Mechanical Technology February 2016

Mechanical Technology — February 2016

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Proactive maintenance, lubrication and contamination management

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Mario on maintenance:

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.

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,

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

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.

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.

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.