PEI Circuits - Overview

In PEI Hierarchy - Overview you can see a visual depiction of the Hierarchy. Have a look to see where Circuits fit in!

A Circuit covers all Piping- or Equipment-Components where the same Corrosion Rate (CR) is Expected/Measured. This is the level on which Wall Thickness (WT) measurements are inputted, and CR calculations CR calculations take place.

The WT measurements are captured per CML/MP, which are the lowest level of the hierarchy. A Measurement Point (MP) is an area on a location on the Equipment. These locations are called Condition Monitoring Locations (CML). Each CML can have multiple MPs and each Equipment can have multiple CMLs. CML’s are grouped in corrosion Circuits with the same expected CR. 

There is a special Schedule type, called Corrosion Schedules. As an exception this is defined directly on the corrosion Circuit and not on the Equipment. This Schedule type simply defines when the CMLs of the corrosion Circuit need to be measured. An active Corrosion Schedule must be available for each active corrosion Circuit. The Circuit also has a Measurement Set (MS) section. The MS specifies which CMLs to inspect. For each inspection, a new MS must be created. The WT measurements are populated in here. This is then used to calculate the CRs and from the CRs the worst Remnant Life (RL) and Next Inspection Data (NID) is calculated.

Workflow

Corrosion Schedules are normally performed by the radiographic / NDE department by doing the WT measurements. The inspector dictates which MPs should be measured by creating a MS. When the Inspector receives the measurements from the radiographic department, he must import it in IMS. The measurements can also be inputted directly into IMS while in the field, by using IMS Offline on a mobile device! 

The data can be further analyzed with the trending module (S-IDAP), which can be accessed from the Circuit details. 

The calculated CRs and NIDs can then be reviewed in the Calc Summary section. The Cal Summary must be calculated and Approved to credit the Corrosion Schedule. By approving the measurement results the Corrosion Schedule of the Circuit is credited and a new NID can be set. 

Inheritance

Components and Circuits can be set to be inherit. This way the Component can inherit the CR information (SCR and RCA) from the Circuit. In turn the Circuit can inherit the RBI Interval Factor (IF), which will influence the Corrosion Schedule’s NID. See Relationship between CLs, Components, Circuits, CMLs and MPs.