Executive Summary
Lubricant cleanliness prevents downtime and maximizes reliability. One reader said, “Lubricant cleanliness is one of the most important factors in providing long equipment life.” However, obstacles including cost, training and storage practices put end-users at risk of contamination and failures. While equipment needs vary, filtering new lubricants and ensuring cleanliness throughout the life of the lubricant is a best practice that most readers agree is worth the expense.
Q.1 What role do you believe lubricant cleanliness plays in equipment reliability?
A key one.
Some equipment is capable of withstanding lower levels of cleanliness, so it’s impossible to issue a blanket statement, but certainly the case could be made for certain equipment experiencing reduced reliability caused by high particle counts.
While I agree that cleanliness is important, it should not be a blanket statement for all applications. Cleanliness, as determined by particle counts, is important for equipment and processes where there are very tight clearances, possibility of process contamination or dirt contamination and the end-user is using the appropriate filtration to monitor and keep lubricant cleanliness in check. It makes no sense to use an ultra-clean fluid, in an engine, for example, when the filtration does not affect anything under 10 microns and the engine itself generates particulate matter—in the form of soot (diesel engines) that will affect the cleanliness.
Very important role; clean lubricant gives more reliability.
Very important. The dirt can cause abrasive wear, which will shorten the life of the equipment.
When particulate filtration is targeted to clearance-sized particles, the resulting cleanliness will significantly reduce wear.
Lubricants cease to function as lubricants if they are no longer clean. Particulate in the lubricant can cause regular damage to the lubricating surfaces and rapidly reduce equipment reliability.
It will depend on the type of equipment; high precision hydraulics will be far more sensitive than, say, mining open gears. The introduction of contaminants should be avoided at all costs.
Lubricant cleanliness, meaning it being free of solid and liquid contaminants, is absolutely critical to equipment reliability and durability.
Very important role.
Lubricant cleanliness, or lack thereof, means the difference between getting the most from equipment (performance and longevity) and marginal cost to value for the operation of a machine over its lifetime.
Lubricant cleanliness is one of the most important factors in providing long equipment life. I would say it is the number one factor, assuming the correct fluid and correct viscosity are being used.
Cleanliness is not a singular term. There are near-term items to be concerned with, such as metal chips and other particles. And, there are longer term concerns with various micron-sized particles that have to be managed. In each step along the way, from production to field deployment, provisions must be made to address the types of contamination encountered. Generally, my experience has been that large particles cause the most failures—and the most expensive failures. Micron-sized particles, even if managed poorly, will generally only result in performance-related failures, which are more manageable from a total cost of ownership point of view.
It plays an important role.
Critical.
A vital role.
Significant role—dirt and other particulates can change chemical and physical properties.
Cleanliness plays a big role in equipment reliability as it induces wear and may plug small orifices and filters.
In most cases, it is a critical factor in ensuring high reliability. Only in rare cases can contaminations with favorable physicochemical properties improve system reliability by reducing the coefficient of friction or the wear intensity of the mating surfaces (playing the unplanned role of an unplanned third body in the interface).
I think a very crucial one! The clearances are getting smaller and smaller, and the systems are, therefore, more and more sensitive to contamination.
It is the life of the equipment.
Water contamination can increase corrosion for decreased reliability. Debris and particulate will lead to increased wear and less reliability.
A large role, as shown by various studies.
How do you determine lubricant cleanliness targets for your equipment?
OEM guidelines/standards
73%
Industry literature
41%
Operational experience
47%
We don’t monitor lubricant cleanliness
3%
Not applicable
7%
Based on responses sent to 15,000 TLT readers. Total exceeds 100% because respondents were allowed to choose more than one answer.
I believe lubricant cleanliness plays an equally important role as viscosity and specific lubricant additive packages. If you are using the correct lubricant (viscosity and additives), but the cleanliness level is not controlled and/or actively monitored, then the lubricant will not perform as it is designed, and the reliability of the equipment will suffer.
Lubricant cleanliness can play a vital role in the reliability of certain equipment that is susceptible to hard particle or other contaminants. Desired cleanliness levels should be determined based on a component’s tolerance to contamination, then the lubricant should be maintained at or below these defined cleanliness levels to avoid failures related to cleanliness. However, lubricant cleanliness may only play a minor role on reliability depending on other conditions that are present.
A major role.
Most failures I’ve seen are not related to lubricant cleanliness, even in “dirty” systems.
Avoids contamination.
Very high.
As long as the application justifies the process, the degree of cleanliness is of utmost importance.
Cleanliness plays a huge role in machinery lifespan.
It plays an extremely important role.
A big role, especially in hydraulic systems and lube applications where purity is needed.
A crucial role. The two main drivers for proactive maintenance are lubrication and contamination control (others are alignment, balancing and bolt tightness). In many cases, lubricant cleanliness is not important as long as viscosity is not too high.
It really depends on the equipment type; however, lubricant cleanliness is very critical in determining machinery reliability, especially when speaking about hydraulics, bearings, turbines and gears. When speed and load are high, lube oil cleanliness is even more critical.
It plays a critical role—however, you have to be careful that when cleanliness is evaluated, it doesn’t count the antifoam additives as contaminants. Cleanliness is more critical for rolling element bearings and hydraulic systems, so the focus should be on these.
Lubricant cleanliness is extremely important for equipment reliability and service life length.
It is an important step of maintenance process. Lubricant cleanliness may ensure the reliability of the system.
A clean lubricant is vital to equipment life, and relatively small measures can have a large impact on equipment life.
Cleanliness plays a critical role in many lubricant applications.
When the lubricant isn’t clean, major damage will occur. For example, we saw many shutdowns as a result of oil impurities.
The level of oil cleanliness will impact the lubrication performance and machine health in one way or another, depending on the nature and intensity of the particulate.
It’s everything!
Q.2 What do you see as the biggest barrier to ensuring new lubricant cleanliness?
Contaminant in lubricant, age of lubricant, cleaning of equipment prior to replacement of lubricant.
End-users understanding the need and the applications where it is critical to have clean lubricants.
Cleanness of packages, drums, pails and kegs.
Storage and handling practices—a general lack of respect toward the preservation of the as-delivered cleanliness, coupled with a disregard for how other activities may further contaminate the lubricant.
Reduced wear when lubricating so no particulate is generated from the surface—and a tight seal around the lubricated surface to ensure no environmental particulate can enter the area.
Price. Many customers are just not willing to pay for “clean hydraulic oil,” for instance. Packaging has to be of a high cleanliness standard as well, adding further cost to an unwilling-to-pay customer.
The biggest barrier to ensuring new lubricant cleanliness is the seemingly infinite number of potential contamination sources and methods that exist, and that can vary from day to day and season to season.
Cost. Some end-users can’t even meet the current cleanliness requirement.
New lubricant cleanliness is a direct expression of the system cleanliness of the manufacturing and delivery processes. The assumption that new oil equals clean oil is a blind one.
The biggest problem we see is when bulk lubricants are shipped using a common carrier. This carrier may be hauling diesel fuel one load and lubricants the next. They do not have dedicated hoses or compartments for specific products. The trailer may be cleaned, but the pump, piping and hoses never are.
New lubricants should be scrubbed prior to being installed into a machine. It’s pure laziness to not do this, as it is far more cost- and labor-efficient to manage large-scale plant-wide filtration systems than to rely on the filters installed on the equipment itself. Failure to scrub the oil ahead of installation will result in a shortened life for the filter(s) on the equipment. (In my world, mostly mobile equipment.) So, the barriers to maintaining new fluid cleanliness is indifference on the part of the lube supplier as well as poor analytical capabilities in the plants to monitor and maintain any given level of cleanliness. In the same way, we have SAE specs for engine fluid viscometrics. Lube suppliers should be held to similarly rigid and visible cleanliness standards.
End-user lack of staff and/or funds to properly maintain the lubricants, the machines and the plant environment.
Should industry standards (i.e., ILSAC, API, ISO, etc.) include requirements for new lubricant cleanliness?
Yes
75%
No
25%
Based on responses sent to 15,000 TLT readers.
Data misinterpretation.
Training and storage condition.
Lubricant handling and filling to equipment.
Storage and handling at the end-user site.
Unidentifiable malfunction of the lubrication system components and the wrong selection of the lubricant properties in relation to the working surfaces, which may contribute to increased wear intensity. I don’t see any barriers other than suppliers having to invest in filtration if they are going to provide clean fluid to customers upfront, or customer expense in cleaning up fluid that is delivered to them outside their cleanliness windows.
Lack of care and concern about additional work (pre-filtering).
Cost.
Culture change.
Recognizing operating conditions impacting the lubricant’s lifespan.
Flushing system of old lubricant that has contamination.
Awareness. New lubricants are supplied at reasonable cleanliness levels. However, some components may require even cleaner levels. End-users should be aware of their new lubricant’s cleanliness levels and ensure that the lubricant is cleaned to the level required for optimal performance in their equipment.
Replacing old containers with new ones.
Availability of specialty filters.
Degradation.
Poor practices.
Environment.
Cost.
Awareness and cost-effective methods to improve cleanliness levels.
New lubricant cleanliness is not relevant since cleanliness always must be performed in the machinery, not in the container.
Lack of knowledge on the user’s part.
Reusing containers that hold lubricants.
Not being filtered.
Poor storage and handling.
Low solvency of existing mainstream base stocks is the biggest barrier. Lubricants, which are based on paraffinic mineral oil or synthetic base stocks like PAO, have poor tolerance to dissolution of contaminants. Naphthenic mineral oils are better, but the best base stocks with regard to contaminant dissolution are derived from esters. They even dissolve metal debris via soap formation. Unfortunately, ester base stocks are poorly categorized and scattered among various manufacturers and applications. Since a long-term demand for a specific ester base stock is not certain, their volumes are low, and they are not manufactured using a continuous process. But when they are made in batch processes, they inherently have some contaminants. So the biggest barrier to lubricant cleanliness is the absence of high-volume ester base stocks.
Supply chain and packaging complexity. Some containers simply aren’t adequate for maintaining oil cleanliness. Also, insufficiently trained lube personnel can be a barrier against keeping lube oil clean.
Who should bear the responsibility of ensuring new lubricant cleanliness?
Lubricants manufacturers should only manufacture products that are suitable for use in equipment, which includes (among other things) meeting cleanliness specifications.
54%
Lubricant manufacturers should provide “clean” lubricants only when specified as part of the procurement process.
22%
End-users should filter lubricants to meet the requirements of their specific equipment and operating conditions.
72%
Based on responses sent to 15,000 TLT readers. Total exceeds 100% because respondents were allowed to choose more than one answer.
The cleanliness is crucial for the oil inside the equipment. Standards for manufacturing at a specified cleanliness are useless when, due to careless transport and handling at the site, cleanliness levels worsen. The end-user is ultimately responsible for getting the required cleanliness in the equipment by preventing contamination (handling, storage, breathers, seals, filling through filter) and maintaining cleanliness levels (ensuring good breathers, seals and filtration).
Lack of filtration and breathers.
Storage and handling of the lubricants at the site or plant.
Exposure to environment during transfer operations.
Chemical limits and product registration (or authorization).
Information and knowledge of the users. Reliability of the measuring tool itself.
The barrier to maintaining new lubricants with a certain level of cleanliness is understanding that it is necessary to develop knowledge of the equipment and its particular operating conditions in order to have appropriate practices to be carried out by users.
Everything. Bulk lubricants are generally not filtered onto tankers. Some are, such as turbine oils for electric generation. However, the majority that I work with only have five tankers segregated for this duty. They use a bag filter when loading and off-loading. Customers and distributors rarely filter going into or out of storage tanks. Some synthetic blenders filter their packaged goods. If filtration is done before the end-user, it is done by the distributor, and it is sold as a value-added service.
There are many players in lubricants. Some (in my country) even have recycled lubricant in the market. Maybe the governments need to revisit the regulations and/or industry (like us). We must continue educating end-user awareness on the effect of non-reliable lubricants.
Human factor.
End-user not able to test or not able to read the test results.
I believe that after any cleaning process, the lubricant performances regarding friction and wear should be tested.
In my opinion, the greatest barrier to lubricant cleanliness is ignorance on the part of the users and maintenance staff.
The cost involved in filtering the new oil and clean oil containers, and the testing involved as well.
Lack of complete inspection of lubricants and equipment.