Why does my lubrication program need the appropriate frequencies, quantities, type of lubricants and procedure?
Several studies1 and case studies have shown that approximately 80% of bearing failures are directly related to lubrication issues. Proper lubrication is indeed a critical aspect of your preventive maintenance program if you are expecting to have reliable operation throughout your plant.
When the lubrication program is neglected or not done correctly, it can lead to multiple issues and eventually, catastrophic failure. Note that the exact percentage of mechanical failure due to lubrication may vary depending on your industry, type of equipments and other factors.
Even though the 80% might not be the exact number for your reality, this statistic still illustrates the importance of an accurate lubrication program and how it can easily address a significant amount of potential failure, which will directly result in your plant’s reliability and performance.
Why is a significant amount of mechanical failure due to lubrication?
Lubrication plays a key role in preventing wear and tear, reducing friction, dissipating heat, and ultimately, ensuring an overall smooth operation between any moving parts on your assets.
That being said, considering that lubrication serves a pivotal role to the functioning of mechanical parts in motion, any inaccuracies in the lubrication process, such as applying the wrong type of grease between two moving parts, can quickly results in issues and failures.
This is why it is commonly stated that 80% of failures are attributed to lubrication issues because moving parts directly involves friction, heat and wear; therefore, any inaccuracies in the lubrication program will directly affect the assets health. On the other hand, if you have an accurate lubrication program, you will easily be able address a significant amount of potential failure!
What makes a great lubrication program?
A great lubrication program is characterized by several key aspects. The ones we will focus on in this article are the following 5 key elements: types of lubricants, quantities, frequencies, procedures and training. Let’s expand on each of these aspects:
1. Type of Lubricants
Choosing the right lubricants is arguably the most important parameter out of the 4. Lubricants come in various types, including oils, greases, and specialty lubricants. When selecting the appropriate lubricant, several factors must be taking into consideration:
- Operating speed of the parts in motion (ex: bearing)
- Operating temperature of the parts in motion
- Load applied on the parts in motion.
- Environmental conditions (moisture, dust, outside/inside, etc.)
Once these variables are established, you will be able to rightfully determine the ideal viscosity you are looking for in your lubricant as well as the additives that your system requires to ensure a smooth operation and longevity of your assets.
When it comes to viscosity, this refers to the thickness of the lubricant and its resistance to motion; typically, a faster operation will require a lubricant with a lower consistency and slower operation will require a higher consistency. When it comes to additives, their role is to modify the base lubricant in a way that will be ideal for its given purpose. Indeed, additives can do 3 main things :
- Improve the existing base oil properties.
- Neutralize undesirable base oil properties.
- Introduce new properties to the base oil
There are numerous potential combinations of base oils and additives, possibly numbering in the hundreds or even thousands. This vast array of options provides multiple choices when it comes to making a selection, ensuring that you can find a suitable option to meet your specific requirements.
2. Quantities
Calculating the correct quantities of lubricants is crucial to ensure that moving parts are properly lubricated. As it will be discussed in point #4, it is highly recommended to perform ultra-sonic greasing when it comes to performing lubrication tasks, we still recommended calculating baselines in terms of quantities.
Injecting the wrong amount of lubricant can lead to both over-lubrication and under-lubrication. Over-lubrication can cause excess lubricant to accumulate, leading to a rise in operating temperature, contamination, energy wastage, and increased wear due to churning.
Under-lubrication results in insufficient lubricant protection between moving parts, leading to increased friction, heat, and wear. In both cases, it will directly affect the moving parts performance and ultimately, their health.
When calculating quantities, the same factors as stated in section #1 should be taken into consideration as well as those factors:
- Position of the bearing (vertical/horizontal)
- Bearings size (outside diameter, inside diameter, bore size, etc.)
- Bearing features (roller, spherical, rubber seals, etc.)
When those parameters are defined, you can easily calculate the required quantity for that bearing. There are several formulas and calculators on the web, see which one fits the most your need.
3. Frequencies
Frequencies and quantities are inherently interconnected. Likewise, when determining quantities and frequencies, you need to consider the same parameters listed in section #2. When calculating quantities and frequencies, you’ll uncover the recommended/optimal lubrication combination of quantities and frequencies for your equipment.
At this point, you will have a bunch of different combinations of frequencies with few little similarities between all the lubrication tasks. It’s vital to align these calculations with your operational reality, this is where the need arises to establish guidelines based on available workforce and past failures.
To optimize your lubrication program, it’s advisable to select specific greasing frequencies and align your calculations with these chosen intervals. For example, your program might have lubrication frequencies set at 2 weeks, 4 weeks, and 12 weeks.
Consequently, any calculated frequency that doesn’t align with these selected intervals should be recalculated. Why is it important to establish such frequency guidelines? It’s primarily to maximize available manpower. It’s more efficient to standardize tasks within a similar area to a common frequency, so that resources address all equipment during the same routes, rather than revisiting the same equipment multiple times a week.
It’s worth noting that when recalculating frequencies and quantities, a cross-product method can be applied to determine the new quantities for the chosen frequency. Furthermore, best practices encourage shortening optimal frequencies rather than extending them. For instance, in the case of a selected 2-4-12 weeks lubrication program, if a calculation recommends greasing 20g every 6 weeks, it’s more advisable to adjust it to 13g every 4 weeks rather than increasing it to 40g every 12 weeks.
Moreover, when deciding which tasks should be assigned to which specific frequencies, it’s crucial to tailor this to your plant’s unique circumstances. This means that when you calculate a task’s optimal frequencies and quantities, you might sometimes encounter a combination such as 10g every 40 weeks.
Keep in mind that not only a lubrication tasks serves the purpose of lubricating equipment, but it also gives the opportunity to have someone boots on the ground physically looking at the equipment to also look for any potential symptoms of failure.
Therefore, in a situation where the optimal frequency is very large, like the example of 40 weeks, instead of scheduling someone to visit every 40 weeks, it’s more practical to have them visit at shorter intervals, apply smaller quantities of grease, and simultaneously conduct a physical examination of the equipment to identify potential signs of failure.
4. Procedures
When it comes to lubrication programs, it’s crucial to implement detailed procedures. Regardless of the chosen lubrication method, tasks must be as objective as possible, including the number of lubrication points, quantities per point, point locations, step-by-step procedures, and ideally, accompanying images to make the program foolproof.
When it comes to procedures, it’s worth noting that ultrasonic greasing stands out as the most accurate and precise lubrication practice. Ultrasonic grease guns feature ultrasonic sensors that emit ultrasonic waves, with reflected waves providing real-time feedback on the lubrication process.
That being said, you will be able to lubricate the optimal amount of grease into a bearing in order to neutralize the resulting dB waves. Therefore, this technique does not require any pre-set quantities, because the quantities will be determined according to the neutralization of the resulting waves.
However, it’s still best practice to equip the personnel with theoretical calculations as this theoretical quantity will serve as a maximum quantity for the tasks. This can help prevent over-greasing in case of ultrasonic gun issues or other malfunctions.
It’s important to recognize that various strategies exist for greasing bearings, but the key is to have detailed, objective task descriptions, potentially with photos, to minimize operator dependency.
5. Training
Closely connected to procedures is the necessity of accurate training of the workforce. Even with meticulously crafted, step-by-step procedures and visual procedures, human error can still occur without proper training. Consequently, it’s imperative that your workforce receives comprehensive training on the tools and procedures in place. Whether it’s ultrasonic greasing or manual greasing, ensure your team is well-versed in current best practices related to lubrication.
A great lubrication program combines these four aspects to ensure that machinery and equipment are well-maintained, reliable, and efficient. It also promotes a safe working environment and can contribute to cost savings by extending the life of equipment and reducing downtime. Continuous improvement through monitoring, feedback, and adjustments is also essential for the ongoing success of the program.
Arnaud Richer, B. Eng.
Reliability solutions – Spartakus technologies
arnaud.richer@spartakustech.com
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