Asset integrity management is essential for operators of all types of process plant. Marc Dabbs discusses best practice solutions for managing corrosion and aspects to consider
28 January 2016 | By Marc Dabbs
Corrosion management is key to controlling asset integrity. Without an effective strategy operators often experience unexpected failures in pipework, vessels and structures that can severely affect health and safety, and cause downtime leading to lost production and repair costs.
Often, particularly on mature assets, managers have more outstanding corrosion-centred maintenance than available resources allow for (budget, manpower, time). The challenge is identifying what to prioritise.
Strategic Corrosion Management has developed a unique way to integrate fabric maintenance (external corrosion management) and integrity data, which allows operators to make better maintenance decisions by 'prioritising these priorities'.
Identifying where we can share resources and optimise work-scopes allows clients to achieve cost-effectiveness, enhanced safety and minimised risk. Most importantly, this delivers the ability to demonstrate objective evidence of integrity and corrosion compliance to regulatory authorities. Here are the key steps essential to implementing a standards-compliant corrosion management programme specific to any facility.
1. Understand your facility
Gain an understanding of the actual condition of every component of your plant and how quickly it degrades. It is vital to include equipment that is often overlooked, such as pipework in culverts, bund-walls, pipe transits and penetrations. When plant is mature, this equipment can cause high risk to operation and safety and may no longer be fit for purpose or legally compliant.
2. A realistic strategy
Develop a strategy in accordance with HSE, ISO55000, & COMAH regulations to deliver maximum safety and optimal production with minimised costs. Key Programme 4 (KP4), a standard specific to offshore plant, is another element worth considering. It discusses safety-critical and safety-related equipment. Consider also plant life expectancy, which may help to prioritise requirements.
3. What, how, where, when
Define and categorise the threats to the facility, such as CUI (corrosion under insulation) and SCC (stress corrosion cracking). Record where it is occurring and where it is likely. This helps you to implement an efficient schedule to inspect, mitigate, manage and monitor.
4. Objective evidence of integrity
Know (and be able to show that you know) the condition of your facility. If it's in poor condition do you have a plan in place to improve it? Where it's in good condition have you a plan to keep it that way? Form a fully integrated management system that links component, corrosion, fabric maintenance and objective evidence of integrity into one toolset.
Know what types are appropriate for your facility. For example, evidence suggests that perhaps risk-based-assessment (RBA) is not always the best inspection method for mature assets (13-25 per cent of substrates have not been inspected for at least eight years because of the loopholes of RBA). Tip: apply 'confidence factors' to inspected items. Rate how confident you are in the current condition of a particular pipe or component (i.e. high/neutral/low). Another tip is to apply a zonal 'corrosivity level', which describes the degradation rate of a component depending on its location and 'micro-climate' class.
6. Measure using KPIs
Implementing key performance indicators or reviewing existing KPI requirements ensures that targets and metrics are applicable, up to date and achievable. For maximum efficiency define these as part of your strategy to prove you are doing it right.
7. Economical maintenance
Consider when will be best for physical repair, temporary repair or replacement when downtime, loss in production and access requirements are also considered. Are you achieving maximum value from previous maintenance (i.e. coatings)? Zonal maintenance often incurs loss of investment by re-coating substrates too early (typically losing 15-60 per cent on previous investment).
8. Integrity management auditing
Review your compliance with ISO 55000. Auditing is often not something well received, but it is important to prove control over your facility. These standards are here to promote a safe and effective working environment.
9. Reporting & inspection results
Implement a competent system for reporting data. The best way is to integrate data where possible from component, corrosion and fabric maintenance systems. High efficiency here results in highly intelligent data outputs and enables you to make better decisions in terms of integrity, corrosion and maintenance.
10. Design for new-build
Consider the threat of SCC, hydrogen-induced cracking, process materials, dissimilar metals and so on, to ensure that you are using the material that is most fit for purpose - design out corrosion.
Marc Dabbs is products and services division coordinator at Strategic Corrosion Management