Mining equipment maintenance - on site oil analysis

Why Oil Analysis Should Be Performed On-Site
By: Drew D. Troyer
Introduction
Why is oil analysis so important to machine reliability and the maintenance organization?
Mechanical machinery literally rides on a 10 micrometer film of oil which is approximately equal to the diameter of a blood cell. Loss of this film means a failure. It is critical to ensure that this oil is kept healthy, clean and dry. Oil analysis accomplishes this goal. Additionally, like blood in the human body, the oil carries important clues about the health of the machine. Oil analysis turns these clues into valuable information which supports operations and maintenance decisions.
Why do conventional oil analysis programs fail to support operations and maintenance decisions?
Conventional oil analysis programs fail for a number of reasons. Here are some of the most common ones; they fail to focus on controlling the root causes of machine failure and lubricant degradation, the information generated is not properly understood by those who need to use it and the information is not available when and where decisions need to be made.
Where do we go from here?
Go on-site. Transform oil analysis from a report that tells you when to change oil into a condition monitoring tool which enables you to make informed operations and maintenance decisions.
Three critical reasons for on-site oil analysis
1. Ensures Proactive Process Control
a. Check the health and cleanliness of lubricants as they arrive at the door.
It is a common assumption that new oil is clean, healthy oil. This is a dangerous assumption. On-site particle counting, moisture monitoring and viscosity measurements enable you to confirm that your fluids arrive in proper condition.
b. Check the health and cleanliness of lubricants as stored at the facility.
Lubricants are apt to ingest contamination on-site even if they are in unopened drums. And they are prone to tank degradation. On-site monitoring of particles, moisture and viscosity again ensures that they are stored in proper condition. Also, the condition of the lubricant as it is added to the system is critical. On-site analysis ensures that the oils you add to your machines are in the proper condition.
c. Quickly identify failed filters.
Nothing compares to a particle counter for identifying failed filters. A pressure differential gauge is a late indicator of when good filters are expired, and offer no value when the filter is damaged.
d. Confirm that seals and breathers are keeping contaminants out.
It costs about 10 times as much to remove contamination once it is in the oil as it does to keep it out in the first place. Moisture and particle monitoring alerts you when seals and breathers are failing to perform so you can schedule those activities for correction.
e. Confirm that oils are healthy.
Any degradation of an industrial lubricant can be detected by a change in viscosity. Monitoring viscosity on-site alerts you of any change so you can schedule action to identify the root cause of the degradation and rectify the situation.
f. Make sure the right oil goes into the right machine.
Routine viscosity measurement quickly reveals situations where the wrong oil has been accidentally added to a system.
g. Confirm that systems are properly cleaned and flushed after repair before being returned to service.
Confirming roll-off cleanliness of new and repaired systems with a particle counter confirms that the systems are fit for use, minimizes early wear and premature failures, and reveals wear being generated by any abnormal loading or operating conditions.
h. Control the calibration, hence the quality, of measurement tools.
You assure the quality of measurement, hence the quality of process control. You never have to wonder if your data is reliable.
2. Develops Effective Predictive Maintenance and Troubleshooting Techniques.
a. Identify wearing components very early stage.
Any wearing mechanism leads to an increase in particle count. Performing routine particle counts ensures awareness of machine problems and maximizes available time to make good decisions, schedule corrective action and minimize chain reaction type failures.
b. Confirm results immediately, avoiding decisions with uncertain information and long delays waiting for lab analysis.
When lab results indicate a problem, there are always questions regarding sample quality and the reliability of the analysis. With on-site monitoring, you can quickly verify your results to ensure that you don’t act upon bad information.
c. Determine immediately if debris detected is wear or ingested dirt.
With a ferrous particle counter attachment, you can quickly determine if debris is wear. The manner in which you respond to wear is quite different than the manner in which you respond to dirt ingestion due to a seal failure, breather failure, etc. Determining the nature of the problem quickly makes all the difference in making the right decision.
d. On complex hydraulic and lubricating systems, localize the source of the debris quickly with secondary sample points.
Contamination can come from a number of different areas in the system. By testing before and after components, filters, etc., you can quickly identify the bad actor so that diagnostic work is focused on the area of concern.
e. Determine problem severity with rate of change analysis.
The question “do I need to act now or can it wait until the next scheduled down period” is a common question when condition monitoring reveals a problem. By assessing the rate at which particle count, ferrous particle count, moisture levels or viscosity change, clearly reveals the severity of a machine problem. Hourly checks of these conditions, for example, are not practical without on-site oil analysis capability.
f. Verify problems identified by other means.
Just like physicians prefer to have confirmation of a human health problem, maintenance technicians (machine doctors) like to have confirmation of machine health problems. If vibration analysis, for example, and particle count both suggest a problem, you have confidence in your actions because you have two measures pointing in the same direction. If they don’t agree, this is your signal to seek additional diagnostic information.
g. Use common sense deductions to quickly determine the root cause problems.
One can usually figure out what is wrong with a system when samples from several points are taken over a short period of time and tested for particle count, wear level, moisture and viscosity. For instance, if all components in a hydraulic system show an increase in wear but the non-ferrous particle count remains low, the wear mode is probably lubricant related (wrong, degraded, water contaminated, etc.). Technicians who review the on-site data regularly begin to get a feel for the meaning of the data relative to other observations.
h. Seek lab analysis on condition, only when required.
Laboratories are invaluable when diagnostic information is required to identify and understand a failure root cause. Let routine on-site monitoring prompt you to submit a sample to a laboratory for extensive oil or wear debris analysis to ensure you have diagnostic information when and where you need it. By localizing problem components before sampling, you improve the accuracy and validity of wear debris analysis.
i. Verify the effectiveness of corrective maintenance actions.
After repairing a system or component, particle count will confirm the success of the corrective action. For instance, replacing a defective filter should result in an immediate reduction in particle count. Or, eliminating an eccentric load should eliminate wear generation.
3. Improves the Effectiveness of the Organization
a. Employees have ownership in the program.
When employees are making measurements themselves, the results are more than just numbers on a paper. They see immediate feedback associated with a machine or lubricant specific condition. They also see the feedback associated with correcting the condition.
b. Oil analysis data is no longer ignored then filed.
Too often, oil analysis results are just filed away, never to be seen again. Electronically collecting and organizing lubricant condition data ensures that the information is available to all to review and trend. It is a shame to have a problem arise which has been solved before but the knowledge was lost because the person who solved the problem resigned or retired.
c. Data is easily understood and relevant to today’s decisions.
On-site analysis is timely and relevant. It ensures that operations and maintenance make asset management decisions which are informed and confident.
d. Individuals at all levels become conscious of the importance of clean, dry, healthy lubrication.
It affects the way in which they conduct their day-to-day business. When an individual is aware that an oil can used to top-off machine sumps is full of dirt and water which degrades the machine, they act responsibly. On-site analysis empowers people with knowledge and data to act in the best interest of the organization.
Implementation Plan
Select what to monitor on-site and what to leave to the labs.
It is not sensible to monitor and analyze all lubricant properties on-site. Particle count ensures cleanliness, a moisture detection device assures that the oil is dry. Dirt and water are the primary root causes of machine and lubricant degradation. Monitoring them on-site ensures that they are controlled. Viscosity is the most important lubricant property. Any degradation of the lubricant, wrong lubricant, etc. will be revealed by viscosity measurement. It should be performed on-site. A ferrous particle counter attachment quickly determines if debris is wear or dirt, thereby streamlining actions.
Manage the data such that it supports decisions.
Data is meaningless unless it is managed in a form by which it becomes information which can be translated into knowledge. Integrate your oil analysis data into a software program that enables the information to become knowledge which supports your operations and maintenance decisions.
Education--the critical link to success.
What they don’t know will hurt them! Education at all levels provides individuals with the knowledge infrastructure to translate information into knowledge, and knowledge into actions.