location Name, Capacity AC Input - Volts, Capacity AC Input - Amps, Capacity DC Output - Volts, Capacity DC Output - Amps…

Rectifier Station Graph

The Graph shows the DC Output_External-Current-As Found and DC Output_External-Voltage-As Found values per location through time.

To change the Location for which you want to see tha data in the Graph:

• Click on the Location drop-down menu.

• Select one of the available options.

Note: The Rectifier Station data is not used in any of the calculations. It is for display purposes only.

Wet Insulation Detection

The Wet Insulation Detection tab shows the Insulation resistance values per Test Post. The grid shows the Insulation resistance values through time.

The data is not used in any of the calculations. It is for display purposes only.

DCVG

The DCVG tab displays the ECH data for IR drop, P/RE and OL/RE per defect and the corresponding Indicator color. The Indicator color is determined based on the "IR %" values from the DCVG survey, as follows:

Red Indicator:

• IR (35%-70%)

• IR (70%-100%)

Orange Indicator:

• IR (15%-35%)

Green Indicator:

• IR (0-15%)

Adding ECH data to Impressed Current CP

All the Data, for each of the Tabs in the Impressed Current CP section, need to be entered via an ECH. To add data you will first need to create an ECH from the ECH grid of the aplicable Tab.

To create the ECH:

• Click the Plus button in the grid.

• Fill in the Condition Date.

• Fill in the Description.

• Click Save.

Clicking Save will open the ECH Details Page. IMS will automatically set the Actions Performed Checklist to the applicable option for (e.g., the Actions Performed will be “CP TEST POST SURVEY” for the ECH to enter data on CP Test Post Potential) and its value to “YES”.

• Click the Grid button.

  

This will open a grid where the survey data can be entered.

Adding Survey Data to ECH

After you create the ECH, add data to it manually or import it from an Excel Sheet.

To add the data manually, first, copy the measuring points from the Ext. Corr tab on the Equipment Details Page, Sectioning section to the ECH. Make sure that the measuring points are created on the Equipment details page. Note: This applies only to the CP test Post Survey Grid.

To copy the measuring points:

• Navigate to the Checklists section of the ECH.

• Click Plus in the grid.

• Locate the column header for the data you wish to enter (e.g., Potential OFF mV).

• Click on the field underneath the column header to activate it for input.

• Enter the desired value.

• Click Save.

• Final Approve the ECH.

Note: For CIPS, Wet Insulation Detection and DCVG you can create new measuring points directly from the applicable Grid on the ECH Details Page Checklist section by clicking the Plus button, filling in the ECH data and clicking Save.

To import the data via the grid in the Checklist section of the ECH Details page:

• Click the Import button.

  

• Follow the Import step-by-step process.

• Click Save.

To import the ECH data in bulk follow the Data import process in the Settings, making sure you select the correct Import Type. Note: To import the data for Rectifier Station ECH Survey, select the Import Type “Imposed Current”.

Adding Availability to the CP Test Post Survey

When adding ECH data in the CP TEST POST, you will also need to specify availibility.

To add Availability:

• On the ECH Details Page of the created ECH, scroll to the Checklist section.

• Above Availability, click Edit.

  

• From the Availability drop-down menu, select one of the available options.

• Click Save.