Should Oil Analysis Form Part Of Your Maintenance Strategy?
Maintenance Strategies and Practices have been around for many years. Early maintenance practices of “when it breaks we’ll fix it” has progressed to preventive, predictive and even proactive maintenance strategies. A number of articles also make reference to World Class Maintenance but no one is really sure what this actually looks like. Identifying the correct maintenance strategy for your equipment can reduce overall operational costs as well as add significant value to your mining operations.
4 Maintenance strategies
The 4 main maintenance strategies can be simply described as:
Breakdown maintenance – basically, fix or repair the equipment when it breaks
Preventive (routine) maintenance – the service, replacement or overhaul of the equipment at predetermined intervals according to a defined set of criteria with the aim of avoiding unwanted failures
Predictive maintenance – identified maintenance activities incorporating condition monitoring techniques (such as Oil Analysis), preventive maintenance and equipment test measurements aimed at making informed decisions as to the overall health of the asset and any associated risk.
Proactive maintenance – the use of both preventive and predictive strategies for improving equipment reliability by identifying root cause of failure and utilise engineering solutions to address the root caus
Choosing the correct maintenance approach for your mining operation
As in most cases, there are pros and cons with each type of maintenance strategy. The best approach is to identify the most cost effective maintenance strategy based on risk and cost of the asset, the risk and consequences in the event of a failure, and how both of these relate to your company’s goals. Each piece of equipment should be reviewed, assessed and treated on its own merits
A breakdown maintenance strategy, (that is to only repair the equipment when it breaks down), is sometimes applied to equipment that if a failure occurs, has minimal disruption to production, is relatively cheap, is quick to replace and will have no impact to safety. Some equipment, such as an excavator, can be identified as critical to your operations and where a breakdown or failure is extremely costly to the company. This could be due to production downtime or a long replacement time, or where safety may be compromised. When it comes to these critical pieces of equipment the maintenance strategy that should be applied would be predictive or proactive so as to reduce the possibility of failure, thereby ensuring maximum value from the equipment.
What is Oil Analysis?
Oil analysis is a condition monitoring tool that involves taking approximately 100 millilitres of oil taken from an oil wetted compartment while it is in use and subjecting it to a variety of chemical and physical tests. In the case of used oil, these tests provide a snap shot as to the current health of the asset, the general health of the oil and any contamination issues that may exist. The practice has proven to be a very successful and cost effective condition monitoring technique for companies that operate large intensive capital equipment (Mining equipment, Construction equipment, Industrial equipment etc).
Into which Maintenance Strategy does Oil Analysis belong?
Oil Analysis as a conditioning monitoring tool has one foot each in predictive and proactive maintenance strategies. The results from the oil analysis can be used as a predictive tool for identifying adverse wear trends and their likely causes such as coolant leaks, fuel dilution or environmental dust entry issues etc. The information from the oil analysis results can then be used to aid in planning and performing appropriate maintenance activities that will reduce the total operating costs arising from premature equipment failures, as well as to optimize oil usage through oil drain extension programs.
In addition oil analysis can assist in identifying whether proactive strategies such as improvements in filtration have achieved the cleanliness (ISO code) target. It can also be used to establish if changes in the maintenance activities have had the overall desired effect of generating equipment improvements over past performance.
When is oil analysis used incorrectly?
Unfortunately, there are many occasions where oil analysis is used on an ad-hoc basis, such as a yearly sample on a main conveyor gearbox, or after a failure. Whilst this could be used to provide a once off indication as to health of the oil and the amount of contaminants that has accumulated in the oil since the last oil change, it cannot be used to ascertain overall equipment health or performance. This type of practise leads to little or no value being realised from this very useful condition monitoring technique.
On other occasions, Oil Analysis may be viewed as the work management tool to drive work maintenance activities rather than using the results as a tool to assist in work maintenance practices. This strategy should not be viewed too favourably either as Oil Analysis does not cover every technical angle. The point is not to confuse a condition monitoring tool as the main driver for maintenance activities. Rather, it should be used to compliment maintenance procedures and allow for forward planning.
How often should you take an oil sample?
To get the best information from ones oil analysis program, one must take oil samples in the same manner and at the same identified scheduled intervals, continuously over an extended period. The ideal oil sampling period will vary depending on the identified criticality of equipment. If the maintenance strategy has been identified as predictive or proactive, then the associated oil analysis sampling regime established may be to sample the equipment/compartment every 250 or 500 hours. The benefits of regular oil sampling and analysis thereof to mining operators for the purposes of predictive and proactive maintenance include:
Monitoring wear (Iron, Chromium, Copper etc) trend deviations
Identifying any contamination issues early (dirt, moisture)
Confirming health of the lubricant (extend or drain the oil)
Evaluating effectiveness of filtration upgrades or changes in maintenance activities
With this information one is able to monitor the equipment condition over a regular and prolonged period which helps identify potential failures before they occur.
If you feel that your mine can benefit from Predictive or Proactive maintenance using oil condition monitoring, then please contact Total Mining Solutions. You can also access more information at http://www.totalminingsolutions.asia/advice-corner.html
Total’s approach to Oil Analysis
Because it is crucial for mining companies to have access to reliable oil analysis laboratories, Total views its ANAC oil analysis program as an integral service to its clients.
To find out more about oil analysis and how Total’s ANAC service can add value to your operations, visit