How many lubrication related failures has your facility experienced? Of those failures, how many could have been prevented through basic asset inspections? Many companies struggle with addressing foreseeable lubrication related failures, due in part to a lack of understanding of what a lubrication related issue looks like, why it matters, and how to appropriately address it. Visual lubrication inspections expand the typical preventive maintenance inspection to include the condition points of the lubricant, which is the lifeblood of the asset. However, it is not just a matter of performing the inspection. It is also necessary to have a strategy for following up on the inspection results.
What IS Visual Lubrication Inspection?
Visual lubrication inspection is a basic methodology for determining the condition of an asset or component’s lubricant by simply using your senses. A visual review of a lubricated component might include the collection of basic information, such as asset condition (cleanliness, visible leaks, state of installed modifications), oil level, oil condition, amount of oil added, filter condition, breather condition, and temperature. The specific items to review are determined by the component type, sump size, how it is equipped, and preexisting conditions or concerns associated with an individual component.
What Information Can It Provide?
Information collected during a visual lubrication inspection can be as extensive or basic as needed. It is dependent on what your maintenance goals are and how much time you wish to designate to the routine inspection process. Most importantly, the inspection depends on a designated follow-up procedure and practice for the information collected. At the most basic level, a routine inspection can provide information about the oil levels (leaks or increases), water contamination and potential sources, particle contamination, and oil condition. This information is determined based on the conditions observed during the inspection process, which are then translated into potential causes to be remedied.
How Do I Implement This Type Of Inspection Program?
The first step to implementing a program is to determine what your goals are. A desire to move away from status quo operation and to implement planning and scheduling practices should exist. This should be the goal first and foremost from management and the maintenance team. Secondly, there should be a desire for a systematic approach to observing, documenting, and addressing lubrication issues before they become lubrication failures. Finally, there should be a goal to monitor progress with metrics over a reasonable timeframe. While some benefits can be readily recognized, long-term goals can take as long as 5-7 years to realize when it comes to changing the maintenance culture.
From a basic level, starting with the overall component or asset condition can give a high-level overview of the asset’s health, but what conditions are you looking for? Perhaps, you may want to know if there are any visible leaks, broken components, or modifications that have been removed. Maybe you are also looking for housekeeping issues.
Next, you can assess the desiccant breather. Is it partially or completely spent? Which end of the breather spent first? If the top is pink there is an internal moisture source from the reservoir headspace, but if the bottom turns pink first then there is an external moisture source from the outside environment. Did the desiccant turn amber or brown instead of pink? If so that points to the likelihood of oil misting. If the breather has turned completely pink then the desiccant is spent and the breather is at full water saturation.
Next on the list is the oil level. Is the oil level at, above, or below the designated level? If below, how much oil needs to be added to bring it to level? The condition of the oil should also be assessed using elements of visual oil analysis. Does the oil appear cloudy, dull, dark, or foamy? Or does the oil appear bright and clear? Assessing oil condition from a visual perspective requires knowledge of how the oil appears before it is put into use, such as the initial colour and clarity because some oils start off darker and more opaque than others.
Filters are also important to check. A filter in bypass does little to remove contamination and wear metals from circulating in the oil, which can damage downstream components. Depending on the type of indicator available, you may want to collect the indicator colour (red, yellow, or green) or the psid across the filter. For spin-on type filters, look for leaks around the filter seal.
Finally, perform a quick scan of the temperature. The temperature may be taken from a permanently installed thermometer or using a temperature gun. If using a temperature gun, a specific spot should be designated for collecting the reading. This will ensure a consistent temperature trend over time since temperatures can fluctuate across a sump or reservoir. It is important to establish baseline values for temperature so that high/low readings can be determined.
From the most general standpoint, you want to be able to gather asset condition, breather condition, oil level and condition, filter state, temperature, and the amount of oil added. However, not all these inspection items are apparent or relevant. The information you collect will be dependent on the component type and size, as well as how the component is equipped with lubrication modifications. In some instances, the asset’s criticality could play an important role as well.
In terms of what information can and should be gathered, an inspection item like asset condition should be applied across the board to all assets. However, to determine what should be applied, start with the component type. In terms of gearboxes, there may not be a filtration system installed, so an inspection item to review the condition of the filter would not be possible. Of course, if we expand on this a little more, it is not abnormal to see larger gearboxes equipped with a filtration system, especially when the gearbox sump volume creeps into the 50 gallons or more range. Setting up inspection item templates based on the component type and size will ensure a consistent inspection approach for all components.
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