TML Groups

Suppose you have an asset, Piping Circuit 101, ) which contains three components, Line A, Line B, and Line C. On those components, there are multiple TMLs. The following image illustrates this example, where the components are represented by shaded regions, and the TMLs are represented by stars.

For a given asset, a TML Group can represent:

• All TMLs that exist on that asset. You would create a TML Group to represent all TMLs that exist on an entire asset if the asset is a standalone asset. You would create one TML Group to represent all of the stars.

• A subset of TMLs that exist on one or more components that belong to the asset. Using this option, you could create:

  • One TML Group per component, where the TML Group represents all TMLs that exist on that component. You would create three TML Groups, one to represent each set of stars.

    

    -or-

  • One TML Group for multiple components, where the TML Group represents all TMLs that exist on those components. Using the previous Piping Circuit 101 example, you could create two TML Groups, where one represents the blue and green stars and one represents the orange stars.

    

Additionally, throughout the life of the asset, you might identify one or more TMLs within a TML Group that you want to analyze separately from other TMLs. In this case, you can create additional TML Groups to represent any subdivision of an existing group of TMLs.

For example, suppose that an asset that you are analyzing in Thickness Monitoring represents a shell and tube heat exchanger. The shell and tube heat exchanger has two components, the shell side and the tube side, each with its own process flow. Since the corrosion environments of these components will differ, you might create the following TML Groups:

• TML Group - Shell Side
• TML Group - Tube Side

When you first begin analysis on the shell and tube heat exchanger, you are not sure what the TM corrosion data will show, (i.e., whether TML Group - Shell Side or TML Group - Tube Side will have more aggressive corrosion). After you have completed some analysis on the shell and tube heat exchanger, you notice that a subset of TMLs on the shell side near the nozzle have very high corrosion rates. At this point, you create a third TML Group, TML Group - Shell Nozzle to represent this component, and you move the TMLs associated with this component from TML Group - Shell Side to TML Group - Shell Nozzle.

Regardless of what they represent, all TML Groups in a Corrosion Analysis will be linked directly to a single asset. If you decide to use TML Groups, all TMLs in your Corrosion Analysis should be linked directly to TML Groups (rather than the asset to which the TML Groups are linked).

Before you can conduct a Corrosion Analysis on an asset, an Equipment record must exist in the GE Digital APM database to represent the asset on which you want to perform the corrosion analysis. The types of records that you create in your Corrosion Analyses will depend upon what your Equipment records represent.

Before you can create TML Groups, an Asset Corrosion Analysis and Corrosion Analysis Settings must be created for an asset, represented by an Equipment record. Equipment records can be created manually via Record Manager, or they may be loaded into your database from another data source (e.g., SAP). After assets exist, you can create TML Groups.

Consider, for example, a piping circuit that contains three piping lines. You might want:

• One Equipment record to store all of the information for the piping circuit and the three piping lines.

  -or-

• One Equipment record to store information for the piping circuit and three TML Groups to store information for the individual piping lines (one TML Group for each piping line). These TML Groups would be linked directly to the Equipment record that stores information for the piping circuit.

The following diagram illustrates the structure of Corrosion Analyses that include TML Groups. Specifically, this diagram illustrates the records and links that would exist if a Corrosion Analysis included one Equipment record (representing an asset), which is linked to three TML Groups. The boxes in the diagram are labeled according to the records that they represent, and the lines connecting the boxes represent the links between these records in a Corrosion Analysis.

To complete this task, you will need to link a TML Group to a Criticality Calculator RBI Component. When you link a Criticality Calculator RBI Component to a TML Group, RBI corrosion rate values for the RBI Analysis that you create are based on the average of the following values in the TML Corrosion Analysis:

• Long Term Corrosion Rate
• Short Term Corrosion Rate

In other words, the values in the preceding list will determine the following values in the Criticality Int. Corr. Deg. Mech. Eval record associated with the RBI Analysis that is created from the linked TML Group record:

• Short Term Avg. Corr. Rate
• Long Term Avg. Corr. Rate