Asset Health Modelling (Pipelines, Special Crossings, Block Valves): Final Report

Abstract:

This document is the final report for the project titled 'Asset Health Modelling (Pipelines, Special Crossings & Block Valves)'.

Following submission of the Gas Distribution Network's (GDN's) business plans, Ofgem recognised the significant work carried out by the GDNs to report asset health, probability of failure and deterioration. However, it was recognised that the framework did not provide consistent results between the GDNs. Ofgem intended the framework to provide a consistent means of comparing information between GDNs and enable GDNs to compare information about the condition of assets over time. In addition, Ofgem sought evolution over time to combine information from different asset classes to form an overall view of the condition of GDN assets and risk therein.

This project looked to overcome the problem of reporting the health and criticality of one of the key group of assets - Local Transmission Pipeline assets; comprising the pipelines themselves plus all the associated assets such as block valves, special crossings and sleeves. The SRWG engaged with the industry experts in PIE due to the inherent knowledge that they held plus the level of interaction that they already had with the GDNs through the UKOPA (United Kingdom Onshore Pipeline Operators Association) group.

This report is contains an Executive Summary, and is split into two technical notes.

Technical Note PIE/14/TN113 :- Development of a Model for classifying the Health Index of non-piggable pipelines:

1. Summary
2. Background
3. Characteristics of external Corrosion
4. Application to Non-piggable Pipelines
5. Allocation of Health Index
6. Categorisation due to fatigue damage
7. Conclusions
8. References

• Appendix 1 - Procedures for 5-Yearly Inspection of Non-Piggable Pipelines
• Appendix 2 -Proposed Process for Defining "Intervention" to Extend Pipeline Life
• Appendix 3 - Calculation of Fatigue Damage due to Cyclic Pressure in Transmission Pipelines

Technical Note PIE/14/TN125 :- Models for Classifying the Health Indices of Block Valves, Sleeves and Above Ground Crossings:

1. Summary
2. Background
3. PoF Models for Block Valves, Sleeves and Crossings
4. PoF Model and Prediction of Health Index for Block Valves
5. Prediction of Health Index for Sleeves
6. PoF Model For Nitrogen Sleeves
7. Non-N2 Sleeves Health Index Predictions
8. Prediction for Health Index for Crossings
9. PoF Model for Above Ground Crossings
10. Prediction of Health index for Above ground crossings
11. PoF Model for River Crossings
12. River Crossings Health Index Predictions
13. Conclusions
14. References

• Appendix 1 - Proposed Definition of Intervention Process required to Reassign Block Valve Health Index
• Appendix 2 - Proposed Definition of Intervention Process required to Reassign Non-Nitrogen Sleeve Health Index
• Appendix 3 - Proposed Definition of Intervention Process required to Reassign Nitrogen Sleeve Health Index
• Appendix 4 - Proposed Definition of Intervention Process required to Reassign Above Ground Crossing Health Index
• Appendix 5 - Proposed Definition of Intervention Process required to Reassign River Crossing Health Index

Publication Year:

2015

Publisher:

Ofgem

DOI:

No DOI minted

Author(s):

Wales & West Utlities