Mechanical Technology February 2016

⎪ Proactive maintenance, lubrication and contamination management ⎪

Asset management and proactive friends or foes? In his column for this month, Mario Kuises talks about the importance of having an asset management system in place to realise long-term benefits from proactive management system investments.

Mario on maintenance:

P reviously we discussed the prin- ciples of proactive maintenance and how it can be of benefit to an organisation wishing to improve the bottom line or enhance the reputation and quality of service of public entities. We examined the various strate- gies and how it is important to use the right combination for optimal results. We spoke about the wide and rapidly growing range of technologies that are available to the reliability engineer and how economics is making this more and more attractive.

without an effective asset management system in place, all manner of things not only can, but will go wrong. In doing so, one’s carefully thought out and imple- mented proactive maintenance strategy will be derailed. Strong words, and only expressed with confidence because of the myriad of personal experiences encoun- tered. This is one instance where rather than explain how things should be done, the concept is better illustrated with examples of what happens when things have not been done as they should. In one example that really stands out, very large medium-voltage motors in a production plant with four yearly sched- uled outages were correctly identified as critical by the reliability engineering team. As a consequence, the motors have been equipped with effective, but rela- tively costly, continuous on-line condition monitoring systems that have automatic defect detection and predictive alarming capabilities. Early warning will be given so as to permit convenient intervention to prevent unplanned failures, which would far exceed the monitoring cost. The monitors are installed, configured and commissioned with appropriate alarm set points. All good so far – everyone is happy that risk of unplanned failure is well managed. And indeed all is well for more than

two years. Then a failure occurs in one of the motors, of exactly the nature that should have been detected by the moni- tor and prevented. All sorts of questions are asked and, most importantly, why did the investment in monitoring not pay off as planned? On investigation, it was found that the monitors were standalone and under the control of the reliability team. No one had bothered to involve asset management/ maintenance or to connect the monitors into a system to bring the predictive alarms to the attention of anyone at all. Nor were any measures put in place to have the monitors inspected regularly to check for alarm conditions. When the monitor’s stored data was examined after the failure, the records showed that the monitor had detected the deteriorating defect and had first been in low- then high-level alarm for months, but no one knew. More specifically, no one who was in a position to recognise the importance of the alarm and do something about it. The above example relates to condi- tion monitoring to improve plant reli- ability. Let us look at another common example where condition monitoring is employed to improve plant efficiency. Valves, glands, gaskets, steam traps, pipes, pressure vessels and the like deteriorate over time. If not attended to, the consequence is huge losses – and potential safety and quality issues – due to compressed air, steam and gas leaks. Many energy managers are well aware of this and engage professionals to survey their plant to locate, tag and report such leaks so that they can be fixed and the losses stemmed. This is recognised to be one of the most basic and beneficial energy saving interventions that any plant employing these utilities can do. It’s simple and obvious. It is also obvious that no benefit will accrue if the leaks are not fixed. Why, then, is it not unusual to go to the same site to conduct repeat leak surveys only to find the same leaks previ- ously reported still unfixed, with the tags

There is no point fixing the symptoms. It is essential to get at the root of the problem, which occurs for one simple reason – the physical asset management system is deficient.

Whilst it is hoped that this was informative, it completely omitted one vitally important point that is the topic for discussion here. Without it, many of the benefits of proactive maintenance will never be realised and sustainability is practically impossible. So what can this be? If you have not already guessed, it is of course the fact that everything we discussed falls under the ambit of physical asset management and that,

Caption: Physical asset management is a structured approach in which techniques and processes are determined and formalised to allow an organisation to both achieve and demonstrate that it is managing its assets optimally.

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Mechanical Technology — February 2016