The Death of Reliability: Is it Too Late to Resurrect the Last, True Competitive Advantage?. Nathan C. Wright
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Inventory assurance is key to your MRO and the hub of your reliability. You are already spending money on the inventory, all you need to do is store it correctly. Your MRO is part of your contamination control program as well, so you can see that these three groups are all intertwined. Training, or more importantly, development of your teams is what will bring this all together. Without a properly developed team, none of these efforts will be sustainable. Improper installation starts with your equipment design. Those charged with the design of your equipment need to understand reliability and design it into your equipment first and foremost. Designing the equipment for reliability and maintainability will set your organization up for success.
Reliability is all about getting out in front of your equipment, understanding its failure modes and how to stop them from happening. A lot of elements cause equipment failure and because of this about 90% of failure happens randomly. You can try to prevent failure by changing your parts before they fail; this works 12-18% of the time. You can attempt to predict their failure but this is only 50% accurate. To achieve reliability, you need to be proactive and stop improper lubrication, control contamination, and eliminate improper installation. This will stop 90% of the random failure and unreliability. Now, to borrow from Stephen Covey, we must start with the end in mind, and we will start by discussing the biggest bang for your buck, improper lubrication.
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. Figure 2.1 illustrates the major causes of unreliability and the breakdown of components.
Figure 2.1 Improper Lubrication.
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. 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.
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.
To start a lubrication program, you need to understand that there are several different substances that can be used to lubricate a surface. The most common are grease and oil. Grease is comprised of oil and a thickening agent. The thickening agent’s job is to retain the desired consistency, while the job of the oil is the actual lubrication. The selection of the proper grease should be done with the utmost diligence to address all equipment needs. Many of the manufacturers sell inferior grease, and the thickening agent and oil separate. This leads to lubrication-based failures because once the oil separates, the grease loses its protective quality. I have seen organizations use extension hoses to make grease points easily accessible. This can be a machine killer depending on your grease. You need to know the amount of time the grease will sit in the line based on the frequency of application and amount. The wrong grease will allow the oil to leach out of the thickening agent and all you will be providing the lubricated asset is the thickening agent, devoid of oil. What would appear to be a great idea to an uninformed organization could be a self-inflicted wound.
Oils come in three common varieties: vegetable, mineralbased, or synthetic. There can also be a combination of these as well. The application dictates which oil, referred to as the base oil should be used. Synthetic oils are designed for extreme conditions while vegetable oil is used where there are environmental concerns. Your decision on which to use needs to go beyond application and should consider your overall program. Resources will play into your decision as the different bases require different proactive approaches. If your organization plan includes in-the-field filtration instead of interval-based replacement, you need to understand the effects on your base and its additives. Reliability leaders need to have experience with this or you will leave this type of decision to a supplier who may be unqualified and most certainly does not have any “skin in the game.” Most organizations leave this important decision up to their supplier because they offer “free” advice. Is it truly “free” if your reliability suffers? Part of your justification for your program start-up is the real cost of “free” advice and its detriment to plant reliability. Suppliers have very little risk in providing free bad advice because if an organization