Many
organizations throughout the world have implemented oil analysis programs to better
manage their equipment and lubricant assets. While some have received only marginal
benefits, a few have reported substantial savings, cost reductions and increased
productivity. Success in an oil analysis program requires a dedicated commitment
to understand the equipment design, the lubricant, the operating environment and
the relationship between the test results and the actions to be performed. This
article discusses the major elements and steps required for implementing a successful
oil analysis program.
Introduction
In North America alone, literally millions of dollars have been invested in
oil analysis programs with little or no financial return. The analysis performed
by Original Equipment Manufacturers (OEM) lubricant manufacturers is often termed
as “free”. In many of those cases, the results from the testing have
little to no affect on the maintenance, planning and/or evaluating equipment
condition. The reason is not because this service is free (the customer pays
for this service with every liter of oil purchased), or the ability of the laboratory,
or the effort of the lubricant supplier to provide a value-added service. The
reason is lack of knowledge: a failure to understand the value lost when a sample
is not representative of the system, the inability to turn equipment and lubricant
data into useful information guiding maintenance activities. More important
is the failure to understand the true requirements and operating characteristics
of the equipment. This dilemma is not restricted to the companies receiving
“free” analysis. In many cases, unsuccessful or ineffective oil analysis
programs are in the same predicament. Conflicting information from equipment
suppliers, laboratories and lubricant manufacturers have clouded the true requirements
of equipment to the maintenance personnel or individuals responsible for the
program.
The following steps provide a guideline for implementing an effective oil analysis program: a program considered one of the critical technologies to increasing equipment reliability while maintaining a safe and cost-effective plant operation.
A dedicated commitment is required to collect and record all information necessary to understanding equipment, the needs of the equipment, the operating environment and ultimately your oil analysis program.
Equipment
Audit
Purpose. An equipment audit is performed to obtain knowledge of the equipment,
its internal design, the system design, and the present operating and environmental
conditions. Failure to gain full understanding of the equipment operating needs
and conditions undermines the technology. This information is used as a reference
to set equipment targets and limits while supplying direction for future maintenance
activities. The information should be stored under an equipment-specific listing
and made accessible to other PdM technologies.
Equipment Mission Criticality. Safety, environmental concerns, historical problems, reliability, downtime costs and repairs must all be considered when determining the equipment included in the program, the frequency and the selections of all health monitoring tests.
Equipment Component and System Identification. Collecting, categorizing and evaluating all design and operating manuals including schematics are required to understand the complexity of modern equipment. OEM’s assistance in identifying the original bearings, wear surfaces and component metallurgy will take the guesswork out of setting targets and limits and also aid in future troubleshooting. Equipment nameplate data with accurate model and serial numbers allow for easy identification by the manufacturer to aid in obtaining this information.
Operating Parameters. Equipment designers and operating manuals reflect the minimum requirements for operating the equipment. These include operating temperature, required lubricant needs, pressures, duty cycles and filtration to name a few. Operating outside the recommended values could require modifications and/or additions to the system to allow the component to run within an acceptable range.
Operating Equipment Evaluation. A visual inspection of the equipment is required to examine and record the components used in the system including filtration, breathers, coolers, heaters, etc. This inspection should also record all operating temperatures and pressures, duty cycle times, rotational direction and speeds, filter indicators, etc. Temperature reading of the major components is required to reflect the component operating system temperature. This information verifies that OEM supplied equipment is still in operation and reflects the present operating characteristics of the equipment.
Operating Environment. Hostile environments or environmental contamination in most cases is not taken into consideration when OEMs establish operating parameters. These conditions can influence lubricant degradation, eventually resulting in damaged equipment. All environmental conditions such as mean temperature, humidity and all possible contaminants must be recorded.
Maintenance History. Reliable history relating to wear and lubricated related failures can assist in the decision-making process of adjusting and tightening targets and limits. These targets should allow for advanced warnings of historical problems and possible root cause detection.
Oil Sampling Location. A sampling location should be identified to allow for trouble-free, repetitive and representative sampling of the health of the equipment and the health of the lubricant. This sampling method should allow the equipment to be tested under its typical operating condition while being nonobtrusive and maintaining a safe sampling method for the technician.
Tests. As a general rule, oil analysis encompasses four categories of tests:
1. fluid physical properties
2. fluid chemical properties
3. fluid contamination
4. machine health.
A general routine group of tests does not necessarily consider the machine specifics. Equipment specific testing produces the required data to effectively monitor and trend the health of the lubricant and the equipment while exception tests verify a root cause of change.
New Oil Baseline. A sample of the new lubricant is required to provide a starting point for the physical and chemical properties of the lubricant. Lubricants and additive packages can change over time and adjusting lubricant targets and alarms should reflect these changes.
Cooling Water Baseline. A sample of the cooling water should be collected, tested and analyzed to obtain the physical and chemical properties of the coolant. These results are used to adjust the lubricant targets to reflect and provide early warnings of leaks in the coolers.
Targets and Alarms. OEM operating specifications or a recognized governing body can be used in setting the minimum alarms. These alarms must be set taking into consideration all of the above collected information. These settings must provide early detection of contaminants, the deterioration of the lubricant and the present equipment health. These achievable targets should be set to supply an early warning of any anomalies that allow corrective actions to be scheduled and performed with little or no effect to production schedules.
Database Development. A database should be developed to organize equipment information and the collected data along with the equipment specific targets and alarms. This database should be easy to use. The end-user must have control of the targets and limits in order to reflect the true equipment specific conditions within the plant.
Lubricant Audit Process
Purpose. Equipment reliability requires a lubricant that meets and maintains
specific physical, chemical and cleanliness requirements. A detailed trail of
a lubricant is required beginning with the OEM (oil supplier) and ending after
disposal. Sampling and testing of the lubricants are important to validate the
condition of the lubricant through its life cycle.
Lubricant Requirements. Information from the equipment audit supplies the physical and chemical requirements of the lubricant to operate within the equipment. After ensuring that the correct type of lubricant is in use, the audit information ensures the correct viscosity is used in relationship to the true operating temperature.
Lubricant Supplier. Quality control programs implemented by the lubricant manufacturer should be questioned and recorded when evaluating the supplier. Sampling and testing new lubricants before dispensing ensures that the vendor has supplied the correct lubricant.
Oil Storage. Correct labeling (including MSDS) must be clearly installed to ensure proper use of the contents. Proper stock rotation and storage methods must be considered to prevent the possibility of the degradation of the physical, chemical and cleanliness requirements of the lubricant throughout the storage and dispensing phase.
Handling and Dispensing. Handling and dispensing methods must ensure that the health and the cleanliness of the lubricant meet the specifications required by the equipment. All opportunities of contamination must be eliminated. Prefiltering of all lubricants must be performed to meet the specific equipment requirements. Preventive Maintenance activities involving oil drains, top-ups, sweetening, flushing or reclaiming information should be recorded and forwarded to the individual responsible for the oil analysis program group in a timely manner. Record keeping of any activity involving lubricant consumption, lubricant replacement and/or lubricant top-ups must be implemented and maintained.
Waste Oil. An oil deemed unfit for equipment usage must be disposed of in the correct storage container for that type of lubricant and properly marked and labeled. The lubricant must then be classified for the type of disposal and removed from the property without delay. Long storage times allow for the introduction of contaminants (e.g., water) and other fluids, and could in some cases result in reclassification.
Base Signature
Purpose. Designed to gather and analyze all data required to determine the current
health of the equipment and lubricant in relationship to the alarms and targets
derived in the audit. The base signature or baseline reading requires a minimum
of three consecutive timely readings preferably in a short duration (one per
month) to effectively evaluate the present trend in the condition of the equipment.
Equipment Evaluation. Observing, recording and trending operating equipment along with the environmental conditions including equipment temperature readings are required at the same time the sample is obtained. This information is used in troubleshooting or detecting the root cause of any anomalies discovered.
Sampling. A sampling method will be supplied to extract a sample for the equipment that will be repetitive and representative of the health of the equipment and the health of the lubricant.
Testing. Equipment specific testing assigned during the audit stage will supply the required data to effectively report the health of the lubricant and the equipment. This testing must be performed without delay.
Exception Testing. Sample data that reports an abnormal condition or an alarm or target that has been exceeded, requires exception testing to be performed. This will help pinpoint the root cause of the anomaly. The oil analysis technician should authorize these tests which are not to be considered as routine testing.
Data Entry. The recorded data should be installed into a system that allows for trending and future reference along with report generation opportunities.
Base Signature Review. After all tests are performed, the data is systematically reviewed. Combining the hard data gathered in the system audit with experience, the root causes of potential failures can be pinpointed. A report should then be generated containing all test results along with a list of recommendations. This report should include testing frequencies and any required improvements necessary to bring the present condition of the lubricant and/or the operating conditions to within the acceptable targets.
Monitoring
Purpose. These activities are performed to collect and trend any early signs
of deteriorating lubricant and equipment condition and/or any changes in the
operating environment. This information should be used as a guide for the direction
of any required maintenance activities, which will ensure a safe, reliable and
cost- effective operation of the plant equipment.
Routine Monitoring. Designed to collect the required data to competently inform the PdM or maintenance group of the present condition of its lubricants and equipment. At this time, observations in the present operating and environmental conditions should be recorded. This schedule of the routine monitoring must remain timely and repetitive for effective trending.
Routes. A route is designed so that an oil sample can be collected in a safe, nonobtrusive manner while the equipment is running at its typical full-load levels. These routes should allow enough time for the technician to collect, store, analyze and report anomalies before starting another route. If the samples are sent to an outside laboratory, time should be allocated for analyzing and recording all information once the data is received.
Frequency of Monitoring. The frequency of the inspections should be based on the information obtained in the audit and base signature stages of the program development. These frequencies are equipment specific and can be changed as the program matures or a degrading condition is observed.
Tests. Testing the present equipment condition is the goal of the oil analysis program. Technicians who report alarms proceed into exception testing mode (troubleshooting) that pinpoints the root cause of the anomaly. At this stage of interfacing, other PdM technologies should also be implemented, if applicable. Testing by the maintenance group or the laboratory group requires a maximum of a 24-hour turnaround time on exception tests. A 48-hour turnaround on routine tests supplied by the laboratory would be considered acceptable.
Post Overhaul Testing. After the completion of an overhaul or replacement of a new component, certain oil analysis tests should be performed to ensure the lubricant meets all equipment requirements. These tests become a quality control check for maintenance activities required to perform the overhaul and also supply an early warning of problem conditions.
Contractor Overhaul Templates. Components not overhauled in an in-house program should have a guideline or template of the overhaul procedures and required component replacement parts. These templates are a quality control measure to ensure the information in the audit database is kept up-to-date but also to ensure compatibility of components and lubricants presently used.
Data Analysis. After all data is collected from the various inspections and tests, the alarms and targets should alert the technician to any anomalies. Instinct combined with sensory and inspection data should warrant further testing. Utilizing the technicians’ wealth of equipment knowledge along with the effects of the operating environment is critical to the success of this program.
Root Cause Analysis. Repetitive failures and/or problems that require a solution to alleviate the unknown cause, require testing to identify the root cause of the problem. All the data and information collected in the audit, base signature and monitoring stages of the program will assist in identifying the underlying problem.
Reports. All completed routes, exception testing and root cause analysis require a report to be filed with the PdM/Maintenance Specialist outlining the anomaly identified and the corrective actions required (if known). These reports should be filed under specific equipment cataloging for future references. The reports should include:
- Equipment Specific Identification
- Date of Sample
- Date of Report
- Present Condition of Equipment and the Lubricant
- Recommendations
- Sample Test Result Data
- Analyst’s Name
Use of a computerized system will allow the reports to be designed as required and, in many cases, will provide an equipment condition overview report.
Program
Evaluation
Purpose. Predictive Maintenance tasks are based on condition measurements and
performance on the basis of defects - before outright failure impacts safety
and production. Well-managed PdM or condition monitoring programs are capable
of identifying and tracking anomalies.
Success is often measured by factors
such as the number of machines monitored, problem recognized, number of saves
and other technical criteria. Few have successfully translated technical and
operating results gained by predictive maintenance into a value and benefits
in the financial terms necessary to assure continued support. Without credible
financial links to the facility’s and organization’s business objectives,
technical criteria is essentially useless. As a result, many successful predictive
maintenance programs are being curtailed, even terminated, as a cost reduction
measure. Dedication to an oil analysis program requires the documenting of all
the obtained cost benefits associated with a properly implemented program.
Summary
Recent developments in competent oil analysis training, oil analysis software,
user-friendly labs, modernized testing equipment for used oil analysis and the
introduction of portable test equipment have allowed maintenance personnel to
obtain data from a sample of oil. Data often remains as data and is not used
properly as information to benefit or direct maintenance activities within the
plant. Data that misses early detection of deteriorating lubricants and equipment
conditions neglects the profitable pinpointing of the root causes. Nonrepresentative
samples, lack of equipment knowledge, uncontrolled testing, generic targets
and limits are all among the inconstencies that affect the legitimacy of actions
requested by maintenance professionals to perform maintenance activities initiated
with this data.
An oil analysis program can be one of the most powerful technologies used to increase equipment reliability while reducing maintenance costs if a dedicated machine oil analysis technician drives the program. This trained specialist must be empowered to set and achieve specific goals based on true profit-producing operating requirements of the equipment.
