S-IDAP - Overview

This online manual explains how to:

• Process, analyze and visualize Wall Thickness (WT) data from one or more Circuits from one or more pieces of Equipment or Corrosion Loops (CLs) to:

  • Detect Anomalies in the WT readings.

  • Flag readings as Good, Verified or Ignored.

  • Estimate Corrosion Rate (CR) and Remnant Life (RL) for each Corrosion Measurement Location (CML) / Measurement Point (MP).

  • Show CR overview plots for each Circuits on one screen.

• Speed up data analysis by concentrating on the CMLs/MPs with Anomalies, high CRs or low RLs. The data from the other CMLs/MPs can also be quickly reviewed.

A Circuit covers all Piping- or Equipment-Components where the same Corrosion Rate (CR) is Expected/Measured. This is the place where the NDE examinations are documented. The Circuit contains Condition Monitoring locations (CMLs). The CMLs can have one or more Measurement Points (MPs) and this is where the NDE inspections are performed. A Corrosion Schedule is registered for the Circuit and is performed by the radiographic department by doing Wall Thickness (WT) measurements. The inspector dictates which MPs should be measured by creating a Measurement Set (MSET). When the Inspector receives the measurements from the radiographic department, he imports it in IMS. The Inspector can then use the trending module (s-IDAP) to fully analyze and trend the measurements to determine the Corrosion Rates (CRs) and subsequently the worst Remnant Life (RL) and Next Inspection Date (NID) for the Circuit. This information is summarized in the Circuit Calc Summary. By approving the measurement results, i.e., the Circuit Calc Summary, the Corrosion Schedule of the Circuit is credited and a new NID set.

In IMS the following CRs are calculated:

On CML level:

• Long CR, using the first and last thickness readings.

• Short CR, using the previous and last thickness readings.

• Linear Regression CR, using all non-ignored data.

• Historical CR.

• Dynamic Linear Model CR (S-IDAP CR) (based on Bayesian statistical methodology).

On Circuit level:

• Average Long and Average Short CR.

• Suggested CR, user specified CR.

• Extreme Value Analysis (EVA) for Heat Exchanger tube (HX) (only if enabled).

For more information see PEI Circuits, PEI Corrosion Calculations and Calc Summary and PEI EVA.

In this online manual we will specifically focus on the trending module (s-IDAP) which can be used to fully analyze and trend the measurements that are used to determine the CRs.