This is the first of a two-part article discussing the role proactive lubrication practices can play in increasing a facilitys reliability.
With China and India aggressively in the game, competition for limited natural resources, jobs and business in the industrialized world has increased at a feverish pace. To remain viable in a global marketplace, manufacturers need to increase reliability -- the anticipated uptime and smooth running of the facilitys machinery -- as they reduce costs.
Many manufacturers have yet to comprehend that managing lubrication effectively and proactively can improve production reliability. U.S. companies lose an estimated $4 billion annually by not adhering to a proactive lubrication maintenance approach and responding to ensuing lubrication-related failures.
Lubrication has multiple ties to reliability. Its most important role is coating sliding surfaces and carrying away friction-generated heat, thus eliminating wear. Also, lubrication determines reliability not only through how a particular lubricant is designed for use in specific machinery, but in the way its applied, or misapplied, in the field. Because a lubricant is the machinerys lifeblood, when its misapplied, reliability decreases. On the other hand, reliability can be increased in numerous ways, such as upgrading the lubricant or filtering it to remove contaminants.
The reliability-changing challenge
No less than 55% of U.S. manufacturing facilities are completely reactive in their approach to maintenance, according to the Work Type Benchmarking Study completed in 2000 by the Society of Maintenance and Reliability Professionals (SMRP). The study shows that 31% have a planned approach, 12% use predictive maintenance and only 2% are proactive. Best-in-class manufacturers report that reliability optimizes at a mix of 10% reactive, 30% planned, 50% predictive and 10% proactive maintenance.
A predictive approach involving oil analysis, vibration analysis and thermography can determine the longest interval between planned shutdowns. Operating in a reactive mode -- waiting for a machine to break down -- is expensive and fosters a hazardous work environment. Despite the seemingly obvious downside to reactive operations, changing to a proactive lubrication maintenance mode involves a number of challenges. These include overcoming years of ingrained habits and convincing operations to lead the charge -- supported by maintenance and purchasing -- as a functional team.
A plants organizational structure and interdepartmental politics might dictate that the operations department alone determines when maintenance can work on any particular machine. Operations is responsible for production, after all, and when operations says it wants something done, it will happen. If a plant isnt producing, everybody sees the loss of customers and profits clearly. Operations, production and maintenance must be aligned to make proactive lubrication management a reality.
Plant personnel can get a better understanding of lubrication through a number of products and services, including:
- Oil analysis.
- Vibration analysis.
- Storage containers.
- Desiccant breathers.
- Tank monitoring.
- Leak detection.
- Used oil disposal.
- Reliability and CMMS consulting.
Deploy these tools as part of an inclusive lubrication management program that extends lubricant life, reduces leaks and decreases changeouts and unscheduled downtime. Lubrication management also can help if the plant uses multiple oil brands having the same functionality. Analysis can show how to consolidate lubricants by as much as 80 percent, which can help increase production reliability.
The term defect, when applied to lubrication, doesnt necessarily mean a lubricant is substandard. It implies that a facility may be misusing the lubricant, either by accident or by design. For example, a simple process change might introduce new, unforeseen stresses that overwhelm the OEMs recommended lubricant. Plant personnel might take it upon themselves to use a nonapproved lubricant having insufficient protective additives.
A facility can minimize lubrication defects by partnering with a lubrication provider. Eliminating defects and common lubrication pitfalls can make production more reliable in several key areas, including quality control, workmanship, operations, maintenance materials and design.
Implement quality controls
A lubricant that enters the manufacturing process as a defect or contaminate and becomes an ingredient in the finished product can decrease the manufacturers reliability. A strong quality control program ensures that every container and system used for producing, transporting and packaging product, as well as the lubricants used within these systems, are kept as clean as possible.
If, for instance, the finished product is food, we know that conveyor chain lubricants, hydraulic oils, ammonia refrigeration oils, low-temperature greases and release oils can be introduced at numerous points in the process. Because the possibility of lubricant contamination is always a concern, food-grade lubricants are de rigueur in the food manufacturing industry.
Engine block production is another example of raw material contamination involving lubricants. Blocks are coated with preservative oil that can interact with metalworking fluids in a machining center. The various oils used throughout the process, including spindle oil, hydraulic fluid and way lubricant, flow into a central reservoir. Cleaning solutions and rust preventives also can be part of this mix, depending on attention to detail. These lubricants need to harmonize in their interaction. If they dont, flash rust may appear on finely machined surfaces. This starts a cascading wear problem, minimizing the product life, which could result in warranty claims hounding the manufacturer.
Quality control standards can ensure lubricants perform as designed in the manufacturing environment and the finished goods exit the assembly line uncontaminated.
People: the weak link
Simply put, people are a factor in the linkage between lubrication and reliability. Human reliability is about translating ones personal lubrication knowledge into proper application. More often than not, adverse lubrication events affect reliability through lack of knowledge rather than intentional misuse.
Increasing the maintenance and production staffs lubrication knowledge rapidly improves overall reliability. Examples abound in this easily remedied, though often neglected, area of potential reliability improvement. Practices that can help eliminate common lubrication issues include:
- Using the correct viscosity: Too thin risks metal-to-metal contact; too thick might increase internal friction and operating temperature.
- Using the right oil: Knowledge, clearly labeled top-off containers and on-machine lubricant nameplates can cure misapplication problems.
- Using compatible oils: Oils and additives must be compatible to avoid malfunctions and complete replacement of costly equipment.
- Improper oil sampling: Inconsistent and improper sampling methods can invalidate oil analysis as a predictive maintenance technique.
Training and attention to detail can help prevent these problems. Also, minimizing maintenance staff turnover is helpful. Annual training upgrades and refreshers only increase personnel competencies. Self-paced, online courses and live Web-based sessions are becoming increasingly popular as no-travel, low-cost training options.
Major oil companies are an adequate source for lubrication training. The better training programs have full-time professional instructors whose sole purpose is to enhance lubrication knowledge among customers, employees and distributors. Additional longstanding sources of high-quality lubrication training, such as the Society of Tribologists and Lubrication Engineers (STLE) and Noria, are becoming increasingly popular. No matter how one acquires lubrication competency, its value in eliminating some classes of reliability defects cant be overstated.
Lubrication fills multiple roles in our efforts to maintain reliability and to face the challenges of promoting defect-free operations. Remember two key facts: First, lubricant management, or the lack thereof, affects reliability in the manufacturing environment. Second, lubricant defects must be addressed in two key areas -- quality control and workmanship.
Part 2 will address three additional key areas of lubricant management -- operations, maintenance materials and design.
Service providers, such as a motor rebuild shop, also can introduce workmanship defects specifically related to lubrication, which may affect an operations reliability. An example is a large chemical processing facility in southern Ohio, which was experiencing premature motor bearing failures.
The plant commissioned Chevron to assist with root cause failure analysis. Investigation of some cooked bearings revealed that the plant had always requested polyurea-thickened grease for bearings used on rebuilt motors. The plant assumed the motor rebuild shop knew what constituted the appropriate type of polyurea grease to be used. But, motor rebuild shop documents specified different grease. Although it had the correct thickener, the particular polyurea grease in question contained a base-oil with the viscosity of ISO 460, formulated with a tackifier for enhanced water resistance. Further research indicated that this grease was formulated for roll-neck bearings in steel mills.
Roll-neck bearings in hot-strip steel mills operate at low-to-moderate speeds, experience high shock loading, moderate-to-high temperatures and severe water wash. The chemical plant, in contrast, used electronic motors that operated at constant moderate-to-high speeds, with low loads at moderate temperatures. Typically, theyre not exposed to water. These applications couldnt be more different.
The physical characteristics of the incorrect grease and the speed produced a rapid temperature rise that exceeded the greases capacity, oxidizing it and breaking it down. This, in turn, led to high bearing temperature (verified by color changes in the steel) and, ultimately, failure. The wrong grease directly and dramatically reduced the chemical plants reliability. This reinforces the importance of ensuring you involve trained and informed personnel who might have prevented this incident and saved the lost revenues.