This is the second part of a two-part article discussing the role proactive lubrication practices can play in increasing a facility’s reliability. Read part 1.
In our first installment of this article, we discussed the challenges of improving production reliability, the effect that lubricants have on the process, and lubrication best practices that promote defect-free operations. We defined defects as misuse of a lubricant, either by accident or by design, and discussed the roles of quality control and workmanship. In this installment, we’ll continue discussing defect elimination in the manufacturing environment within operations, maintenance materials and design.
Operational decisions need lube know-how
Operations departments in the manufacturing environment normally are responsible for production, safe machinery operation, basic machine upkeep and ensuring quality control. Unfortunately, in the manufacturing world, lubrication knowledge doesn’t always translate across departments automatically. By the very nature of its work, the maintenance department typically has most of this lube knowledge. On the other hand, operations, which normally decides which machines Maintenance can work on and when, has comparatively little lubrication knowledge.
That’s where problems begin. The deeper the understanding that Operations has of lubrication and predictive maintenance methods, the better the entire system will work.
Because of this general lack of lubrication knowledge and a desire to squeeze out every ounce of production from each piece of equipment, Operations frequently directs machine operators to push equipment far beyond designed lubrication limits. This excessive mechanical stress leads to increased friction that generates more heat. In turn, elevated temperatures render the originally recommended lubricant no longer suitable. For instance, if maintenance personnel are using a rust and oxidation inhibited lubricant designed for lightly loaded gears when production demands impose heavier loads on the gears, the lubricant cushion will begin to break down. With a lack of EP additives, the gears will subsequently touch and generate even more friction through metal-to-metal contact. Eventually, cyclical fatigue loading tears off small surface fragments that end up in the lubricant as highly abrasive, work-hardened bits of metal. Ultimately, operational requests to push machinery cause catastrophic machine malfunction with cascading part failures. Pushing and overloading compromises safety and reliability.
This is why operations must have a keen understanding of lubrication issues and must be supportive of maintenance in effective lubrication management. Cooperation and awareness guarantees increased production reliability. Plants should make every effort to increase cross-departmental communications to ensure any equipment that must run beyond its design limits receives the proper lubrication upgrade. As operators’ lubrication knowledge increases their respect for its importance, relations with maintenance will improve. An operator with increased knowledge of lubrication best practices becomes more aware of the value of proactive maintenance and its effect on production reliability.
The material link to lubrication
Maintenance materials, as used in this article, are simply the items maintenance technicians choose, or are instructed to use, in repair and upkeep of plant equipment. For this discussion, we focus specifically on lubricants.
The maintenance concern with defect elimination holds the strongest link to lubrication. The complexities of manufacturing environments can make it difficult to purchase the optimum lubrication. The two primary reasons for not using premium lubricants in a plant are cost pressure and lack of understanding of the true benefits.
For example, a company might experience maintenance problems that would potentially force operations to miss production goals and maintenance to exceed its budget. If too much attention is focused on meeting short-term budget constraints, purchasing might select an inexpensive, inadequate lubricant, rather then following a maintenance recommendation for a superior product.
Although purchasing inexpensive maintenance materials can help meet short-term budget issues, it won’t resolve worsening maintenance and reliability problems. It becomes a question of price versus cost. If price is your primary consideration when purchasing maintenance materials and related services, then lost productivity is often the cost.
It’s one thing to realize, in theory, the value of premium lubricants, but it’s another to be able to build a case for plant management that will justify the additional cost. In many cases, maintenance personnel might be too busy putting out fires from a reactive mindset to build a very strong argument for premium maintenance products and support services.
If this is the case at your plant, consulting with your supplier might help. A lubricant supplier that understands the effect lubrication has on reliability can review a situation quickly and help with a strong cost/benefit analysis for using the right product or service.
Don’t be afraid to consult with your supplier. A rational supplier knows it’s best to provide long-term solutions. These consultations may provide maintenance personnel with necessary information to make a solid case for investing in products that guarantee the lowest cost of use over time.
Choices involving lubrication are critical in every operation. The value of a well-informed decision in this area and its effect on productivity can’t be overstated.
Design and reliability
Everything that is manufactured, including lubricants, begins with a design that not only must reflect expected performance specifications but also must work with the other pieces of the production puzzle. Along the manufacturing pathway, every piece of equipment, every process and every decision must fulfill a current business need, by design.
Understanding the effects of lubrication on equipment during the design phase is critical to ensuring continuous worry-free operations. Whether a plant relies on its OEM for these calculations or designs its own equipment, it’s vitally important to appreciate the role lubricants play in equipment reliability. The primary areas of interest for lubrication in equipment design are:
- The entire range of operating speeds
- Expected loading
- Operating temperature
The amount and nature of expected chemical contamination, the systems required to provide effective lubrication, the thermodynamic effects of oil circulation, residence time and flow rate are additional factors that should considered.
These factors determine the lubricant viscosity. This calculation of approximate oil film thickness determines if the lubricant will be adequate for sustained, reliable equipment operations. The American Society for Testing and Materials standard ASTM D 341 has viscosity-temperature charts for liquid petroleum products that are helpful in determining expected lubricant viscosity at temperature.
Many suppliers of lubrication, machinery and components also provide tools that can assist end users in determining the correct lubrication, be it oil or grease. Some are easy-to-use tools that lead users through a series of detailed questions to determine the appropriate grease for a particular application. The key is to recognize that this analysis is required, and to be especially thorough in assessing potential equipment operating conditions. The American Gear Manufacturers Association (AGMA) also has useful guidelines that consider factors such as pitch line velocity, operating temperatures and expected loading.
Once a lubricant is selected, consider the most efficient method to apply it. Circulating oil systems, air-oil mist systems, automatic multiple-point oil delivery systems, automatic grease systems and oil bath/splash lubrication systems are just some of the approaches to getting the lubricant to the right place in the right quantity at the right time. Manufacturers can obtain assistance with designing lubrication systems from lubrication companies, consultants and distributors. This task can be daunting, however, it’s absolutely essential for reliable equipment design.
Designing for reliability
The worst-case scenario is to design a spectacular machine only to ignore proper lubricant and lubrication system selection. If equipment fails and gains a reputation as being unreliable, brand image and reputation suffer and a promising product line may never get off the ground. Litigation and wrangling among customers, lubrication companies and local service agents can damage relationships and waste time and resources. Attention to lubrication in the early design stages can prevent many headaches.
With the average overall equipment effectiveness of American manufacturing facilities in the 60% range, and world-class levels at 85%, the potential to save hundreds of thousands of dollars through reliability improvements is real. Incorporating lubrication best practices into equipment and system design is a key step in improving this vital metric.
Understanding the effect of lubrication in the five key areas of defect elimination —— quality control, workmanship, maintenance materials, operational, and design —— can help in developing a comprehensive action plan that ensures consistent, uninterrupted production.
Even though lubrication is the plant’s lifeblood, its importance remains poorly understood. A dedicated, consistent and enduring effort to increase your plant’s lubrication knowledge and awareness of best-practices is an inexpensive way to improve reliability, uptime and profitability.
R. Eric Bevevino, CLS, CMRP, is Business Manager, Industrial and Integrated Solutions at Chevron Products Co., Medina, Ohio. Contact him at [email protected] and (330) 350-2870.