A Proactive Approach to Reducing Machine Part Failures

Reliability engineering at its best is a sub-discipline of systems engineering that emphasizes dependability in the lifecycle management of a product. New parts fail in three phases along the bathtub curve (a widely used example in reliability engineering).

The bathtub curve has three phases – the early failure, constant or random failures, and wear-out failures, where the middle phase has the lowest failures. One of the goals of proactive maintenance and reliability is to ensure the parts reach the third and final phase known as “wear out”. Any failure in the first two phases results in loss of component life and possibly unscheduled downtime (increased costs).

The three main reasons (forced deterioration) a part fails prematurely, in infant mortality, is:

• Improper lubrication
• Contamination
• Improper installation

You need to work to reduce and eliminate these main reasons for infant mortality (first phase) through continuous and proactive improvement.

Elimination of the problem before it ever occurs gives the desired results of a reliability process, instead of the common approach of Root Cause Failure Analysis (RCFA).

What You Need to Focus On

Many organizations do not realize that there are significant differences in the various types of lubricants available in the market. If you are using a lubricant with a gas company’s name on it, you could be using an inferior product. I often hear maintenance leaders tell me “we don’t have a lube issue”, or “what lube we use does not matter because it all comes from the ground”.

I will quote Luke Skywalker in Star Wars Eight “Amazing — every word of what you just said was wrong.” Lubrication or better Proper Lubrication is the single most important aspect to reliability. You need to get this right before moving on to anything else.

The biggest common mistake made by most organizations in reliability is allowing your lubricant provider to manage your lubrication program. This is a fatal mistake, as their interest is selling lubricants to you, specifically those that makes them the most money.

Additionally, they will tell you they have lubrication engineers that will set up your program, but there is no college degree for a lubrication engineer. They make up titles to falsely communicate their qualification, which is usually limited to their product line. Most of these “lubrication engineers” are salespeople with no real-world experience running a plant or mine.

Lubrication Program

70% of all unreliability in rotating assets is caused by the lack of proper lubrication. For those who are saying, we do not have a lube problem, you are wrong.
Mechanical wear of equipment components is common, and this is particularly true where improper lubrication is an issue. Particles and moisture contamination along with wrong or degraded lubricants are the prevalent causes creating rust on metal components, increasing oxidation rate, which leads to increased acid within the components. Your focus needs to be on:

Lubrication program design, lubrication application design, lubrication selection, lubrication storage, handling, and delivery, ISO cleanliness standards, route development, ultrasonic procedure development, sampling, and tribology.

Having the wrong lubrication even though you may be doing everything else right is like putting “lipstick on a pig”. You must start with the right lubricants.

Lubrication is a must with respect to reliability, but what exactly is lubrication? Webster’s Dictionary defines lubrication as the application of some oil or grease substance to diminish friction.

Although this definition is valid, it does not encompass everything that proper lubrication can achieve. It is this simple definition that often explains why organizations place little or no importance on lubrication. They lack a thorough knowledge of reliability and how lubrication impacts it.

I am giving organizations the benefit of the doubt here, because if they understand the importance of lubrication and do nothing to ensure its complete, proper application, they would be criminally liable. Think of your lubrication systems as the circulation system in your body. To stay alive, you need to do a lot of proactive reliability efforts.

The driving force behind the need for a lubrication program is the fact that 70% of all unreliability is caused by a lack of a lubrication program. Improper lubrication causes mechanical wear and premature equipment/component failure, or unreliability.

Mechanical Wear

Mechanical wear of equipment components is common, and this is particularly true where improper lubrication is an issue. Particle and moisture contamination, along with the wrong or degraded lubricants, are the prevalent factors in creating rust on metal components. This increases oxidation rate, which leads to increased acid within the components.

Mechanical wear happens when machine surfaces rub against each other. Abrasive wear happens when particles enter the system, commonly through contaminated lubricants. Here is where you need to understand that third part distributors create a contamination issue as well as mark up costs to do little in return. These particles are usually dirt or wear materials, and they lead to three-body abrasion known as surface fatigue, which pits and scores the machine surfaces.

This results in premature failure, also known as unreliability. Adhesive wear results when two surfaces come in direct contact and transfer material from one face to the other. This happens because lubricants cannot support the load, or in areas where the surfaces suffer from lubricant starvation or the use of the wrong lubricant.

Metal fatigue is another form of mechanical wear. An example would be when you work a wire back and forth to cut it without tools. The more you move a wire back and forth, the harder the metal works; the fatigue increases, ultimately resulting in a brittle point that snaps. This is the effect contaminants have on metal surfaces. Over time, this constant flexing will fatigue the metal, resulting in premature failure.

The Institute of Mechanical Engineers has found that “every $1,000 invested in proper lubrication yields a savings of $4,000, which is a $3,900 return on investment.” This is a great return on investment in anyone’s book, and an example of how to justify a project and fund your reliability efforts.

Corrosion

Acid is a by-product of the reaction between additives in the oil and water. Lubricant contamination has many paths. The manufacturing process of the lubricants is the first-place contamination enters the system, but it can enter through seals, creating a caustic environment that results in wear.  This can also happen if you do not understand the lubricant’s additive package, because you can end up with corrosive damage.

An example would be using an extreme pressure additive with yellow metal (copper, brass, etc.) because some of these additives are corrosive to them. This is another example where you need someone on your team who understands this problem and is qualified to review and eliminate it from happening.

Equipment loses its functionality in three ways, but it is the lubrication (life blood) of the parts that is the root cause of much of these failures. Keeping your plant equipment properly lubricated, controlling the contamination, and ensuring the proper installation can extend the equipment life and contribute to a more reliable operation.  To proactively address the single most common cause of unreliability, you need to develop a lubrication program.

My next article will focus on how to start a lubrication program and what you must know to sustain a robust proactive approach to reliability. The key elements behind my approach will lead to reliable plant operations. Feel free to drop me a note or call if there is a topic you would like to see, if you have questions, or would just like to chat.