CONCLUDING COMMENTS

This Chapter will end by listing some wider issues and general advice for engineers to consider when conducting a structural assessment of a pipeline:

1. THINK SAFETY – Pipeline codes are safety standards, and an engineer’s prime role in any industry is to ensure safety. Structural assessments are safety assessments. Always ‘think’ safety.

2. CODES ARE ‘DAY 1’ CODES – Pipeline design codes give us minimum structural integrity requirements – they are the starting point for integrity, not the end point. A pipeline designed and built to code will be very safe on its first day in service. However, after day 1 the pipeline’s management dictates its safety, not the design code. Therefore, good managers and good management systems²³ are the key to pipeline structural integrity. This means a continual appraisal of technical issues such as smart pigging, risk management programmes, correct routeing etc., to achieve high integrity. But remember - only good management will guarantee integrity

3. ADOPT AN HOLISTIC APPROACH – Pipelines fail for a reason, and most of these reasons can either be avoided or mitigated by good pipeline management. Structural assessments must address all elements of the problem including consequences of failure, and the management systems that need to be in place to implement any recommendation. Therefore, pipeline integrity management must consider all aspects of our pipeline system, as it is an integrated process, where all elements affect safety. Holistic solutions must be applied [Hopkins, 2001a; Hopkins 2001b]. Pipelines are safe if we adopt an holistic approach.

4. DO NOT DO THE ‘MINIMUM’ - Codes. Regulations, etc., are minimum requirements. Aim to do more than your peers. It makes sense… if you do only one thing more than your peers, his/her pipeline has a higher probability of failing first. You will learn from their experience, and act accordingly, so it does not happen to you. They will then copy your practices, but you will then move one step ahead again… and then their pipeline will again fail before yours!

5. DO NOT AUTOMATICALLY SELECT LOWEST BIDS - Do not automatically select the lowest bid in engineering: a trained monkey can select the smallest of three objects. An engineer can select the safest and best.

6. CHANGE IS DIFFICULT – It is difficult to change pipeline engineering practices in companies, because it is difficult to change people [Hopkins, 2000; Hopkins, 2002]. However, as pipelines age we must continually change our approach to pipeline structural integrity.

7. REGULATIONS AND COMPANY PRIORITY - Your company/work will be limited by both company codes/practices and your national/state legislation/regulation. These may not allow fitness for purpose assessments, or the defects you consider acceptable. You must always check local and national limits and legislation, before applying ‘fitness for purpose’: i) can I apply it, and ii) can I use the results?

8. ORIGINS – Always understand the origin or cause of your structural defect before you assess it. A structural assessment may not be enough; for example,

23 Management Systems are covered in Hopkins, 1998 and Hopkins, 2001b.

defects can be due to bad design (e.g. fatigue cracking), and hence the design will also need changing, and some defects can be due to a hostile environment (e.g. external stress corrosion cracking), and in this case the pipeline coating may need replacing.

9. CONSEQUENCES - Always appreciate the consequences of your assessment.

If I have made an error, if the defect measurement is wrong, etc., and the pipeline fails, what are the consequences? Consequences will dictate your safety margin on your calculations.

10. NEVER ASSESS A MESS – There will be some situations where an engineer is asked to assess the structural significance of defects, where the defects are extensive, or the structure itself is in poor condition. Sometimes even the best surgeon has to pronounce the patient dead….

11. CALCULATIONS ARE NOT ENGINEERING [Kardon, 2000] - Calculations convey the thought process and design intent, and are an essential part of any engineering appraisal. The quality, etc. of calculations indicates the level of care and diligence; however, calculations substantiate, but do not substitute, for judgement.

12. ENGINEERING RESPONSIBILITY - It is your responsibility to ensure that any fitness for purpose assessment is correct. Try and use the best possible practices available. Check calculations, inputs and assumptions. Use all available data (historical, current and circumstantial) when you assess a defect – inspection data, operations records, maps, etc., may give you more information about the defect, its cause, etc.. Your appreciation of the wider practical issues, and your understanding of all engineering aspects of the problem, are why you have been hired to conduct the assessment, rather than someone who can simply work out an equation.

13. PROFESSIONAL AND PERSONAL INTEGRITY – Engineers performing structural assessments, where decisions can effect company profits, career progression, environment, etc., must put safety first, and remember that engineers have professional (institutional requirements), legal (‘standard of care’) and ethical (moral) criteria to also satisfy [Anon, 2002a; Hopkins 2002]

in all aspects of their work.

Acknowledgements

The author would like to thank all his colleagues at Penspen Group UK, in particular, Mr Andrew Cosham, who have contributed to this Chapter.

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