by Jonathan Coombs, RSE – Director, Reliability Services
The core of a good oil sample is that it effectively represents the actual condition of in-service oil in a machine. To ensure a proper sample is collected, sampling procedures should be built into the oil analysis program. If good samples are not collected, it can lead to flawed results which can lead to incorrect maintenance decisions and reduced confidence in your oil analysis program.
A vital element of any sampling procedure is sampling frequency. Determining the correct sampling frequency for your assets depends upon several factors such as the criticality of the asset (the value of the machine to the operations), possible failure modes, age of the machine, safety (associated risks if the machine should fail), and environmental concerns. As a result, sample frequencies could be different for each machine, though if your operation has similar machinery, frequencies can be assigned for the entire group.
Importance of Compliance
Consistency and compliance with sampling frequencies can often be a challenge and your oil analysis program can be less effective if intervals are missed. For many industries, regular intervals are critical for warranty or safety requirements. By maintaining a consistent schedule, oil analysis can help to identify potential failures and support maintenance decisions that can impact on operations.
By using routine oil analysis as a condition monitoring tool, you can proactively monitor the condition of your equipment and project the rate of deterioration over time using a P-F curve. A P-F curve is a way to show an asset/component’s condition over time to identify when failure starts (potential failure) and when equipment has passed it’s useful limit and no longer operates (functional failure). The P-F Interval is the time between when a failure is noticed and when the asset/component fails completely. before failure is reached.
One of our customers, a hardrock mining company, samples their dozer fleet on a strict schedule. They utilize myLab’s Sample Scheduling system and are also supported by Fluid Life’s team of condition monitoring specialists. Because of consistent sampling at regular intervals for their equipment, combined with reporting to track their machines in or out of compliance, they had sufficient warning for this dozer (see charts below) to identify an early transmission bearing problem before an in-use failure occurred.
Sampling Frequencies
Below is a chart outlining recommended sampling frequencies for mobile and fixed plant equipment. Note that these are only guidelines. Depending on your individual circumstances, sampling frequencies may need to be adjusted.
Sample Frequency Scheduling
The task for scheduling may be a manual process or through your maintenance management system. Another option is to utilize the Sample Scheduling function within myLab. You can schedule each component individually or make specific schedule rules that apply to different pieces of equipment or oil types. You can then set email reminders for your set rules and create reports for scheduled and unscheduled components. These tools allow you and your team to find and setup samples that are due or past due.
To access Sample Scheduling, from the myLab home page go to: Equipment > Sample Scheduling.
View the full tutorial on our Resource Center.
Summary
By partnering with Fluid Life to monitor your equipment, you have access to the tools and expertise to identify potential issues early on and take corrective action before they escalate into major problems. Talk to us today to help you set your sample frequencies and improve your oil analysis program.
