Category: Lubricant Degradation

Can Lube Oil Varnish be Eliminated?

Varnish can be likened to cholesterol in the human body. It can build up in our arteries and eventually clog those, causing restrictions in blood flow to our heart which may lead to a heart attack.

Humans cannot simply change their blood to remove the cholesterol build-up. However, cholesterol is controlled through proper diet, exercise, and with some condition monitoring in the form of blood tests to help gauge the presence of it in the bloodstream. Similarly, a couple of approaches can be used to reduce the varnish build-up or eliminate it.

As per Livingstone et al. (2011), the lifecycle of varnish is critical. Particular attention should be paid to the double arrows between the stages of Solubility to Varnish formation in the figure below.

This means that even after varnish has been deposited, it can be solubilized back into the oil. This can only occur if conditions are met per Hansen’s Solubility principles where the solvent and degradation products meet using the three parameters of Polarity, Hydrogen Bonding, and Dispersive Forces as discussed in “The Hansen Solubility Principles and Its Relation to Varnish” (2022).

The Varnish Lifecycle as per Livingstone et al. (2011)

Varnish exists in various forms and can consist of differing compositions. Hence, it is essential to understand the characteristics of the varnish being formed in a system before attempting to eliminate it.

There are certain technologies, such as solubility enhancers or specifically engineered filtration media, which can be effective at removing lube oil varnish. However, this technology is heavily reliant on the type of varnish being formed and can be customized as per the system accordingly.

Solubility enhancers can solubilize the varnish back into the oil solution. When these deposits are reintroduced into the oil, they can be removed using resin-based filtration. In this method, the media is specifically designed to allow for the adsorption and removal of the varnish which presently exists in the oil.

When these methods are used together, they can prove quite effective and prevent manufacturing plants from experiencing unwanted downtime.

To summarize, it is of utmost importance to first understand the characteristics of the varnish being produced in your equipment before attempting to remove it from your system.

There is no cookie-cutter method to eliminate varnish from a system as it is a complex deposit. Similar to practices we observe with our bodies in the instances of cholesterol build-up, we can employ methods of dissolving the varnish and removing it while monitoring for possible recurrences in the future.

Want to read the entire article? Find it here on Precision Lubrication Magazine!

References:

Livingstone, Ameye, & Wooton. (2015.). Antioxidant Monitoring as Part of Lubricant Diagnostics – A Luxury or a Necessity? OilDoc, Rosenheim, Germany.

Livingstone, Overgaag, & Ameye. (2011). Advanced removal Techniques for Turbine oil Degradation Products. Powergen Milan.

Mathura, S. (2020). Lubrication Degradation Mechanisms (CRC Press Focus Shortform Book Program) (1st ed.). CRC Press.

The Hansen Solubility Principles and its Relation to Varnish. (2022, July 31). Fluitec International. https://www.fluitec.com/the-hansen-solubility-principles-and-its-relation-to-varnish/

Lubricant Degradation

Is Oil Analysis the Only Method of Varnish Detection?

Varnish will deposit in layers and adhere to the metal surfaces inside the equipment. As it continues to deposit, the layers will eventually accumulate until it reaches a point whereby it can cause significant changes to the clearances of the components.

There have been instances where shafts in rotating pieces of equipment have been moved due to the build-up varnish. This is where vibration analysis can be instrumental.

When the vibration analysis method is used, it can detect any small changes in the alignment of the shaft in rotating equipment. As varnish continues to build on the inside of the component, vibration analysts can detect if the shaft observes some misalignment over a period.

This may be easy to miss as sometimes the varnish which has built up can be wiped away, causing the shaft to resume its proper alignment. Thus, these technologies should be used in tandem before conclusions are made about the presence of varnish.

Another detection method that can be employed is the monitoring of temperature fluctuations. As stated earlier, varnish can form an insulating layer trapping heat. There have been case studies that demonstrate that bearings experiencing varnish tend to display temperature increases.

Typically, these temperature patterns assume a saw-tooth pattern where temperatures rise continuously as the varnish builds up. The varnish becomes wiped away, and the temperature is reduced drastically.

This saw tooth pattern of temperature variation is characteristic of varnish formation. In some cases, the formation of localized deposits on bearing surfaces may cause temperature escalations without a corresponding MPC increase. In this case, the bulk oil may not show any degradation, yet temperature excursions may be experienced at the bearing surface.

Want to read the entire article? Find it here in Precision Lubrication Magazine!

Lubricant Degradation

Can Lube Oil Varnish be Detected?

Detecting something is the first step towards formulating a solution to minimize its effects or eliminate it from a system. In the case of varnish for lubricated assets, a few technologies are currently being used to detect its presence.

As seen at the beginning of this article, varnish can exist with various characteristics depending on the degradation mechanism which aided in its formation. For this article, the degradation mechanism of oxidation will form the main focus as it is the most prevalent pathway to lube oil varnish formation.

During oxidation, the first chemical change which can be observed in the lubricant is the depletion of the antioxidant additives. This is where the knowledge of phenols and amines is critical.

As per Livingstone et al. (2015), these antioxidants can form synergistic mixtures in mixed antioxidant systems. When the free radicals react with the phenols, they become depleted but can regenerate amines. Thereby, the phenols are sacrificial.

Thus, when performing the RULER analysis, one can find that the concentration of the phenols will typically deplete quicker than the amines. This provides the analyst with a good overview of the amount of oxidation that has taken place in the lubricant.

The RULER analysis is one of the oil analysis methods which can provide early detection of the occurrence of oxidation.

It has been shown that the physical changes, such as polymerization, will only begin after this chemical change of the depletion of antioxidants. It is at this point that the actual deposits will begin formation.

Unfortunately, oil analysis tests such as viscosity and acid number only show significant changes after the deposits have been formed. At this time, it may be too late to implement technologies to mitigate varnish formation.

The Membrane Patch Calorimetry (MPC) oil analysis test (ASTM D7843) can offer analysts insight into the estimated amount of insoluble varnish currently within the system. These results have three main ranges which identify the severity of the varnish, namely, 0-20 (Normal), 20-30 (Abnormal), and >30 (Critical). Oil analysis tests can effectively provide the operators with some awareness of the current condition of the lubricant and its tendency to form varnish.

Want to read the entire article? Find it here in the Precision Lubrication Magazine.

Lubricant Degradation

The Six Forms of Lubricant Degradation

Oxidation

The most common form of degradation is oxidation. While this is the most recurrent form of degradation, the term is often misused to describe all forms of degradation. During Oxidation, a free radical is formed, which is highly reactive. Its primary purpose is to create other free radicals which can attack the base oil.

However, lubricants have been formulated with antioxidants. These knights in shining armor react with the free radicals to neutralize them and protect the base oil. As such, during the oxidation process, one will notice a decline in the concentration of antioxidants typically evaluated using the RULER® (Remaining Useful Life Evaluation Routine) test.

Eventually, the antioxidants become depleted, and the free radicals begin attacking the base oil. During this stage, polymerization can occur, which leads to the formation of deposits within the lubricant. Not every deposit is chemically similar.

The deposit will gain its characteristics from its environment and the products present during the chemical reaction. When these deposits occur, they can get lodged in the smaller clearances (particularly servo valves), which leads to possible malfunctioning of the equipment. Due to the nature of lube oil varnish, it can act as an insulating layer that increases the temperature throughout the equipment.

Thermal Degradation

Another form of degradation is called thermal degradation. As its name suggests, heat is one of the environmental conditions required for this degradation mechanism. During thermal degradation, the oil can experience temperatures over 200°C.

The Arrhenius equation is one of the industry’s rules of thumb whereby for every 10°C rise over 60°C, the life of the oil is essentially halved. At 200°C, the oil is cooked and produces carbon-based deposits, which is this mechanism’s characteristic type of deposit. The FTIR (Fourier Transform Infrared) test is instrumental in identifying the presence of these deposits.

Microdieseling

One can argue that microdieseling is a form of thermal degradation and should be classed as such. However, during microdieseling, air becomes entrained in the oil and moves from a low-pressure zone to a high-pressure zone.

If the oil does not have good air release properties, then the entrained air will not make its way to be dissipated at the surface. This entrained bubble in the oil can cause temperatures to rise to 1,000°C.

The bubble interface usually experiences some carbon accumulation and then implodes. This can be through a high implosion pressure which results in soot, tars, or sludge, or through a low implosion pressure which can form carbon insolubles such as coke, tars, or resins.

Electrostatic Spark Discharge

Electrostatic spark discharge may be classified under thermal degradation as it involves temperatures over 10,000°C. During this mechanism, oil builds up static electricity at a molecular level when the dry oil passes through tight clearances in the equipment.

Eventually, the static will build to a point where it produces a spark, and free radicals are formed. This can lead to uncontrolled polymerization producing varnish, sludge, or other insoluble materials. One of the tell-tale signs of this mechanism is the presence of burnt patches of membranes on the filters.

Additive Depletion

Additive depletion is often a form of degradation which gets left behind. As stated earlier, additives are sacrificial and will be depleted over time. Their purpose is to protect the lubricant and the machine, but they can be significantly depleted in some instances, leaving them vulnerable.

This type of degradation can produce two types of deposits, organic or inorganic. During degradation, rust and oxidation additives can become reacted with other components. These types of reacted additives can form organic deposits.

Alternatively, inorganic deposits such as ZDDP (Zinc dithiophosphate) can deplete and form a tenacious layer. The Depletion of ZDDP will impact the wear rate as this is the antiwear additive.

Contamination

Often, the most unrecognized form of degradation is contamination. Some may argue that this is not a form of degradation. On the contrary, this degradation mode can be the initiator for other mechanisms such as oxidation, thermal degradation, or even microdieseling.

Essentially, contamination occurs when foreign material is present in the lubricant. Often, this foreign material can become a catalyst for one of the other forms of degradation. Therefore, it must be acknowledged separately, as only the degradation mode can be eliminated by removing the contaminant.

Want to read the entire article? Find it here on Precision Lubrication Magazine!

Lubricant Degradation

What is varnish or oil degradation?

Varnish is a type of deposit that forms on the surface of equipment in lubrication systems. It is caused by the oxidation of the base oil and the buildup of additives in the oil over time, forming a sticky, varnish-like substance. Lube oil varnish can cause problems in equipment operation by clogging filters, reducing oil flow, and leading to valve sticking and pump failures.

Lube oil varnish is no stranger to the manufacturing industry. It constitutes the substance of most operators’ worst nightmares and plant managers’ ultimate fears. For those who have been in the industry for the last decade, varnish is the sticky subject that unites all facility departments.

It can cause an entire manufacturing plant to shut down while sending the finance department into a frenzy trying to balance production loss with incoming repair costs. In the fight against lube oil varnish, all teams need to work together to ensure that it can be managed and possibly eliminated from the system.

What Is Oil Degradation?

Before diving into the world of varnish, one must first understand how it forms and the circumstances which have led to its existence. Within the industry, the term varnish is used loosely to define any form of lubricant-derived deposit found in industrial.

However, oil can degrade by several mechanisms, which require various conditions for degradation—as such, using the term varnish to describe any deposit formed within a machine does not suggest its mechanism of formation.

The lubricant begins its degradation journey from the moment the lubricant enters the machine.

A lubricant is composed of base oil and additives, of which infinite combinations exist. Additives are carefully engineered to protect the base oil and the equipment. As such, they can become depleted over time, leading to the degradation of the lubricant.

This becomes concerning when the additive levels have depleted to a threshold where they can no longer protect the base oil or the machine. At this stage, degradation is the most serious concern because its rate is greatly accelerated.

According to Mathura (2020), there are six major forms of degradation under which a lubricant can undergo. While some may argue that these can be grouped, some characteristics set these mechanisms apart.

Each mechanism has unique environmental factors which contribute to producing different types of deposits. It is critical to note that identification of the type of mechanism can assist operators in performing remedial works on their equipment to aid in preventing the formation of varnish.

Want to read the full article? Check it out here in the Precision Lubrication Magazine.

Certifications / Lubricant Degradation / Reliability

Varnish Badges of Honour

Varnish is widely known as a primary culprit of equipment failure. This sticky enemy effectively finds its way into most of our equipment and causes operators, maintenance personnel and plant managers a series of nightmares. From unplanned shutdowns costing millions of dollars to sticking of servo valves on startup, or increases in bearing temperature, varnish usually announces its arrival. Once it has been found, there is typically a cause for panic but perhaps it just needs to be understood rather than feared?

The ICML VPR & VIM Badges

Recently (August, 2021), the International Council for Machinery Lubrication launched two new badges. These badges are, VIM (Varnish & Deposit Identification and Measurement) & VPR (Varnish & Deposit Prevention & Removal). These were created after the culmination of 3 years of work from the global varnish test development committee. It has been designed for those involved in all aspects of managing or advising lubricant programs especially those with the responsibility of recommending, selling or installing appropriate deposit control equipment or other mitigation strategies.

Most of the readers will already be familiar with my enthusiasm for understanding lubricant degradation. Thus, when these badges came out, I knew I had to secure them! While the requirements for taking the test suggest the possession of the MLT I or MLA I certification or 1 year of experience, I figured that my MLE certification would be an asset (as I haven’t gotten my MLT I certification yet, it’s on the list!). However, I wanted to make sure that I covered all of the elements in the BoK for both the VIM & VPR badges, so naturally I turned to the varnish guru himself, Greg Livingstone!

Fluid Learning – All the way!

1604954736_Fluid Learning Splash 2020-01

Greg is the CIO at Fluitec but he’s also the facilitator for the ICML VPR & VIM badges. What a treat! If you’ve never heard the name Greg Livingstone then you’re obviously not in the lubrication field. Greg has penned hundreds of papers on varnish and can be thought of as the varnish guru since he has extensive experience in this area. It’s a no brainer that I chose Fluid Learning to get me up to speed on what I needed to know for these exams!

Greg was an amazing facilitator and not only covered information relevant to the BoK for the exams but gave students a full overview about everything you needed to know about varnish. These on demand sessions kept me scribbling notes and nodding to myself and saying, “Oh that’s what really happens!” He presents the information clearly and adds some much needed humour into the sessions. It was an absolute privilege having him as my tutor for these badges.

VPR & VIM- What you need to know!

VPR - Varnish & Deposit Prevention and Removal

The VPR badge ensures that candidates understand proactive methods and technologies which can be employed to reduce the degree of degradation. It is also designed to confirm that they can sufficiently evaluate combinations of technologies to prevent and remove varnish including the proper steps to set up and implement an effective varnish removal system.

The topics covered in the VPR include:

Problems associated with Varnish & Deposits (20%)
Factors affecting Breakdown (28%)
Proactive Methods that can be used to minimize oil breakdown (16%)
Methods / Technologies that can be used to remove oil breakdown products and/or prevent deposits (36%)

The complete BoK for the VPR badge can be found here.

VIM (Varnish & Deposit Identification & Measurement)

The VIM badge on the other hand is more ideally suited for personnel responsible for recommending suitable oil analysis tests and mitigation efforts related to the deposit tendencies of various in-service fluids (application dependent). They would also be responsible for monitoring and adjusting these strategies accordingly.

The topics covered in VIM include:

Problems associated with Varnish and Deposits (20%)
Varnish and Deposit Composition (24%)
How Breakdown Products / Contaminants become Deposits (24%)
Oil Analysis Techniques that can be used to gauge Breakdown and Propensity towards Deposit Formation (32%)

The complete BoK for the VIM badge can be found here.

Exam tips!

The actual exams for both the VPR & VIM are set at 45 minutes with 25 multiple choice questions. Candidates must achieve 70% grade to attain the badges. Currently, the fee for the exam is USD75. Since there were overlaps of the content and the exam durations weren’t that long, I decided to sit both exams in one day. I will only advise this for those who are comfortable with doing this as exam anxiety and all that comes along with it can be stressful!

Here are a couple tips for taking these exams:

Log into the system 30 minutes prior to your scheduled exam time. This allows you to clear your mind, settle yourself and gives you an extra 15 minutes to figure out where the email is with your credentials! If you can’t remember your password to login to the system, this also gives you enough time to get that reset and sorted before the actual exam time.
The session only opens 15 minutes before the appointed time. During this time, you will converse with the moderator as they do the checks of the room and your National Identification. The moderators will engage with you and ensure that you are sitting the correct exam.
Ensure you have your National Identification on hand (your passport can be used as well). As long as it has your picture and the expiration date on the same side, it will be acceptable. For the Trinidadians, do not use your National ID card as we have our pictures on the front with the information on the back (I used my Driver’s permit).
Candidates have the option of “Flagging” questions to come back to them later. This is a great tool to help you to mark those questions you want to return to or double check.
There is a timer in the screen layout which helps you to keep track of your time. 45 minutes passes very quickly when you’re running through the questions!
Exam results for these badges come back very quickly as much as within a few hours or one day depending on the time of your exam.

Why do you need these badges?

As long as you work within the lubrication sector or interface with machines requiring lubrication, then you need to get these badges! Oil degradation occurs throughout the life of the lubricant whether it’s a small or large operation. By understanding how it degrades and ways to mitigate that degradation, you can save your equipment and avoid unwanted downtime. These badges were designed for the personnel in the field to allow them to make decisions regarding the lubricant and to empower them in taking steps to avoid degradation or mitigate it should the need arise. Consider it as getting your passport stamped by the ICML!

The courses offered by Fluid Learning are perfect for those seeking to understand lubrication deposits, what causes them and how they can be mitigated. While the content covered during these sessions align with the ICML VPR & VIM badges, they also add to a more holistic approach to varnish and deposits. Fluid Learning is an official ICML Training Partner and is currently the only one (of which I am aware) offering training prep for these badges. I highly recommend them for anyone seeking to learn more about or avoid sticky varnish situations.

At the moment of writing this article, there are only 8 people globally who have acquired these badges from ICML. I am the first female in the world to attain these badges but I will not be the only female for very long. Varnish is an issue which affects us all and we need to understand it, so we can prevent it and keep our equipment safe. I hope to see many more candidates with these badges in the near future!

Lubricant Degradation / Used Oil Analysis

Additives and their properties

Properties of Additives in Lubricants

Each lubricant has a varying percentage of additives as not all lubricants are created equally. Lubricants are designed based on their application or use within the industry. For instance, an engine oil is typically composed of 30% additives, 70% base oil while turbine oils comprise 1% additives and 99% base oil.

Therefore, particular attention must be paid to getting the additive compositions to be just right for the application and ensuring that the additives can perform their functions.

Each additive has a particular function and is used as per the application of the lubricant. We have adapted the following from Analysts Inc – Basic Oil Analysis which describes the purpose of some of the most commonly used additives in lubricants.

Lubricant Degradation / Reliability / Storage & Handling of Lubricants

ICML 55 – the revolution in the lubrication sector

What is ICML 55?

ICML 55 is revolutionizing the lubrication industry! It is so exciting to be around at this time when it has started its implementation. For those who aren’t aware of ICML 55, here are a couple of notes on it.

ICML 55 was born out of ISO 55000 which speaks to Asset Management. From this standard, 3 standards were developed to guide the lubrication industry since no previous standards existed within the lubrication industry.

ICML 55.1 - Requirements for the Optimized Lubrication of Mechanical Physical Assets
ICML 55.2 - Guideline for the Optimized Lubrication of Mechanical Physical Assets
ICML 55.3 - Auditors' Standard Practice and Policies Manual

ICML 55.1 has already been completed, while 55.2 should be done at the end of this year and 55.3 scheduled for 2020.

These are exciting times!

Here’s the official press release:

https://info.lubecouncil.org/2019/04/04/icml-introduces-icml-55-asset-management-standards-mle-engineer-certification/

While ICML 55.1 was only launched in April of this year (2019), it is a standard that the lubrication industry has been in need of for several years. It addresses the “Requirements for the Optimized Lubrication of Mechanical Physical Assets”.

What exactly are the assets covered? Here they are:

Rotating & Reciprocating Machines, Powertrains, Hydraulic Systems and lubricated subcomponents
Assets with lubricants that reduce friction, wear, corrosion, heat generation or facilitate transfer of energy
Finished products from API categories I-V
Non Machinery support assets (Personnel, policies, procedures, storage facilities and management)

There are also fluids and assets which are NOT covered:

Fuels, coolants, metal-working fluids, pastes, fogging agents, preservative fluids, coating materials, heat-transfer fluids, brake fluids, cosmetic lubricants
Solid lubricants (e.g., powders and surface treatments used as coating rather than to reduce friction between surfaces in motion)
Additives independent of the finished lubricant
Electrical transformer oils and anti-seize compounds
Fluids and materials derived from a petroleum or petroleum-like base
Fluids that do not serve a lubrication function

Photo Credit: https://info.lubecouncil.org/icml-55-standards/

ICML 55.1 speaks to the “Requirements for the Optimized Lubrication of Mechanical Physical Assets” it also describes and defines 12 interrelated areas that can be incorporated in a lubrication program. This has never been officially documented before, nor has any standard been published as a guideline for lubrication programs.

The 12 areas are outlined below:

SKILLS: Job Task, Training, and Competency
MACHINE: Machine Lubrication and Condition Monitoring Readiness
LUBRICANT: Lubricant System Design and Selection
LUBRICATION: Planned and Corrective Maintenance Tasks
TOOLS: Lubrication Support Facilities and Tools
INSPECTION: Machine and Lubricant Inspection
LUBRICANT ANALYSIS: Condition Monitoring and Lubrication Analysis
TROUBLESHOOT: Fault/Failure Troubleshooting and RCA
WASTE: Lubricant Waste Handling and Management
ENERGY: Energy Conservation and Environmental Impact
RECLAIM: Oil Reclamation and System Decontamination
MANAGEMENT: Program Management and Metrics

As per ICML's website, here's a list of people that the new standard can benefit:

Photo Credit: https://info.lubecouncil.org/icml-55-standards/

Check out the ICML 55 standards today and apply it to your organization!

Lubricant Degradation / Storage & Handling of Lubricants

Lubricant Deterioration Identifications

What the difference between Shelf Life and Service Life?

There’s a major difference between Shelf life and Service life especially when it concerns lubricants!

No one wants to put expired lubricants into their equipment! This can cause unexpected failures which can lead to unplanned downtime which can continue to spiral down the costly path of unproductivity!

Shelf Life

The Shelf life is usually what is stamped by the Manufacturer indicating the length of time the product can remain in its current packaging before being deemed unsuitable for use. These can typically be found on the packaging.

Service Life

The Service life however is determined by the application and conditions under which the lubricant is being used. Usually, estimated running hours / mileage are given by the equipment manufacturer in the maintenance section of the manual. (Condition monitoring can also be used to determine appropriate service intervals.)

However, how will someone know if the product has deteriorated while still in its original packaging? What should someone typically look for?

Above are some tips for identification of deterioration in lubricants. Take a note of these for the next time you are unsure of the integrity of your lubricants.

Lubricant Degradation / Storage & Handling of Lubricants

Conditions that affect lubricants

What conditions affect lubricants?

How are your lubricants currently stored?

Are you storing lubricants under the correct conditions?

These questions have come up a dozen times during audits and countless warehouse meetings!

To answer these questions, there are five main conditions that can affect lubricants. We have detailed them along with the effects of these conditions on the lubricant.

Temperature – if incorrect can lead to oxidation. For every 10C rise in temperature above 40C the life of the lubricant is halved.
Light – too much can lead to oxidation especially for light sensitive lubricants such as transformer oils. Hence the reason that most packaging is opaque.
Water – this usually works with additives to cause their depletion or contamination of the product. Water in any lubricant is bad (especially for transformer oils as they are involved in the conduction of electricity.
Particulate contamination – contamination can occur by air borne particles if packaging is left open or if dirty containers/vessels are used to transfer the lubricant from its packaging to the component.
Atmospheric contamination – this affects viscosity and promotes oxidation and can occur if packaging is left open. For instance, if a drum is not properly resealed or capped after usage or the most common practice of leaving the drum open with the drum pump on the inside.

Different types of lubricant degradation

Why is it important to know the types of lubricant degradation?

It’s important since it helps us to figure out why or in some instance how, the lubricant degraded! Usually degradation is the change that occurs when the lubricant can no longer execute its five main functions:

the reduction of friction
minimization of wear
distribution of heat
removal of contaminants and
improvement of efficiency.

Types of lubricant Degradation Mechanisms

There are 6 main types of Lubricant Degradation as detailed below. Each type produces various by products which can enable us to understand the reason for the degradation and eliminate that / those reasons.

Here are the 6 main types of Lubricant Degradation:

1. Oxidation
2. Thermal Breakdown
3. Microdieseling
4. Additive Depletion
5. Electrostatic Spark Discharge
6. Contamination

As discussed, each mechanism produces distinct results which help us in their identification! Check out our article on why lubricants fail for more info!